THE POTENTIAL OF FOOD-TO-FOOD FORTIFICATION WITH TURKEY BERRY AND COWPEA LEAF POWDERS TO ENHANCE DIETARY IRON AND FOLATE INTAKE AMONG WOMEN OF REPRODUCTIVE AGE : FROM PROCESSING TO BIOAVAILABILITY
Iron and folate deficiencies are critical public health challenges in low- and middle-income countries, particularly among women of reproductive age and children. Food-to-food fortification with indigenous foods has been suggested as a complementary approach to traditional food fortification and supplementation strategies in resource-poor settings. However, research gaps persist regarding the effectiveness of this strategy for women of reproductive age, particularly concerning processing challenges and the impact of different methods on nutrient retention, as well as the acceptance of fortified foods. Additionally, the bioavailability of iron and folate from food fortificants and their contribution to dietary intake among women in Ghana have not been adequately explored. This study tested the hypothesis that food-to-food fortification with two locally available vegetables, turkey berries, and cowpea leaves would significantly enhance dietary iron and folate intake among women of reproductive age and possibly children in Ghana. The research focused on: (1) overcoming common processing challenges such as color degradation and drying kinetics in turkey berries, and (2) evaluating the effects of various processing methods on the physicochemical properties, including iron content in both vegetables and folate, a water soluble-heat-labile vitamin in cowpea leaves, and (3) assessing iron bioavailability in the powders and fortified culturally acceptable tomato-based soup and mango-banana-based smoothie, as well as acceptability of the fortified foods among African women of reproductive age. The findings indicated that excessive browning and prolonged drying times in turkey berries were mitigated with appropriate pretreatments, specifically blanching and osmotic treatments. We developed optimal kinetic models for color degradation and drying kinetics in turkey berries, providing a useful tool for researchers and food processors. Cowpea leaves, although underutilized, were found to contain significantly higher levels of iron and folate than turkey berries, which are widely recognized in Ghana for their purported anti-anemic properties. However, both powders showed low iron bioavailability. Steaming emerged as the most effective method for retaining iron, folate, and other bioactive compounds in cowpea leaves, compared to boiling, which is typically used for domestic cooking. Cowpea leaf-fortified tomato-based soup contributed up to 26% of the recommended daily allowance (RDA) of iron and 12% of the RDA of folate per serving for women. The soup could potentially contribute up to 100% of the RDA of iron and 48% of the RDA of folate per typical Ghanaian adult soup portion of up to four cups. The mango-banana-based smoothie provided 16% of the RDA of iron and 9% of the RDA of folate per serving. Iron bioavailability was high in the unfortified soup, but low in the unfortified smoothie. Adding cowpea leaf powder reduced iron bioavailability in the soup but had no significant impact on the smoothie. Regarding perceptions and acceptability of the fortified foods, there was a general preference for fresh vegetables, among a group of African women who were however willing to incorporate cowpea leaf powders in their foods, especially for children and use the fortified smoothie and the soup for their potential health benefits. Raw cowpea leaf powder can be used to enrich soups and stews, while steamed powder is ideal for ready-to-eat foods like smoothies, especially in Northern Ghana, where micronutrient deficiencies are common, and fresh leaves are a staple. Exploring the development of innovative food products with enhanced bioavailability using cowpea leaves and turkey powders, is a promising approach. These products should be designed to integrate seamlessly into culturally accepted foods while providing optimal nutritional benefits. Coupling this with targeted nutrition education is critical for successful adoption of food-to-food fortification.
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- In Collections
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Electronic Theses & Dissertations
- Copyright Status
- Attribution 4.0 International
- Material Type
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Theses
- Authors
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Borbi, Makafui
- Thesis Advisors
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Dolan, Kirk D.
Weatherspoon, Lorraine J.
- Committee Members
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Bourquin, Leslie D.
Jackson-Malete, Jose
- Date Published
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2024
- Subjects
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Food--Composition
- Program of Study
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Food Science - Doctor of Philosophy
- Degree Level
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Doctoral
- Language
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English
- Pages
- 318 pages
- Embargo End Date
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December 9th, 2025
- Permalink
- https://doi.org/doi:10.25335/2hd6-we05
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