Biotechnological approaches to reduce the phytic acid content in millets to improve nutritional quality.

MAIN CONCLUSION: The review article summarizes the approaches and potential targets to address the challenges of anti-nutrient like phytic acid in millet grains for nutritional improvement. Millets are a diverse group of minor cereal grains that are agriculturally important, nutritionally rich, and the oldest cereals in the human diet. The grains are important for protein, vitamins, macro and micronutrients, fibre, and energy sources. Despite a high amount of nutrients, millet grains also contain anti-nutrients that limit the proper utilization of nutrients and finally affect their dietary quality. Our study aims to outline the genomic information to identify the target areas of research for the exploration of candidate genes for nutritional importance and show the possibilities to address the presence of anti-nutrient (phytic acid) in millets. So, the physicochemical accessibility of micronutrients increases and the agronomic traits can do better. Several strategies have been adopted to minimize the phytic acid, a predominant anti-nutrient in cereal grains. In the present review, we highlight the potential of biotechnological tools and genome editing approaches to address phytic acid in millets. It also highlights the biosynthetic pathway of phytic acid and potential targets for knockout or silencing to achieve low phytic acid content in millets.

Bioavailability of Australian pre-schooler iron intakes at specific eating occasions is low.

PURPOSE: Poor bioavailability may contribute to iron deficiency among children in high-resource countries, but iron bioavailability of Australian pre-schooler diets is unknown. This study aimed to estimate the bioavailability of Australian pre-schooler iron intakes across the day and by eating occasions to identify optimal timing for intervention, by using five previously developed algorithms, and to estimate the proportion of children with intakes of absorbable iron below the requirements. METHODS: Dietary data of children aged 2 to < 6 y (n = 812) from the 2011-12 National Nutrition and Physical Activity Survey were collected via two 24-h recalls. Usual food and nutrient intakes were estimated via Multiple Source Method. Phytate, polyphenol, and heme iron values were sourced from international databases or the literature. Five previously published algorithms were applied to observed dietary data to estimate iron bioavailability and calculate the prevalence of children with intakes of absorbable iron below requirements. RESULTS: Pre-schooler daily iron bioavailability was low (2.7-10.5%) and corresponded to intakes of 0.18-0.75 mg/d of absorbable iron. The proportion of children with inadequate intakes of absorbable iron ranged between 32 and 98%. For all eating occasions, dinner offered iron of the greatest bioavailability (4.2-16.4%), while iron consumed at breakfast was of the lowest bioavailability (1.2-5.6%). CONCLUSION: Future strategies are required to improve intakes of bioavailable iron for pre-schoolers to prevent the risk of deficiency. These strategies could include the encouragement of concomitant consumption of enhancers of iron absorption with iron-rich sources, particularly at breakfast.

Impact of milling on the nutrients and anti-nutrients in browntop millet (Urochloa ramosa) and its milled fractions: evaluation of their flour functionality.

BACKGROUND: Browntop millet has gained popularity in recent years owing to its nutritional superiority and health benefits. However, the usage of browntop millet flours as ingredients in composite flours and functional foods is constrained due to a lack of information regarding the grain composition and its flour functionality. Therefore, the distribution of nutrients, anti-nutrients in browntop millet milled fractions and their flour functionality was evaluated in comparison to whole grain flour. RESULTS: Bran fraction comprised the highest protein (13.7%) and fat contents (27%) among other fractions. Pearling of dehulled grains considerably reduced phytic acid, saponins and flatulence-causing oligosaccharides in pearled grain flours. Besides, this led to the enrichment of soluble fibre, minerals, phenolics and trypsin inhibitors in bran fraction. Milling also impacted flour functionality. Despite its lower water holding ability, dehulled grain flour exhibited significantly higher oil absorption capacity than whole grain flour due to the removal of fibre-rich hull fraction. Although emulsion (45.2%) and foaming capacities (12.5%) were superior in bran flour, foam stability was greater in pearled grain flours. CONCLUSION: These findings suggest the potential utilisation of browntop millet milled flours as ingredients in the development of distinct food formulations and as partial substitutes to wheat flour in confectionary and bakery products. © 2024 Society of Chemical Industry.

Effects of removing phytic acid on the bioaccessibility of Ca/Fe/Zn and protein digestion in soymilk.

BACKGROUND: Soymilk is a high-quality source of protein and minerals, such as calcium (Ca), iron (Fe), and zinc (Zn). However, phytic acid in soymilk restricts mineral and protein availability. We here investigated the effects of removing phytic acid on the physicochemical properties, mineral (Ca, Fe, and Zn) bioaccessibility, and protein digestibility of soymilk. RESULTS: Physicochemical property analysis revealed that the removal of phytic acid reduced protein accumulation at the gastric stage, thereby facilitating soymilk matrix digestion. The removal of phytic acid significantly increased Zn bioaccessibility by 18.19% in low-protein soymilk and Ca and Fe bioaccessibility by 31.20% and 30.03%, respectively, in high-protein soymilk. CONCLUSION: Removing phytic acid was beneficial for the hydrolysis of high-molecular-weight proteins and increased the soluble protein content in soymilk, which was conducive to protein digestion. This study offers a feasible guide for developing plant-based milk with high nutrient bioaccessibility. © 2024 Society of Chemical Industry.

The occurrence, role, and management strategies for phytic acid in foods.

Phytic acid, a naturally occurring compound predominantly found in cereals and legumes, is the focus of this review. This review investigates its distribution across various food sources, elucidating its dual roles in foods. It also provides new insights into the change in phytic acid level during food storage and the evolving trends in phytic acid management. Although phytic acid can function as a potent color stabilizer, flavor enhancer, and preservative, its antinutritional effects in foods restrict its applications. In terms of management strategies, numerous treatments for degrading phytic acid have been reported, each with varying degradation efficacies and distinct mechanisms of action. These treatments encompass traditional methods, biological approaches, and emerging technologies. Traditional processing techniques such as soaking, milling, dehulling, heating, and germination appear to effectively reduce phytic acid levels in processed foods. Additionally, fermentation and phytase hydrolysis demonstrated significant potential for managing phytic acid in food processing. In the future, genetic modification, due to its high efficiency and minimal environmental impact, should be prioritized to downregulate the biosynthesis of phytic acid. The review also delves into the biosynthesis and metabolism of phytic acid and elaborates on the mitigation mechanism of phytic acid using biotechnology. The challenges in the application of phytic acid in the food industry were also discussed. This study contributes to a better understanding of the roles phytic acid plays in food and the sustainability and safety of the food industry.

Permeability of the HIV-1 capsid to metabolites modulates viral DNA synthesis.

Reverse transcription, an essential event in the HIV-1 life cycle, requires deoxynucleotide triphosphates (dNTPs) to fuel DNA synthesis, thus requiring penetration of dNTPs into the viral capsid. The central cavity of the capsid protein (CA) hexamer reveals itself as a plausible channel that allows the passage of dNTPs into assembled capsids. Nevertheless, the molecular mechanism of nucleotide import into the capsid remains unknown. Employing all-atom molecular dynamics (MD) simulations, we established that cooperative binding between nucleotides inside a CA hexamer cavity results in energetically favorable conditions for passive translocation of dNTPs into the HIV-1 capsid. Furthermore, binding of the host cell metabolite inositol hexakisphosphate (IP6) enhances dNTP import, while binding of synthesized molecules like benzenehexacarboxylic acid (BHC) inhibits it. The enhancing effect on reverse transcription by IP6 and the consequences of interactions between CA and nucleotides were corroborated using atomic force microscopy, transmission electron microscopy, and virological assays. Collectively, our results provide an atomistic description of the permeability of the HIV-1 capsid to small molecules and reveal a novel mechanism for the involvement of metabolites in HIV-1 capsid stabilization, nucleotide import, and reverse transcription.

[The role of phytates in human nutrition].

Claims that consumption of phytate-rich grains, by definition, worsens mineral status needs to be clarified as new evidence emerges about the role of phytic acids (FA) from whole grains in improving population health outcomes. In this regard, it seems appropriate to draw the attention of practitioners to the need to correct patient's diet in order to prevent non-communicable diseases. The aim of this review was to generalize and analyze the modern data on the role of phytates in human nutrition. Material and methods. A search for domestic and foreign literature in the bibliographic databases of articles on medical sciences was carried out using the PubMed, MEDLINE and eLibrary search engines. Results. Deficit of minerals and trace elements in the diet, especially deficiency of iron, calcium, selenium, zinc, iodine, is an urgent public health problem in many countries. Calcium, magnesium, zinc, selenium, and iron deficiencies are associated with impaired immune function and an increased risk of both acute and chronic diseases. Vegan and vegetarian behavior styles with the restriction and exclusion of animal sources of bioavailable minerals and trace elements are gaining more and more popularity in our country. FA is the main storage form of phosphorus in nuts, grains, legumes, and seeds, which satisfies the biosynthesis needs of growing tissues during germination. FA is known as a dietary inhibitor that chelates minerals and trace elements, limiting their bioavailability and reducing their absorption. Pre-treatment methods to reduce phytate levels and increase the nutritional value of diets are fermentation, soaking, and sprouting. Reducing phytate content in plant foods by processing leads to a measurable improvement in mineral status, however, the chelating and antioxidant properties of phytates may be beneficial and their potential in the prevention of cancer, cardiovascular disease, diabetes mellitus and kidney stone formation is currently being studied. Conclusion. Essential components of a healthy diet are whole whole grains, legumes, vegetables, seeds and nuts, despite the fact that most of them are relatively high in FA. Despite some antinutrient properties, FAs have preventive effects on public health.

Revisiting phytate-element interactions: implications for iron, zinc and calcium bioavailability, with emphasis on legumes.

Myo-Inositol hexakisphosphate or phytic acid concentration is a prominent factor known to impede divalent element bioavailability in vegetal foods including legumes. Both in vivo and in vitro studies have suggested that phytic acid and other plant-based constituents may synergistically form insoluble complexes affecting bioavailability of essential elements. This review provides an overview of existing investigations on the role of phytic acid in the binding, solubility and bioavailability of iron, zinc and calcium with a focus on legumes. Given the presence of various interference factors within legume matrices, current findings suggest that the commonly adapted approach of using phytic acid-element molar ratios as a bioavailability predictor may only be valid in limited circumstances. In particular, differences between protein properties and molar concentrations of other interacting ions are likely responsible for the observed poor correlations. The role of phytate degradation in element bioavailability has been previously examined, and in this review we re-emphasize its importance as a tool to enhance mineral bioavailability of mineral fortified legume crops. Food processing strategies to achieve phytate reduction were identified as promising tools to increase mineral bioavailability and included germination and fermentation, particularly when other bioavailability promoters (e.g. NaCl) are simultaneously added.[Formula: see text].

Development of LC-MS-ESI-TOF method for quantification of phytates in food using 13C-labelled maize as internal standard.

In this work, the LC-MS-ESI-TOF method for simultaneous determination of phytates (inositol mono-, bis-, tris-, tetrakis-, pentakis-, and hexakisphosphates, abbreviated to IP1, IP2, IP3, IP4, IP5, and IP6, respectively) in food samples was developed and validated. The suitability of U-13C-labelled maize as a source for labelled internal standards for quantification of phytates was elucidated. The effectiveness of liberating IP1, IP2, IP3, IP4, and IP5 from phytic acid extracted form U-13C-labelled maize was evaluated for a variety of hydrolysis conditions, including enzymatic and acid hydrolysis. Enzymatic degradation of phytic acid using phytase (PHYZYME XP 5000 L) was very effective; phytic acid was degraded to lower phytates, but their distribution was unequal. Chemical hydrolysis was conducted under acidic conditions using hydrochloric acid and elevated temperatures up to 140 °C. The highest yields of IP4, IP5, and IP6 and of IP1, IP2, and IP3 were achieved by chemical hydrolysis at 105 °C for 7 h and 24 h, respectively. Thus, a combination of these two chemical treatments was selected for internal standard production. The developed LC-MS-ESI-TOF method was tested and successfully validated using plant-based food samples with different distribution of phytates. With this method, different forms of phytates in foods were separated and quantified simultaneously within 20 min. The high accuracy and precision of the developed method were guaranteed using respective labelled internal standards derived from U-13C-labelled maize.

Usability of microfluidized flaxseed as a functional additive in bread.

BACKGROUND: Flaxseed is a rich source of protein, omega-3 fatty acids, lignans, and dietary fiber. However, it also contains phytic acid, which inhibits mineral absorption and has the potential to adversely affect the properties of bread. Microfluidization prevents these negative effects, reduces the amount of phytic acid, and improves functional properties. In this study, the possibility of using full-fat and defatted flaxseed flours as well as microfluidized flaxseed flours in bread formulation was investigated. For this purpose, crude and microfluidized flaxseed flours were added to the bread in different proportions (0, 25, 50, and 75 g kg-1 ), and the effects of the partial replacement of wheat flour with flaxseed flours on the functional, quality, and sensory properties of breads were analyzed. The effects of the microfluidization process on the antioxidant properties, phenolic, dietary fiber, and phytic acid content of flaxseed were also observed. RESULT: Flaxseed flours increased the dietary fiber, phenolic contents, and antioxidant activities of breads. The crumb color became darker with increasing level of flaxseed flours, and their addition also detrimentally affected the sensory properties of breads. It was seen that the microfluidization process has beneficial effects on functional properties of full-fat and defatted flaxseed flours, as well as on their quality characteristics. CONCLUSION: The study showed that flaxseed flour is a rich source of functional compounds, and it is even possible to further improve these functional properties with microfluidization treatment. Microfluidized flaxseed flour can also be used as a promising alternative functional food to enrich breads. © 2021 Society of Chemical Industry.

Biofortification and bioavailability of Zn, Fe and Se in wheat: present status and future prospects.

KEY MESSAGE: Knowledge of genetic variation, genetics, physiology/molecular basis and breeding (including biotechnological approaches) for biofortification and bioavailability for Zn, Fe and Se will help in developing nutritionally improved wheat. Biofortification of wheat cultivars for micronutrients is a priority research area for wheat geneticists and breeders. It is known that during breeding of wheat cultivars for productivity and quality, a loss of grain micronutrient contents occurred, leading to decline in nutritional quality of wheat grain. Keeping this in view, major efforts have been made during the last two decades for achieving biofortification and bioavailability of wheat grain for micronutrients including Zn, Fe and Se. The studies conducted so far included evaluation of gene pools for contents of not only grain micronutrients as above, but also for phytic acid (PA) or phytate and phytase, so that, while breeding for the micronutrients, bioavailability is also improved. For this purpose, QTL interval mapping and GWAS were carried out to identify QTLs/genes and associated markers that were subsequently used for marker-assisted selection (MAS) during breeding for biofortification. Studies have also been conducted to understand the physiology and molecular basis of biofortification, which also allowed identification of genes for uptake, transport and storage of micronutrients. Transgenics using transgenes have also been produced. The breeding efforts led to the development of at least a dozen cultivars with improved contents of grain micronutrients, although land area occupied by these biofortified cultivars is still marginal. In this review, the available information on different aspects of biofortification and bioavailability of micronutrients including Zn, Fe and Se in wheat has been reviewed for the benefit of those, who plan to start work or already conducting research in this area.

Quantification of phytic acid in baby foods by derivatization with (trimethylsilyl)diazomethane and liquid chromatography-mass spectrometry analysis.

RATIONALE: Phytic acid (PA) is both a naturally occurring nutrient and a widely used food additive for conferring antioxidant properties to food. PA can be found in baby foods and it is essential to monitor PA content due to its anti-nutritional properties when present in excess. Current methods for determining PA content are unsatisfactory because interference from inositol phosphates and inorganic phosphates complicates PA quantification. METHODS: Baby foods were extracted using aqueous HCl, and the extractant was subjected to derivatization with (trimethylsilyl)diazomethane after de-metalation using a cation exchange resin. The PA derivative was quantified using liquid chromatography-mass spectrometry (LC/MS/MS) with a multi-response monitoring mode (m/z 829 to 451). RESULTS: The linearity of the developed analytical method ranged from 10 to 1000 ng/mL for PA with R2 > 0.999. Reasonable reproducibility was obtained with an intraday relative standard deviation (RSD; N = 5) of 4.5% and an interday RSD (N = 5) of 5.7% at a concentration of 10 ng/mL. The developed method was successfully applied to determine PA content in various baby foods, with PA recovery between 90.6% and 119.8%. CONCLUSIONS: A robust and sensitive method for the determination of PA in baby foods has been developed by methyl esterification with (trimethylsilyl)diazomethane and using LC/MS/MS analysis. The established method showed good anti-interference and precision, and it has been applied for the determination of PA in various baby foods.

Determination of phytic acid in wheat products by complete methyl esterification and liquid chromatography-mass spectrometry analysis.

Phytic acid, the principal storage form of phosphorus in wheat, plays both beneficial and antinutrient functions for human being, and its analytical method still needs further development. In this work, we have developed a new method for the determination of phytic acid in wheat products based on derivatization with (trimethylsilyl)diazomethane in combination with liquid chromatography-mass spectrometry analysis. Methyl esterification greatly decreased the polarity and the acidity of phytic acid, and thus the corresponding derivative can be easily analyzed by liquid chromatography-mass spectrometry under common conditions. Furthermore, treatment with cation exchange resin removed the polyvalent metal ions in the solutions, and thus derivatization of phytic acid can be achieved efficiently and completely. The standard curve for phytic acid has been well established in the linear range of 0.5-100 ng/mL with squared correlation coefficient more than 0.999 and the quantification limit of 0.25 ng/mL. The phytic acid content varies greatly in different wheat products, ranging from 153.5 to 17299.0 µg/g.

Fermentation performance and nutritional assessment of physically processed lentil and green pea flour.

BACKGROUND: Significant amounts of nutrients, including dietary fibers, proteins, minerals, and vitamins are present in legumes, but the presence of anti-nutritional factors (ANFs) like phytic acid, tannins, and enzyme inhibitors impact the consumption of legumes and nutrient availability. In this research, the effect of a physical process (sonication or precooking) and fermentation with Lactobacillus plantarum and Pediococcus acidilactici on the ANFs of some legumes was evaluated. RESULTS: Total phenolic content was significantly (P < 0.05) reduced for modified and fermented substrates compared with non-fermented controls. Trypsin inhibitory activity (TIA) was reduced significantly for all substrates except for unsonicated soybean and lentils fermented with L. plantarum and P. acidilactici. When physical processing was done, there was a decrease in TIA for all the substrate. Phytic acid content decreased for physically modified soybean and lentil but not significantly for green pea. Even though there was a decrease in ANFs, there was no significant change in in vitro protein digestibility for all substrates except for unsonicated L. plantarum fermented soybean flour and precooked L. plantarum fermented lentil. Similarly, there was a change in amino acid content when physically modified and fermented. CONCLUSION: Both modified and unmodified soybean flour, green pea flour, and lentil flour supported the growth of L. plantarum and P. acidilactici. The fermentation of this physically processed legume and pulse flours influenced the non-nutritive compounds, thereby potentially improving nutritional quality and usage. © 2021 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Detoxification of jatropha kernel meal to utilize it as aqua-feed.

BACKGROUND: Jatropha is an oilseed crop with high kernel oil (55-58%) and protein (26-29%) contents, which makes it a good source of biodiesel and animal/aqua-feed. However, the presence of anti-nutritional toxins, such as phorbol esters, lectins, trypsin inhibitor, phytate, and saponins, restricts its use as feed. This paper describes chemical, ultraviolet (UV) radiation, and biological treatments for detoxification of jatropha kernel meal. Raw, defatted, and one-time and two-times mechanically expressed oil samples were analyzed for toxins. Chemical treatment involved heating with 90% methanol and 4% sodium hydroxide. UV treatment was carried out at UV light intensity of 53.4 mW cm-2 for 30 min. For biological treatment, cell-free extract from Pseudomonas aeruginosa (strain PAO1) was mixed with kernel meal for detoxification. RESULTS: Among treatments, chemical treatment was most effective in reducing all toxins, with phorbol esters in the range 0.034-0.052 mg g-1 , lectin 0.082-10.766 mg g-1 , trypsin inhibitor 10.499-11.350 mg g-1 , phytate 2.475-5.769 mg g-1 , and saponins 0.044-0.098 mg g-1 . Biological treatment reduced all toxins except phytate, whereas UV treatment could not reduce any of toxins and, hence, cannot be used for aqua-feed preparation. Pellets prepared from chemically detoxified kernel meal with the least oil content (defatted) resulted in the highest strength (70.93 N). CONCLUSION: Chemically treated jatropha kernel meal can be used for aqua-feed pellet preparation because of its low toxin content. The highest compressive strength was obtained for pellets with the least oil content (defatted). Biological treatment time must have been extended for many hours instead of 24 h. Jatropha kernel meal treated chemically can be recommended for aqua-feed manufacturing. © 2021 Society of Chemical Industry.

Increasing CO2 threatens human nutrition.

Dietary deficiencies of zinc and iron are a substantial global public health problem. An estimated two billion people suffer these deficiencies, causing a loss of 63 million life-years annually. Most of these people depend on C3 grains and legumes as their primary dietary source of zinc and iron. Here we report that C3 grains and legumes have lower concentrations of zinc and iron when grown under field conditions at the elevated atmospheric CO2 concentration predicted for the middle of this century. C3 crops other than legumes also have lower concentrations of protein, whereas C4 crops seem to be less affected. Differences between cultivars of a single crop suggest that breeding for decreased sensitivity to atmospheric CO2 concentration could partly address these new challenges to global health.

Analytical Methods for Determination of Phytic Acid and Other Inositol Phosphates: A Review.

From the early precipitation-based techniques, introduced more than a century ago, to the latest development of enzymatic bio- and nano-sensor applications, the analysis of phytic acid and/or other inositol phosphates has never been a straightforward analytical task. Due to the biomedical importance, such as antinutritional, antioxidant and anticancer effects, several types of methodologies were investigated over the years to develop a reliable determination of these intriguing analytes in many types of biological samples; from various foodstuffs to living cell organisms. The main aim of the present work was to critically overview the development of the most relevant analytical principles, separation and detection methods that have been applied in order to overcome the difficulties with specific chemical properties of inositol phosphates, their interferences, absence of characteristic signal (e.g., absorbance), and strong binding interactions with (multivalent) metals and other biological molecules present in the sample matrix. A systematical and chronological review of the applied methodology and the detection system is given, ranging from the very beginnings of the classical gravimetric and titrimetric analysis, through the potentiometric titrations, chromatographic and electrophoretic separation techniques, to the use of spectroscopic methods and of the recently reported fluorescence and voltammetric bio- and nano-sensors.

Bioactive Compounds, Antioxidant Activity, and Antinutritional Content of Legumes: A Comparison between Four Phaseolus Species.

Beans (Phaseolus spp.) are one of the most important legumes for their nutritional value and health benefits in many world regions. In addition to Phaseolus vulgaris, there are four additional species that are cultivated in many regions of the world and are a source of food for human consumption: P. lunatus, P. coccineus, P. polyanthus, and P. acutifolius. In this work, phenolic compounds, antioxidant activity, and anti-nutritional compounds of 18 bean accessions, corresponding to four different species of the genus Phaseolus, were analyzed. In addition, their physical characteristics, proximate composition, and amino acid content were determined in order to compare their phytochemical composition and nutritional value. The species closest to each other in terms of essential amino acid content were P. polyanthus with P. vulgaris and P. lunatus with P. coccineus. Furthermore, there was a strong positive correlation between antioxidant activity and flavonoids, anthocyanins, and lectins with all the accessions collected. Significant differences in the content of phenolic compounds were found among the bean species studied. Therefore, in addition to P. vulgaris, other species such as P. coccineus and P. lunatus have high biological and antioxidant potential that could be beneficial to human health when consumed as nutraceutical foods.

Phytic acid content may affect starch digestibility and glycemic index value of rice (Oryza sativa L.).

BACKGROUND: Phytic acid (PA) is an anti-nutrient present in cereals and pulses. It is known to reduce mineral bioavailability and inhibit starch-digesting α-amylase (which requires calcium for activity) in the human gut. In principle, the greater the amount of PA, the lower is the rate of starch hydrolysis. It is reflected in the lower glycemic index (GI) value of food. People leading sedentary lifestyles and consuming rice as a staple food are likely to develop type 2 diabetes. Hence, this study was planned to understand how PA content of different rice varieties affects the GI. RESULTS: Rice Khira and Mugai which had very low PA (0.30 and 0.36 g kg-1 , respectively) had higher GI values and α-amylase activity, while Nua Dhusara and the pigmented rice Manipuri black rice (MBR) which had high PA (2.13 and 2.98 g kg-1 , respectively) showed low α-amylase activity and GI values. This relationship was statistically significant, though a weak relationship was found for the pigmented rice. Expression levels of MIPSI, IPKI and GBSSI markedly increased in the middle stage of grain development in all of the six genotypes having contrasting PA and GI. Maximum expression of MIPSI and IPKI was observed in Nua Dhusara and MBR (which had high PA) while that of GBSSI was observed in Khira and Mugai (with higher GI) at middle stage showing a negative correlation between PA and GI. CONCLUSIONS: The data indicate that high PA content in rice might have an adverse effect on starch digestibility resulting in slower starch digestion in the human gut and consequently low glycemic response. © 2019 Society of Chemical Industry.

Combining ability and heterosis for grain iron biofortification in bread wheat.

BACKGROUND: Iron is one of the nutrients that is essential for the human body. Despite the abundance of iron on earth, about two billion people worldwide are affected by iron deficiency. Iron biofortification of wheat, instead of supplementation and food fortification, provides a pragmatic approach to solve the problem of iron deficiency. In this study, 144 diverse wheat genotypes were evaluated for grain iron and yield potential, to estimate the potential for the iron biofortification of high-yielding wheat varieties. RESULTS: Genotypes did not differ significantly across the species, but within species the differences were significant for grain iron content and the phytate:iron molar ratio. Triticum aestivum (bread wheat) had the highest yield potential with more diversity than other Triticum species. Genotypes with high iron contents were crossed with high-yielding genotypes in line × tester fashion to check the gene action controlling these traits. The combining ability analysis showed non-additive gene action controlling grain iron, grain phytate, and grain yield. Heterosis manifestation also indicated some transgressive segregates with high specific combining ability effects. CONCLUSION: There was considerable genetic potential for improving the grain iron content in the germplasm to provide an economical and long-lasting solution to benefit an iron-deficient population. Triticum aestivum had the highest variation and potential for iron biofortification. This study indicated the possibility of simultaneous improvement in grain iron and grain yield by producing a new variety through continuous selective breeding. © 2019 Society of Chemical Industry.