T353 E§FEC? 05 SAT Aha DMGE 5?"???
(EN TH? FREEZ:“G OF BEEF

'E'ffiwzés ft»: {in ammo a? M. S.
EQCEZ‘SAN STAR COLLEGE

'$
:iabe-é Quin a. 'E'ucxer, 32'.

f

0-169

 

This is to certify that the

thesis entitled

The Effect of Fat and
Moisture on the Freezing of Beef

presented by
Hubert Quinton Tucker, Jr.
has been accepted towards fulfillment

of the requirements for
14.3. (109133 in mg HIISband-ry

. mm.

Major professé/

 

Date July 15’ 1953

 

—.—___—_.__'.__fi
R F

THE EFFECT OF FAT AND MOISTURE
ON THE FREEZING OF BEEF

By
Hubert Quinton Tucker, Jr.

A THESIS

Submitted to the School of_Graduate Studies of Michigan
State College of Agriculture and Applied Science
in partial fulfillment of the requirements
for the degree of

MASTER OF SCIENCE

Department of Animal Husbandry
1953

“76694.67 '
7891

ACKNOWLEDGMENTS

The author wishes to express his most sincere thanks to
Lyman J. Bratzler, Associate Professor of Animal Husbandry,
for his patience and helpful guidance during the process of
this study.

He is also deeply grateful to Dr. Erwin J. Benne, of
the Agricultural Chemistry Department, and his associates,
for their interest in the problem and advice in relation to
the analytical determinations.

The timely suggestions of Professor D. E. Wiant, G. M.
Hanson, and J. B. Gawood, of the Department of Agricultural
Engineering, are most gratefully acknowledged; and the coopera-
tion of the Department in providing facilities and equipment

was much appreciated.

’3 I.
Saw
F‘f‘t
'uh’
1"" N

a
VI
’Wfl
\Ju

TABLE OF CONTENTS

INTRODUCTION. . . . . . . .
REVIEW OF LITERATURE. . . .

Structure and Composition

Preservation by Freezing .

The Freezing Process .
Thermal PrOperties . .

Rates of Freezing . .

Factors Affecting Rates of

PUMOSE O O O O O O C O O O
PROCEDURE 0 0 O O O O O O 0

Preparation of Meat .1

Forms . . . . . . . .
Thermocouples. . . . .
Freezer . . . . .
Trials . . . . . . . .
Fat Coverings . . . .
Wrapping Materials . .
Chemical Analysis .. .
RESULTS AND DISCUSSION. . .
SUMMARX. . . . . . . . . .
LITERATURE CITED . . . .

Freezing

(DCfithNl-J

10
12
15
16
16
16
17
17
19
20
22
25
24
44
45

LIST OF ILLUSTRATIONS

TABLE I Composition and freezing time of 15 samples... 25
TABLE 1(a) Thermal properties of selected materials...... 14a
TABLE II Analysis of Freezing curves. ...... ............ 34

TABLE III Comparative composition, weight and freezing
time of fat covered samples, Part I and II.... 37

TABLE IV Summary of wrapping material data..... ........ 43
FIGURE]. Equipment OOOOOOOOOOOOOOOOOOOOOOO0000......0.. 18
FIGURE 2 The arrangement of samples in the freezer..... 21

FIGURE 5 Relationship of fat to moisture content of 15
samples of beef............................... 26

FIGURE 4 Relationship of moisture content to protein- .
ash content of 13 samples of beef..... ...... .. 27

FIGURE 5 Correlation of percent fat in 15 beef osamples
with time to freeze from 55° F. to 100 F. .... 28

FIGURE 6 Correlation of percent water in 13 bgef samples
with time required to freeze from 35 . to
100 F. .00.00.00.00.00.00.000000... 00000000 .00 29

FIGURE 7 Freezing curves for six samples of beef with
varying water and fat contents................ 33

FIGURE 8 Freezing curves for Part I of the fat cover-
ing studyOOOOOOOOOOOO0.000000000IOOOOOIOOOOOO. 36

FIGURE 9 Freezing curves for Part II of the fat cover-
ing studyOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO 58

FIGURE 10 Freezing curves of the single wrap samples.... 40
FIGURE 11 Freezing curves of the multiple wrap samples.. 41

INTRODUCTION

Temperature, its action and its control in the food
industry, has been and is an ever increasing challenge to
the food technologist. The methods of food preservation
and merchandising are constantly changing in order to meet
the increasing demands of the public. The comparatively
recent pOpularity of frozen foods has created the problem
of handling a much larger variety of foodstuffs. It is
generally agreed that freezing alters food from its natural
state to a lesser degree than any other method of preserva-
tion. However, there are still unsolved problems involving
such factors, as deterioriation, quality, physical appear-
ance, and marketing. There is voluminous literature on the
effect of temperature, storage, and all phases of processing
on the quality of food products.

The literature relating to the thermal preperties of
meat and their effect on freezing is not as complete as it
should be. It is realized that the thermodynamics of meat,
as well as other foodstuffs, is a very complicated subject
because of the influence of many variables. This study was
undertaken in an attempt to illustrate and explain the ef-

fect of certain components of beef on its freezing rate.

REVIEW OF LITERATURE

The importance of temperature in the food industry was
expressed by Basalt and Ball (1947) by basing the progress
of civilization on the develOpment of the food industry.
The first line of resistance was conquered when man learned
how to store food and make it available when needed. The
temperature range that man must deal with is not wide when
one considers the limits of -40° F. and 4500° F. Seldom

in the food industry does one get out of this range.

Structure and Composition

It was of interest to note the descriptions given by
the many authors of the material with which they were deal-
ing. These descriptions indicated from which phase of
science the product was of interest to each worker.

Hiner (1950) described the structure of muscle as con-
sisting of multinucleated elongated fibers, oval in cross
section, surrounded by a sheath called the sarcolemma.
Groups of these cells surrounded by connective tissue formed
muscle bundles, and groups of bundles formed a muscle. The
composition of muscle substance was a complex fluid, plus
longitudinal running myofibrils with dark and light bands

that gave the appearance of striations. The fat of meat was

dispersed in the connective tissue between the bundles of
fibers. Muscle contained 60-75 percent water, most of which
was in the fibers or within the sarcolemma.

Short and Staph (1951) stated that foods such as fruits,
vegetables and meats were chemical and mechanical mixtures.
These mixtures consisted of water, fat, sugars, salts and sol-
ids. Suganm salts and other compounds were considered water
soluble solids.

H. E. Staph (1951) summarized twenty years of work on the
thermal properties of foods, and presented a complete defini-
tion of the materials with which he had been working. He
broke foodstuffs into six components. water was present in
two forms - free and bound. The free water was contained with-
in the cell and was readily removable by osmosis. Bound water
was held by colloids as a part of a disperse phase. .It was
stabilized so that it could not be removed by pressure, and
was not frozen at -200 C. A protein group consisted of pro-
teins, complex amino acids, alkaloids, and other nitrogenous
substances. The fat group consisted of glycerides, sterols,
lecithins, and some amino acids were said to be present. The
nitrogen-free extract group was composed of starches, gums,
sugars and organic acids in the case of plant foods, and gly-
cogen in the case of meats. Fiber was cell wall material con-
sisting of cellulose, lignin, and pentosans, and was applicable

only to plants. The mineral group consisted of potassium,

- 5 -

magnesium, calcium, phosphorous, chlorine, iron, sulfur and
aluminum. A portion of this ash was considered soluble.
Hawk, Deer and Sumerson (1948) described the minerals
present in muscle tissue as being present in the form of in-
organic salts. The most predominating cation of muscle was
potassium, followed by sodium, magnesium and calcium. The

anions included chloride, phosphate, and traces of sulfate.

Preservation by Freezing

The literature seemed in agreement as to how freezing
preserves foodstuffs, but varied as to which function of the
process was most important.

Woodroof (1940) stated that preservation by freezing was
based on the slowing of chemical, physical and biological ac-
tivities, which practically stOp when ice is formed in the
tissues. The activity was reduced one-half for each eighteen
degrees drOp in temperature. Some enzymatic action may con-
tinue, however, at low temperatures.

Bartlett (1944), in his study on the latent heat of food-
stuffs, stated that low temperature preservation was based on
the retardation of microbial, enzymatic and chemical reactions.

Gortner, Erdman and Masterman (1948) went into some detail
in explaining the effect of low temperatures on enzymatic and
microbial activity.

Tressler and Evers (1945) quoted work that indicated that

from 60 to 99 percent of the microorganisms on fruits and

-4...

vegetables were killed, and on meat and fish only 50 percent of
the microorganisms were killed due to freezing. The activity
of those not killed wasof little consequence at low storage
temperatures, but may be of concern after thawing. This work
also stressed the effect of freezing on chemical and enzymatic
actions.

Moran (1929) stated that controlling enzymes is probably
one of the most important factors in the preservation of food-
stuffs, except for lean meat, in which it is of a secondary
nature. The control of enzyme activity is of importance in

preserving animal fats.

The Freezing Process

Moran (1929) explained what happened when meat was sub-
Jected to freezing temperatures. He defined the composition
and structure of muscle, and stated that the most active cen-
ters of crystallization were formed between the fibers, and
the bulk of ice at normal temperatures was located between the
fibers and between the bundles. This was explained.by the fact
that lymph bathed each individual fiber, and its solidification
temperature was higher than that of the muscle substance; so
crystallization started there first.

Hiner (1950) stated that muscle contained 60 to 75 percent
water - most of it contained in the fibers. If this is true,
Moran's reason for the formation of ice crystals between the

bundles and fibers may not be adequate.

-5-

Woodroof (1940) described the movement of water in and out
of cells during the freezing and thawing process, which may be
a more logical explanation for Moran's.observation.

The cpinion of most workers was that the solidification of
foods was dependent on the crystallization of the water present.

Winter (1952) wrote that during freezing there was a pro-
gressive separation of water in the form of ice crystals. The
slower the process the fewer the number and larger the crystals.
The more rapid the freezing the higher the number and smaller
the crystals. The large crystals were located between the
fibers and between the bundles, and the small crystals were
evenly distributed throughout the tissue.

Richardson and Scherubel (1908) discussed the formation
of ice crystals and their distribution.

Diehl (1952) presented one of the more purely scientific
articles and discussed the freezing process from a physiolog-
ical point of view. He stressed the part the composition of
the frozen material had on the resultant product.

Much of the work was typified by that of Birdseye (1951)
who tried to explain the action of freezing through its effect
on the quality of the resulting product. He discussed quick
freezing under two distinct theories - mechanical and physico-
chemical. Both theories were required to explain the beneficial
results obtained from rapid freezing. The mechanical theory
involved the location and size of crystals. The physicochemical

theory evolved around the continuous freezing process where the

-6-

first crystals of pure water formed tended to concentrate the
remaining salts and lower the point of solidification. This
process was most important, mainly from 510-25o F. If this
range was traversed slowly, the resulting high concentration
of salts would denature the protein, thus altering the final
product.

Staph (1951) gave an interesting dissertation on the
subject in which he said to visualize food as a simple mix-
ture of pure water and a dry material. He assumed this mix-
ture had some of the properties of a solution, and as
concentration increased the fusion point of the water was
depressed. When the temperature was reduced to Just below
52° F., the mixture started to freeze. (Pure water would con-
tinue to freeze at 52° F.) Heat was eliminated and removed as
the water froze, and as it froze the remaining mixture changed
in concentration, resulting in less water, and a depression of
the temperature of solidification. No more water would freeze
until that point was reached. The temperature of the food
lowered as heatwas constantly removed. There was a contin-
uous process of more water freezing and the freezing point
being lowered. This continual depression of freezing point
was where the process of freezing in foods differed from that
of water.

Taylor (1950) made a critical review of the work presented
in the literature. According to him, the theory of large crys-

tals puncturing cell membranes and allowing Juices to escape

- 7 _

did not hold true, because sausage and other lacerated
materials did not yield large quantities of Juice. In answer
to the theory that rapid freezing caused fluid to freeze in
cells and rupture them, due to expansion, he stated this was
not necessarily true because of the great elasticity of animal
tissue. The advance of freezing as a new preservative agent
should conform to a knowledge of what really happens when food

freezes.

Thermal Properties

The thermodynamics of foodstuffs is an important but very
perplexing problem. If one could apply the laws of heat and
heat transfer, which are based on homogeneous materials, as
found in texts such as Faires (1950) or Brown and.Marco (1951),
the problem would be easily solved. One of the outstanding
works in attempting to explain the thermal properties of food-
stuff, and how such factors were involved in the freezing
process, was that of walter Stiles (1922). Since then, com-
paratively few researchers have attempted to establish con-
stants for thermal properties of foods.

WOolrich (1950) demonstrated that the latent heat of
foodstuff was closely related to its moisture content.
Wbolrich (1955) published conclusions from four years' work
on the latent heat of foodstuffs:

1. Experiments indicate that the latent heat of

fusion of fresh vegetables, fruits, meats and

dairy products is directly pr0portiona1 to the
moisture content by weight.

- a -

2. The fusion points of food products are con—
siderably depressed by the presence of salts,
starches, fats and sugars.

5. Most foodstuffs have a freezing range, often
extending from Just below the frgezing point
of water to a temperature near 0 .

4. The presence of any alcohol by breaking down
starches or sugars lowers the fusion point.

5. The presence of fats, starches and mineral salts

has no measurable effect on the value of the
latent heat of fusion of foodstuffs examined.

Awbery and Griffiths (1955) published a paper on thermal
properties of meat. They gave experimentally obtained values
for thermal conductivity, thermal diffusivity, specific heat
and density of lean beef.

Values in B.t.u. of the heat required to lower tempera-
ture of meat containing various percentages of water were
demonstrated by the American Society of Refrigerating Engi-
neers (1954-1956).

Short, Woolrich, and Bartlett (1942) came to the conclu-
sion that, in a broad sense, the specific heat of foodstuff
was proportional to the liquid content in the frozen region.

Bartlett (1944) produced a paper in which he stated:
'Refrigeration is now a science and no longer an art.I After
making five assumptions, he proceeded to give formulae from
which the following information might be obtained: (1) the
percent of ice; (2) temperature rate of ice formation; (5)
thermal capacity in partially frozen region; (4) quantity of
heat removed in chilling.

-9-

Short (1944) experimentally produced values for specific
heats of a number of foodstuffs.

Staph (1951) attempted to sum up the work done to that
date and stated that the thermal characteristics of all food-
stuffs seemed to follow the same general pattern regardless
of the chemical prOperties or their amounts. -THe'did, hows
ever, determine relative values of the thermal characteristics.

Short and Staph (1951) stated that the energy that must
be removed from a particular foodstuff was the sum of the
sensible energy removed from each constituent and the latent
heat of fusion of water and fat. Fats may not undergo a change
in the normal freezing and storage range; hence, only the heat
of fusion of water which is frozen should be considered.

Since water plays such an important role in the thermal
properties of foodstuffs, a more thorough understanding may-
be obtained of it in its several forms by reference to Dorsey
(1940). The physics involved in the crystallization of water,

thermal properties of water and ice were adequately discussed.

Rates of Freezing
In the freezing of foodstuffs, interest in freezing rates
has centered around a single zone. This range has been called
the 'zone of maximum crystal formation", and the limitations
of the zone, as well as the definition of the term Imaximum”,

varied with the many writers.

-10..

Tressler and Evers (1945) gave the range as from 51° F. to
' 25° F.

Moran (1952) described this zone as being represented by
a thermal arrest in a freezing curve of a substance. He meas-
ured the range from 45° C. to -5° C., and stated that these
values were chosen because in this zone 82 percent of the
water in muscle was crystallized.

Woodroof (1940) said that complete freezing was not ob—
tained until temperatures of -60° F. to ~80° F. were reached.
He mentioned the zone of water crystallization as 50° F. to
0° F.

The American Society of Refrigerating Engineers (1954-
1956) stated that about 75 percent of the freezing occurred
between 51° F. and 25° F., and 100 percent when the tempera-
ture was -60° F. to -80° F.

Wiesman (1947) stated that the major portion, or 62 per-
cent of the moisture, was frozen in the range from 52° F. to
25° F.

Birdseye (1951) said that a very large portion of the
total water was changed in the temperature range from 510 F.
to 250 F., and this range has become known as the IIzone of
maximum crystal formation“. Most foods were frozen solid at
200 F., and most all free moisture was solidified at 0° F. but
small quantities continued to freeze until -70° F. was reached.
It was generally agreed that crystal size, and quality of the
product was greatly influenced by the rapidity with which

- 11 -

the material froze through an average of the above-mentioned
zones.

Winter (1952) summed up as to what rate of freezing was
required to produce a quality product by stating: “As late
as 1952 few people are in agreement as to what constitutes
quick freezing. Probably the best definition is getting the

product frozen before deterioration in quality sets in.“

Factors Affecting Rates of Freezing

Stiles (1922) asserted that factors affecting the time
of cooling may be grouped into two classes: internal factors
depending on the nature of the cooled substance; and external
factors depending on the properties of the external medium.
The former is the thermal conductivity, specific heat, density,
latent heat, specific surface and nature of the surface of the
cooled body; the latter is the temperature, conductivity, spe-
cific heat, density and degree of agitation of the external
medium. He determined the thermal conductivity for beef fat
as .155 calories per meter, per hour, per degree Centigrade.
He also obtained a value of .227 for muscle, and, in doing so,
illustrated that there was no significant difference in conduc-
tion along or across the muscle fibers. The insulating quality
of fat covering muscle was also demonstrated in his work.

Joslyn and Marsh (1950), by the use of various sugar solu-
tions, showed that as the concentration of sugar increased the

rate of temperature change increased.

-12..

Woolrich (1951) stated that heat of fusion was directly
proportional to moisture content. Salt, starch, sugar and
fats had no measurable effect on heat of fusion.

Birdseye (1951) remarked that the amount of water solidi-
fied at any given temperature is substantially the same whether
the temperature drop is slow or fast.

Nicholas (1945) demonstrated the effect of several dif-
ferent methods of freezing on freezing rates. He also demon-
strated the effect. size of package and number of layers of
wrapping material had on the freezing rate of foodstuffs.

Finnegan (1941) produced a very interesting study on the
effect of frozen mass formation on the freezing rate of foods.
If a food was uniformly frozen, the point of final solidifica-
tion would normally be located at the approximate center of the
greatest vertical and horizontal cross sections. Each food has
an optimum point of final solidification which will give the
highest freezing rate at a given temperature regardless of the
method. Some methods of handling during freezing change the
point of final solidification and decrease the freezing rate.

Ramsbottom, Goeser and Strandine (1949) presented an ex—
cellent paper on the effect of different factors on the freez-
ing rate of meats. They discussed the effect of air blast on
freezing rate, as related to ice crystal size at varying depths
in beef rounds. It was concluded that meats containing a high

percentage of fat tissue froze more quickly than meats containing

- 15 _

very little fat tissue. The freezing rate of meat decreased
with an increase in the insulating value of the package.
Ramsbottom (1951) stated that if there are air pockets
between the package material and the meat, the rate of freez-
ing at that location is delayed.
Table I(a) presents an accumulation of data that lead to

certain conclusions that are given in "Results and Discussion"

-14..

THERMAL PROPERTIES OF SELECTED MATERIALS

TABLE 1(a)

 

Thermal Conductivity1

 

Total

 

Material k): Btu/(hr.)(sq.ft.) Emissivityz
___ (deg. F./in.)
Aluminum 1475.00 .040
Aluminum foil -- .087
Paper, thin -- .924
Paper 1.00 -—
Refractory materials
Poor radiators -- .67 - .75
Good radiators —- .80 - .90
Water 5.50 .95
Beef - lean 5.87 --
Beef - fat 1.04 --
k = Calories/(hr.;/5
(meter)/(deg. C.
Pork fat 0.155 --
Beef fat 0.150 --
Muscle (along fibers) 0.227 --
Muscle (across fibers) 0.221 --

 

1
Compiled from American Society of Refrigerating Engineers

(1954-1956).

2
Compiled from Brown and Marco (1951).

chmpiled from Stiles (1922).

143

_ PURPOSE

The principal objective of this study was to investi-
gate the freezing of beef as affected by several selected
factors. This study was adapted to demonstrate the effect

of the following factors on the freezing of beef:

1. Moisture content
2. Fat content
5. Distribution of fat

4. Selected wrapping materials

_ 15 _

‘PROCEDURE

Preparation of Meat .

The lean meat used in this work was obtained from cutter
grade beef rounds. Cod fat from good and choice grade rounds
was used as the fat portion. The lean and fat were cut uni-
formly into cubes about one inch square. Portions of each
were weighed and mixed in the appropriate pr0portions to
obtain the various percentages of fat in the samples used.
All samples were first ground through a 5/8 inch plate and
then through a 5/52 inch plate. The batches were then well
mixed, wrapped in Dupont 450 MSAT #80 cellophane, and stored
in a cooler. Approximately three pounds of meat were pre-
pared for each percentage used. A one hundred gram sample
of each batch was placed in a sealed Jar and placed in frozen

storage until it was used for moisture and fat determinations.

Forms
The volume of samples frozen was maintained as constant
as possible through the use of plastic forms. Forms which
had inside dimensions of six centimeters were constructed of
Plexiglass, a methyl methacrylate type plastic, selected
because of its thermoplastic and low heat conducting prOper-

ties. Strips of this material 1/16 inch thick were patterned

- l6 -

so that by drilling 1/8, 7/52 and 5/8 inch holes, approxi-
mately 54 percent of the surface area of the four sides of
the cube was removed. A bottom was made by adhering strips
5/16 inch wide at 5/16 inch intervals across one end of the
form. The top was not enclosed. Figure 1(a) shows the form

as it was used.

Thermocouples

The conventional twisted type thermocouple was not con-
sidered adequate for this work because the exact point of
temperature recording was difficult to determine. Butt-weld
thermocouples were constructed under the guidance of members
of the Department of Agricultural Engineering, Michigan State
College. These thermocouples were constructed so they could
be threaded through the meat samples and temperatures recorded
at the geometric center of the cubes. The materials used in
construction of these thermocouples were ccpper and constantan
wire of Number 24 gauge. The temperatures were recorded on
a 12 lead Brown Electronik Strip Chart Recorder. The constan-
tan end of the butt-weld thermocouple was spliced permanently
to the constantan lead from the recorder. The more rigid
ccpper end was not spliced until it was threaded through the
meat sample. This type thermocouple is shown in Figure 1(b).

Freezer
A Revco ten cubic foot chest type frozen food storage

unit was used in this study. This unit was manufactured by

_ 17 -

.Acxdmp .Ha on can ofinaosac wooom on “mammoooammxm
oaoelppsm Any ”Show caveman Amy .pcoamasem .H onsmam

 

Revco, Incorporated, of Dearborn, Michigan. A small fan dis-
placing 200 cubic feet of air per minute was secured close to
the top of the freezer. The blast from the fan was directed
parallel across the top, so a direct stream did not hit the
samples, which were in the bottom of the freezer. The fan
was used only in the first part of the work involving the
thirteen samples of different fat content. Freezer tempera-
tures averaged -10° F., plus and minus three degrees. The
unit cycled through a range of six degrees every twenty min-
utes. No fan was present in the work on fat coverings and
wrapping materials. The temperature at the same adjustment

averaged approximately -140 F., plus and minus three degrees.

Trials

Meat samples of the various fat contents were frozen in
groups of three. Each group consisted of a lean sample and
two samples of varying fat content. The meat was packed in
the Plexiglass forms, as uniformly as possible, and weights
of samples and forms recorded. Thermocouples were positioned
in the center of the forms, which were placed in the freezer
as shown in Figure 2. Two paper cartons containing two
hundred and fifty milliliters of distilled water were frozen
and placed between each outside sample and the wall of the

box. This reduced the effect of direct radiation from the

- 19 -

side of the freezer to outside samples. Each sample was
placed on the top of an overturned petri dish.

The frozen samples were removed, allowed to thaw, the
thermocouples removed, and the meat emptied from the forms.
A second and third run was conducted using samples from the
original batch of meat. The only difference was that each
sample was in a different position in the freezer each time,
as indicated in Figure 2. An average of the three runs for
each percent of fat was used to lessen any variation that

position in the freezer would have on the freezing time.

Fat Coverings

In determining the effect of fat covering, fat was molded
in the forms so that a one centimeter cube of space was left
in the center. This space was packed with ground lean beef
and topped with fat. The finished product was a six centi-
meter cube of fat with the one centimeter cube of lean in its
center. Two samples were prepared in this manner. A third
sample was prepared by mixing fat and lean in the same propor-
tions as in the first two. Thermocouples were inserted; the
filled forms were placed in the freezer in the same manner as
previously described. The samples, after freezing, were
thawed and frozen again at different positions in the freezer.

Another trial consisted of fashioning a one-half centi-
meter layer of fat, as uniformly as possible, on the sides of

the form. Lean was packed in, and then a layer of fat one-half

- 20 -

4 .0 355.955 .5538 .m .4 .udegaehcrecaall .5!
is." .3002. on» an £3.03 e5 5 3.3!.- uo «deg-393 on... .N chum“.-

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

-21...

centimeter thick was placed on top. The finished sample was
a six centimeter cube - the outside one-half centimeter was
fat and the remaining portion ground lean beef. A second
form was filled with a mixture of fat and lean in the same
prOportions by weight as in the first sample. A third form
contained all lean ground beef. A thermocouple was inserted
in the center of each sample and the samples placed in the

freezer, as previously described.

wrapping Materials

Three forms were packed with lean ground beef from the
same batch. The samples were wrapped in various wrapping
materials (6 x 12% inches), using the confectioners' or drug-
store wrap. Thirty pound Kraft brown wrapping paper, Dupont
450 MSAT #87 cellophane, and aluminum foil of .015 inch
thickness were used, respectively, on the three samples.
Thermocouples were positioned and the samples placed in the
(freezer as before. As in the previous work, these samples
were thawed and frozen again in different positions to check
the results.

A similar trial was made using forms of lean ground beef
and wrapping materials of the same dimensions. In this trial
one sample was wrapped in a single layer of aluminum foil;
another had two layers of cellophane. A third sample was
wrapped in one layer of cellOphane and two layers of thirty

pound Kraft brown wrapping paper. The thermocouples were

inserted and the samples frozen as before.

-22..

Chemical Analysis

Water and fat determinations were made, in duplicate, as
outlined in "Official Methods of Analysis of the Association
of Agricultural Chemists" (1950), with a modification sug-
gested by Dr. Erwin Benne (1952) of the Agricultural Chemistry
Department, Michigan State College. This method enabled the
use of a single sample for both fat and moisture determinations.
Asbestos padded crucibles were placed in thirty milliliter
tall type beakers (Figure 1(0)), the samples added to the
crucible and a cotton pad placed on top. After drying for
twenty-four hours in a 75° C. vacuum oven, the samples were
weighed. Moisture was determined by difference. The dried
samples in the crucibles were removed from the beakers and
ether extraction made by the Bailey Walker Method. The beak-
ers served the purpose of collecting any fat that filtered
through or crept over the crucible during the drying process
for the water determination. The fat was removed from the
beakers with ether, and each beaker matched with its respective
crucible after the extraction for drying and weighing. The
difference in weight represented the ether extract, or fat

portion of the sample.

-23..

RESULTS AND DISCUSSION

Table I shows that the fat content varied from 5.5 per-
cent to 90.8 percent, and the moisture ranged from 72.5 per-
cent to 6.7 percent in thirteen lean beef, lean beef and
fat mixture, and beef fat samples. The extreme values
represented the variation found between lean beef and beef
fat. Intermediate values were the results of mixing the two
components. Figure 5 illustrates that there was a very sig-
nificant inverse relationship between fat and moisture
composition of all samples.

Water content of meat was closely correlated with the
protein-ash portion, as illustrated in Figure 4. These
observations were used in explaining certain results ob-
tained.

The time, in minutes, required for the various samples
to traverse the range in temperature from 55° F. to 10° F.
are given in Table I. Relationship between these values and
fat and moisture content are presented in Figures 5 and 6.

Freezing rate depends basically on two principles:

HOw much heat is present and how rapidly it can be removed.
There are many factors, such as temperature, cooling medium,
air velocity, atmospheric pressure, composition of the sub—

stance, and others involved in both of these principles.

-24..

TABLE I

COMPOSITION AND FREEZING TIME OF THIRTEEN SAMPLES

 

Time B

—__—

 

Sample Pnggnt §§§Z§33. 553T§0°F. 5233549F. ‘TIEETI' (5)
A 5.5 72.5 118 91 77
B 5.1 71.1 115 86 75
0 6.0 71.7 115 85 75
D 7.6 71.6 111 85 75
E 7.8 66.7 114 87 76
F 21.7 58.2 109 80 75
G 27.0 54.5 105 75 75
H 56.0 47.2 98 72 75
I 48.6 58.9 87 64 74
K 60.1 50.0 82 58 71
L 70.8 22.4 79 45 57
M 90.8 6.7 62 19 51

 

*Time, in minutes, average of three runs.

-25..

.Hoon no eeagace n no anon

taco easaeacl on use no Mdnwsouuedem .n enemas

have: acccuom

 

 

l

 

 

as; access;

 

 

-26..

eaohn

. o nodule. nH no penance neelma

ea ”Mums“. 9:530! no man-moaned...“ v chew...—
Aevea aceoaeh

OOH 00 O. o. ON
A id ‘

 

0.

 

 

 

 

8H

qua-ureioad auecaea

-27...

gamma 3 .u an some 888 3 on: 5.... .38....
u 2 S «on 33.85 no 8333.28 .e .93.—

28 «seats

 

8a 8 8 3,. £8 6
J . . . m ~14

1H

 

 

 

 

g s s s 3 °
seanurn - curn Burrow

§

3

-28..

0H8 .hogg

cuoeuu 3 condone." and... 5.!— eennlee new

 

on a." bead: «cocked no nodueuoEoo .0
heads agom
00H 8 on o... w on
_ a a _ 1 q a _
.‘nmmo+ ..l.. H
rl.
\\
\\ \\
T \\
\\
I \\
\t.‘
T\\ \.\\
\\
L p p p P P p . .

 

«h

0
M
Y!
m
I.
. t.
u
.
u m
n
.oH”.
I
.....n

 

OCH

-29..

An attempt was made to consider the factors that were
characteristic of the individual specimens, such as specific
heat, thermal conductivity, freezing point, and latent heat
of fusion.

Specific heat of meat, or of any foodstuff, as described
in the review of literature, is a difficult value to obtain
because of the many variables that can affect it. It has
been established, however, that the specific heat of food-
stuffs is closely associated with their water content.

Very little data were found on thermal conductivity
coefficients for meat. Enough were found to establish the
fact that lean meat is a more efficient conductor of heat
than beef fat.

Moisture content may be said to play an important part
in the thermal conductivity of foodstuffs, since water is
one of the best conductors of heat in the class of non-
metallic liquids. There are many values for the freezing
point of meat and for all practical purposes these values,
or ranges, are sufficient.

A freezing point of meat indicates only that tempera-
ture at which the crystallization of the water present
begins, and therefore indicates that removal of the greater
portion of the heat load has begun. Actually, the term

'freezing point of a foodstuff“ is a misnomer, because it

-30..

indicates only the beginning of a phase. A much better
expression would be l'freezing zone“, which would include the
range within which a greater percentage of the water was
solidified. There were several ranges for this zone given
in the literature.

The "latent heat of fusion" is another term that can
only be used loosely when applied to foods. The definition
states that it is the amount of heat required to change the
state of a unit of substance without a change in temperature.
The change of state in meat starts at about 51.5° F., and
continues through.the temperature scale until 100 percent sol-
idification is reached at about -60° F. to -80° F., according
to Woodroof (1940). water is the most important constituent
of meat to change state, and it requires approximately one
B.t.u. to lower the temperature of one pound water one degree
in the range above its freezing point. However, 144 B.t.u.'s
are required to lower it one degree through the freezing
point. These facts will help explain the distribution of
the load of heat as the freezing curves in Figure 7 show
them. The leveling of the curves through the region from
52° F. to 24° F. represented increased heat removal due to
the change of state of the water. As mentioned in the re-
view of literature, the first cyrstals to form represent a
decrease in water and consequently an increase in salt and
colloid concentration of the remaining fluid which, in turn,

lowers its point of solidification. This concentration of

- 31 -

the remaining fluid and lowering of the freezing point is
mainly of significance through the zone of maximum crystal-
lization. Moran (1952) and Wiesman (1947) have calculated
that between 60 and 80 percent of the water present is solidi-
fied in this range.

A variation in the curve of a single sample indicated a
change in the amount of heat being removed. Curves of six of
the samples are shown in Figure 7. Table I also gives the pare
cent of the total time that each sample spent in the zone from
52° F. to 24° F. Approximately 75 percent of the total time
was spent in the range that water was changing state. The
comparison of water and fat content to time required to drop
the temperature one degree in three ranges is contained in
Table II. It can be concluded from these data that the thermal
properties of water played the largest role in the thermodyna-
mic properties of meat; therefore, water is the most important
single factor affecting the freezing rate of beef.

Fat exerts its action on freezing rate in an indirect man-
ner by being inversely correlated with the moisture content.
Fat may also exert a marked direct effect on rate of freezing
if it is layered over a surface of lean.‘ The results of Part I
of this phase of the study are presented in Figure 8. The du-
plicated samples of a cubic centimeter of lean, surrounded by
2% centimeters of fat, followed almost identical freezing

curves. These samples required a considerably longer period

-32...

HbOOHO
“38988

TQTQSE
F3533”

0.—
.EhgfiaahufianHEngfibipfiga

uoon.uo unease: ud- neé nephse meauochu .b enemas

:éafifuRFBNEHERC
06 00 0' ON 0

 

 

 

 

 

 

 

 

 

«1 _ 41 _ 4 u a _ 41 q . 0
lo
M. R H I I .lOH
lad”
them
0
In
jam.
r !/ 13
an
F F f» b p . p _ b P p

 

-35...

TABLE II
ANALYSIS OF FREEZING CURVES

W

 

 

 

Minutes Required to Lower 1
Temperature 1° F.
Sample Pe;::nt :::::::e Temperature Ranges
55°-52° &
._§5°-lO° 52°-24° 24°;;9°

A 5.5 72.5 4.7 11.4 1.6
B 5.1 71.1 4.6 10.7 1.7
C 6.0 71.7 4.5 10.4 1.8
D 7.6 71.6 4.4 10.4 1.6
E 7.8 66.7 4.6 10.9 1.6
F 21.7 58.2 4.4 10.0 1.7
G 27.0 54.5 4.1 9.4 1.6
H 56.0 47.2 3.9 9.0 1.5
I 48.6 58.9 5.5 8.0 1.6
J 56.2 56.5 5.5 7.0 1.8
X 60.1 50.0 5.5 7.2 1.4
'L 70.8 22.4 5.2 5.6 2.0
M 90.8 6.7 2.5 2.4 2.5

 

l .
These values were obtained by dividing time required

to traverse the range by the number of degrees in the range.

-34..

and the characteristics of the curves varied greatly from the
mixed sample containing the same amount of water, fat, and
other constituents. The variation between curves was due to
difference in the rate of heat removal. A variation in dis-
tribution of fat and lean was the only significant difference
in the samples. Table III, Part I, illustrates the composi-
tion and its distribution of the samples used. The lean meat
contained about 57 percent of the total moisture in the sample
and this was concentrated in the center, which meant that a
greater percentage of the heat load had to travel a greater
distance through the slower conducting fat. In the mixed sam-
ple, the lean, and consequently the heat load, was distributed
uniformly throughout the sample. This indicated that a greater
portion of the heat had to travel a shorter distance, and it
could travel at a somewhat faster rate by taking the path of
least resistance over connecting particles of lean.

Figure 9 represents the similar trial in which one cube
contained lean, surrounded by a one-half centimeter layer of
fat; another, a mixture of fat and lean in the same pr0por-
tions; and a third contained all lean. The Paths of these
curves were very similar, the main difference being the amount
of time spent in the zone 52° F. to 24° F. .As in the preceding
trial, the heat load was more concentrated in the fat covered
sample, and most of the heat load had to travel through the

slower conducting medium. The mixed sample had a higher

-35-

Evacuate
gen-«chum
0.90504

.93. wsaheeoo new on... we H «a hog earn—ac med—eons

nova-a .- vodka Enoch...

 

owe 8... 8» com 8." one
x... 141 8+ 11 l
on 4
T!

 

 

 

 

-56-

COMPARATIVE COMPOSITION, WEIGHT

TABLE III

AND FREEZING TIME OF FAT COVERED SAMPLES

Part I

(One Cm. Cube of Lean Covered with 2% Cm. Fat

(Samples A a 5))

 

 

Time in Minutes

 

 

Sample (ggégg) Moisture Fat 40°-0°F. 52°-24°F.
Sample A:
Mixture 220 17.6%(58.7 gms) 77.0% 185 54
Sample B 220 --_ --- 219 111
Lean 51 71.5%(22.1 gms) 6.4% —- --
Fat 189 9.0%(17.0 gms) 88.1% -- --
Sample C 220 --- --- 222 115
Lean 51 71.5%(22.1 gms) 6.4% -- --
Fat 189 9.0%(17.0 gms) 88.1% -_ --

 

Part II

(Five Cm. Cube of Loan Covered with.§ Cm. Fat

(Sample 0))

 

Weight

Time in Minutes

 

 

Sample Moisture Fat
(grams) 4o°-O°F. 52°-24°F.

Sample D:

Mixture 226 46.9%(106.0 gms) 58.1% 256 141
Sample E:

All lean 246 71.7%(176.4 gms) 7.9% 262 176
Sample F 226 --- --- 274 141

Lean 126 71.7%(90.5 gms) 7.9% -- --

Fat 100 9.5% (9.5 gms) 87.4% -- -—

 

- 57 -

00856 we.- .. .-
53." and .. a
055N2- .. n
.36». 93.3.50 new 05 no HH «.3.— now .6th men—ooh..- .o chem:

ceased- .. cogen Mada-E

 

 

ONO. can con ovm 8H 8." om o
q A . a - q 4 a - q - . - - A
h H n I.
1! l

 

 

____l _.b.P2y

 

on

Ca.

-58-

dpercantaga of its load traveling a slightly shorter distance
but also taking the path through the faster conductor. The
difference in ability to conduct heat may also have caused the
all lean sample, which spent more time in the crystallization
zone, to travel at a faster rate than the covered sample after
leaving that zone. There was no concrete proof found in the
literature, but study has indicated that part of the difference
in heat loss through fat and lean may be due to their differ-
ences in efficiency of surface radiation - lean being a more
efficient radiator than fat.

A comparison of three commonly-used wrapping materials as
to their affect on freezing rate is shown in Figure 10. The
main means of transfer were by radiation and convection since
the samples were located in the freezer in such a manner that
conduction accounted for a negligible portion of the heat trans-
fer. Assuming that still air is a poor conductor of heat, a
good portion was probably transmitted from the sample by means
of radiation. No work was cited that gave thermal conductivity
values of these wrapping materials, but from a study of the
qualities of insulating and conducting materials in critical
tables, the conclusion was drawn that, from the basis of thermal
conductivity, brown paper was the best insulator, followed in
order by cellOphane and aluminum foil. Good qualities of radia-
tion are associated with dark color and rough surface and the

poorer radiators are polished, light colored metal surfaces.

-59-

.5 5.8. 38 555.2 .. a
5.. nau- ofiadofloe .. e
.895 3.6.3 .3 on aura u a
canine deadeninm c 4

 

.eeaasee can: edwcae can no accuse medueeAh .oa enemas
.333. a 63.3.- 8382..

oue 8r. 8... 95 . 8a 8H . 8

l 4 q d a N .J a H . — q #
T. .H o m 4
r.
r...-

L _ _ _ 1 - l P m L p -

 

 

 

CHI

0»
S

-; IOOJSOQ

3

“hogan nichn .nn on no nudhda a
snag uohca H 5m\_u¢ul ondnnoaaoo a_n
:55 a 5‘ 93.. .3938 .. a
anchda Hy .nd ado. Hana laud-add c «
ouglau conndnlua

.uoaglan nun: candauua any no cabana unauoohh .HH ounmuh
.885. .. 8.98m 9:80.:

 

om... 8» con o3. 8a 8a 8
4 4 1“ a q 4 4 a a.

+

a “u n d

 

 

 

 

 

O

8 S
-1 condfloa

- 41 -

These materials would then be classed in reverse according to
their radiating efficiency. The results in Figure 10 indi-
cate that radiation qualities of the wrapping material had
more effect on freezing rates than the factor of conductivity
in this study.

. The multiple wrap trial, where a sample with two layers
of ce110phane, and another with one layer of cellOphane and
two layers of brown paper were compared to a single layer of
aluminum foil, is plotted in Figure 11. These results may be
explained partially on the insulating quality of trapped air,
as well as that of the materials. The aluminum foil wrap had
trapped between it and the meat a single layer of air; the

double wrap cellOphane had one between it and the meat, and

another between the first and second layers; and the ce110phane-

brown paper wrap had three layers of trapped air. These layers

of air, plus the insulating qualities of the materials them-
selves, were sufficient to offset the effect of radiation
indicated in the preceding trial. A summary of the data in
these two trials is presented in Table IV.

- 42 -

TABLE IV
SUMMARY OF WRAPPING MATERIAL DATA

W

Time in Minutes

 

1
Sample
40°-00F. 55°-10°F. 32°-24°F.

 

Single wrap trial:

Aluminum foil .015 in..... 355 288 259
Cellophane MSAT #87....... 528 264 216
Kraft 50 1b. brown paper.. 312 251 205

Multiple wrap trial:
Aluminum foil .015 in. ... 344 282 233

Cellophane MEAT #87 (2
layers) ................ 362 292 239

Cellophane MSAT #87 (1
layer plus 2 layers
brown paper) ........... 378 510 250

Unwrapped sample2 ........... 267 215 176

 

1All samples of ground lean beef in the single and
multiple wrap trials weighed 240 grams and contained 64.1
percent water and 16.2 percent fat.

2This lean beef sample weighed 246 grams and con-
tained 71.7 percent water and 7.9 percent fat. It was
run in a separate trial but under the same conditions.

-43-

SUMMARY

1. There was an inverse relationship found between the
fat and moisture content of the meat samples used in this
study.

2. There was a positive relationship between the por-
tion of the meat, not fat and not moisture, and the moisture
content.

5. There was a positive correlation between the water
content of beef and the freezing time in the ranges studied.

4. Fat distributed throughout the meat sample inversely
affected the freezing time.

5. External fat layers decreased the freezing rate of
beef.

6. Common wrapping materials decreased the freezing
rate of beef. Of the materials used, aluminum foil, cello-
phane, and brown wrapping paper decreased the freezing rate,
in the order named, under the conditions of this study.

7. Multiple wrappings decreased the freezing rate of

beef.

-44-

LITERATURE CITED

American Society of Refrigerating Engineers. 1954-1956.
Ch. 24. Freezing of Foods. American Society of
Refrigerating Engineers, Editors and publisher.
ggfri gratingData Book and Catalog. Ed. 2. New York.

$-35 ,

American Society of Refrigerating Engineers. 1954-1956.
0p.cit. A table on Thermal Conductivity. 65.

Association of Agricultural Chemists. 1950. Official
Methods ofAnalysis of the Association of Agricultural
Chemists. Ed. 7. Wasfington, D. 5.

Awbery, J. H., and Griffiths, E. 1955. Thermal Properties
of Meat. Journal of Society of Chemical Industry.

Bartlett, L. H. 1944. A Thermodynamic Examination of the
Latent Heat of Food. Refrigerating Engineering.

Baselt, F. C., and Ball, C. 0. 1947. Temperature Measure-
ment and Control in the Food Industry. American
Institute of Physics, Editors. Tem erature, Its
Measurement and Control. ReinhoId.§u5Iishing Co.,

New Kori. 866-87I.

Benne, Erwin. 1952. Personal communication.

Birdseye, C. 1951. Chap. 1. Theories of Quick Freezing.
American Society of Refrigerating Engineers, Editor and
Publisher. Refri eratin Data Book, Refrigeration
Application Volume. Ed. . Nengork. 5-10.

Brown, A. I., and Marco, S. M. 1951. Introduction to Heat
Transfer. Ed. 2. MacGraw-Hill Book Co., Ihc., New
ork.

Diehl, C. C. 1952. A Physiological View of Freezing Pre-
servation. Industrial and Engineering Chemistry. 24,
NO 0 6: 661-664 0

Dorsey, E. N. 1940. Properties of Ordinary:water-Substance.
Reinhold Publishing Corp., New York.

-45..

Faires, V. M. 1950. Applied Thermodynamigg. MacMillan
Co., New York.

Finnegan, W. J. 1941. Effect of Frozen Mass Formation on
Freezing Rate of Foods. Refrigerating Engineering.

Gortner, W. A., Erdman, F. S., and Masterman, N. K. 1948.
Principles of Food Freezing. John Wiley & Sons, Inc.,
New‘York.

Hawk, P. 3., Oser, s. L., and Sumerson, w. H. 1948.
Chap. 10. Muscular Tissue. Practical Pgfisiolo ical
Chemistry. Ed. 12. The BlakistonCEl, iiadeffifila

Hiner, R. L. 1950. Some Results of Studies on Freezing
and Freezer Storage of Meats. Proceedings of the
Second Conference on Research of the American Meat
Institute at‘Chicag_. 92:II1

Joslyn, M. A., and Marsh, G. L. 1950. Heat Transfer in
Foods During Freezing and Subsequent Thawing. Indus-
trial and Engineering Chemistry. 22, No. 2: 1I95-1197.

Moran, T. 1929. Recent Advances in the Low Temperature Pre-.
servation of Foodstuffs. Journal of Society of Chemical
Industries. 48: 245T-2515T

Moran, T. 1952. Rapid Freezing. Critical Rate of Cooling.
Journal of Society of Chemical Industries. 51: 16T-20T.

Nicholas, J. E. 1945. Freezing Rates of Foods. Pennsylvania
State College Agricultural Experimental Station Bulletin
471.

Ramsbottom, J. M., Goeser, P. A., and Strandine, E. J. 1949.
' The Effects of Different Factors on the Freezing Rate of
Meats. .Proceedings of the Conference on Research of the
AmericanfiMeat Institute at thegU. of’Chicago. ‘Reprint.
4- 5.

Ramsbottom, J. M. 1951. Chap. 5. Freezing of Meats. Ameri-
can Society of Refrigerating Engineers, Editor and Pub.
Refrigerating Data 399k, Refrigeration Application Volume.

d. 5. New York. 47-58.

Richardson, W. D., and Scherubel, E. 1908. General Introduc-
tion and Experiments on Frozen Beef. _Jgurna1 of American
Chemical Society. 50: 1515-1564.

 

-46..

Short, B. E., Woolrich, W. R., and Bartlett, W. H. 1942.
Specific Heat of Foodstuffs. Refrigeratinngngineer-
ing. 44: 585-588.

Short, B. E. 1944. The Specific Heat of Foodstuffs,
Part I - An Experimental Determination. The University
of Texas Publication Engineering Research Series No. 40.

Short, B. E., and Staph, H. E. 1951. The Energy Content of
Foods. Ice and Refrigeration. 121, No. 5: 25-26.

Staph, H. E. 1951. Specific and Latent Heat of Foods in
the Freezing Zone. RefrigeratingflEngineering. 1086-
1089, 1114.

Stiles, W. 1922. The Preservation of Food by Freezing
with Special References to Fish and Meat: A study in
General Physiology. British Department of Scientific
and Industrial Research, Food Investigation, Special
Report No. 7.

Taylor, H. F. 1950. Solving the Problems of Rapid Freezing.
‘Egod Industries. 2: 146-151.

 

Tressler, D. K., and Evers, C. F. 1945. The Freezing Pre-
servation of Foods. The Avi Publishing Co., Inc.,
New York.

Wiesman, C. K. 1947. Factors Influencing Quality of Frozen
Meats. Ice and Refrigeration. 112, No. 4: 21-24.

Winter, J. D. 1952. Changes that Occur in Meat during Freez-
ing and Storage. Quick Frozen Foods. 15, No. 4: 170-171.

Woodroof, J. G. 1940. Chap. 2. Theory of Freezing Foods.
Refri erating Data Book. American Society of Refrigera-
‘ting ngineers,Editor and Publisher, New York. 6-11.

Woolrich, W. R. 1950. Some Physical and Chemical Preper-
ties of Foodstuffs. Ice and Refrigeration. 79, No. 6:
495-494.

Woolrich, W. R. 1951. Latent Heats of Foodstuffs. Refrig-
erating Engineering. 22: 21-24.

Woolrich, W. R. 1955. The Latent Heat of Foodstuffs. U. of

Tennessee Engineering Experimental Station Bulletin No.
11.

-47...

 

 

 

. _. _ ‘0 ‘ 3," I .‘ ‘rfxl IL? ... I" V - ’ ‘ . ‘V' . .’ r’ " 1
I .- I. . - ~ 14x I 7....» I. .
\ - . - - ' o‘a- ' c s H _.
. . ‘ 0'. '. - .8 . — '
. C l.
. I O 0 I
*4
V ‘ . '
. ’ . v
a -.
I ' u . '
r
i | I!
o .1
_ I
V ) - ' a.
K ‘ . t \
i I
o | r
.' I
' K
I P,
I" .‘.
I '\
. .
' -
I .
' I
U ' .‘
0
I
j I
u \
.‘ fl
- O
4.
. ‘ .
- - )I
.0 I
I I'."
\
‘ I —.——~— — ——— — —— - — I
f . F
. .
. _r~
I O , I
\ 9
. I ’ .
I . I
J I
\ ‘
~ ‘ a
3 .
II‘
0 § ' —
I A . ‘ I
‘ l f I
-1 ' x ’ i.
c I ' ‘
I . x I
. V D . o
.t 0
U ‘ .
- If (,— - ' -
- ‘I ‘ ‘. . l
.v' - '
' 9 I
l g ‘ | o
I I | .-\ ~ - . ’ l
o ' ~ I ' I.
..L ' .' ‘1 I A
II t’
‘ x I '
I- . l i
4 b
- o" . . v . - 1
- v I ' . \
_ I . "
.. I I . ' . lo
0 1 ’. . C
" l I § .
I I ' fl
" I
‘ I
I Q
j A; , f 0 " I ‘
_ a -- - I
‘I ' o ‘ J J '
- Q . 0;,
s . .. ' ' '
I ‘ . L‘» I L A '\ I
s I ' ' I“ “ I o . ' J ‘x I
I I o . ' O " e u
‘7 ° "A“ J. lb." \ «HH- I': 4 1h. 1"
- , ‘I _ ' ,t‘ 0‘ . 'I’ ...4 ‘ u i.“ p. I 9
- ’ | I.
q & o I I c K: 3 K . \' - }

 

 

(uh EIVHSIILY 1.11%". A 1;”; ‘f'

I l3564.9 508658
'2392 Tucker

 

IIUIWIIIHHIIIIIIllllllllllllllllllI’IIIIIIIIHIHIllll‘lll

31293 02446 6918