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Bioaccessibility of Beta Carotene in Processed Products from Orange-Fleshed Sweetpotatoes
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| 자료유형 | 학위논문 |
|---|---|
| 서명/저자사항 | Bioaccessibility of Beta Carotene in Processed Products from Orange-Fleshed Sweetpotatoes. |
| 개인저자 | Chilungo, Sarah. |
| 단체저자명 | North Carolina State University. |
| 발행사항 | [S.l.]: North Carolina State University., 2019. |
| 발행사항 | Ann Arbor: ProQuest Dissertations & Theses, 2019. |
| 형태사항 | 142 p. |
| 기본자료 저록 | Dissertations Abstracts International 81-03B. Dissertation Abstract International |
| ISBN | 9781085633925 |
| 학위논문주기 | Thesis (Ph.D.)--North Carolina State University, 2019. |
| 일반주기 |
Source: Dissertations Abstracts International, Volume: 81-03, Section: B.
Advisor: Harris, Gabriel |
| 이용제한사항 | This item must not be sold to any third party vendors. |
| 요약 | Orange-Fleshed sweetpotatoes (OFSP) contain significant quantities of 棺-carotene, a precursor for vitamin A. The crop is being promoted to tackle vitamin A deficiency, a serious public health problem affecting children and pregnant/lactating women in sub-Saharan Africa. Significant studies have reported the efficacy of OFSP in improving serum retinol. The aim of the thesis was to evaluate the bioaccessibility of 棺-carotene in processed products from OFSP as affected by processing method and oil type. Bioaccessibility is the fraction or quantity of nutrients in food that is released from the matrix during digestion in the gastrointestinal tract and becomes available for absorption. Static in vitro digestion methods were used to determine carotene bioaccessibility. Bioconversion of 棺-carotene into VA and carotene retention stored in different packaging material were also investigated.This first study evaluated the effect of storage and packaging materials on carotene content, color and water activity of OFSP flours. Flours from Vita and Kabode OFSP genotypes were packed in aluminum foil laminate (AFL), high density polyethylene (HDPE) and Kraft paper and stored under light and dark conditions for 4 months. The highest carotenoid loss after 4 months was found in Kraft paper while AFL was the least. Similarly, flours in Kraft paper registered significant color value changes compared to flours in HDPE and AFL. Significant increase in water activity was observed in all packed samples and results were not dependent of storage environment. It is concluded that AFL with vacuum sealing is an appropriate packaging material due to better carotene retention, minimal color change and less water activity.Porridge and chapati were prepared with either puree or flour from the two sweetpotato genotypes. Digestive stability and bioaccessibility of the products were evaluated following in vitro methods. Beta-carotene digestive stability of porridge was significantly lower than chapatis. In the same line, 棺-carotene bioaccessibility was significantly lower for porridge than chapatis. It was also found that puree-based products registered low 棺-carotene bioaccessibility compared to flour-based products. For all the products, the study found no effect of sweetpotato genotype of 棺-carotene bioaccessibility while similar products had comparable carotene bioaccessibility. The findings confirm the effect of processing methods on carotene bioaccessibilty.Sunflower oil, margarine and beef fat were evaluated on their effect on 棺-carotene bioaccessibility. The amount of oil added was 10% (w/w) of chapati formulation. The results showed that digestive stability was non-significant among the products implying that oil type has no effect on digestive stability. Among the three oil types, sunflower oil had the highest carotene bioaccessibility followed by margarine while beef fat was the least. The low melting point of sunflower oil was the possible reason for high carotene bioaccessibility. Therefore, consumers should consider replacing margarine with sunflower oil due to low price and availability.The study further investigated the in vitro bioconversion efficiency of 棺-carotene into VA to determine VA value of OFSP supplemented porridge and chapati. When 棺-carotene extract was incubated with chicken intestinal mucosa post mitochondrial fractions, retinal (RAL) and retinoic acid (RA) were formed. No RAL and RA were formed when pure all-trans 棺-carotene standard was incubated without chicken intestinal mucosa post mitochondrial fraction. On average, the conversion ratio of 棺-carotene to RAL was 5:1. The results are of significance to people in developing countries who depend on plant food to meet their VA requirements. Further investigation of the study is suggested to validate the findings. |
| 일반주제명 | Food science. |
| 언어 | 영어 |
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