IMPROVEMENT OF MUSCLE PROTEIN FUNCTIONALITY AND EVALUATION OF
SODIUM REDUCTION POSSIBILITY BY COMBINING CRUST-FREEZE-AIRCHILLING AND COLD-BATTER-MINCING TECHNOLOGIES
By
Marianela Medellin Lopez

A THESIS
Submitted to
Michigan State University
in partial fulfillment of the requirements
for the degree of
Food Science – Master of Science
2014

ABSTRACT
IMPROVEMENT OF MUSCLE PROTEIN FUNCTIONALITY AND EVALUATION OF
SODIUM REDUCTION POSSIBILITY BY COMBINING CRUST-FREEZE-AIRCHILLING AND COLD-BATTER-MINCING TECHNOLOGIES
By
Marianela Medellin Lopez
Combined effects of crust-freeze-air-chilling (CFAC) and cold-batter-mincing (CM)
technologies were evaluated for the improvement of meat protein functionality, and sodium
reduction possibility. In study I, hot-boned (HB) turkey breasts were subjected to CM, or to
CFAC and CM, and meat quality, and protein functionality parameters were compared to
those of the control treatment (cold-boned minced traditionally (CB-T)). HB-CFAC
treatments had a higher processing rate than CB-T (chilled by water immersion chilling
(WIC), due to the lower chilling times (1 – 1.5 h for CFAC vs 5.5 h WIC). HB-CFAC breast
showed higher pH, lower R-value, higher fragmentation index, and similar sarcomere length
than CB. CB-T meat was minced at ~10ºC, while HB-CFAC was minced at ~2ºC, all for 7
min. After cooking the minced batter, higher cooking yield and stress values were found in
HB-CFAC gels than in CB gels. In study II, CB-T and HB-CFAC batters were minced for 27
min, at two sodium levels (1% or 2.0% table salt). During the first 12 min, the temperature of
HB-¼CFAC batter was significantly lower than that of CB-T. Higher protein extraction
values were seen on 2% salt HB-¼CFAC batters compared to 1% and 2% salt CB batters
when minced for less than 24 min. Stress values of 1% salt HB-CFAC gels were similar to
those of CB-T 2% salt, higher than CB-T 1%, but lower than HB-CFAC 2%. In Scanning
Electron Microscope images, HB-CFAC cold minced batter proteins seemed to have more
protein-coated fat particles, and less denaturation than those of post-rigor batters.

Copyright by
MARIANELA MEDELLIN LOPEZ
2014

To my beloved parents, for teaching me
the value of determination and hard work.
To my sisters, my aunt, and my grandma,
whose courage is always an inspiration.

iv

AKNOWLEDGMENTS

I want to thank Dr. Ike Kang for giving me the opportunity to join his research team
and supporting my professional development throughout my degree. I also want to thank my
committee members: Dr. Gale Strasburg, Dr. Bradley Marks, and Dr. Richard Balander for
their support and valuable suggestions. I would also like to extend my gratitude to Dr. Steve
Bursian for his genuine advice and support, and for encouraging me to follow my beliefs.

I want to recognize Jennifer Dominguez, Ryan Varner and the whole Meat Lab team
for their extraordinary work and support during the time of this research. My gratitude is
extended to Nicole Hall and Ian Hildebrandt for their time spent troubleshooting issues in the
lab, and teaching us the best practices.

I also want to give a special thanks to my lab mates, Thanikarn Sansawat and Pranjal
Singh, who dedicated many hours of their time helping in the Meat Lab, and assisting when
needed. I want to thank Dr. Hungchul Lee for assisting with this project as well.

I can never thank the many new friends I met here enough for treating me as family
and making my time in the US much better.

Finally, I want to thank my family for supporting all my decisions, and for their
unconditional their love. Most importantly, I want to thank God for the many blessings and
the wisdom He gave me that help me complete this degree.

v

TABLE OF CONTENTS

LIST OF TABLES

viii

LIST OF FIGURES

xi

KEY TO ABBREVIATIONS

xiii

I. CHAPTER I: INTRODUCTION
1.1.
Problem Statement

1
2

II. CHAPTER II: LITERATURE REVIEW
2.1
Turkey meat products
2.1.1 Emulsified products (meat gels)
2.1.2 Commercial processing of meat gel products
2.1.3 Processing defects of meat gel products
2.2
Novelties in processing
2.2.1 Hot-boning/prerigor
2.2.2 Crust-freeze-air chilling
2.2.3 Cold Mincing
2.3
Factors affecting meat gels
2.3.1 Effect of raw meat quality
2.3.2 Effect of salt content
2.3.3 Effect of mincing temperature
2.3.4 Effect of mincing time

4
5
6
6
9
9
9
10
11
11
11
12
12
12

III. CHAPTER III: EFFECT OF COLD-BATTER MINCING, HOT-BONING AND
CRUST-FREEZE-AIR CHILLING ON PROCESSING TIME, AND QUALITY OF
TURKEY BREAST GELS
13
3.1
Abstract
14
3.2
Introduction
15
3.3
Materials and methods
17
3.3.1 Turkey slaughter and dressing, carcass chilling, and sample preparation
17
3.3.2 Breast mincing
20
3.3.3 Gel preparation
21
3.3.4 Sample testing
21
3.3.5 Statistical analysis
25
3.4
Results and discussion
25
3.5
Conclusions
32
IV. CHAPTER IV: EFFECT OF SODIUM REDUCTION ON COLD-BATTER
MINCED,
HOT-BONED,
¼-SECTIONED-CRUST-FREEZE-AIR-CHILLED
TURKEY BREAST GEL QUALITY
33
4.1 Abstract
34
4.2 Introduction
35
4.3 Materials and methods
37
4.3.1 Turkey slaughter and dressing, carcass chilling, and sample preparation
37
4.3.2 Breast mincing
39
vi

4.3.3 Gel preparation
4.3.4 Sample testing
4.3.5 Statistical analysis
4.4 Results and discussion
4.5 Conclusions

40
40
43
43
56

V.
CHAPTER V: AREAS FOR FURTHER STUDY
5.1 Areas for further study

57
58

APPENDICES
APPENDIX A. GLOSSARY OF TERMS
APPENDIX B. PRODUCTION FLOW FOR EMULSIFIED PRODUCTS
APPENDIX C. RAW DATA STUDY 1
APPENDIX D. RAW DATA STUDY 2

59
60
61
62
86

LITERATURE CITED

121

vii

LIST OF TABLES

Table 3.4.1. pH and R-value (±SEM)1 of turkey breasts that were chill-boned (CB), hotboned (HB), or hot-boned/crust freeze–air-chilled (HB-CFAC)
28
Table 3.4.2. Temperature changes1 of meat batters during 7 min mincing of turkey breasts
that were chill-boned (CB) or hot-boned/crust-freeze–air-chilled with (HB-¼ CFAC)/without
(HB-CFAC) ¼ sectioning
29
Table 3.4.3. Cooking yield, stress and strain values (±SEM)1 of turkey breast gels that were
made with breast muscles chill-boned (CB), hot-boned (HB), or hot-boned/crust-freeze-–airchilled (HB-CFAC)
31
Table 4.4.1. pH and R-value (±SEM)1 of turkey breasts before and after being chill-boned
(CB) or hot-boned/¼ sectioned/crust-freezing air chilled (HB-¼CFAC)
44
Table C.1. Temperature monitoring - Replication 1

62

Table C.2. Batter and raw meat pH – Replication 1

63

Table C.3. R-value - Replication 1

64

Table C.4. Sarcomere length – Replication 1

65

Table C.5. Fragmentation index – Replication 1

67

Table C.6. Cooking yield – Replication 1

68

Table C.7. Torsion test – Replication 1

69

Table C.8. Temperature monitoring – Replication 2

70

Table C.9. Batter and raw meat pH – Replication 2

71

Table C.10. R-value - Replication 2

72

Table C.11. Sarcomere Length - Replication 2

73

Table C.12. Fragmentation index - Replication 2

75

Table C.13. Cooking yield - Replication 2

76

Table C.14. Torsion test – Replication 2

77

Table C.15. Temperature control – Replication 3

78

Table C.16. Batter and raw meat pH – Replication 3

79

viii

Table C.17. R-value – Replication 3

80

Table C.18. Sarcomere Length – Replication 3

81

Table C.19. Fragmentation index – Replication 3

83

Table C.20. Cooking yield – Replication 3

84

Table C.21. Fragmentation Index – Replication 3

85

Table D.1. Batter temperature monitoring – Replication 1

86

Table D.2. pH before and after chilling – Replication 1

87

Table D.3. R-value before and after chilling – Replication 1

87

Table D.4. Batter pH – Replication 1

88

Table D.5. Protein Solubility, CB-T 2% – Replication 1

89

Table D.6. Protein Solubility, CB-T 1% – Replication 1

89

Table D.7. Protein Solubility, HB- ¼ CFAC 2% – Replication 1

90

Table D.8. Torsion test, CB-T 2% – Replication 1

91

Table D.9. Torsion test, CB-T 1% – Replication 1

92

Table D.10. Torsion test, HB- ¼CFAC 2% – Replication 1

93

Table D.11. Batter temperature monitoring – Replication 2

94

Table D.12. pH raw meat before and after chilling – Replication 2

95

Table D.13. Raw meat R-value before and after chilling – Replication 2

96

Table D.14. pH batter– Replication 2

97

Table D.15. Protein Solubility CB-T 2% – Replication 2

98

Table D.16. Protein Solubility CB-T 1% – Replication 2

98

Table D.17. Protein Solubility HB- ¼CFAC 2% – Replication 2

99

Table D.18. Protein Solubility HB- ¼CFAC 1% – Replication 2

99

Table D.19. Torsion test CB-T 2% – Replication 2

100

Table D.20. Torsion test CB-T 1% – Replication 2

101

ix

Table D.21. Torsion test HB-¼CFAC 2% – Replication 2

102

Table D.22. Torsion test HB-¼CFAC 1% – Replication 2

103

Table D.23. Batter temperature monitoring – Replication 3

104

Table D.24. Raw meat pH – Replication 3

104

Table D.25. Raw meat R-value – Replication 3

105

Table D.26. Batter pH – Replication 3

106

Table D.27. Protein solubility CB-T 2% – Replication 3

107

Table D.28. Protein solubility CB-T 1% – Replication 3

107

Table D.29. Protein solubility HB-¼CFAC 2% – Replication 3

108

Table D.30. Protein solubility HB-¼CFAC 1% – Replication 3

108

Table D.31. Torsion test CB-T 2% – Replication 3

109

Table D.32. Torsion test CB-T 1% – Replication 3

110

Table D.33. Torsion test HB-¼CFAC 2% – Replication 3

111

Table D.34. Torsion test HB-¼CFAC 1% – Replication 3

112

Table D.35. Batter temperature monitoring – Replication 4

113

Table D.36. Batter pH during mincing– Replication 4

114

Table D.37. Raw meat pH – Replication 4

115

Table D.38. Raw meat R-value – Replication 4

115

Table D.39. Protein solubility– Replication 4

116

Table D.40. Torsion test CB-T 2% – Replication 4

117

Table D.41. Torsion test CB-T 1% – Replication 4

118

Table D.42. Torsion test HB- ¼CFAC 1% REP 3 – Replication 4

119

Table D.43. Torsion test HB- ¼CFAC 1%– Replication 4

120

x

LIST OF FIGURES

Figure 2.1.1. Poultry products market share

5

Figure 2.1.2.1. Typical temperature profiles for meat batters during emulsification

7

Figure 2.1.2.2. Emulsion theory a, a’, and physical entrapment theory b, b’

8

Figure 3.3.1. Process flow for study 1

18

Figure 3.3.2. Graphic representation of turkey breast portions

19

Figure 3.3.3. Left turkey breast in quarter portions

19

Figure 3.3.4. Water immersion chill (WIC) of whole turkey carcass and crust-freeze-air chill
(CFAC) of hot boned (HB) breast with/without ¼ section. A: Whole turkey carcass,
A’: WIC, B: HB breast half, B’: HB/CFAC, C: HB/¼ sectioned breast, C’: HB/ ¼
sectioned/CFAC
20
Figure 3.4.1. Temperature change profiles of turkey breast fillets during water immersion
chill (WIC), hot-boned/crust-freeze-air-chill (HB-CFAC), and hot-boned/¼ sectioned/crustfreeze-chill (HB-¼CFAC) (n=9)
27
Figure 4.3.1. Process flow for study 2

38

Figure 4.4.1. Temperature changes of meat batters during 27 min mincing of turkey fillets
that were chill-boned (CB) or hot-boned/¼sectioned/crust-freeze–air-chilled (HB-¼ CFAC).
Means (n = 8) with no common letters within the same mincing time differ significantly
(P < 0.05).
45
Figure 4.4.2. pH changes of meat batters during 27 min mincing of turkey fillets that were
chill-boned (CB) or hot-boned/¼sectioned/crust-freeze-air-chilled (HB-¼ CFAC). Means
(n = 8) with no common letters within the same mincing time differ significantly
(P < 0.05)
46
Figure 4.4.3. pH changes of overnight-stored (4oC) meat batters that were made with turkey
fillets chill-boned (CB) or hot-boned/¼sectioned/crust-freeze-air-chilled (HB-¼ CFAC).
Means (n = 8) with no common letters within the same mincing time differ significantly
(P < 0.05)
47
Figure 4.4.4. Stress value (kPa) of meat batters during 27 min mincing of turkey fillets that
were chill-boned (CB) or hot-boned/¼sectioned/crust-freeze-air chilled (HB-¼ CFAC).
Means (n = 8) with no common letters within the same mincing time differ significantly
(P < 0.05)
48

xi

Figure 4.4.5. Strain value of meat batters during 27 min mincing of turkey fillets that were
chill-boned (CB) or hot-boned/¼sectioned/crust-freeze-air-chilled (HB-¼ CFAC). Means
(n = 8) with no common letters within the same mincing time differ significantly
(P < 0.05)
49
Figure 4.4.6. Protein solubility (%) of meat batters during 27 min mincing of turkey fillets
that were chill-boned (CB) or hot-boned/¼sectioned/crust-freeze-air-chilled (HB-¼ CFAC).
Means (n = 8) with no common letters within the same mincing time differ significantly
(P < 0.05)
50
Figure 4.4.7 Scanning electron micrography (SEM) images of meat batters (2% salt) at 6, 12,
24 min mincing. Arrow: emulsified fat globule, Circle: connective tissue, bar=1µm.
A: Meat batter of HB¼CFAC minced- 6 min, A’: Meat batter of CB- 6 min, B: Meat batter of
HB¼CFAC minced-12 min, B’: Meat batter of CB minced-12 min, C: Meat batter of
HB¼CFAC minced-24 min, C’: Meat batter of CB minced-24 min
52
Figure 4.4.8 Scanning electron micrography (SEM) images of meat batters (1% salt) at 6, 12,
24 min mincing. Arrow–emulsified fat globule, circle– connective tissue, bar = 1 µm.
A: Meat batter of HB¼CFAC minced-6 min, A’: Meat batter of CB minced-6 min, B: Meat
batter of HB¼CFAC minced -12 min, B’:Meat batter of CB minced -12 min, C: Meat batter
of HB¼CFAC minced-24 min, C’.Meat batter of CB fillet minced -24 min
53
Figure 4.4.9. Scanning electron micrography (SEM) images of gels (2% salt) cooked after 6
min, 12, 24 min mincing. Circle– connective tissue, bar = 1 µm.
A: Meat gel of HB¼CFAC minced -6 min, A’: Meat gel of CB minced -6 min, B: Meat gel
HB¼CFAC minced-12 min, B’: Meat gel of CB minced-12 min, C: Meat gel of HB¼CFAC
minced -24 min, C’: Meat gel of CB fillet minced 24 min
54
Figure 4.4.10. Scanning electron micrography (SEM) images of gels (1% salt) after 6,12, 24
min mincing. Circle– connective tissue, bar = 1 µm.
A: Meat gel of HB-¼ CFAC minced 6 min, A’: Meat gel of CB minced 6 min, B: Meat gel of
HB-¼ CFAC minced -12 min, B’: Meat gel of CB minced- 12 min, C: Meat gel of
HB-¼CFAC minced -24 min, C’: Meat gel of CB minced- 24 min
55
Figure B.1. Production flow for cold emulsions

61

Figure B.2. Production flow for hot emulsions

61

xii

KEY TO ABBREVIATIONS

HB
CFCA
CB
¼ CFAC
WIC
PR
CM
RTE
WHC
CO2
MT
NC

Hot-boning
Crust-freeze-air-chilling
Cold-boning
Crust-freeze-air-chilling in quarter portions
Water immersion chilling
Pre-rigor state
Cold-batter mincing
Ready to eat
Water holding capacity
Chilled with CO2
Minced-traditionally
No-chilling

xiii

CHAPTER I: INTRODUCTION

1

1.1 Problem Statement
Pre-rigor (PR) or hot-boned (HB) meat has been reported to have superior quality over
chill-boned (CB) meat (Claus and Sorheim, 2006; Sorheim et al., 2006; Dibble, 1993;
Cuthbertson, 1980; Kastner, 1977). Froning and Neelakantam (1971) reported that batter
made with pre-rigor muscle exhibited higher emulsifying capacity and stability than the batter
made with post-rigor muscle.
Additionally, several authors have reported some benefits derived from using HB,
such as energy saving, high throughput, improved processing yield, and reduced chilling
time/space (McPhail, 1995; Lyon and Hamm, 1986; Troy, 2006). These may represent an
advantage for processors compared to the current CB. However, HB meat may result in lower
texture quality, lower juiciness score, and irregular shape of final products, if not processed
immediately and appropriately (Seabra, 2001; Thomas, 2007). Furthermore, the HB technique
has not been adopted in the poultry industry, mainly due to the difficulty synchronizing the
slaughter and boning lines, in addition to other issues, such as stricter hygiene and
temperature control, facility modification or extension, and employee training (Troy, 2006;
Pisula and Tyburcy, 1996).
Currently the estimated average intake of sodium in the US is 4000 mg/day, from
which about 20% is believed to come from processed meats (Havas, 2004). This is one of the
reasons why processed meats are believed by consumers to have adverse health effects. The
meat industry thus faces the challenge to provide reduced-sodium products to consumers;
nevertheless, these have been linked to reduced acceptability in texture, flavor, yield, and
shelf life. A better understanding on how HB meat will behave under different processing
conditions is needed to evaluate its potential in the meat industry.
Crust freeze-air chilling (CFAC) is a technique that reduces meat temperature at a
high chilling rate causing the freezing of the meat surface. This method, depending on the
2

meat size, temperature, and air speed, can take less than an hour to achieve the desired
internal temperature, which can reduce issues in processing (Herbert, 1980). Regarding cold
mincing (CM), Bard (1965) reported that protein extraction was dramatically increased when
CM was used, compared to mincing at temperatures higher than 2oC.
Raw meat quality indicators (pH, R-value, etc.), and meat batter properties (pH, batter
temperature, protein solubility), both can be used to predict the efficacy of processing
technology and subsequent quality of finished meat products.
Therefore, the objectives of this research were:
a) To evaluate the physicochemical properties of raw meat before and after chilling
b) To assess the physicochemical properties of meat batter during mincing at different
temperatures, times, and salt levels.
c) To determine the impact of boning-time, chilling conditions, batter-mincing
temperature/time, and salt content on protein functionality of turkey breast gels.
In study I, different combinations of HB, CFAC, and CM were used to evaluate the
efficacy of chilling time on quality of raw meats, meat batters, and cooked gels. Raw meat
quality was assessed using pH, R-value, sarcomere length, and fragmentation index
before and after chilling, whereas the quality of meat batter and cooked protein gel was
evaluated using batter pH, cooking yield, and stress/strain values for gels.
In study II, four batters were prepared using traditional mincing technology with CB
breasts or cold mincing technology with HB-¼CFAC breasts, which were selected based
on the results of study I, at 2% or 1% sodium levels. Batter quality, and protein
functionality were evaluated.

3

CHAPTER II: LITERATURE REVIEW

4

2.1

Turkey meat products

Turkey meat demand has been increasing for over 20 years, which has triggered changes in
the poultry processing industry, the meat industry, the scope of turkey products available, and
consumer preferences. The trend of poultry products being commercialized, moved from live
and whole birds in the early 1900’s, to cut-ups and further processing in the present years.
The latter combined represent over 70% of recent market share. (Figure 2.1.1) (Barbut, 2002).

Figure 2.1.1 Poultry products market share
Further processed, ready-to-eat (RTE) turkey products are considered convenient,
tasty, nutritious and generally healthier than pork or beef products. These can include deli
meats, turkey-bacon, and comminuted products like bologna and hot-dogs, as well as many
others.
These products vary as much in their manufacturing as they do in flavor and
appearance. Each of them requires certain specific conditions and processes to achieve their
desired characteristics. Comminuted meats share a similar basic technology that impact
sensory attributes. These products have a long history of using meat of less commercial value,
however due to its convenience and increase in popularity new processed products have been
developed to meet the different market demands.

5

2.1.1

Emulsified products (meat gels)

Comminuted products, depending on the degree of particle reduction, can be coarse or
finely ground. The latter, also referred to as emulsified, can yield a wide variety of
commercial products to cover multiple niches depending on the quality, labeling demands
(low fat, low sodium, etc.), price-range, convenience, etc. (Mead, 2002). Finely-ground
products can also be divided into two main groups: “cold emulsions” and “hot emulsions”,
where significant differences in processing (see Appendix 1) yield either sliceable or
spreadable products, respectively (Toldrá 2010). According to Hoogenkamp (2005), a raw
meat emulsion (cold emulsion) can be described as dispersion, and under thermal conditions
this changes into a gel. The most typical meat gel products are frankfurters, bologna, and
lunch or deli meats. Common ingredients include salt, nitrate/nitrite, erythorbate, phosphates,
starch and non-starch binders, proteins, sugar, and seasonings (Tarté, 2009). One of the main
characteristics of these products is their homogeneous structure resulting from the extensive
comminution and uniform gelation. The process by which finely-ground meat structure is
formed has been studied for several years and two theories, the emulsion and the physical
entrapment, are most accepted. However, there is still a lot of controversy with knowledge
gaps.
2.1.2

Commercial processing of meat gel products

Meat processing can be started at animal slaughter or with raw meats already prepared
(fresh, chilled, frozen, mechanically separated meats), depending on the manufacturer.
Processors now have an extensive range of equipment options to better fulfill their needs
when performing the two main comminuting steps, grinding and chopping. For mincing, most
machines fall into two basic types, mixers (screw or paddle) and bowl choppers (with or w/o
vacuum) (Owens et al 2010; Varnam et al 1995; Toldrá 2010). Alternatively, co-extrusion has

6

been used to improve consistency, efficiency, automation and adaptability, as well as to
simultaneously produce the product in its casing (Hoogenkamp, 2005).
Some authors define the main processing stages differently, but the core concepts are similar
and can be classified as follows according to Owens (2010):


Preblending



Protein extraction and swelling



Emulsion formation and fat encapsulation



Formation of a heat-set gel

Figure 2.1.2.1 Typical temperature profiles for meat batters during emulsification
Preblending. It is also referred to as lean fragmentation or grinding, which is the first
particle reduction point in the comminution process; it is usually done in a screw or paddle
mixer. During pre-blending, coarse ground trimmings are formed where fiber bundles are
separated, myofibrils are liberated, and in some cases salt or curing salts are added to further
increase protein extraction (Owens 2010; Toldrá 2010).
Protein extraction and swelling. The three major groups of proteins in meat are:
Sarcoplasmic (water soluble), Myofibrillar (myosin and actin; salt soluble), and Stromal
(collagen and elastin; insoluble). Myofibrillar porteins contribute to meat batter stability,
whereas stromal proteins at high levels can be detrimental (Barbut, 1995). Proteins are
further extracted and solubilized in this stage by the action of the bowl chopper in presence of
water, salt and phosphates. Both salt and phosphate play a major role in protein swelling and
7

improvement of water holding capacity with a high pH by phosphate. A colloidal structure is
formed where protein-water interactions have an important function in forming the meat
batter/emulsion (Owens 2010, Hoogenkamp 2005).
Emulsion formation and fat encapsulation. Homogenization and fat particle reduction
continues and solubilized proteins surround fine fat particles during the stage of emulsion.
Hydrophobic portions of myofibrillar proteins orient towards the lipid droplets, and
hydrophilic ones towards the water phase. Protein-fat interactions play a major role during
this stage however the mechanism responsible for holding the fat within the product is still
debated. According to the emulsion theory, fat is stabilized in the meat batter by the
formation of an interfacial protein film around the small fat globules, whereas the physical
entrapment theory suggests that the fat droplets are entrapped within the three-dimensional
matrix of the protein, thus stabilizing the gel. Both theories have been supported with
micrographs (figure 2.1.2.1), suggesting the existence of both types of interactions (Barbut,
1995; Hoogenkamp 2010; Varnam 1995). Both protein extraction, and emulsion formation
take place during the mincing step, typically in a bowl chopper. Regardless of the model, the
presence of protein-fat interactions during comminution is undeniable as well as the
importance of maintaining protein functionality during this stage.
a

a

b

b

Figure 2.1.2.2. Emulsion theory a, a’, and physical entrapment theory b, b’

8

Formation of a heat-set gel. Products are typically heated to an internal temperature of
68.3ºC to 73.9 ºC to denature proteins. The thermally induced events include conformational
changes in the proteins, exposure of hydrophobic groups, and gelation. Collagen transforms
into gelatin in the presence of heat and binds some water and fats. The three-dimensional
matrix formed by the cross-linking of proteins immobilizes fat and water, which is
irreversible. Products are then subjected to a rapid temperature reduction and cool storage
(Owens 2010, Varnam 1995, Toldrá 2010).
2.1.3

Processing defects of meat gel products

Variations in the processing conditions can render different types of defects, from
microbiological to organoleptic, being fragile, grainy, rubbery or tough texture the most
common of the latter. Fat pockets, fat rendering and fat separation are also undesirable
defects, occurring during comminution, that emerge after cooking (Owens 2010). The use of
novel technologies may help processors target some of these defects at the same time.
2.2

Novelties in processing

2.2.1

Hot boning/Pre-rigor

Hot-boning (HB) is the process of muscle removal from an animal carcass before its
internal temperature drops significantly and before rigor mortis develops. Several authors
have reported many advantages of the processing such as energy saving, high throughput,
improved processing yield, and reduced chilling time/space (McPhail, 1995; Lyon and
Hamm, 1986; Troy, 2006). The HB processing provides a favorable choice over the
traditional CB processing. However, early deboning is typically associated with toughness in
the finished products when not processed immediately. (Seabra, 2001). Still the HB meat has
been reported to have superior quality over the CB meat (Sorheim et al., 2006; Dibble, 1993;
Cuthbertson, 1980; Kastner, 1977). It has been reported by many researchers that more saltsoluble proteins are extracted in pre-rigor muscle compared to post-rigor muscle (Saffle and

9

Galbreath, 1964; Bernthal et al., 1989; Claus and Sorheim, 2006). The hot boning technique,
however, has not been fully adopted in the meat industry mainly due to synchronizing issues
(hot-boning line is faster than the further processing line), safety problems (fast microbial
growth in hot/warm muscles), and extra cost (initial investment, facility modification,
employee training, etc.) (Troy, 2006; Pisula and Tyburcy, 1996). At the industrial scale, HB
has been further challenged because poultry muscles have to be obtained and processed no
later than 30 min after slaughter due to a rapid onset of rigor mortis (Aberle et al., 2001),
which can be difficult when dealing with higher carcass volume.
2.2.2

Crust-freeze –air-chilling

Crust-freeze-air-chilling is a technique that differs from a traditional air chilling in the
use of sub-zero temperatures for a rapid chilling, resulting in surface freezing. It is expected
for the meat to achieve a desirable texture for slicing, and for HB meat in particular, to have
an ideal temperature so that it can be processed with a flexible schedule and place. Its use in
the meat industry is relatively new, and research has not been conducted enough for the
application of the technology.

Conventional air chilling, however, has been widely

researched and used in the poultry industry especially in European community, showing
benefits on quality improvement, minimal water usage, reduced labor, and no chlorine use
(Jeong et al, 2011). The conventional air chilling, however, takes from two to several hours to
achieve the desired internal temperature, depending on the size of carcasses or muscles. In
beef, the cooling times are relatively longer (> 15 h) than poultry (1 – 2 h) (Herbert, 1980;
Jeong et al., 2011). The success of the HB method relies on good hygiene, fast chilling for an
automated system, and maintaining of the superior quality (James, 2002). In Denmark, the
hot-boning of pork, followed by air chilling (-25 to -30 ºC) has been practiced, allowing fast
processing with the reduction of surface temperature to -2ºC in 80 min (Hermansen, 1987).
Based on the results, the combination of hot-boning and crust-freeze-air-chilling appears to
10

present a potential technique to rapidly chill poultry carcasses and maintain the high quality
of HB meat.
2.2.3

Cold Mincing

Cold-batter mincing (mincing at sub-zero temperatures for a long period of time) is an
emerging technology, which is thought to improve protein functionality and gel forming
ability. Bard (1965) reported that protein extraction dramatically increased in the range of -5
to 2oC compared to the protein extraction at the temperatures higher than 2oC. The
combination of HB-CFAC and cold-batter mincing shows to have 4 major advantages:
1) Increased processing efficacy due to the rapid meat turnover, 2) Reduced synchronizing
issues due to the rapid chilling, 3) No issues of muscle thawing and thaw-rigor contraction
and 4) Production of pre rigor-quality meat products.
2.3

Factors affecting meat gels

2.3.1

Effect of raw meat quality

Low muscle pH is associated with low water-holding capacity, due to structure
alterations and reduced charges in muscle proteins (Guerrero-Legorreta, 2010). Once an
animal is slaughtered, biochemical changes occur in the muscle that causes rigor mortis to
develop along with a pH drop. The decline of pH is a result of lactic acid accumulation in the
muscle when oxygen is not available. The rapid chilling of HB muscle can minimize the
postmortem change in the muscle and the loss of high quality of HB meats. Bernthal (1989)
reported that HB minced meat resulted in higher amounts of extracted protein and higher
water holding capacity (WHC) when compared to the results from CB minced batter. Meat
batter made with HB meat exhibited both higher emulsifying capacity and emulsion stability
than that of CB muscle (Froning and Neelakantam, 1971; Hamm, 1982). Wyche and
Goodwin (1974) reported a higher cooking yield in hot-cut broiler than in the chill-cuts.

11

2.3.2

Effect of salt content

In sausage mincing, raw meats are chopped with salt (NaCl) to extract tacky and
adhesive muscle proteins. The salt in processed meats not only contributes to flavor
enhancement and shelf life extension, but also plays a major role in enhancing protein
functionality. As a result, salt reduction without food quality loss is a significant technical
problem.
2.3.3

Effect of mincing temperature

Brown and Toledo (1975) recommended that batter-mincing temperature should not be
higher than 15oC at the end of chopping for a good quality of protein extraction. Upon
reaching over 16oC, both water and fat are released from the batter, which resulted in quality
loss of finished products (Deng et al., 1976).
Comparing five temperatures from -3.9 to 23.9oC during a 6 min paste mincing period, Gillett
et al (1977) reported that the optimum mincing temperature for protein extraction was 7.2ºC.
Conversely, Hamm (1966) stated that no major changes occurred in chemical-colloidal or
binding properties of protein in the mincing temperatures below 30oC. When salted pre-rigor
meats were ground with solid carbon dioxide, Sorheim et al. (2006) observed that the prerigor patty had higher pH, lower cooking loss, and firmer texture than those of post-rigor
controls
2.3.4

Effect of mincing time

A loss of protein functionality, due to over-chopping, is likely associated with
irreversible protein denaturation. However, Bard (1965) reported that the extraction of saltsoluble proteins from post-rigor meat increased proportionally as the extraction time was
extended up to 15 h, and that muscle protein extraction from pre-rigor meat was greater at 15
min mincing than that from post-rigor muscle minced for 15 h.

12

CHAPTER III: EFFECT OF COLD-BATTER MINCING, HOT-BONING AND
CRUST-FREEZE-AIR CHILLING ON PROCESSING TIME, AND QUALITY OF
TURKEY BREAST GELS

13

3.1

Abstract

The purpose of this study was to evaluate the combined effects of turkey hot-boning and
cold-batter mincing technology on throughput rate, and meat quality. For each of 3
replications, 15 turkeys were slaughtered and eviscerated. Three of the eviscerated carcasses
were randomly assigned to water immersion chilling (WIC) for chill-boning (CB), while the
remaining were immediately hot-boned (HB), half of which were used without chilling, while
the remaining were subject to crust-freezing air chilling (CFAC) in an air freezing room
(–12oC/1.0 m/s) without (HB-CFAC) or with ¼-sectioning (HB-¼CFAC). CB and HB breasts
were then minced using one of 5 mincing treatments: 1) chill-boned/ mincing traditionally
(CB-T), 2) hot-boned/mincing with no chilling (HB-NC), 3) hot-boned/mincing with CO2
(HB-CO2), 4) hot-boned/mincing after crust-freezing air chill (HB-CFAC), and 5) hotboned/mincing after ¼crust-freezing air chill (HB-¼CFAC). The traditional WIC took an
average of 5.5 h to reduce the breast temperature to 4oC, while HB-CFAC and HB-¼CFAC
took 1.5 and 1.0 h, respectively. The breast of HB-CFAC and HB-¼CFAC showed
significantly higher pH (6.0 – 6.1), higher fragmentation index (FI, 196 – 198) and lower Rvalue (1.0 – 1.1) (P < 0.05) than those of chill-boned controls. No significant differences
(P > 0.05) in sarcomere length were seen between CB-T and HB-CFAC fillets regardless of
¼sectioning. When muscle was minced, the batter pH (5.9) of CB-T was significantly lower
(P < 0.05) than those (6.1 – 6.3) of HB-NC, HB-CO2, and HB-¼CFAC, with the intermediate
pH (6.0) seen for the HB-CFAC. When meat batters were cooked, higher cooking yield
(90 – 91%) (P < 0.05) was found in HB-CFAC, HB-¼CFAC, and HB-CO2, followed by
HB-NC (90%) and finally CB-T (86%). Stress values (47 – 51 kPa) of HB-CFAC gels were
significantly higher (P < 0.05) than those of CB-T (30 kPa) and HB-NC (36 kPa). A similar
trend was found in strain values.
Key words: turkey, hot boning, crust-freezing, cold batter-mincing, protein functionality
14

3.2

Introduction

Accelerated animal processing is always desirable to meat processors and packers. Hotboning (HB) or pre-rigor process is the removal of muscles from an animal carcass before the
body temperature is substantially lower (chilled carcass) and before rigor mortis develops.
The HB process has many advantages such as energy savings, high throughput, improved
processing yield, and reduced chilling time/space over cold-boning (McPhail, 1995; Lyon and
Hamm, 1986; Troy, 2006). In addition, HB muscle produces superior quality meats than chillboned (CB) muscles (Sorheim et al., 2006; Dibble, 1993; Cuthbertson, 1980; Kastner, 1977).
When HB muscle was minced, more protein was extracted, and higher water holding capacity
was obtained than those of CB muscle (Bernthal et al., 1989). The meat batter made with HB
meat exhibited both higher emulsifying capacity and emulsion stability than that of CB
muscle (Froning and Neelakantam, 1971; Hamm, 1982). Wyche and Goodwin (1974)
reported a higher cooking yield in hot-cut broiler than the chill-cuts.
The hot boning technique, however, has not been fully implemented in the meat industry
mainly due to synchronization (the hot-boning line is faster than the further processing line)
and safety issues (fast microbial growth in hot/warm muscles). Costs associated with facility
modification and employee training might be another influential factor (Troy, 2006; Pisula
and Tyburcy, 1996). In poultry processing, the hot-boning has been further challenged
because muscles have to be obtained and processed no later than 30 min after slaughter due to
a rapid onset of rigor mortis (Aberle et al., 2001).
In sausage mincing, raw meats are chopped with sodium chloride to extract salt-soluble
muscle proteins. Brown and Toledo (1975) recommended that mincing temperature should
not be higher than 15oC at the end of chopping for a good protein extraction. Above 16oC,
water and fat are both released from the batter, which results in quality loss of finished
products (Deng et al., 1976).

15

Comparing five temperatures from -3.9 to 23.9oC during a 6 min mincing period, Gillett
et al (1977) reported that the optimum mincing temperature for protein extraction was 7.2 oC.
Conversely, Hamm (1966) stated that no major changes occurred in chemical-colloidal or
binding properties of protein at mincing temperatures below 30oC. When pre-rigor meats
were salted and ground with solid carbon dioxide, Sorheim et al. (2006) observed that the
resulting patty had higher pH, lower cooking loss, and firmer texture than those of post-rigor
controls. Mincing at sub-zero temperatures, thus suggests that protein functionality may be
improved; this has been known as cold-mincing in the meat industry and is considered an
emerging technology.
Considering the individual advantages of hot-boning, crust-freeze-air chilling, and coldmincing, may suggest that the combination of these techniques can affect the meat industry in
a positive way. Some of the potential benefits of the combined methods are: fewer
synchronization issues, no thaw-rigor contraction, higher processing rate and throughput, and
the potential for lower sodium formulations to yield high quality products.
Regarding batter mincing at different temperatures and time, Bard (1965) reported three
interesting results of protein extraction: 1)The extraction of salt-soluble proteins from postrigor meat proportionally increased as the extraction time was extended up to 15 h, 2)Protein
extraction dramatically increased in the range of -5 to 2oC compared to temperatures higher
than 2oC; and 3)Muscle protein extraction from pre-rigor meat in 15 min of mincing was
greater than that of post-rigor muscle extracted for 15 h.
The purpose of this study was to evaluate the effect of HB-CFAC on processing time, and
the effect of cold-batter mincing on protein functionality of the HB-CFAC gels.

16

3.3

Materials and methods
3.3.1Turkey slaughter and dressing, carcass chilling, and sample preparation
Three batches of fifteen live Nicolas tom turkeys (16 weeks-old, ~18 kg in live

weight) each, were obtained in three different occasions between July and December of 2011
from a farm in north Indiana. Three replications were completed at the end of this study, and
a total of forty-five turkeys (fifteen turkeys per batch) were used.
After birds were withdrawn from feed for 12 h and cooped in plastic cages, the birds
were transported to the Michigan State University meat and poultry processing laboratory. On
the morning of the arrival, the birds were electrically stunned for 6 s (80 mA, 60 Hz, 110 V),
and bled for 90 s by severing both carotid artery and jugular vein on one side of the neck. The
turkeys were then scalded (59ºC, 120 s), mechanically defeathered (25 s), and manually
eviscerated. After washing, carcasses were weighed, and their internal temperatures were
recorded from the center of the turkey breast using a digital thermometer/logger (model
800024, Sper Scientific Ltd., Scottsdale, AZ).
In each replication three out of the fifteen carcasses were randomly assigned to one
the following treatments (Figure 3.3.1.):
1) Water Immersion Chilling (WIC), cold-boned (CB), and minced traditionally (CB-T)
2) Hot-boned, minced at room temperature (HB-NC)
3) Hot-boned, minced at sub-zero temperatures with solid CO2 (HB-CO2)
4) Hot-boned, crust-freeze-air chilled, and minced at sub-zero temperatures (HB-CFAC)
5) Hot-boned, crust-freeze-air chilled in quarter portions, and minced at sub-zero
temperatures (HB-¼CFAC)

17

Figure 3.3.1. Process flow for study 1
All three WIC turkeys were chilled in a plastic tank containing a mix of water and ice
(~40 L @approximately 0.5ºC) (Figure 3.3.3 A, A’) with mechanical agitation (0400–
025GV1S portable agitator, Grovhac Inc., Brookfield, WI). The temperature of one
representative carcass was measured every five minutes and recorded. The carcasses were
taken out of the chilling tank after reaching 4ºC. The carcasses were then cold-boned (CB),
and samples were immediately taken (1 cm thickness) from the cranial, medial, and caudal
portions (Figure 3.3.2) of the right breasts (three samples per carcass), placed in temperature
resistant plastic bags, properly tagged, frozen in liquid nitrogen, and stored in a freezing room
(-20.0ºC) for further testing. The left breasts were stored in gallon-size Ziploc bags in a
chilling room (4.0ºC) for overnight storage (~16 h).

18

Cranial
Medial
Caudal
Figure 3.3.2. Graphic representation of turkey breast portions
The remaining twelve birds were hot-boned (HB), and samples from the right breasts
were taken and stored, immediately after hot-boning, in the same way as mentioned above.
HB-NC and HB-CO2 breasts were processed immediately as described in the Breast mincing
and gel preparation section of this chapter. The left HB-CFAC breasts were placed in an air
freezing room (~1 m/s, @-12oC) for crust-freeze-air chilling (CFAC) (Figure 3.3.4 B, B’),
while left HB-¼CFAC breasts were manually sliced into four portions of similar size (Figure
3.3.3) before CFAC (Figure 3.3.4 C, C’).
The temperature of one representative breast was taken every 5 min for each CFAC
treatment. The breasts were taken out of the freezing room after reaching an internal
temperature of 4ºC. Samples from the frozen meat were then taken and stored in the same
fashion as for WIC treatment. The remaining frozen meat was minced directly after chilling.

Figure 3.3.3. Left turkey breast in quarter portions

19

Figure 3.3.4. Water immersion chill (WIC) of whole turkey carcass and crust-freezeair chill (CFAC) of hot boned (HB) breast with/without ¼ section. A: Whole turkey carcass,
A’: WIC, B: HB breast half, B’: HB/CFAC, C: HB/¼ sectioned breast, C’: HB/ ¼
sectioned/CFAC
3.3.2 Breast mincing
All five treatments were minced in a food cutter (256 rpm, Models 84181, Hobart,
Troy, OH) in the meat processing lab at Michigan State University. Each batch (~25 Kg) was
mixed for 7 min using the following formulations (% from total batch mass):
CB-T: 78% chilled-boned meat, 4% water (25ºC), 16% ice (0ºC), and 2% table salt
HB-NC: 78% hot-boned meat, 20% water (25ºC), and 2% table salt
HB-CO2: 78% hot-boned meat, 4% water (25ºC), 16% ice (0ºC), 2% table salt, and solid
CO2 (enough to reduce and maintain the temperature around -2ºC)
HB-CFAC: 78% crust-freeze-air chilled whole breasts, 20% ice (0ºC), and 2% salt.
HB-¼CFAC: 78% crust-freeze-air chilled breasts in quarter portions, 20% ice (0ºC), and
2% table salt.
Samples (50 g) of each batter were taken, placed in temperature resistant plastic bags,
labeled, and stored in a freezing room (-20ºC) until being tested for pH. Each batter was

20

placed in gallon size Ziploc bags, and stored overnight in a chilling room (4ºC) before gel
preparation.
3.3.3 Gel preparation
After mincing, batters were cooked into gels using the method of Jeong et al. (2011).
Each treatment batter was stuffed into pre-weighed stainless steel cylindrical tubes, and put
into a water bath (model 25, Precision Scientific Co., Chicago, IL) at 80°C for 20 min. After
cooking, the tubes were immediately placed in an ice bed (~30 min) to reach room
temperature, before being tested for cooking yield and texture.
3.3.4 Sample Testing
The samples for pH determination were measured from the previously frozen medial
portions of the right fillets and from frozen batters. The sample preparation followed the
procedure used by Sams and Jancky (1986), and done in duplicates for each sample. After
storage (-20ºC) the frozen samples were individually placed in new temperature-resistant
plastic bags, immersed in liquid nitrogen for further freezing, double wrapped in aluminum
foil and paper towel, and pulverized using a hammer. 2.5 g of each powdered sample were
homogenized in 25 mL of homogenizing solution (0.005M Iodacetate) for 30 sec. using a
benchtop homogenizer. The homogenized samples were let to reach room temperature before
determining the pH, which was measured with a pH electrode (model 13-620-631, Fisher
Scientific Inc., Houston, TX) attached to a pH meter (Accumet AR15, Fisher Scientific Inc.,
Pittsburgh, PA).
The ratio of inosine-monophosphate:adenosine-triphosphate (R-value) was assessed as an
indicator of adenosine triphosphate (ATP) depletion in the muscle, using the method of
Thompson et al. (1987). Previously frozen medial portions of the right fillets were used to
determine R-value. After storage (-20ºC) the samples were individually placed in
temperature-resistant plastic bags, immersed in liquid nitrogen, double wrapped in aluminum

21

foil and paper towel, and pulverized using a hammer. 3.0 g of powdered sample were placed
into a plastic beaker with 20 ml of 1M perchloric acid, and homogenized for 1 min on 60%
power using a benchtop homogenizer. The homogenized samples were then filtered through
filter paper, and 0.1 ml of the filtrate was transferred to a disposable glass tube, where 4.0 ml
of 0.1M phosphate buffer were added. The absorbance of this solution was read at 250 nm
(IMP) and 260 nm (ATP), as indicators of Inosine and Adenosine respectively. The following
equation was used to get the R-value:
=R-value
The distance between one Z disk to the next Z disk in a sarcomere (muscle functional
unit) is known as sarcomere length; sarcomeres in a striated muscle act as a diffraction that
break light into a measureable pattern.
The sarcomere length was measured from the caudal portion of the previously frozen
right breasts following Voyle (1971), and Cross et al (1981). The frozen samples were taken
out of storage (-20ºC), cut into small cubes (~1 cm3), and about 10-15 g of the sample were
homogenized (@90% power) in 50 ml of iodoacetate solution (0.25M sucrose, 0.002M KCL,
0.005M iodoacetate @4ºC) on an ice bed for about 12s. A drop of homogenate was placed
between a slide and a coverslip, and placed onto the stage of the laser stand; the board of the
laser stand was place at 100 mm from the top of the slide. Once the laser was on, the slide
was moved carefully until a diffraction pattern was seen on the base of the board, the
distance between the origin and the first order diffraction band was measured; 10 readings
were recorded for each sample in a dark room.

22

The readings were used in the following equation to get the sarcomere length:
[( )

]

0.6328 = Wavelength of the Helium-Neon laser light
D = Distance in mm from specimen to the diffraction screen
T = Distance in mm from the origin to the first order diffraction band
The myofibril fragmentation was measured as and indicator of the degradation of the
Z-discs (Fragmentation Index). This was evaluated using Sams (1991) gravimetric method.
To obtain the Fragmentation Index (FI), nylon screens (250µm) were cut into a circular,
dried for 16 h in a drying oven (100ºC); after drying the screens were handled with nitrile
gloves to avoid moisture transfer. The weights of the screens were measured in an analytical
balance, and recorded. 4-5 g of previously frozen cranial samples were cut into 2x2 mm
cubes, and homogenized in 40ml of cold (4ºC) homogenizing solution (0.25M sucrose,
0.002M KCL, 0.005M iodoacetate @4ºC, pH=7 KOH) using a benchtop homogenizer for
about 30 s. The homogenate was vacuum-filtered through the pre-weighted screen and a
filter paper, using a Buchner funnel and flask. The screens with the unfiltered sample were
dried overnight for about 18 h in a drying oven (102ºC), and then cooled in a desiccator (20
min) before the final weight was recorded. The weight of the dried sample was obtained
using the following formula:

Wtds= Weight of dry sample with screen
Wts Weight of screen
Wtws=Weight of wet meat sample

23

The cooking yield (percentage of the initial weight of the meat batter retained after cooking)
was determined by individually weighing the ten tubes used for each treatment, prior to
(empty tube and two caps), and after stuffing (stuffed tube and two caps). After cooking and
cooling, the purged water was drained off the tubes, and each cooked gel and its cooking
tube were dry with paper towels, and weighed together. All weights were recorded and the
final cooking yield was determined with the following formula:

Wtbs= Weight of tube before stuffing
Wtst= Weight of stuffed tube
Wtap= Weight of dried drained tube with cooked gel
To determine shear stress and shear strain, as indicators of hardness and elasticity
respectively, the cooled cooked gels were cut perpendicularly in 3.0 cm length cylinders after
reaching room temperature (25ºC). Styrene disks were glued to the upper and lower bases of
the 3.0 cm cylinders using Loctite® Super Glue Liquid. The samples were then milled into a
dumbbell shape (10 mm in diameter at the midsection) by using a shaping machine (KCI24A2, Bodine Electric Co., Raleigh, NC). Each specimen was placed on a viscometer (DV-III
Ultra, Brookfield Engineering Laboratories Inc., Middleboro, MA) and twisted at 2.5 rpm.
Ten samples were evaluated for each treatment for 3 separate replications. At the breaking
point, both shear stress and shear strain were calculated with the recorded torque and elapsed
time using the following equations (Hamann, 1983).

[(

)

(

)]

t= Time at fracture
Tq= Torque (%)
24

3.3.5 Statistical Analysis
All experiments were replicated 3 times. Data were evaluated using PASW 18 statistic
program (2009) by one-way ANOVA, and a post-hoc analysis was performed with Duncan’s
multiple range test to evaluate difference among treatments.
3.4

Results and discussion

The carcass temperature after evisceration was 40.5°C ± 2.0, which decreased to 4°C with
an average chilling time of 5.5 h in ice slurry chilling (approximately 0.2oC, Figure 3.3.1 A,
A’). When breasts were hot-boned (HB) and crust-freeze-air chilled in a freezing room (~1
m/s, @-12oC), the average chilling times were 1 and 1.5 h, for the HBCFAC fillets without
(Figure 3.3.1 B, B’) and with ¼ sectioning (Figure 3.3.1 C, C’), respectively. Sams (1999)
indicated that turkeys take 3 – 6 h to reduce the postmortem carcass temperature to 4oC in
WIC, depending on their body size. Sams and McKee (2011) reported that air is 25 times less
efficient than water in heat convection, explaining why AC took longer times than WIC for
turkey and broiler (James, 2002; Jeong et al., 2011). The heat removal from the food surface
is a direct function of the surface heat transfer convection coefficient (h), which ranges from
5 W/m2.oC for slow-moving air to 500 W/m2ºC for agitated water (James, 2003).
The reduction of chilling time from 4 – 6 h (whole carcasses) to 1h (HB fillets) can make
the process more efficient, with less synchronization issues, reduced labor, lowered
maintenance fee, and minimized chilling space (Kang 2011-personal communication).
Additionally, the rapid chilling method may reduce the effects of PSE (pale, soft, and
exudative) turkey, which is induced by the combination of high muscle temperature and rapid
pH reduction, causing annual losses of over $200 million in the turkey industry (Owens et al.,
2000). Alvarado and Sams (2002) also found that product integrity was negatively affected in
turkey carcasses when chilling was delayed or conducted slowly.
Turkey breast pH ranged from 6.28 to 6.35 immediately after hot boning (Table 3.4.1),

25

indicating that they were normal glycolyzing breasts (pH > 6.0 at 15 min postmortem) rather
than rapid glycolyzing breasts (pH ≤ 5.80), according to Rathgeber et al. (1999). After
chilling, the breast pH of 5.5 h WIC lowered to 5.82, which was significantly lower (P < 0.05)
than those of 1.5 h HB-CFAC (pH 5.99) and 1 h ¼CFAC (pH 6.12) (Table 3.4.1). Owens et
al. (2000) indicated that the breast pH (6.09) of normal turkey was higher than that (pH 5.72)
of pale turkey at 1.5 h post-mortem. Marsh and Thompson (1958) reported that glycolysis
proceeds slowly with ATP depletion in lamb muscle at -5oC, which supports the higher
muscle pH seen in turkey breast at -12oC than at 0oC in this study. The combination of early
pH decline (0.5–1 h) and high body temperature (~37oC) is detrimental to protein
functionality (water holding capacity and texture cohesiveness) and visual appearance
(Warris and Brown, 1987; Bendell and Wismer-Pedersen, 1962; Offer, 1991).
R-value (the ratio of inosine:adenosine-containing compounds) of HB breasts ranged
from 0.87 to 0.98 (Table 3.4.1). After CFAC, the value increased to 0.99 – 1.08, which is
significantly lower (P < 0.05) than that (1.31) of WIC fillets, indicating that ATP was less
depleted in the AC breasts at -12oC (Table 3.4.1). In accordance with these results, Owens and
Sams (1997) reported that the R-value of turkey breasts after 2 h WIC was 0.94, which
increased to 1.11 and 1.21, respectively, at 8 and 24 h postmortem. McKee and Sams (1998)
indicated that higher R-values were seen in turkeys subjected to water at 40ºC, compared to
those in water at 20oC and 0oC, after 15 min and 4 h post-mortem.
Sarcomere length is an indicator of muscle contraction that is correlated with muscle
tenderness; longer sarcomeres suggest higher expressed tenderness (Locker, 1960). Muscles
that undergo rigor mortis while still attached to the bone, like in WIC, are known to yield
higher sarcomere length values when compared to hot-boned muscles (muscles deboned
before the development of rigor mortis). Hot-boned muscles have high ATP concentration
which makes them prone to muscle fiber shortening during chilling due to the high energy

26

used for muscle contraction. Papa and Fletcher (1988) indicated that muscles had less
sarcomere shortening when stored at 16oC, while more shortening was seen at either 0ºC or
40ºC at 2 h post-mortem. Rapid chilling with air at -12oC was reported to induce cold
shortening (irreversible contraction of actin and myosin filaments) in broiler carcass with pH
values ≥ 6.70 at 15 min post-mortem, although shear force value was reported to be 1.00 kg
cm-2 lower than those chilled in air at 0oC (Dunn et al., 1995). In this study sarcomere length
values for HB-CFAC and WIC (1.8 – 1.84 µm) were not significantly different (P < 0.05)
from each other, but were significantly higher than the values obtained (1.24 – 1.32 µm) from
HB meat with no chilling (Table 3.4.1). The gravimetric stretch that occurred during hanging
of HB-CAFC muscles (Figure 3.4.1C’) is a possible explanation to the sarcomere length
values found in these treatments, the stretch may have caused a similar effect than the one
produced by chilling while muscles are still attached to the bone.
Sarcomere shortening was reported to decrease when breasts were physically stretched
(Papa et al., 1989; Janky et al., 1992; Walker et al., 1994). In beef, Simmons et al. (1999) also
reported that longissiumus thoracis muscle had a significantly lower shear force, when

Internal temperature (ºC)

stretched by 20%, than the non-stretched control.
45
40
35
30
25
20
15
10
5
0

WIC
HB-CFAC

HB-¼CFAC

0

100

200
Chilling time (min)

300

400

Figure 3.4.1. Temperature change profiles of turkey breast fillets during water immersion
chill (WIC), hot-boned/crust-freeze-air-chill (HB-CFAC), and hot-boned/¼ sectioned/crustfreeze-chill (HB-¼CFAC) (n=9)

27

Fragmentation index is inversely related with the level of muscle aging and/or protein
degradation rather than physical tearing of muscle fibers (Birkhold and Sams 1993). The
fragmentation index (178.6) of CB fillets was significantly lower than those (193.5 – 200) of
HB fillets regardless of CFAC (Table 3.4.1). The low value is expected from the aging that
occurred during 5.5 h WIC, whereas the HB and HB-CFAC fillets had almost no or short
aging times, respectively. Owens and Sams (1997) reported that fragmentation index was
reduced from 186.9 to 164.5 as the harvest of turkey breast was delayed from 2 to 24 h
postmortem. Veeramuthu and Sams (1999) showed that both calpain activity and
fragmentation index were gradually decreased as broiler carcasses were aged up to 24 h.
Table 3.4.1. pH and R-value (±SEM)1 of turkey breasts that were chill-boned (CB), hotboned (HB), or hot-boned/crust freezing air chilled (HB-CFAC)
2

3

Parameter

CB-T

HB-NCM

pH-before
chill

n/a

6.28 ± 0.14

pH-after chill

5.82 ± 0.18

b

a

4

HB-CMCO2 HB-CFCM
6.25 ± 0.15

n/a

n/a

a

5

6.22 ± 0.09
5.99 ± 0.09

a
a

HB6
¼CFCM
6.35 ± 0.13
6.12 ± 0.16

a
a

R-valuea
a
a
a
n/a
0.97
±
0.21
0.98
±
0.13
0.93
±
0.10
0.87
±
0.28
before chill
R-value-after
a
b
b
n/a
n/a
1.08 ± 0.10
1.31
±
0.13
0.99
±
0.28
chill
Sarcomere
a
b
a
a
b
length after
1.24 ± 0.10
1.84 ± 0.11
1.32 ± 0.02 1.82 ± 0.08
1.85 ± 0.06
chill/no chill
Fragmentation
b
a
a
a
a
index-after
179 ± 3.07
194 ± 7.22
200 ± 4.70 196.± 7.52
198 ± 18.7
chill
a,b
Means within a row with the same superscripts are not significantly different (P < 0.05).
1

The number of observations in each chilling, n = 10 – 15.

2

CB-T – chill-boned fillets (after water immersion chilling) for mincing traditionally

3

HB-NCM –hot-boned fillets for mincing with no chilling

4

HB-CMCO2 –hot-boned flllets for mincing with CO2

5

HB-CFCM–hot boned/crust-freezing air chilled fillets for mincing in cold temperatures

6

HB-¼CFCM –hot boned/¼ sectioned/crust-freezing air chilled fillets for mincing in cold
temperatures
28

The temperatures of the batters differed between treatments. CB-T started with meat at
approximately 2ºC, and after the addition of water and ice, and 7 min of mincing the
temperature of the batter reached 10ºC. For HB-NCM, the initial T was close to 40ºC and
after mincing it lowered to 25ºC. HB-CO2 also started with meat at 40ºC, and after the
addition of CO2, and 7 min of mincing, the T was close to -2.0ºC. Both HB-CFAC treatments
started with meat at approximately -2.5ºC, and after the addition of ice, and 7 min of mincing
a drop of 0.5ºC was observed (Table 3.4.2). The higher temperatures observed during HBNC mincing may have an impact in WHC due to protein denaturation. It is expected that cold
mincing treatments (final T~ -2.0) result is higher cooking yield values.
Table 3.4.2. Temperature changes1 of meat batters during 7 min mincing of turkey
fillets that were chill-boned (CB) or hot-boned/crust-freeze- air chilled with (HB-¼
CFAC)/without (HB-CFAC) ¼ sectioning
2

CB-T

Parameter

HB-NC

2

HB-CO2

HB-CFAC

Before mincing
2 ± 2oC 40 ± 2oC 40 ± 2oC
-2.5 ± 1oC
(raw meats)
After 7 min mincing (batter) 10 ± 1oC 25 ± 1oC -2.0 ± 1oC -2.0 ± 0.5oC
1
The number of observations in each chilling/mincing, n = 10 – 15.

HB-¼CFAC
-2.5 ± 1oC
-2.0 ± 0.5oC

2

Chilling/mincing conditions as in Table 3.4.1.
Upon the completion of batter mincing, the pH (5.87) of CB-T batter was significantly

lower (P < 0.05) than those (6.07 – 6.26) of HB-NC, HB-CO2, and HB-¼CFAC, with the
intermediate (pH 6.0) seen for HB-CFAC (Table 3.4.3). Sorheim et al. (2006) reported that
the pH of CB beef batter was slightly lower (P < 0.05) than that of HB batter minced with
CO2. When the minced batters were stored at 4oC overnight, the pH (5.90 – 5.92) of CB-T
and HB-¼CFAC were significantly lower (P < 0.05) than those (6.06 – 6.10) of HB-WC and
HB-CO2, with the intermediate (5.97) seen for HB-CFAC (Table 3.4.3).
After cooking the resulting gels for CB-T had significantly lower cooking yield values
(86.1%) compared to all HB treatments (Table 3.4.3). This can be explained by the lower
29

initial meat pH (Table 3.4.1) in combination to higher mincing temperatures (with HB-CO2,
and both HB-CFAC). No significant differences were observed between HB-NC and HB-CO2
gel cooking yield values (89.73 and 90.32) suggesting that cold mincing is capable to retain
the protein functionality of pre-rigor meat. Both HB-CFAC gels treatments had similar
(p<0.05) cooking yield to HB-CO2. Sorheim et al., (2006) reported higher cooking yield
(~97%) values in beef patties from pre-rigor/CO2 chilling than that (88.8%) of post-rigor
control.
The texture of cooked gels assessed by torsion test, in which shear stress (a measure of
gel strength) and the shear strain at failure (a measure of gel deformability) are correlated
with sensory hardness and cohesiveness, respectively (Hamann and Lanier, 1987). The stress
values (47.7 – 50.9 kPa) of hot-boned/chilled meat gels (HB-CO2, HB-CFAC and HB¼CFAC) were significantly higher (P < 0.05) than those (29.6 – 36.0 kPa) of chill-boned or
hot-boned/no-chilled meat gels (Table 3.4.3). Similarly, the strain values (1.58 – 1.67) of hotboned/chilled-meat gels were higher than that (1.21) of chill-boned control, with the
intermediate (1.52) seen for the hot-boned/no-chilled.

30

Table 3.4.3. Cooking yield, stress and strain values (±SEM)1 of turkey breast gels that
were made with breast muscles chill-boned (CB), hot-boned (HB), or hot-boned/crust-freezeair chilled (HB-CFAC)
Parameter2

CB-T

HB-NC

HB-CO2

Batter pH
after mincing

5.87 ±0.18c

6.12 ± 0.14ab

6.26 ± 0.15a

5.90 ± 0.18b

6.06 ± 0.21a

6.10 ± 0.13a

86.14 ±
0.18c

89.73 ±
0.21b

Batter pH
after
overnight
storage
Cooking
yield (%)

6.00 ± 0.09bc

90.32 ± 0.13ab

6.07 ± 0.13ab

5.97 ± 0.09ab

90.21 ± 0.10ab

5.92 ±
0.16b
91.29 ±
0.28a

Stress (kPa)

29.56 ±
0.13b

36.02 ± 0.10b

47.70 ± 0.10a

47.98 ± 0.10a

50.92 ±
0.28a

Strain

1.21 ± 0.10c

1.52 ± 0.10b

1.67 ± 0.10a

1.58 ± 0.10ab

1.61 ±
0.10ab

a,b,c
1

HB¼CFAC

HB-CFAC

Means within a row with the same superscripts are not significantly different (P < 0.05).

The number of observations in each chilling/mincing, n = 10 – 15.

2

Chilling/mincing conditions as in Table 3.4.1.
In support of these findings in CB gels, Rathgeber et al. (1999) indicated that stress

and strain values for normal glycolyzing turkey breast (pH >6.0 at 15 min postmortem) were
significantly higher than those of rapid glycolyzing breast (pH ≤ 5.8 at 15 min postmortem).
Alvarado and Sams (2004) showed that slow rates of turkey chilling at 30oC resulted in
reduced gel strength, greater cook loss, greater lightness (L* value) and lower pH than those
of fillets chilled at 0oC. Jeong et al. (2011b) also reported stress (25.6 kPa) and strain (1.3)
values from CB broiler breast gels, which are similar to the findings in turkey gels. Delaying
of initial carcass chilling reduced both stress and strain values of turkey breast gels,
potentially due to low protein extractability for protein to form gels (Rathgeber et al., 1999).
The strength of PSE meat gels was reported to 45% of that from normal pork gels in the same
protein concentration (Camou and Sebranek, 1991).
The results of this study suggest that the combination of hot-boning and crust-freezing air
31

chill, and cold-mincing on turkey breast provides various advantages such as fast hot-boning
process, meat with pre-rigor quality, high cooking yield, and superior protein functionality.
Based on these results, the combination of cold-mincing and crust-freezing air chill could be a
viable processing method for academic research and industrial application. Additional
research like microbial evaluation, sensory analysis, and preliminary trials are required to
evaluate how effectively and practically the technology can be further developed and
implemented in the meat industry.
3.5

Conclusions

Pre-rigor meat, although superior in protein functionality, has not been largely implemented
due to the limits of speed synchronization, excessive refrigeration, and intensive labor (Saffle,
1968). Once meat is hot boned, it is difficult to maintain the pre-rigor condition and hygiene
standard unless the meat is processed immediately or frozen. With the combination approach
(hot-boning and crust-freezing) in this study, some of the issues associated with
synchronizing the processing line appear to be improved, while the cold-mincing helped in
maintaining the functional and economical value of hot-boned muscles.

32

CHAPTER IV: EFFECT OF SODIUM REDUCTION ON COLD-BATTER MINCED,
HOT-BONED, ¼-SECTIONED-CRUST-FREEZE-AIR-CHILLED TURKEY BREAST
GEL QUALITY

33

4.1 Abstract
In previous studies, the combination of Crust-freezing air chilling (CFC) and Cold-mincing
(CM) during processing showed an improvement of Hot-boned (HB) meat on cooking yield
and on sensory quality when compared to the commercial Cold-boning (CB) process, which
could be beneficial to overcome the technical issues brought by salt reduction. Therefore the
purpose of this research was to evaluate the effect of sodium reduction in turkey gels made
out of HB breasts and processed by CFAC in quarter portions, and CM on overall protein
functionality. For each replication, two processing methods at two sodium levels were
studied. Half of the carcasses were assigned to either WIC or to the HB-¼CFAC process.
After chilling HB-¼CFCM fillets had a significantly (P< 0.05) higher pH (5.94) and
significantly lower R-value (1.19) compared to CB fillets (pH=5.73; R-value=1.32),
suggesting less ATP depletion and glycolization, and better protein functionality at that stage.
Chilled fillets were traditionally (T) minced (15ºC) for CB-T, and cold minced (-2.5oC) for
HB-¼CFCM fillets, each group at 1% and 2% salt. After mincing, the pH of batters showed
no significant difference (P> 0.05) between the CB-T and the HB-¼CFCM batters after 6 min
in 2% salt, whereas for 1% salt batters, significantly lower pH was seen in HB-¼CFCM after
15 min mincing, suggesting similar protein functionality when minced for less than that time.
Additionally HB-¼CFCM batter had more solubilized protein than CB batter after min 9 for
the 2% treatments, and after min 12 for those with 1% salt. Stress values in 2% salt HB¼CFAC gels were higher (P < 0.05) than in 1 and 2% salt CB gels, with intermediate values
seen for 1% salt HB-¼CFAC gels. In scanning electron microscope (SEM) images, pre-rigor
batter appears to have more air pockets, less protein aggregation, and fat particles coated with
more protein than the SEM of post-rigor batters.
Key words: Sodium reduction, hot-boning, crust-freezing, cold mincing, protein functionality

34

4.2 Introduction
Many Americans are consuming excessive amounts of salt, which can lead to negative
health impacts. The largest portion (77%) of salt in American diet comes from processed
products and restaurant foods (Mattes and Donnelly, 1991). As a result, meat processors are
challenged on how sodium levels can be reduced in their products. Hot-boning or pre-rigor
processing has been known to generate superior quality to chill-boning for raw and processed
meat products (Cuthbertson, 1980; Kastner, 1977). Froning and Neelakantam (1971) reported
that the meat batter made from pre-rigor muscle exhibited higher emulsifying capacity and
emulsion stability than those of post-rigor muscle. A higher cooking yield was observed from
hot-cut broiler than the chill-cuts in broiler meat (Wyche and Goodwin, 1974). Due to the
rapid muscle retrieval, hot-boning process has been known for many advantages such as
energy saving, high processing yield, high throughput, reduced chilling time, and chilling
space (McPhail, 1995; Lyon and Hamm, 1986).
In poultry, however, hot-boned processing has to be completed in < 0.5 h post mortem
because rigor in poultry muscle starts early while rigor in pork and beef develops in 0.25 – 3
h and 6 – 12 h, respectively (Aberle et al., 2001). Furthermore, HB presents difficulties in
synchronizing speed between slaughtering and boning lines, controlling hygiene, and making
initial investment with worker retraining (Troy, 2006; Pisula and Tyburcy, 1996).
Cold-batter mincing is an emerging technology, which improves protein functionality
and gel forming ability during mincing the meat batter for a long period of time at sub-zero
temperatures. As a result, the hot-boned/crust-frozen muscles have the great potential for
cold-batter mincing rather than the simultaneous mincing of hot-boned muscles
(synchronizing issue, PSE-like softening issue if delayed for chilling) or freezing of hotboned muscle (thaw-rigor issue after thawing).

35

In 1965, Bard (1965) reported interesting results in protein extraction as follow: 1) the
extraction of salt-soluble proteins from post-rigor meat increased proportionally as the
extraction time was extended up to 15 h, 2) protein extraction increased dramatically in the
range of -5 to 2oC compared to the temperatures higher than 2oC, and 3) muscle protein
extraction from pre-rigor meat was greater in 15 min mincing than that from post-rigor
muscle minced for 15 h. When pre-rigor meats were salted and ground with carbon dioxide,
patties from the pre-rigor meat had higher pH, lower cooking loss, and firmer texture than
those from post-rigor control (Sorheim et al., 2006).
Previously cold-batter mincing of hot-boned/¼ sectioned/crust-freezing air chilled
turkey fillets minced for 7 min generated higher stress and strain values in cooked gels than
those of chill-boned control and hot-boned/no-chilled muscles. Therefore, the purpose of this
research was to evaluate the potential for protein functionality improvement and sodium
reduction capability by extending cold-batter mincing time for HB-¼CFAC fillets up to 24
min.

36

4.3 Materials and Methods
4.3.1 Turkey slaughter and dressing, carcass chilling, and sample preparation
Four batches of twelve live Nicolas tom turkeys (16 weeks-old, ~18 kg in live weight)
each, were obtained locally in four different occasions between July and December of 2012.
Four replications were completed at the end of this study, and a total of forty-eight turkeys
(twelve turkeys per batch) were used.
After birds were withdrawn from feed for 12 h and cooped in plastic cages, the birds
were transported to the Michigan State University meat and poultry processing laboratory. On
the morning of the arrival, the birds were electrically stunned for 6 s (80 mA, 60 Hz, 110 V),
and bled for 90 s by severing both carotid artery and jugular vein on one side of the neck. The
turkeys were then scalded (59ºC, 120 s), mechanically defeathered (25 s), and manually
eviscerated. After washing, carcasses were weighed, and their internal temperatures were
recorded from the center of the turkey breast using a digital thermometer/logger (model
800024, Sper Scientific Ltd., Scottsdale, AZ).
In each replication three out of the twelve carcasses were randomly assigned to one
the following treatments (Figure 4.3.1.):
1) Water Immersion Chilling, cold-boned, and minced traditionally with 2% table salt
(CB-T 2%)
2) Water Immersion Chilling, cold-boned, and minced traditionally with 1% table salt
(CB-T 1%)
3) Hot-boned, crust-freeze-air chilled in quarter portions, and minced at sub-zero
temperatures with 2% salt (HB-¼CFAC-2%)
4) Hot-boned, crust-freeze-air chilled in quarter portions, and minced at sub-zero
temperatures with 1% salt (HB-¼CFAC-1%)

37

Figure 4.3.1. Process flow for study 2
All six WIC turkeys were chilled in two plastic tanks (3 birds per tank), each
containing a mix of water and ice (~40 L @approximately 0.5ºC) (Figure 3.3.3 A, A’) with
mechanical agitation (0400–025GV1S portable agitator, Grovhac Inc., Brookfield, WI). The
temperature of one representative carcass was measured every five minutes and recorded. The
carcasses were taken out of the chilling tank after reaching 4ºC. The carcasses were then coldboned (CB), and samples (1 cm thickness) from the cranial, medial, and caudal portions
(Figure 3.3.2) of the right breasts (one sample per carcass) were immediately taken and
tagged, placed in temperature resistant plastic bags, frozen in liquid nitrogen, and stored in a
freezing room (-20.0ºC) for further testing. The left breasts were stored in gallon-size Ziploc
bags in a chilling room (4.0ºC) for overnight storage.

38

The remaining six birds were hot-boned (HB), and samples from the right breasts
were taken and stored immediately after hot-boning in the same way as mentioned above.
HB-NC and HB-CO2 breasts were processed immediately as described in the Breast mincing
and gel preparation section of this chapter. The left HB-CFAC breasts were manually sliced
into four portions of similar size (Figure 3.3.3), and placed in an air freezing room (~1 m/s,
@12oC) for CFAC (Figure 3.3.4 C, C’).
The temperature of one representative breast was taken every 5 min for each CFAC
treatment. The breasts were taken out of the freezing room after reaching an internal
temperature of 4ºC. Samples from the frozen meat were then taken and stored in the same
fashion as for WIC treatment. The remaining frozen meat was minced directly after chilling.
4.3.2 Breast mincing
All four treatments were minced in a food cutter (256 rpm, Models 84181, Hobart,
Troy, OH) in the meat processing lab at Michigan State University. Each batch (~25 Kg) was
mixed for 27 min using the following formulations:
CB-T 2%: 78% chilled-boned meat, 4% water (25ºC), 16% ice (0ºC), and 2% table salt
CB-T 1%: 78.5% chilled-boned meat, 4.25% water (25ºC), 16.25% ice (0ºC), and 1%
table salt
HB-¼CFAC 2%: 78% crust-freeze-air chilled breasts in quarter portions, 20% ice (0ºC),
and 2% table salt.
HB-¼CFAC 1%: 78.5% crust-freeze-air chilled breasts in quarter portions, 20.5% ice
(0ºC), and 1% table salt.
Two separate sets of 50 g samples were taken from each batter every 3 min, starting at
min 6, until min 27, placed in temperature resistant plastic bags, and labeled; one of the two
sets was stored in an ice bed, and immediately taken to the testing lab for protein solubility
determination, while the second set was immersed in liquid nitrogen, and placed in a freezing

39

room (-20ºC) until tested for pH. Each batter was placed in a gallon size Ziploc bag, and
stored overnight in a chilling room (4ºC) before gel preparation.
4.3.3 Gel preparation
After mincing, batters were cooked into gels using the method of Jeong et al. (2011).
Each treatment batter was stuffed into pre-weighed stainless steel cylindrical tubes, and put
into a water bath (model 25, Precision Scientific Co., Chicago, IL) at 80°C for 20 min. After
cooking, the tubes were immediately placed in an ice bed to reach room temperature, before
being tested for cooking yield and texture.
4.3.4 Sample Testing
The samples for pH determination were measured from the previously frozen medial
portions of the right fillets and from frozen batters. The sample preparation followed the
procedure used by Sams and Jancky (1986), and done in duplicates for each sample. After
storage (-20ºC) the samples were individually placed in new temperature-resistant plastic
bags, immersed in liquid nitrogen for further freezing, double wrapped in aluminum foil and
paper towel, and pulverized using a hammer. 2.5 g of each powdered sample were
homogenized in 25 mL of homogenizing solution (0.005M Iodacetate) for 30 sec. using a
benchtop homogenizer. The homogenized samples were let to reach room temperature before
determining the pH, which was measured with a pH electrode (model 13-620-631, Fisher
Scientific Inc., Houston, TX) attached to a pH meter (Accumet AR15, Fisher Scientific Inc.,
Pittsburgh, PA).
The ratio of inosine-monophosphate:adenosine-triphosphate (R-value) was assessed as an
indicator of adenosine triphosphate (ATP) depletion in the muscle, using the method of
Thompson et al. (1987). Previously frozen medial portions of the right fillets were used to
determine R-value. After storage (-20ºC) the samples were individually placed in
temperature-resistant plastic bags, immersed in liquid nitrogen, double wrapped in aluminum

40

foil and paper towel, and pulverized using a hammer. 3.0 g of powdered sample were placed
into a plastic beaker with 20 ml of 1M perchloric acid, and homogenized for 1 min on 60%
power using a benchtop homogenizer. The homogenized samples were then filtered through
filter paper, and 0.1 ml of the filtrate was transferred to a disposable glass tube, where 4.0 ml
of 0.1M phosphate buffer were added. The absorbance of this solution was read at 250 nm
(IMP) and 260 nm (ATP), as indicators of Inosine and Adenosine respectively. The following
equation was used to get the R-value:
=R-value
To determine the degree of solubilized protein in each treatment, the batter samples
were tested immediately after mincing following the method and formula of Xiong and
Brekke (1989). To prepare the salt-soluble protein sample, 1.0 g of fresh batter was mixed
with 40 ml of extraction buffer (DDW-double distilled water), stomached for 1 min, placed
in centrifuge tubes (1 ml), and centrifuged for 5 min (12 g, 40ºC). To determine total protein,
2g of turkey batter sample (from min 3 sample) were mixed with 15 mL of urea buffer (8M
urea in 20mM Tris-HCL, pH 5.7-5.9), stirred magnetically overnight, and centrifuged for 5
min (12 g, 40ºC). Protein concentration of all salt-soluble samples (eight samples per
treatment, one for each 3 min of mincing), and total protein samples (one per treatment from
min 3) was determined using Thermo Scientific™ Pierce™ BCA™ Protein Assay. Protein
solubility was calculated using the following formula:
[

]
[

]

The cooking yield (percentage of the initial weight of the meat batter retained after cooking)
was determined by individually weighing the ten tubes used for each treatment, prior to (empty
tube and two caps), and after stuffing (stuffed tube and two caps). After cooking and cooling, the
purged water was drained off the tubes, and each cooked gel and its cooking tube were dry with
41

paper towels, and weighed together. All weights were recorded and the final cooking yield was
determined with the following formula:

Wtbs= Weight of tube before stuffing
Wtst= Weight of stuffed tube
Wtap= Weight of dried drained tube with cooked gel
To determine shear stress and shear strain, as indicators of hardness and elasticity
respectively, the cooled cooked gels were cut perpendicularly in 3.0 cm length cylinders after
reaching room temperature (25ºC). Styrene disks were glued to the upper and lower bases of
the 3.0 cm cylinders using Loctite® Super Glue Liquid. The samples were then milled into a
dumbbell shape (10 mm in diameter at the midsection) by using a shaping machine (KCI24A2, Bodine Electric Co., Raleigh, NC). Each specimen was placed on a viscometer (DV-III
Ultra, Brookfield Engineering Laboratories Inc., Middleboro, MA) and twisted at 2.5 rpm.
Ten samples were evaluated for each treatment for 3 separate replications. At the breaking
point, both shear stress and shear strain were calculated with the recorded torque and elapsed
time using the following equations (Hamann, 1983):

[(

)

(

)]

t= Time at fracture
Tq= Torque (%)
For SEM evaluation, both meat batters and cooked gels (3 mm × 3 mm × 3 mm cube)
were fixed at 4oC for 2 h in 4% glutaraldehyde buffered with 0.1 M sodium phosphate at pH
7.4. Following a brief rinse in the buffer, samples were post-fixed in 1% osmium tetroxide
buffered with 0.1M sodium phosphate for a minimum of 4 h. Samples were then briefly
42

rinsed in 0.1 M phosphate buffer and dehydrated by exchanging with graded ethanol series
(25, 50, 75, and 95%) for 1 h at each gradation with additional three 1 h changes in 100%
ethanol. The resulting samples were then mounted on aluminum stubs using carbon
suspension cement (SPI Supplies, West Chester, PA) and coated with osmium (~10 nm
thickness) in a NEOC-AT osmium coater (Meiwafosis Co., Ltd., Osaka, Japan). Samples on
the aluminum stubs were examined in a JEOL JSM-7500F (cold field emission electron
emitter) scanning electron microscope (JEOL Ltd., Tokyo, Japan).
4.3.5 Statistical Analysis
All experiments, with the exception of SEM, which was only done once, were
replicated 3 times. Data were evaluated using PASW 18 statistic program (2009) by one-way
ANOVA, and a post-hoc analysis was performed with Duncan’s multiple range test to
evaluate difference among treatments.
4.4 Results and discussion
The initial temperature (41.3oC) of the eviscerated turkey carcasses decreased to 4oC,
with an average chilling time of 5.5 h for water immersion chill (WIC), and of 1.0 h for the
fillets in crust-freeze-air room (~1 m/s, @-12oC) after hot-boning/¼sectioning/crust-freezing
air-chill (HB-¼CFAC). These results were similarly noticed in the previous chapter of this
thesis. Before chilling, there were no significant differences between two groups of fillets
(chill boning and hot boning) for pH (6.04 – 6.14) and R-values (0.98 – 1.01) (Table 4.4.1).
After chilling, higher pH (5.94) and lower R-value (1.19) (P < 0.05) were observed in HB¼CFAC fillets than those (pH 5.72, R-value 1.32) of chill boned (CB) fillets (Table 4.4.1),
indicating that less glucose and ATP have been hydrolyzed in the HB-¼CFAC fillets than
those in CB fillets, primarily due to a shorter PM time (15 min) than that (345 min) of CB
fillets. Alvarado and Sams (2002) also observed that turkey breasts at 15 min postmortem had
higher pH (6.16) and lower R-value (1.02) than those (pH 5.91, R-value 1.3) of 24 h.

43

Table 4.4.1. pH and R-value (±SEM)1 of turkey breasts before and after being chill-boned
(CB) or hot-boned/¼ sectioned/crust-freezing air chilled (HB-¼CFAC)

a,b
1

Parameter/Chilling

CB

HB-¼CFAC

pH before chill

6.04 ± 0.18

pH after chill

5.73 ± 0.09

R-value before chill

1.01 ± 0.09

R-value after chill

1.32 ± 0.05

a

b
a
a

6.14 ± 0.21
5.94 ± 0.10
0.98 ± 0.08
1.19 ± 0.13

a
a
a

b

Means within a row with the same superscripts are not significantly different (P < 0.05).

The number of observations in each chilling for each part, n = 16.
After chilling, breast fillets were minced with 1 or 2% salt for a batter preparation. For

a cold-batter mincing, HB-¼CFAC fillets (surface temperature at -1.5 to -3.5oC) were minced
with 2% salt/20% ice or 1% salt/21% ice, while CB fillets (surface temperature at ~ 0.5oC)
were traditionally minced with 2% salt/4% ice/16% water or 1% salt/4% ice/17% water.
During the first 6 min of mincing, temperatures of traditional-minced batter sharply increased
to 17 – 18oC, while those of cold-mincing batter remained at -1oC (Figure 4.4.1). After 6 min,
the temperature of cold-minced batter continuously increased and had no significant
difference (P > 0.05) from the traditionally-minced batters at 15 min for 2% salt and 24 min
for 1% salt (Figure 4.4.1). Regarding the traditional chopping time and batter temperature,
Deng et al. (1981) reported that temperature increased to 16oC at 5 min mincing and 33oC at
20 – 25 min, which supports these results of traditional batters.

44

Figure 4.4.1. Temperature changes of meat batters during 27 min mincing of turkey
fillets that were chill-boned (CB) or hot-boned/¼sectioned/crust-freeze-air-chilled (HB-¼
CFAC). Means (n = 8) with no common letters within the same mincing time differ
significantly (P < 0.05)
At 6 min mincing, the pH (5.97) of 2% salt HB-¼CFAC batter was higher (P < 0.05)
than that (pH 5.82) of 1% salt CB batter, with intermediate values (pH 5.83 – 5.90) for the 1%
salt HB-¼CFAC and 2% CB. After 6 min, the pH of 1 and 2% salt HB-¼CFAC batters
continuously decreased to 5.75 and 5.55, respectively at the end of mincing, resulting two
lowest pH values (Figure 4.4.2). Unlike the HB-¼CFAC, the pH of CB batters remained
constant in the range of 5.8 ± 0.2 throughout the mincing period, regardless of salt content.
As a result, the CB batter pH was the same as the 2% salt HB-¼CFAC batter and
significantly higher (P < 0.05) than the 1% salt HB-¼CFAC batter after 15 min mincing. It
has been known that the pH of pre-rigor meat rapidly drops when the pre-rigor meat are
ground or turned into batter.

45

Figure 4.4.2. pH changes of meat batters during 27 min mincing of turkey fillets that
were chill-boned (CB) or hot-boned/¼sectioned/crust-freeze-air-chilled (HB-¼ CFAC).
Means (n = 8) with no common letters within the same mincing time differ significantly (P <
0.05)
Newbold and Scopes (1971) reported that the pH of minced pre-rigor beef decreased
from 6.7 to 5.4 – 5.5 during 400 min storage, while the intake muscle pH remained in 6.3 –
6.4. Bernthal et al. (1989) also observed that beef muscle pH was significantly reduced when
pre-rigor muscles were ground and stored, while high ultimate pH values were observed at
high NaCl concentrations. Hamm (1977) reported that grinding of pre-rigor beef muscle with
2 – 4% sodium chloride inhibited glycolysis in several hours postmortem, due to the
denaturation of glycolytic enzymes in low pH (< 6) and high ionic strength. In follow-up
research, salt was recommended to add to pre-rigor blend for 1.5% (Farouk and Swan, 1997),
1.8% (Hamm, 1982), or 2.0% (Bernthal et al., 1989) for high muscle pH and high protein
functionality.
When the batters were taken during mincing and stored at 4oC overnight, the overall
pattern of the overnight batter pH was similar those of fresh batter pH except the 1% salt HB
batter, resulted in additional pH reduction by 0.1 – 0.2 units (Figure 4.4.3). It appears that the
grinding time of pre-rigor muscle for batter generation might more affect the batter pH than
46

the storage of the batter for overnight. These outcomes are consistent with the previous
findings that the ultimate pH of 1.5% salt HB beef mince was always higher than that of
unsalted controls (Farouk and Swan, 1997), indicating that the mincing of HB muscle at high
salt maintains a high pH compared to the mincing of HB muscle at low salt. Torres et al.
(1988) also indicated that ground HB beef containing 2.0% salt had lower pH (0.7 – 0.9 units)
than those of 4.0% salt. Regardless of pH values at the time of freezing, mincing of unsalted
muscles reached ultimate pH values to 5.6 – 5.75, indicating that the glycolysis continued
during thawing at 4oC for 48 h (Farouk and Swan, 1997). In this study, glycolysis was
presumed to occur in the 1% salt more than the 2% salt HB-¼CFAC batter during overnight
storage.

Figure 4.4.3. pH changes of overnight-stored (4oC) meat batters that were made with
turkey fillets chill-boned (CB) or hot-boned/¼sectioned/crust-freeze-air-chilled (HB-¼
CFAC). Means (n = 8) with no common letters within the same mincing time differ
significantly (P < 0.05)
Studies have shown that salt-soluble proteins in pre-rigor muscle are extracted more
than post-rigor muscle (Saffle and Galbreath, 1964; Bernthal et al., 1989; Claus and Sorheim,
2006). The solubilized proteins in HB-¼CFAC batters ranged from 44% to 54% during the
entire mincing, except the 6 – 12 min batters in 1% salt, while those of CB controls did not
exceed more than 37% (Figure 5). Similarly, Bernthal et al. (1989) reported that the
extractable protein values were 50 and 49% in pre-rigor homogenates in 1 and 2% salt,
47

respectively, while the extractable protein value of post-rigor homogenate was 29%, regard
ess of the salt content.
Shear stress (a measure of gel strength), representing sensory hardness, at breaking
point of gel in Hamann Torsion Gelometer is primarily affected by protein content water
content of gels, whereas shear strain (a measure of gel deformability, representing sensory
cohesiveness) at failure of gel is affected by protein quality (Hamann and Lanier, 1987).
During mincing, failure stress values of 1 and 2% salt HB-¼CFAC gels sharply
increased to the highest value of 48 kPa at 9 min and 39 kPa at 15 min, respectively, after
both values gradually decreased to 32 – 36 kPa. Similarly, the stress values from CB gels
increased to 26 kPa for 2% salt at 9 min and 23 kPa for 1% salt at 12 min, which were
significantly lower (P < 0.05) than those of HB-¼CFAC (Figure 4.4.4).

Figure 4.4.4. Stress value (kPa) of meat batters during 27 min mincing of turkey
fillets that were chill-boned (CB) or hot-boned/¼sectioned/crust-freeze-air-chilled (HB-¼
CFAC). Means (n = 8) with no common letters within the same mincing time differ
significantly (P < 0.05)
Unlike the stress values, no significant differences were found in strain values with the
range difference of 1.0 ± 0.2, regardless of boning type and sodium content (Figure 4.4.5).
The higher stress values in HB-¼CFAC can be explained by more protein extracted during
48

the cold mincing (Figure 4.4.6), and the similar strain values can be explained potentially by
the protein integrity, which affected during the preparation of fillets and gels.

Figure 4.4.5. Strain value of meat batters during 27 min mincing of turkey fillets that
were chill-boned (CB) or hot-boned/¼sectioned/crust-freeze-air-chilled (HB-¼ CFAC).
Means (n = 8) with no common letters within the same mincing time differ significantly (P <
0.05)
Different from these results, Dibble (1993) reported that beef sausages made from prerigor salted beef has a lower stress value (29 kPa) than that (33 kPa) of post-rigor with a
similar strain value (1.69 – 1.65) (Hamann and MacDonald, 1992). The lower stress value can
be potentially explained by a higher water holding capacity, lowering the protein content, in
the pre-rigor gel prepared from a traditional mincing but the HB-¼CFAC protein in this study
is extracted significantly more during the cold-batter mincing than the CB protein in
traditional mincing (Figure 4.4.5), potentially resulting in less reduction of stress value.
Farouk and Swan (1997) also reported similar stress (~ 28 kPa) and strain (~1.7) values when
hot-boned beef muscle was used at pH 6.0. In the previous study, the similar cold mincing
method was used for 7 min mincing and generated similar strain (51 kPa) and stress (1.61)
values of turkey gel.

49

Figure 4.4.6. Protein solubility (%) of meat batters during 27 min mincing of turkey
fillets that were chill-boned (CB) or hot-boned/¼sectioned/crust-freeze-air-chilled (HB-¼
CFAC). Means (n = 8) with no common letters within the same mincing time differ
significantly (P < 0.05)
The functional property of heat-induced gels is closely related with three-dimensional
gel-structure influenced by types of meats, muscles, amounts of connective tissues, pH, salt,
and heating conditions (Clark and Lee-Tuffnell, 1986). In scanning electron micrographs, the
batter properties of structural integrity, fat droplet entrapment, and matrix complex with
connective tissues were detected more clearly in 2% salt HB-¼CFAC batter at 6, 12, and 24
min (Figure 7A, B, C) than those of 2% salt CB batter (Figure 4.4.7. A’, B’, C’). A similar
pattern of results was observed in 1% salt HB-¼CFAC batter (Fig 4.4.8. A, B, C), whereas
collapsed structure and fluffed appearance were seen in 1% salt CB batters at 12 and 24 min
(Figure 8B’, C’), respectively. These structural differences observed in SEM are closely
related to the higher stress values seen in the HB-¼CFAC batters than the CB batters.
Froning and Neelakantan (1971) stated that the photomicrographs of pre-rigor emulsions
showed a thicker matrix around the fat globules, which might improve cohesive properties
thereby high rubberiness. The fat particles in 2% salt HB-¼CFAC batters appeared to be
sufficiently encapsulated with proteins at 6 min mincing (Figure 4.4.7 A), which became
50

smaller in size as the chopping was continued (Figure 4.4.7 B, C), whereas the fat particles in
2% salt CB batters were small in size at 6 min mincing (Figure 4.4.7 A’) and became almost
undetectable at 12 and 24 min mincing (Figure 4.4.7 B’, C’).
Comparing cooked gels prepared from comminuted turkey batters at different pH values
(4.5 – 7.5), Barbut (1997) reported that a dense structure with a considerable number of
aggregates presented in the gels of pH 4.5 while more open structure with less aggregation
were observed as the gel pH was raised from 5.5 to 7.5. In accordance with the Barbut’s
report, more open space and less aggregation were seen in 2% salt HB-¼CFAC gels (Figure
4.4.9 A, B, C) than those of 2% CB gels (Figure 4.4.9 A’,B’,C’). However, those structural
properties were observed less clearly between 1% HB-¼CFAC and 1% CB gels (Figure
4.4.9), presumably due to a rapid pH reduction (to pH 5.56) of 1% HB-¼CFAC batter and
continuous low pH (5.8) of 1% CB batter during mincing (Figure 4.4.3). Hamm (1977)
reported that high values of adenosine triphosphate (ATP), tissue pH and ionic strength in
pre-rigor meat contributed to a strong repulsion between adjacent protein molecules that leads
to an expanded structure for more fat and water binding after heat coagulation.

51

Figure 4.4.7 Scanning electron micrography (SEM) images of meat batters (2% salt)
at 6, 12, 24 min mincing. Arrow: emulsified fat globule, Circle: connective tissue, bar=1µm.
A: Meat batter of HB¼CFAC minced- 6 min, A’: Meat batter of CB- 6 min, B: Meat batter of
HB¼CFAC minced-12 min, B’: Meat batter of CB minced-12 min, C: Meat batter of HB¼C
FAC minced-24 min, C’: Meat batter of CB minced-24 min

52

Figure 4.4.8 Scanning electron micrography (SEM) images of meat batters (1% salt) at
6, 12,24 min mincing. Arrow–emulsified fat globule, circle– connective tissue, bar = 1 µm.
A: Meat batter of HB¼CFAC minced-6 min, A’: Meat batter of CB minced-6 min, B:
Meat batter of HB¼CFAC minced -12 min, B’:Meat batter of CB minced -12 min, C: Meat
batter of HB¼CFAC minced-24 min, C’.Meat batter of CB fillet minced -24 min

53

A

B

C

A
’

B
’

C
’

Figure 4.4.9. Scanning electron micrography (SEM) images of gels (2% salt) cooked
after 6 min, 12, 24 min mincing. Circle– connective tissue, bar = 1 µm.
A: Meat gel of HB¼CFAC minced -6 min, A’: Meat gel of CB minced -6 min, B: Meat gel
HB¼CFAC minced-12 min, B’: Meat gel of CB minced-12 min, C: Meat gel of HB¼CFAC
minced -24 min, C’: Meat gel of CB fillet minced 24 min

54

A

B

C

A
’

B
’

C
’

Figure 4.4.10. Scanning electron micrography (SEM) images of gels (1% salt) after 6,
12, 24 min mincing. Circle– connective tissue, bar = 1 µm.
A: Meat gel of HB-¼ CFAC minced 6 min, A’: Meat gel of CB minced 6 min, B: Meat gel of
HB-¼ CFAC minced -12 min, B’: Meat gel of CB minced- 12 min, C: Meat gel of
HB-¼CFAC minced -24 min, C’: Meat gel of CB minced- 24 min

55

4.5 Conclusions
Over the past 25 years the average salt intake has increased approximately 56% in
America, which has been related to an increase of negative health effects. However salt is a
fundamental component of processed meat foods, and its reduction impacts the quality and
processability of these products. The use of HB, to obtain pre-rigor meat, and CFC for rapid
chilling, retained raw meat quality with high pH values, which when followed by CM with 2%
and 1% sodium yielded similar results for pH, protein solubility, and gel strength and
elasticity, to traditional chill-boned products with 2% salt when minced for less than 12
minutes. Particularly the use of HB-¼CFAC fillets in 1% of salt resulted in the extraction of
more or similar amounts of protein when compared to the cold-boned/traditionally-minced
control fillets in 2% salt. After cooking, the stress and strain values of HB-¼CFAC gel
containing 1% salt were same as those of chill-boned control containing 2% salt. Lastly, the
HB-¼CFAC technique provides additional advantages such as rapid meat turn over and high
quality meats for various other applications. The use of scanning electron microscopy adds to
previous studies about the structure of meat batter and gels, providing a general and broad
overview about what happens to the structure of the components at different conditions.

56

CHAPTER V: AREAS FOR FURTHER STUDY

57

5.1. Areas for further study
The following topics are recommended for future study:
•

Methods for maintaining constant temperature during batter mincing.

•

Microbiological tests throughout the process, and on final products.

•

Sensory analysis of finished products.

•

Scale up costs and energy usage analysis.

58

APPENDICES

59

APPENDIX A

GLOSSARY OF TERMS
Protein functionality: in food processing, refers to any property of the protein that affects
the attributes of the final product, such as water and fat binding, emulsifying capacity, and
solubility.
Mincing: in meat processing, is the reduction of the meat particle size through the
mechanical action of blades (usually in a bowl chopper), also refer to as comminution.
Batter: in meat processing refers to the homogeneous product resulting from mincing, also
refer to as meat emulsion.
Traditional mincing: in this thesis, refers to the mincing of meat under conditions similar to
those used currently in the meat industry (i.e. T= 10ºC)

60

APPENDIX B

PRODUCTION FLOW FOR EMULSIFIED PRODUCTS

Figure B.1. Production flow for cold emulsions

Figure B.2. Production flow for hot emulsions

61

APENDIX C

RAW DATA STUDY 1
Table C.1. Temperature monitoring - Replication 1

62

Table C.2. Batter and raw meat pH – Replication 1

63

Table C.3. R-value - Replication 1

64

Table C.4. Sarcomere length – Replication 1

65

Table C.4. (contd’)

66

Table C.5. Fragmentation index – Replication 1

67

Table C.6. Cooking yield – Replication 1

68

Table C.7. Torsion test – Replication 1

69

Table C.8. Temperature monitoring – Replication 2

70

Table C.9. Batter and raw meat pH – Replication 2

71

Table C.10. R-value - Replication 2

72

Table C.11. Sarcomere Length - Replication 2

73

Table C.11. (cont’d)

74

Table C.12. Fragmentation index - Replication 2

75

Table C.13. Cooking yield - Replication 2

76

Table C.14. Torsion test – Replication 2

77

Table C.15. Temperature control – Replication 3

78

Table C.16. Batter and raw meat pH – Replication 3

79

Table C.17. R-value – Replication 3

80

Table C.18. Sarcomere Length – Replication 3

81

Table C.18. (cont’d)

82

Table C.19. Fragmentation index – Replication 3

83

Table C.20. Cooking yield – Replication 3

84

Table C.21. Fragmentation Index – Replication 3

85

APPENDIX D

RAW DATA STUDY 2
Table D.1. Batter temperature monitoring – Replication 1

86

Table D.2. pH before and after chilling – Replication 1

Table D.3. R-value before and after chilling – Replication 1

87

Table D.4. Batter pH – Replication 1

88

Table D.5. Protein Solubility, CB-T 2% – Replication 1

Table D.6. Protein Solubility, CB-T 1% – Replication 1

89

Table D.7. Protein Solubility, HB- ¼ CFAC 2% – Replication 1

90

Table D.8. Torsion test, CB-T 2% – Replication 1

91

Table D.9. Torsion test, CB-T 1% – Replication 1

92

Table D.10. Torsion test, HB- ¼CFAC 2% – Replication 1

93

Table D.11. Batter temperature monitoring – Replication 2

94

Table D.12. pH raw meat before and after chilling – Replication 2

95

Table D.13. Raw meat R-value before and after chilling – Replication 2

96

Table D.14. pH batter– Replication 2

97

Table D.15. Protein Solubility CB-T 2% – Replication 2

Table D.16. Protein Solubility CB-T 1% – Replication 2

98

Table D.17. Protein Solubility HB- ¼CFAC 2% – Replication 2

Table D.18. Protein Solubility HB- ¼CFAC 1% – Replication 2

99

Table D.19. Torsion test CB-T 2% – Replication 2

100

Table D.20. Torsion test CB-T 1% – Replication 2

101

Table D.21. Torsion test HB-¼CFAC 2% – Replication 2

102

Table D.22. Torsion test HB-¼CFAC 1% – Replication 2

103

Table D.23. Batter temperature monitoring – Replication 3

Table D.24. Raw meat pH – Replication 3

104

Table D.25. Raw meat R-value – Replication 3

105

Table D.26. Batter pH – Replication 3

106

Table D.27. Protein solubility CB-T 2% – Replication 3

Table D.28. Protein solubility CB-T 1% – Replication 3

107

Table D.29. Protein solubility HB-¼CFAC 2% – Replication 3

Table D.30. Protein solubility HB-¼CFAC 1% – Replication 3

108

Table D.31. Torsion test CB-T 2% – Replication 3

109

Table D.32. Torsion test CB-T 1% – Replication 3

110

Table D.33. Torsion test HB-¼CFAC 2% – Replication 3

111

Table D.34. Torsion test HB-¼CFAC 1% – Replication 3

112

Table D.35. Batter temperature monitoring – Replication 4

113

Table D.36. Batter pH during mincing– Replication 4

114

Table D.37. Raw meat pH – Replication 4

Table D.38. Raw meat R-value – Replication 4

115

Table D.39. Protein solubility– Replication 4

116

Table D.40. Torsion test CB-T 2% – Replication 4

117

Table D.41. Torsion test CB-T 1% – Replication 4

118

Table D.42. Torsion test HB- ¼CFAC 1% REP 3 – Replication 4

119

Table D.43. Torsion test HB- ¼CFAC 1%– Replication 4

120

LITERATURE CITED

121

LITERATURE CITED

Aberle, E.D., J.C. Forrest, D.E. Gerrard, E.W. Mills, H.B. Hedrick, M.D. Judge, and R.A.
Merkel. 2001. Conversion of muscle to meat and development of meat quality. Pages
117-154 in Principles of Meat Science. E. D. Aberle, J. C. Forrest, D. E. Gerrard and
E. W. Mills, 4th ed, Kendell/Hunt Publishing, Dubuque, IA.
Alvarado, C.Z., and A.R. Sams. 2002. The role of carcass chilling rate in the development of
pale, exudative turkey pectoralis. Poult. Sci. 81:1365–1370.
Barbut, S. 1997. Microstructure of white and dark turkey meat batters as affected by pH. Br.
Poult. Sci. 38:175-182.
Barbut, S. 2002. Poultry Products Processing: An industry guide. CRC press, Boca Raton Fl.
18-28: 233
Bard, J.C. 1965. Some factors influencing extractability of salt-soluble proteins. Page 96-98
in Proc. Meat Ind. Res. Conf. Am. Meat Sci. Assoc. and Am. Meat Inst. Foundation,
Chicago, IL.
Bernthal, P.H., A.M. Booren, and J. I. Gray. 1989. Effect of sodium chloride concentration on
pH, water-holding capacity and extractable protein of prerigor and postrigor ground
beef. Meat Sci. 25:143-154.
Bendell, J.R., and J. Wismer-Pedersen, 1962. Some properties of the fibrillar proteins of
normal and watery pork muscle. J. Food Sci. 27:144.
Birkhold, S.G., and A.R. Sams, 1993. Fragmentation, tenderness, and post-harvested broiler
breast fillets from carcasses treated with electrical stimulation and muscle
tensioning. Poult. Sci. 72:577-582.
Brown, D.L., and R.T. Toledo, 1975. Relationship between chopping temperatures and fat
and water binding in comminuted meat batters. J. Food Sci. 40:1061.
Camou, J.P., and J.G. Sebranek. 1991. Gelation characteristics of muscle proteins from pale,
soft. Extractive (PSE) pork. Meat Sci. 30:207-220.
Claus, J.R., and O. Sorheim. 2006. Preserving pre-rigor meat functionality for beef patty
production. Meat Sci. 73:287-294.
Clark, A.H., and C.D. Lee-Tuffnell. 1986. Gelation of globular proteins. Pages 203-272 in
Functional Properties of Food Macromolecules. J. R. Mitchell and D. A. Ledward,
ed. Elsevier Applied Science. New York, NY.
Cross, H.R., R.L. West, and T. R. Dutson. 1980. Comparison of methods for measuring
sarcomere length in beef semitendinosis. Meat Sci. 5:261–266.

122

Cuthbertson, A. 1980. Hot processing of meat: a review of the rational and economical
Implications. Pages 61-88 in Developments in Meat Science, Volume1. Applied
Science Publishers Ltd., London.
Deng J.C., R.T. Toledo, and D. A. Lillard. 1976. Effect of temperature and pH on proteinprotein interaction in actomyosin solution. J. Food Sci. 41:273.
Deng, J.C., R.T. Toledo, and D. A. Lillard. 1981. Protein-protein interaction and fat and water
binding in comminuted flesh products. J. Food Sci. 46:1117-1121.
Dibble, W.H. 1993. Functional properties of pre-rigor bull beef: Effect of phosphates,
cooking method and post-mortem salting time. Page 916 in MIRINZ Series. Meat
Ind. Res. Inst. N.Z., Hamilton, N.Z.
Dunn, A.A., D.J. Kilpatrick, and N.F.S. Gault. 1995. Contribution of rigor shortening and
cold shortening to variability in the texture of pectoralis major muscle from
commercially processed broilers. Brit. Poult. Sci. 36:401-413.
Farouk, M.M., and J.E. Swan. 1997. Effect of pH at time of salting on the functional
properties of pre-rigor beef. Meat Sci. 45:463-472.
Froning, G.W., and S. Neelakantan, 1971. Emulsifying characteristics of pre-rigor and postrigor poultry muscle. Poult. Sci. 50:839-845.
Gillett T.A., D.E. Meiburg, C. L. Brown, and S. Simon. 1977. Parameters affecting meat
protein extraction and interpretation of model system data for meat emulsion
formation. J. Food Sci. 42:1606-1610.
Guerrero-Legorreta, I. and Hui Y.H. Handbook of poultry science and technology. 2010.
Wiley & Sons Inc. Hoboken, N.J. Page 455-459
Hamann, D.D. 1983. Structural failure in solid food. Pages 351–376 in Physical Properties of
Foods. H. M. Peleg and E. Bagley, ed. AVI Publ. Co. Inc., Westport, CT.
Hamann, D.D., and T.C. Lanier. 1987. Instrumental methods for predicting seafood sensory
texture quality. Page 123 in Seafood Quality Determination, D.E. Kramer and J.
Liston ed. Elsevier Science Publishers, Amsterdam.
Hamann, D.D., and G.A. MacDonald. 1992. Rheology and texture properties of surimi and
surimi-based foods. Pages 429–500 in Surimi Technology. T. C. Lanier and C. M.
Lee, ed. Marcel Dekker Inc., New York, NY.
Hamm, R. 1966. Heating of muscle systems. In physiology and biochemistry of muscle as
food. E. G. Briskey, R. G Cassens and J. C. Trautman. Eds. The University of
Wisconsin Press, Madison. WI.
Hamm, R. 1977. Postmortem breakdown of ATP and glycogen in ground muscle: A
review.Meat Sci. 1:15-39.

123

Hamm, R. 1982. Postmortem changes in muscle with regard to processing of hot-boned beef.
Food Technol. 36:105-115.

Hamann, D.D., and T.C. Lanier. 1987. Instrumental methods for predicting seafood sensory
texture quality. Page 123 in Seafood Quality Determination. D. E. Kramer and J. Liston, eds.
Elsevier Science Publishers, Amsterdam.
Havas, S., E.J Roccella, and C Lenfant. 2004. Reducing the Public Health Burden From
Elevated Blood Pressure Levels in the United States by Lowering Intake of Dietary
Sodium. Am J Public Health. 2004 January; 94(1): 19–22.
Herbert E. F., and M. G Smith. 1980. Hot-boning of meat: refrigeration requirements to meet
microbiological demands. Food Res Quart, Sydney, AU.
Hermansen, P. 1987. Warm boning of pigs including problems of interfactory transport of
chilled meat. Accelerated Processing of Meat. Elsevier. 127-130
Hoogenkamp H.W. 2005. Soy protein and formulated meat products. CABI Publishing.
Cambridge, MA. 94-132
James, S.J. and C. James. 2002. Meat refrigeration. CRC Press. Boca Raton, Fl. 129-155
Janky, D.M., M.G. Dukes, and A. R. Sams, 1992. Research note: The effects of postmortem wing restraint (muscle tensioning) on tenderness of early-harvested broiler breast
meat. Poult. Sci. 71:574-576.
Jeong, J.Y., K.K. Janardhanan, A. M. Booren, J. B. Harte, and I. Kang. 2011. Breast meat
quality of consumer sensory properties of broiler carcasses chilled by water, air, or
evaporative air. Poult. Sci. 90:694-700.
Kastner, C.L. 1977. Hot processing: Update on potential energy and related economies. Page
43 in Proc. Meat Ind. Res. Conf., Am. Meat Sci. Assoc., and A. Meat Inst. Foundation,
Chicago, IL.
Locker, R.H., 1960. Degree of muscular contraction as a factor in tenderness of beef. Food
Res. 25:304-307.
Lyon, B.G., and D. Hamm. 1986. Effects of mechanical tenderization with sodium chloride
and polyphosphates on sensory attributes and shear values of hot-stripped broiler
breast meat. Poult. Sci. 65:1072-1707.
Marsh, B.B., and J.F. Thompson. 1958. Rigor mortis and thaw rigor in lamb. J. Sci. Food
Agric. 9:417-424.
Mattes, R.D., and D. Donnelly. 1991. Relative contributions of dietary sodium sources. J.
Am. Coll. Nutr. 10:383-393.
McKee, S.R., and A. R. Sams. 1998. Rigor mortis development at elevated 124emperaturas
124

induces pale exudative turkey meat characteristics. Poult. Sci. 77:169–174.
McKee, S.R., B.M. Hargis, and A.R. Sams. 1998. Pale, soft, and exudative meat in turkeys
treated with succinylcholine. Poult. Sci. 77:356-360.
McPhail, N.G. 1995. Implementation of hot boning. Pages 5-6 in CSIRO Meat Ind. Res.
Conf.,
Aus.
Meat
Technol.
Pty
Ltd.,
AU.
http://www.meatupdate.csiro.au/data/Meat_95_73.pdf
Mead, G.C. 2002. Poultry meat processing and quality. Woodhead Publishing, Cambridge,
EN. 123.
Newbold, R.P., and R.K. Scopes. 1971. Post-mortem glycolysis in ox skeletal muscle:
Effects of mincing and of dilution with or without addition of orthophosphate. J.
Food Sci. 36:209-214.
Offer, G., 1991. Modeling of the formation of pale, soft, and exudative meat: Effects of
chilling regime and rate and extent of glycolysis. Meat Sci. 30:157–184.
Owens, C.M., and A.R. Sams. 1997. Muscle metabolism and meat quality of Pectoralis
from turkeys treated with postmortem electrical stimulation. Poult. Sci. 76:10471051.
Owens C.M. 2010. Poultry Meat Processing. CRC Press. Boca Raton, Fl 231-244
Owens, C.M., E.M. Hirshler, S.R. McKee, R. Martinez-Dawson, and A.R. Sams. 2000. The
characterization and incidence of pale, soft, exudative turkey meat in a comercial
plant. Poult. Sci. 79:553-558.
Papa, C.M., C.E. Lyon, and D.L. Fletcher, 1989. Effect of post-mortem wing restraint on the
development of rigor and tenderness of broiler breast meat. Poult. Sci. 68:238 243.
Pisula A, and A. Tyburcy. 1996. Hot processing of meat. Meat Sci. 43:S125-S134.
Rathgeber, B.M., J.A. Boles, and P. J. Shand. 1999. Rapid postmortem pH decline and
delayed chilling reduce quality of turkey breast meat. Poult. Sci. 78:477-484.
Saffle, R.L., and J.W. Galbreath. 1964. Quantitative determination of salt-soluble protein in
various types of meat. Food Technol. 18:1943-1944.
Saffle, R.L., 1968. Meat emulsions. Advances in Food Research, 16:105-160.
Sams, A.R., and D.M. Janky. 1986. The influence of brine chilling on tenderness of hot
boned, chilled-boned, and age-boned broiler fillets. Poult. Sci. 65:1316-1321.SPSS.
2011. PASW Statistics 18 for windows. Chicago, IL, USA.
Sams, A.R., S.G. Birkhold., and K.A Mills. 1991. Fragmentation and tenderness in breast
muscle from broiler carcasses treated with electrical stimulation and hightemperature conditioning. Poultry Sci. 70:1430-1433.

125

Sams, A.R., 1999. Meat quality during processing. Poult. Sci. 78:798-803.
Sams, A.R., and S.R. McKee. 2011. First processing: Slaughter through chilling. Pages 25–49
in Poultry Meat Processing. C. M. Owens, C. Z. Alvarado, A. R. Sams, ed. CRC
Press LLC, Boca Raton, FL.
Seabra L.M., J.F. Zapata., M.F. Fuentes., C.M. Aguiar., E.R. Freitas, and M.C. Rodrigues.
2001. Effect of deboning time, muscle tensioning, and calcium chloride marination
on texture characteristics of chicken breast meat. Poultry Science 2001, 80:109-112.
Simmons, N.J., J. M. Cairney, M. M. Auld, T. A. Nagle, and C. R. Mudford. 1999. Effect of
pre-rigor stretching of beef M. Longissumus thoracis muscles on structural changes
and key meat quality attributes. Pages 464 – 465 in 45th International Congress of
Meat Science and Technology. Yokohama, Japan.
Sorheim O., S. Uglem, P. Lea, J. R. Claus, and B. Egelandsdal. 2006. Functional properties of
pre-rigor, pre-salted ground beef chilled with solid carbon dioxide. Meat Sci. 73:459466.
Tartre, R. 2009. Ingredients in Meat Products: Properties, functionality and applications.
Springer Science. New York, NY.
Thomas, R., A.S.R. Anjaneyulu,. And N. Kondaiah. 2007. Effect of hot-boned pork on the
quality of hurdle treated pork sausages during ambient temperature (37 ± 1 °C)
storage. Food Chemistry 107 804–812.
Thompson, L. D., D. M. Janky, and S. A. Woodward. 1987. Tenderness and physical
characteristics of broiler breast fillets harvested at various times from post-mortem
electrically stimulated carcasses. Poult. Sci. 66:1158-1167.
Torres, E., A. M. Pearson, J. I. Gray, A. M. Booren, and M. Shimokomaki. 1988. Effects of
salt on oxidative changes in pre- and post-rigor ground beef. Meat Sci. 23: 151-163.
Toldra, F. 2010. Handbook of Meat Processing. Wiley-Blackwell. Amens, IA Pages 143-169,
313-327.
Troy, D.J. 2006. Hot boning of meat: A new perspective. Pages 74-83. In Advanced
Technologies for Meat Processing. L. M. L. Nollet and F. Toldra, ed. CRC Press,
Taylor and Francis Group, Boca Raton, FL.
Varnam A.H. 1995 Meat and Meat Products. Chapman and Hall. Reading, UK 123:145
Veeramuthu G. I., and A. R. Sams. 1999. Postmortem pH, myofibrillar fragmentation, and
calpain activity in Pectoralis from electrically stimulated and muscle tensioned
broiler carcasses. Poult. Sci. 78:272-276.
Voyle C.A. 1971. Proc. 17th European Meeting Meat Res. Workers, Bristol, England p. 95.
Walker, L.T., S. G. Birkhold, I. S. Kang, and A. R. Sams. 1994. A comparison of treatments
for reducing the toughness of early-harvested broiler Pectoralis. Poult. Sci. 73:464
467.
126

Warris, P.D., and S. N. Brown, 1987. The relationship between initial pH, reflectance and
exudation in pig muscle. Meat Sci. 20:65–72.
Wyche, R.C., and T.L. Goodwin. 1974. Hot-cutting of broilers and its influence on
tenderness and yield. Poult. Sci. 53:1668-1675.
Xiong, Y.L., and C.J. Brekke. 1989. Changes in protein solubility and gelation properties of
chicken myofibrils during storage. Journal of Food Science. 54:1141-1146.

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