PHD-Department of Foods, Nutrition & Dietetics

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Browsing PHD-Department of Foods, Nutrition & Dietetics by Author "Nakhauka, Ekesa Beatrice"

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    Retention and bioaccessibility of provitamin a carotenoids in popular musa fruit and their derived products consumed in eastern democratic republic of Congo
    (2013-07-19) Nakhauka, Ekesa Beatrice
    In the Democratic Republic of Congo (DRC), bananas and plantains (Musa spp.) production is predominant in the Eastern region where they are also a major part of the diet. Recent micronutrient analyses on raw bananas from The Philippines, Uganda and Hawaii indicate that certain cultivars can contribute substantially to the daily vitamin A requirements. The objective of this study was to establish the retention and bioaccessibility of provitamin A carotenoids (pVACs) in the most popular Musa fruit and their locally derived products consumed in Eastern DRC. The study sites included Beni territory (North Kivu-NK) and Bukavu territory (South Kivu-SK). The localities, villages and specific households were established through multistage sampling. Sample size was calculated using Fisher‟s formula. A total of 14 focus group discussions were carried out and 371 households visited and mothers/caregivers interviewed. The most popular Musa cultivars identified were sub-sampled at ripening stages 1, 3, 5 and 7 based on peel color and another sub-sample processed into most common products. All the samples were then frozen at -200c and lyophilised. Using HPLC, these samples were subsequently analysed for fruit pulp pVACs contents. For bioacessibility studies, Musa samples and ingredients were processed into products following local procedures and bioaccessibility was estimated using an in vitro digestion method, content of pVACs in the products and dishes was verified using HPLC. Findings showed that the preferred cooking banana varieties included yellow-pulped AAA-East African Highland bananas [AAA-EAHBs] „Nshikazi‟ (SK) and „Vulambya‟ (NK). Preferred plantains (AAB genome), were orange-pulped and included „Musheba‟ (SK) and „Musilongo‟ (NK). The most common cooking method was simply boiling of bananas/plantains and the main accompaniments included beans and amaranth leaves. The predominant pVACs in both raw and processed fruit pulp were all-trans β- and all-trans α-carotene, together constituting about 90% of total pVACs. The proportion of β-carotene was twice that of α-carotene in the plantains varieties, while in the EAHBs tested, the proportion was almost equal. Provitamin A carotenoids observed in the fruit pulp of the tested Musa cultivars were retained and a significant increase observed during ripening. The highest levels of the pVACs were observed at ripening stage 3 in all four cultivars. Values were as high as 1081μg/100gFM in „Vulambya‟ and 1820μg/100gFM in „Musilongo‟. Although boiling AAA-EAHB cultivars led to substantial losses (40%-60%) in total pVACs contents, boiling and deep frying of the plantains led to retention and an apparent increase. After in-vitro digestion, the percentage of micellarized t-BC was higher in „Vulambya‟ (29 %) than in „Musilongo‟ (16.6 %). In the two Musa cultivars, the incorporation into micelles was similar for t-BC and t-AC, but significantly higher for 13-cis isomer. The best performing Musa-based dishes made from „Musilongo‟ and „Vulambyo‟ provided about 22% and 28% of the daily vitamin A Recommended Dietary Allowance (RDA) for a child under 5 years old. These results can guide consumer consumption patterns to maximize vitamin A intake for improved health in these regions and also direct researchers in the selection of Musa cultivars to be fast-tracked in the fight against VAD. 1 CHAPTER ONE: INTRODUCTION 1.1 Background of the study The highlands of the Great Lakes region (Eastern Democratic Republic of Congo-DRC, Rwanda, Burundi, and Western Uganda) contain the most intensely cultivated agricultural regions of Africa. In DRC, 67% of the population depends on agricultural production for both food and income and the principal food crops include; cassava, banana and sweet potatoes (Ndungo, Fiaboe, & Mwangi, 2008). Banana and plantain production occurs predominantly in forest regions of the equator in North and South Kivu. The most dominant banana types in DRC are the plantains and cooking bananas accounting for 27% of the global production estimated to be 282,520 tonnes and 1,071,900 tonnes respectively (Ndungo et al., 2008). Studies and reports (Karamura, Karamura, & Gold, 1996; Karamura, 1998; Lescot, 1999) indicate that the majority of bananas and plantains grown within this region are consumed locally in various forms. Even though the consumption rates/patterns for the various forms of banana-based foods are not known, the different forms in which they are prepared and consumed include; cooked green, cooked ripe, cooked in the peel, steamed, prepared as juice, ripened for desert, roasted, chipped and fried or dried and floured to make a host of confectionaries. In other words, there is an affordable banana dish for virtually every income category of consumers in the region (HarvestPlus, 2007). In addition, apart from being intercropped with other nutritious ground covering food crops such