Lactating mothers' perceptions and sensory acceptability of a provitamin A carotenoid-iron-rich composite dish prepared from iron-biofortified common bean and orange-fleshed sweet potato in rural western Uganda

Uganda's lactating mothers are vulnerable to deficiencies of vitamin A and iron because they consume plant-based conventional foods such as white-fleshed sweet potato (WFSP) and non-iron biofortified common bean (NIBCB) that are low in provitamin A (PVA) and iron, respectively. A PVA carotenoid-iron-rich dish was prepared from a combination of orange-fleshed sweet potato (OFSP) and iron-biofortified common bean (IBCB). This study evaluated the perceptions and sensory acceptability of OFSP+IBCB (test food) against WFSP+NIBCB (control food) among lactating mothers in rural Uganda. A total of 94 lactating mothers participated in the study. The sensory attributes (taste, color, aroma, texture, and general acceptability) of test and control foods were rated using a five-point facial hedonic scale (1 = dislike very much, 2 = dislike, 3 = neutral, 4 = like 5 = like very much). An attribute was acceptable if the participant scored from like to like very much. Focus group discussions (FGDs) were conducted to assess participant perceptions about their future consumption of OFSP+IBCB. The chi-square test was used to detect the proportion difference for each sensory attribute between OFSP+IBCB and WFSP+NIBCB, while FGD data were analyzed by thematic analysis. Taste, color, and aroma were acceptable to the mothers and not significantly different between OFSP+IBCB and WFSP+NIBCB (p > .05). Participants had positive perceptions of the taste, aroma, and color of the OFSP+IBCB and negative perceptions about the soft texture of OFSP. The lactating mothers had positive perceptions of consuming OFSP+IBCB provided they were accessible, affordable, and feasible to prepare.

Legumes and common beans in sustainable diets: nutritional quality, environmental benefits, spread and use in food preparations

In recent decades, scarcity of available resources, population growth and the widening in the consumption of processed foods and of animal origin have made the current food system unsustainable. High-income countries have shifted towards food consumption patterns which is causing an increasingly process of environmental degradation and depletion of natural resources, with the increased incidence of malnutrition due to excess (obesity and non-communicable disease) and due to chronic food deprivation. An urgent challenge is, therefore, to move towards more healthy and sustainable eating choices and reorientating food production and distribution to obtain a human and planetary health benefit. In this regard, legumes represent a less expensive source of nutrients for low-income countries, and a sustainable healthier option than animal-based proteins in developed countries. Although legumes are the basis of many traditional dishes worldwide, and in recent years they have also been used in the formulation of new food products, their consumption is still scarce. Common beans, which are among the most consumed pulses worldwide, have been the focus of many studies to boost their nutritional properties, to find strategies to facilitate cultivation under biotic/abiotic stress, to increase yield, reduce antinutrients contents and rise the micronutrient level. The versatility of beans could be the key for the increase of their consumption, as it allows to include them in a vast range of food preparations, to create new formulations and to reinvent traditional legume-based recipes with optimal nutritional healthy characteristics.

Genome-wide association and genomic prediction for iron and zinc concentration and iron bioavailability in a collection of yellow dry beans

Dry bean is a nutrient-dense food targeted in biofortification programs to increase seed iron and zinc levels. The underlying assumption of breeding for higher mineral content is that enhanced iron and zinc levels will deliver health benefits to the consumers of these biofortified foods. This study characterized a diversity panel of 275 genotypes comprising the Yellow Bean Collection (YBC) for seed Fe and Zn concentration, Fe bioavailability (FeBio), and seed yield across 2 years in two field locations. The genetic architecture of each trait was elucidated via genome-wide association studies (GWAS) and the efficacy of genomic prediction (GP) was assessed. Moreover, 82 yellow breeding lines were evaluated for seed Fe and Zn concentrations as well as seed yield, serving as a prediction set for GP models. Large phenotypic variability was identified in all traits evaluated, and variations of up to 2.8 and 13.7-fold were observed for Fe concentration and FeBio, respectively. Prediction accuracies in the YBC ranged from a low of 0.12 for Fe concentration, to a high of 0.72 for FeBio, and an accuracy improvement of 0.03 was observed when a QTN, identified through GWAS, was used as a fixed effect for FeBio. This study provides evidence of the lack of correlation between FeBio estimated in vitro and Fe concentration and highlights the potential of GP in accurately predicting FeBio in yellow beans, offering a cost-effective alternative to the traditional assessment of using Caco2 cell methodologies.

A systematic review of the impacts of post-harvest handling on provitamin A, iron and zinc retention in seven biofortified crops

Post-harvest handling can affect micronutrient retention in biofortified crops through to the point of consumption. Here we conduct a systematic review identifying 67 articles examining the retention of micronutrients in conventionally bred biofortified maize, orange sweet potato, cassava, pearl millet, rice, beans and wheat. Provitamin A crops maintain high amounts compared with non-biofortified counterparts. Iron and zinc crops have more variability in micronutrient retention dependent on processing method; for maximum iron and zinc content, whole grain product consumption such as whole wheat flour or only slightly milled brown rice is beneficial. We offer preliminary suggestions for households, regulatory bodies and programme implementers to increase consumer awareness on best practices for preparing crops to maximize micronutrient content, while highlighting gaps in the literature. Our online, interactive Micronutrient Retention Dashboard ( https://www.cpnh.cornell.edu/mn-retention-db ) offers an at-a-glance view of the compiled minimum and maximum retention found, organized by processing method.

Trait stacking simultaneously enhances provitamin A carotenoid and mineral bioaccessibility in biofortified Sorghum bicolor

Vitamin A, iron, and zinc deficiencies are major nutritional inadequacies in sub-Saharan Africa and disproportionately affect women and children. Biotechnology strategies have been tested to individually improve provitamin A carotenoid or mineral content and/or bioaccessibility in staple crops including sorghum (Sorghum bicolor). However, concurrent carotenoid and mineral enhancement has not been thoroughly assessed and antagonism between these chemical classes has been reported. This work evaluated two genetically engineered constructs containing a suite of heterologous genes to increase carotenoid stability and pathway flux, as well as phytase to catabolize phytate and increase mineral bioaccessibility. Model porridges made from transgenic events were evaluated for carotenoid and mineral content as well as bioaccessibility. Transgenic events produced markedly higher amounts of carotenoids (26.4 μg g^-1 DW) compared to null segregants (4.2 μg g^-1 DW) and wild-type control (Tx430; 3.7 μg g^-1 DW). Phytase activation by pre-steeping flour resulted in significant phytate reduction (9.4 to 4.2 mg g^-1 DW), altered the profile of inositol phosphate catabolites, and reduced molar ratios of phytate to iron (16.0 to 4.1), and zinc (19.0 to 4.9) in engineered material, suggesting improved mineral bioaccessibility. Improved phytate : mineral ratios did not significantly affect micellarization and bioaccessible provitamin A carotenoids were over 23 times greater in transgenic events compared to corresponding null segregants and wild-type controls. A 200 g serving of porridge made with these transgenic events provide an estimated 53.7% of a 4-8-year-old child's vitamin A estimated average requirement. These data suggest that combinatorial approaches to enhance micronutrient content and bioaccessibility are feasible and warrant further assessment in human studies.

Biofortification of common bean (Phaseolus vulgaris L.) with iron and zinc: Achievements and challenges

Micronutrient deficiencies (hidden hunger), particularly in iron (Fe) and zinc (Zn), remain one of the most serious public health challenges, affecting more than three billion people globally. A number of strategies are used to ameliorate the problem of micronutrient deficiencies and to improve the nutritional profile of food products. These include (i) dietary diversification, (ii) industrial food fortification and supplements, (iii) agronomic approaches including soil mineral fertilisation, bioinoculants and crop rotations, and (iv) biofortification through the implementation of biotechnology including gene editing and plant breeding. These efforts must consider the dietary patterns and culinary preferences of the consumer and stakeholder acceptance of new biofortified varieties. Deficiencies in Zn and Fe are often linked to the poor nutritional status of agricultural soils, resulting in low amounts and/or poor availability of these nutrients in staple food crops such as common bean. This review describes the genes and processes associated with Fe and Zn accumulation in common bean, a significant food source in Africa that plays an important role in nutritional security. We discuss the conventional plant breeding, transgenic and gene editing approaches that are being deployed to improve Fe and Zn accumulation in beans. We also consider the requirements of successful bean biofortification programmes, highlighting gaps in current knowledge, possible solutions and future perspectives.

Phenotype based clustering, and diversity of common bean genotypes in seed iron concentration and cooking time

Common bean is the world's most important directly consumed legume food crop that is popular for calories, protein and micronutrients. It is a staple food in sub-Saharan Africa, and a significant source of iron for anemic people. However, several pests, soil and weather challenges still impede its production. Long cooking time, and high phytic acid and polyphenols that influence bioavailable iron also limit the health benefits. To inform population improvement strategies and selection decisions for resilient fast cooking and iron biofortified beans, the study determined diversity and population structure within 427 breeding lines, varieties, or landraces mostly from Alliance Uganda and Columbia. The genotypes were evaluated for days to flowering and physiological maturity, yield, seed iron (FESEED) and zinc (ZNSEED) and cooking time (COOKT). Data for all traits showed significant (P≤0.001) differences among the genotypes. Repeatability was moderate to high for most traits. Performance ranged from 52 to 87 ppm (FESEED), 23-38 ppm (ZNSEED), 36-361 minutes (COOKT), and 397-1299 kg/ha (yield). Minimal differences existed between the gene pools in the mean performance except in yield, where Mesoamerican beans were better by 117 kg/ha. The genotypes exhibited high genetic diversity and thus have a high potential for use in plant breeding. Improvement of FESEED and ZNSEED, COOKT and yield performance within some markets such as red and small white beans is possible. Hybridization across market classes especially for yellow beans is essential but this could be avoided by adding other elite lines to the population. Superior yielding and fast cooking, yellow and large white beans were specifically lacking. Adding Fe dense elite lines to the population is also recommended. The population was clustered into three groups that could be considered for specific breeding targets based on trait correlations.

Sila D, N. Orina I. Nutritional Composition and Antinutrient to Mineral Molar Ratios of Selected Improved Common Beans Grown in Kenya

A decline in common bean production has been ascribed to climate change. The adoption of improved beans aims to increase productivity, profitability, and consumption, thus reducing food and nutrition insecurity in the country. The aim of this study was to determine the proximate composition, antinutrient content, mineral content, and bioaccessibility of zinc and iron in two improved bean varieties grown in Kenya; Faida (biofortified) and RM 01 (drought tolerant)). The protein content of RM 01 (22.48%) was significantly higher than the Faida bean variety (20.90%). RM 01 bean variety had higher crude fat (4.20%) and crude fiber (4.31%) content compared to Faida which had 3.78% and 3.31% for crude fat and crude fiber respectively. Faida recorded significantly higher levels of iron (61.5 mg/kg) and zinc (26.8 mg/kg) content. Faida beans also had significantly (p< 0.05) high levels of phytates (11.70 mg/g) and tannins (4.39 mg CE/g). Phytate to iron ratio for Faida was 17.08 and RM 01 was 15.19 while the phytate-to-zinc ratio was 42.26 and 35.36 for Faida and RM 01 respectively. The RM 01 bean variety had iron bioaccessibility of 35% and zinc bioaccessibility of 65% compared to the Faida bean variety which had bioaccessibility of 29% and 42% for iron and zinc respectively. In conclusion, RM 01 variety is a better source of iron, zinc, and protein compared to the Faida variety.

A Narrative Review: In-vitro Methods for Assessing Bio-Accessibility/Bioavailability of Iron in Plant-Based Foods

In-vitro measurement has the advantage of rapid and convenient method of screening the iron bioavailability within the range of plant-based foods. It is important to do preliminary screening as it provides information which will be useful to identify promising plant sources of iron before moving to human trials. A review on in-vitro methods of bio-accessibility and bioavailability of iron in plant-based foods including fruits, vegetables, cereals and legumes is entailed here. The review will focus on in-vitro methods of iron bioavailability in plant-based foods and the effects of inhibitors and processing on the iron bioavailability. The variation of the methods and updates on a recent INFOGEST method used to measure the bioavailability of iron in plant-based foods will also be discussed.