Effect of parboiling conditions on zinc and iron retention in biofortified and non-biofortified milled rice.

BACKGROUND: Zinc-biofortified rice could contribute to zinc intake in deficient populations, but processing it into parboiled rice could affect this potential benefit. Zinc and iron true retention (TR) in milled rice produced under conditions resembling household and commercial parboiled methods was evaluated. Zinc and iron TR in milled rice obtained from biofortified and non-biofortified rice subjected to different soaking temperatures during parboiling was also evaluated. RESULTS: Conditions resembling commercial parboiling methods resulted in 52.2-59.7% zinc TR and 55.4-79.1% iron TR, whereas those used for household parboiling resulted in 70.7-79.6% zinc TR and 78.2-119.8% iron TR. Zinc TR in milled (8-16% bran removal) biofortified and non-biofortified parboiled rice was 50.6-66.8% when soaking rough rice at 20 °C and 29.9-56.0% when soaking rough rice at 65 °C; both had lower zinc TR than non-parboiled rice (58.0-80.6%). Iron TR was generally similar between milled non-parboiled and parboiled rice (26.2-67.6%) and between parboiled biofortified and non-biofortified milled rice. CONCLUSION: Parboiling conditions used to obtain milled rice targeted for own household consumption resulted in higher zinc and iron TR compared to parboiling conditions used for milled rice targeted for markets. More zinc from the inner endosperm moved towards the outer layers at high soaking temperature, resulting in lower zinc TR for milled parboiled rice soaked in hotter water. Parboiled rice soaked at temperatures used in households could provide more zinc to diets compared to rice soaked in hotter water commonly used in large rice mills, especially when rice is extensively milled. © 2021 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Effect of maize processing methods on the retention of minerals, phytic acid and amino acids when using high kernel-zinc maize.

High kernel-zinc maize varieties are available to consumers in several countries in Latin America to contribute to increase the zinc intake of their populations. Minerals, phytic acid and amino acids retention were measured after processing six maize varieties including three high kernel-zinc, one quality protein maize and two conventional maize. Grain for each variety was processed into tortillas, arepas and mazamorra, common maize dishes in the region. To evaluate the effect of processing kernel-zinc maize varieties on zinc retention, varieties were grouped in zinc biofortified maize (ZBM) and non-ZBM. Iron, zinc, phytic acid, tryptophan and lysine concentrations in non-processed maize were 17.1-19.1 â€‹µg/g DW, 23.9-33.0 â€‹µg/g DW, 9.9-10.0 â€‹mg/g DW, 0.06-0.08% and 0.27-0.37%, respectively. In tortillas, the iron, zinc, phytic acid and lysine content did not change (p â€‹< â€‹0.05) compared to raw grain, while tryptophan decreased by 32%. True retention of iron in arepas and mazamorra was 43.9 and 60.0%, for zinc 36.8 and 41.3%, and for phytic acid 19.3 and 25.1%. Tortillas had higher zinc retention than arepas and mazamorra due to use of whole grain in the nixtamalization process. Therefore, to contribute to higher zinc intake, nixtamalized tortilla prepared with biofortified zinc maize is recommended. Additionally, promotion of whole grain flour to prepare arepas should be explored to enhance the intake of minerals that are usually confined to aleurone layers and germ.

Retention of Zn, Fe and phytic acid in parboiled biofortified and non-biofortified rice.

Biofortified rice with high Zn concentration could reduce Zn deficiency in South Asia. This population frequently parboils rice. True retention (TR) of Zn, Fe and phytic acid after parboiling and milling was evaluated in biofortified and non-biofortified rice. TR in milled non-parboiled rice was 63.8-89.6% for Zn, 21.1-44.5% for Fe and 16.4-40.3% for phytic acid, whereas in milled parboiled rice TR was 49.8-72.2% for Zn, 23.4-36.7% for Fe and 22.0-33.3% for phytic acid. Milled parboiled rice resulted in lower Zn TR compared to milled non-parboiled. These results suggest that Zn moves from the inner endosperm towards the outer layers during parboiling, regardless of initial Zn concentration, consequently, once milled, the potential impact of Zn intake on Zn deficiency from parboiled rice is less than non-parboiled rice. Despite Zn losses during processing, biofortified rice could provide over 50% of the Zn EAR for children.

Iron, Zinc and Phytic Acid Retention of Biofortified, Low Phytic Acid, and Conventional Bean Varieties When Preparing Common Household Recipes.

Biofortification is an effective method to improve the nutritional content of crops and nutritional intake. Breeding for higher micronutrient mineral content in beans is correlated with an increase in phytic acid, a main inhibitor of mineral absorption in humans. Low phytic acid (lpa) beans have a 90% lower phytic acid content compared to conventional beans. This is the first study to investigate mineral and total phytic acid retention after preparing common household recipes from conventional, biofortified and lpa beans. Mineral retention was determined for two conventional, three biofortified and two lpa bean genotypes. Treatments included soaking, boiling (boiled beans) and refrying (bean paste). The average true retention of iron after boiling was 77.2-91.3%; for zinc 41.2-84.0%; and for phytic acid 49.9-85.9%. Soaking led to a significant decrease in zinc and total phytic acid after boiling and refrying, whereas for iron no significant differences were found. lpa beans did not exhibit a consistent pattern of difference in iron and phytic acid retention compared to the other groups of beans. However, lpa beans had a significantly lower retention of zinc compared to conventional and biofortified varieties (p < 0.05). More research is needed to understand the underlying factors responsible for the differences in retention between the groups of beans, especially the low retention of zinc. Combining the lpa and biofortification traits could further improve the nutritional benefits of biofortified beans, by decreasing the phytic acid:iron and zinc ratio in beans.

Carotenoids retention in biofortified yellow cassava processed with traditional African methods.

BACKGROUND: Biofortified yellow cassava is being cultivated in countries with high cassava consumption to improve its population's vitamin A status. The carotenoid retention in biofortified cassava when processed as boiled, fufu, and chikwangue was evaluated in this study. Commercial biofortified varieties Kindisa and Vuvu and the experimental genotypes MVZ2011B/360 and MVZ2012/044 were used. Fresh cassava roots were processed as boiled, fufu, and chikwangue. Provitamin A carotenoids (pVACs) content of fresh and processed cassava was measured by high-performance liquid chromatography, and total carotenoids was measured by spectrophotometer. RESULTS: pVACs content of fresh peeled cassava was 1.79-6.65 µg g-1 on a fresh weight basis, whereas in boiled cassava, fufu, and chikwangue the pVACs content was 1.71-6.91 µg g-1 , 0.04-0.37 µg g-1 , and 0.52-1.75 µg g-1 respectively. True retention of carotenoids after cooking was 93.2-96.8%, 0.8-3.1%, and 4.0-18.1% for boiled cassava, fufu, and chikwangue respectively. Significant total carotenoids loss was observed during storage. CONCLUSION: The results indicated that biofortified boiled cassava could be an effective food product to improve pVACs intake in areas where vitamin A deficiency exists, and processing of chikwangue and fufu should be improved before promoting biofortified cassava in vitamin-A-deficient areas with high cassava consumption. © 2018 The Authors. Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Carotenoid retention in biofortified maize using different post-harvest storage and packaging methods.

Orange maize is being promoted as a source of provitamin A carotenoids (pVAC) in Zambia. Carotenoid retention in orange maize grains stored in metal silos, multilayer polyethylene and common woven bags, and maize meal packaged in single and multilayer polyethylene bags was evaluated. Significant differences in total pVAC retention were found between grain storage methods (48.1-57.2%) after 6months of storage. Total pVAC retention in hammer meal (73.1-73.5%) was higher than in breakfast meal (64.3-69.3%) after 4months of storage; however, no differences in pVAC retention were found between meal types when stored in single and multilayer polyethylene bags. In general, ß-cryptoxanthin (ßCX) had higher retention than ß-carotene (ßC). Potential contribution of stored orange maize to the estimated average requirement of children and women was 26.5% and 24.3%, respectively. Orange maize meal can provide significant amounts of provitamin A to diets of Zambians even after 4months of storage.