35 research outputs found
Content and In Vitro Accessibility of Provitamin. A Carotenoids in Some Tanzanian Vegetables and Fruits Effects of Traditional Processing and Preparation, and Influence on Vitamin A Status
No full textVitamin A deficiency is among the major nutritional problems in Tanzania as in many developing countries. It mainly affects children and pregnant and lactating women. The basic cause of this problem is related to the diet, which contains little preformed vitamin A and plant foods with a low content and bioavailability of provitamin A carotenoids. This thesis reports studies conducted to evaluate the content and bioavailability of provitamin A carotenoids in selected fruits and vegetables from Tanzania and to elucidate the effects of different processing and preparation methods. The vitamin A and provitamin A carotenoid status in pregnant women was assessed in relation to the dietary intake pattern of provitamin A carotenoids and after supplementation with cooking oil. Results showed that leafy vegetables contain high but variable amounts of all-trans-β-carotene (399-914 µg/g dry weight) and minor amounts of α-carotene, 9-cis- and 13-cis-β-carotene. Fruits contain variable amounts of all-trans-β-carotene (191-5502 µg/100g fresh weight) and some fruits have minor amounts of β-cryptoxanthin and lycopene. Open sun dried leafy vegetables had significantly (
Content and In Vitro Accessibility of Provitamin. A Carotenoids in Some Tanzanian Vegetables and Fruits Effects of Traditional Processing and Preparation, and Influence on Vitamin A Status
No full textVitamin A deficiency is among the major nutritional problems in Tanzania as in many developing countries. It mainly affects children and pregnant and lactating women. The basic cause of this problem is related to the diet, which contains little preformed vitamin A and plant foods with a low content and bioavailability of provitamin A carotenoids. This thesis reports studies conducted to evaluate the content and bioavailability of provitamin A carotenoids in selected fruits and vegetables from Tanzania and to elucidate the effects of different processing and preparation methods. The vitamin A and provitamin A carotenoid status in pregnant women was assessed in relation to the dietary intake pattern of provitamin A carotenoids and after supplementation with cooking oil. <p />Results showed that leafy vegetables contain high but variable amounts of all-<I>trans</I>-β-carotene (399-914 µg/g dry weight) and minor amounts of α-carotene, 9-<I>cis</I>- and 13-<I>cis</I>-β-carotene. Fruits contain variable amounts of all-<I>trans</I>-β-carotene (191-5502 µg/100g fresh weight) and some fruits have minor amounts of β-cryptoxanthin and lycopene. Open sun dried leafy vegetables had significantly (p<0.05) lower amounts of all-<I>trans</I>-β-carotene (53%) than the fresh vegetables, whereas vegetables dried in solar cabinets showed losses of only about 23%. Cooking caused variable losses (6-51%) in all-<I>trans</I>-β-carotene content of the vegetables. The bioaccessibility (amount available for absorption) of the provitamin A carotenoids was estimated with an <I>in vitro </I>digestion method that simulates conditions in the human gastrointestinal tract. The <I>in vitro</I> accessibility of all-<I>trans</I>-β-carotene was low (4-15%) in vegetables cooked without added oil. However, higher (2 to 5-fold) <I>in vitro</I> accessibility of all-<I>trans</I>-β-carotene was obtained in vegetables cooked with added cooking oil. An addition of red palm oil provided significant amounts of accessible provitamin A carotenoids due to its high content of α- and β-carotene. Conversion of the amount of accessible provitamin A carotenoids into retinol equivalents according to FAO/WHO recommendations revealed that a median portion of a vegetable relish as consumed by children provided 88 to 477% of the recommended safe daily intake level (RSDIL) of vitamin A. Portions cooked without oil provided only between 23 and 46%. The <I>in vitro</I> accessible all-<I>trans</I>-β-carotene in fruits varied between 7% and 100%, and an edible portion of fruit (150g) would provide between 27 and 216 % of the RSDIL of vitamin A to children. <p />Consumption of preformed vitamin A by pregnant women was very low and higher plasma retinol levels were correlated (p=0.03) with higher intakes of vegetables with oil. Supplementation with red palm oil increased α- and β-carotene concentrations significantly (p<0.001) in both plasma and breast milk. The breastmilk retinol concentration tended to decrease from 1 to 3 months postpartum in the control group but was maintained in the groups given supplements of either red palm oil or sunflower oil
Effect of traditional open sun-drying and solar cabinet drying on carotene content and vitamin A activity of green leafy vegetables
No full textEffect of traditional open sun-drying and solar cabinet drying on carotene content and vitamin A activity of green leafy vegetables
No full textIn vitro accessibility and intake of Β-carotene from cooked freen leafy vegetables and their estimated contribution to vitamin A requirements
No full textIn vitro accessibility and intake of Β-carotene from cooked freen leafy vegetables and their estimated contribution to vitamin A requirements
No full textIn vitro accessibility of carotenes from green leafy vegetables cooked with sunflower oil or red palm oil
No full textXanthophyll and Hydrocarbon Carotenoid Patterns Differ in Plasma and Breast Milk of Women Supplemented with Red Palm Oil during Pregnancy and Lactation
No full textIn vitro accessibility of carotenes from green leafy vegetables cooked with sunflower oil or red palm oil
No full textMicronutrient composition and nutritional importance of gathered vegetables in Vietnam
No full textThis article presents the nutrient composition and nutritional contribution of naturally occurring vegetables (NOV) in four villages in Vietnam. The frequency of consumption and quantities eaten were evaluated within the overall diet of 101 and 110 women in the Mekong Delta (flood period and rainy season, respectively) and of 103 women in the Central Highlands (rainy season). The concentrations of Ca, Fe and Zn were analysed in 28 species, and presence of tannins and phytic acid in 19 species. Provitamin carotenoids were determined in 11 species. Over 90% of the women consumed NOV, and they contributed 43, 72 and 75% (Central Highlands, Mekong rainy and Mekong flood period, respectively) of the total quantities of vegetables eaten. Aquatic species such as lpomoea aquatica and Limnocharis flava, and terrestrial vegetables such as Schismattoglottis calyptrata, were among the most commonly consumed vegetables. They were eaten in mean daily quantities exceeding 50 g and had high concentrations of Ca, Fe and beta-carotene. Other major aquatic vegetables included the stems of Eleocharis sp., Nelumbo nucifera and Nymphea lotus, all of which were used as salad vegetables and had relatively low nutrient density. The problems of assessing the current role of NOV due to lack of data on intakes in the context of the overall diets, as well as data on their composition, are addressed.</p
