Degradation of phytic acid in cereal porridges improves iron absorption by human subjects

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.

Effect of lipid-based nutrient supplements on micronutrient status and hemoglobin among children with stunting: secondary analysis of a randomized controlled trial in Uganda

BACKGROUND

Micronutrient deficiencies and anemia are widespread among children with stunting.

OBJECTIVES

We assessed the effects of lipid-based nutrient supplements (LNS) containing milk protein (MP) and/or whey permeate (WP) on micronutrient status and hemoglobin (Hb) among children with stunting.

METHODS

This was a secondary analysis of a randomized controlled trial. Children aged 12-59 mo with stunting were randomly assigned to LNS (100 g/d) with milk or soy protein and WP or maltodextrin for 12 wk, or no supplement. Hb, serum ferritin (S-FE), serum soluble transferrin receptor (S-TfR), plasma cobalamin (P-Cob), plasma methylmalonic acid (P-MMA), plasma folate (P-Fol), and serum retinol-binding protein (S-RBP) were measured at inclusion and at 12 wk. Data were analyzed using linear and logistic mixed-effects models.

RESULTS

Among 750 children, with mean age ± SD of 32 ± 11.7 mo, 45% (n = 338) were female and 98% (n = 736) completed follow-up. LNS, compared with no supplementation, resulted in 43% [95% confidence interval (CI): 28, 60] greater increase in S-FE corrected for inflammation (S-FEci), 2.4 (95% CI: 1.2, 3.5) mg/L greater decline in S-TfR, 138 (95% CI: 111, 164) pmol/L greater increase in P-Cob, 33% (95% CI: 27, 39) reduction in P-MMA, and 8.5 (95% CI: 6.6, 10.3) nmol/L greater increase in P-Fol. There was no effect of LNS on S-RBP. Lactation modified the effect of LNS on markers of cobalamin status, reflecting improved status among nonbreastfed and no effects among breastfed children. LNS increased Hb by 3.8 (95% CI: 1.7, 6.0) g/L and reduced the odds of anemia by 55% (odds ratio: 0.45, 95% CI: 0.29, 0.70). MP compared with soy protein increased S-FEci by 14% (95% CI: 3, 26).

CONCLUSIONS

LNS supplementation increases Hb and improves iron, cobalamin, and folate status, but not vitamin A status among children with stunting. LNS should be considered for children with stunting. This trial was registered at ISRCTN as 13093195.

Sorghum and health: An overview of potential protective health effects

Whole-grain sorghum foods may elicit health-promoting effects when consumed regularly in the diet. This review discusses key functional sorghum grain constituents, including dietary fiber, slowly digestible and resistant starches, lipids, and phytochemicals and their effects on metabolic processes that are associated with the development of chronic diseases, such as heart disease and diabetes. Currently, the range of sorghum food products available to consumers is limited globally, hindering the potential consumer benefits. A collaborative effort to innovate new product developments is therefore needed, with a focus on processing methods that help to retain the grain's favorable nutritive, health-enhancing, and sensory attributes. Evidence for sorghum's purported health effects, together with evidence of impacts of processing on different sorghum foods, are presented in this review to fully elucidate the potential of sorghum grain to confer health benefits to humans.

Approaches to Address the Anemia Challenge

Anemia is a multifactorial condition; approaches to address it must recognize that the causal factors represent an ecology consisting of internal (biology, genetics, and health) and external (social/behavioral/demographic and physical) environments. In this paper, we present an approach for selecting interventions, followed by a description of key issues related to the multiple available interventions for prevention and reduction of anemia. We address interventions for anemia using the following 2 main categories: 1) those that address nutrients alone, and, 2) those that address nonnutritional causes of anemia. The emphasis will be on interventions of public health relevance, but we also consider the clinical context. We also focus on interventions at different stages of the life course, with a particular focus on women of reproductive age and preschool-age children, and present evidence on various factors to consider when selecting an intervention-inflammation, genetic mutations, nutrient delivery, bioavailability, and safety. Each section on an intervention domain concludes with a brief discussion of key research areas.

Iron Nutrition of Pre-Schoolers in High-Income Countries: A Review

Pre-schoolers are vulnerable to iron deficiency, which, in high-resource countries, is mainly caused by suboptimal or poorly absorbable iron intakes. This review examines the prevalence of inadequate iron intakes and status, and the non-dietary factors associated with these, among children aged between 2 and 5 years within high-income countries. It then considers the quality of the pre-schooler diet in terms of dietary factors, dietary patterns, and iron intakes. Additionally, it discusses the assessment of iron bioavailability and examines the various methods used to estimate the amount of absorbable iron in pre-schooler diets. Knowledge of the adequacy of iron intakes and bioavailability of iron intakes, and dietary patterns associated with iron intakes can facilitate the design and implementation of effectively targeted community-based intervention studies to improve iron intakes and iron bioavailability to minimise the risk of iron deficiency.

Iron Deficiency and Iron Deficiency Anemia: Potential Risk Factors in Bone Loss

Iron is one of the essential mineral elements for the human body and this nutrient deficiency is a worldwide public health problem. Iron is essential in oxygen transport, participates in many enzyme systems in the body, and is an important trace element in maintaining basic cellular life activities. Iron also plays an important role in collagen synthesis and vitamin D metabolism. Therefore, decrease in intracellular iron can lead to disturbance in the activity and function of osteoblasts and osteoclasts, resulting in imbalance in bone homeostasis and ultimately bone loss. Indeed, iron deficiency, with or without anemia, leads to osteopenia or osteoporosis, which has been revealed by numerous clinical observations and animal studies. This review presents current knowledge on iron metabolism under iron deficiency states and the diagnosis and prevention of iron deficiency and iron deficiency anemia (IDA). With emphasis, studies related to iron deficiency and bone loss are discussed, and the potential mechanisms of iron deficiency leading to bone loss are analyzed. Finally, several measures to promote complete recovery and prevention of iron deficiency are listed to improve quality of life, including bone health.

Can consumption of local micronutrient- and absorption enhancer-rich plant foods together with starchy staples improve bioavailable iron and zinc in diets of at-risk African populations?

Iron and zinc deficiencies remain prevalent in developing countries, often due to monotonous starchy diets that are low in bioavailable minerals. This review addresses the question as to whether consumption of starchy staple foods in Africa together with micronutrient-dense and absorption enhancer-rich plant foods can enhance iron and zinc bioavailability in the diets of at-risk populations. While green leafy vegetables (GLVs) fortification of starchy staples can improve mineral contents, especially iron, it may not improve bioavailable iron and zinc, due to GLVs' high contents of mineral absorption inhibitors, notably polyphenols, phytate and calcium. Fruits, although low in minerals, could improve bioavailable iron and zinc in the staples because of their high ascorbic and citric acid and/or β-carotene contents, which can form soluble chelates with the minerals. More human studies are needed to establish whether such a technology or fortification strategy can improve bioavailable iron and zinc in African-type plant-based diets.

Iron requirements of broiler chickens as affected by supplemental phytase

Iron is routinely supplemented in broiler feeds intending to prevent dietary deficiencies. The present research was conducted with the objective of assessing Fe requirements of broilers when fed supplemental phytase. A total of 1,280 1-d-old male Cobb × Cobb 500 were distributed in a 2 × 5 factorial arrangement (phytase-supplemented feeds × 5 graded increases of supplemental Fe) in 80 battery cages, eight replications of eight chicks each. The trial was replicated once. Chicks were fed a Fe-deficient diet without phytase (Fe analyzed at 31.30 ± 3.79 mg/kg) from placement to 7 d and then randomly distributed into battery cages with corresponding dieting treatments with or without phytase and graded increases of supplemental Fe. Feeds were formulated with corn and soybean meal (SBM), laboratory-grade calcium carbonate, and phosphoric acid; therefore, the vast majority of dietary Fe originated from corn and SBM (analyzed diet had 53.3 ± 1.41 mg/kg Fe). Phytase was added in excess to the producer recommendation of 1,000 FYT (4,452 ± 487 FYT/kg analyzed) such that phytate degradation was expected to be maximized. Supplemental Fe was from laboratory-grade ferrous sulfate heptahydrate (FeSO47H2O) which was increasingly added to the feeds (analyzed Fe in the supplemented feeds were: 53.3 ± 1.41, 65.5 ± 0.59, 77.2 ± 1.97, 87.6 ± 1.72, 97.7 ± 1.33 mg/kg). There were no interactions between phytase and dietary Fe for any response throughout the study (P > 0.05). Supplementing phytase had no effects on Fe intake or Fe excretion, as well as on hematocrit (Ht), hemoglobin (Hb), ferritin, Fe contents in the liver or thigh muscle color (P > 0.05). However, phytase-supplemented feeds produced better live performance as well as higher ileal digestible energy and Fe digestibility (P < 0.05). No effects were found for dietary Fe in live performance at day 28 (P > 0.05). On the other hand, increasing dietary Fe led to linear increases in Fe retention and excretion, Fe contents in livers, as well as Ht and Hb at 14 d (P < 0.05). Quadratic responses (P < 0.05) were observed for Hb at 21 d, serum ferritin on days 14, 21, and 28 (maximum responses were 83.3, 104.0, 91.9, and 88.3 mg/kg Fe, respectively). In conclusion, supplementing Fe adding to a total of 97.7 mg/kg dietary Fe did not affect live performance traits. However, the average of Fe-related blood parameters was maximized at 91.9 mg/kg dietary Fe. Supplementing phytase provided a significant increase in Fe digestibility.

Lower Non-Heme Iron Absorption in Healthy Females from Single Meals with Texturized Fava Bean Protein Compared to Beef and Cod Protein Meals: Two Single-Blinded Randomized Trials

Meat analogs based on plant protein extracts are rising in popularity as meat consumption declines. A dietary shift away from meat, which has a high iron bioavailability, may have a negative effect on the amount of iron absorbed from the diet. Iron absorption from legumes cultivated in regions not suitable for soy production, such as fava bean, has not yet been explored. The aim of this study was to evaluate non-heme iron absorption from a meal with texturized fava bean protein compared to beef and cod protein meals. The study included two single-blinded iron isotope trials in healthy Swedish women of the ages 18–45 years, each of whom served as their own control. The participants were served matched test meals containing beef and fava bean protein (Study 1) or cod and fava bean protein (Study 2) with radiolabeled non-heme iron 55Fe and 59Fe. The absorption of non-heme iron from test meals was measured by whole-body counting and erythrocyte incorporation. The absorption of non-heme iron, measured as erythrocyte incorporation ratio, from beef protein meal was 4.2 times higher compared to texturized fava bean meal, and absorption from cod protein meal was 2.7 times higher compared to the fava bean meal. The adjusted non-heme iron absorption, normalized to a 40% reference dose uptake, was 9.2% for cod protein meal, 21.7% for beef protein meal, and 4.2% for texturized fava bean meal. A fava bean protein meal has markedly lower iron bioavailability in healthy females compared with a meal of beef or cod protein. Therefore, a dietary shift from meat and fish protein to fava bean protein may increase the risk of iron deficiency.

Estimation of Iron Availability in Modified Cereal β-Glucan Extracts by an in vitro Digestion Model

For cereal-based foods rich in dietary fibers, iron bioavailability is known to be poor. For native cereal β-glucan extracts, literature has demonstrated that the main factor impacting the bioavailability is phytic acid, which is often found in association with dietary fibers. During food processing, β-glucan can undergo modifications which could potentially affect the equilibrium between phytic acid, fiber, and iron. In this study, an in vitro digestion was used to elucidate the iron dialysability, and hence estimate iron availability, in the presence of native, chelating resin (Chelex)-treated, oxidised, or partially hydrolysed oat and barley β-glucan extracts (at 1% actual β-glucan concentration), with or without phytase treatment. It was confirmed that pure, phytic acid-free β-glucan polysaccharide does not impede iron availability in cereal foods, while phytic acid, and to a smaller extent, also proteins, associated to β-glucan can do so. Neither Chelex-treatment nor partial hydrolysis, 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO) or NaIO₄ oxidation significantly influenced the phytic acid content of the β-glucan extracts (ranging 2.0–3.9%; p > 0.05). Consequently, as long as intrinsic phytic acid was still present, the β-glucan extracts blocked the iron availability regardless of source (oat, barley) or Chelex-treatment, partial hydrolysis or NaIO₄-oxidation down to 0–8% (relative to the reference without β-glucan extract). Remarkably, TEMPO-oxidation released around 50% of the sequestered iron despite unchanged phytic acid levels in the modified extract. We propose an iron-mobilising effect of the TEMPO product β-polyglucuronan from insoluble Fe(II)/phytate/protein aggregates to soluble Fe(II)/bile salt units that can cross the dialysis membrane. In addition, Chelex-treatment was identified as prerequisite for phytase to dramatically diminish iron retention of the extract for virtually full availability, with implications for optimal iron bioavailability in cereal foods.

Nutritional and antioxidant changes in lentils and quinoa through fungal solid-state fermentation with Pleurotus ostreatus

Solid-state fermentation (SSF) may be a suitable bioprocess to produce protein-vegetal ingredients with increased nutritional and functional value. This study assessed changes in phenol content, antinutrient content, biomass production and protein production resulting from the metabolic activity of Pleurotus ostreatus, an edible fungus, in lentils and quinoa over 14 days of SSF. The impact of particle size on these parameters was also assessed because the process was conducted in both seeds and flours. Fungus biomass increased during fermentation, reaching 30.0 ± 1.4 mg/g dry basis and 32 ± 3 mg/g dry basis in lentil grain and flour and 52.01 ± 1.08 mg/g dry basis and 45 ± 2 mg/g dry basis in quinoa seeds and flour after 14 days of SSF. Total protein content also increased by 20% to 25% during fermentation, in all cases except lentil flour. However, the soluble protein fraction remained constant. Regarding phytic acid, SSF had a positive impact, with a progressive decrease being higher in flours than in seeds. Regarding antioxidant properties, autoclaving of the substrates promoted the release of polyphenols, together with antioxidant activity (ABTS, DPPH and FRAP), in all substrates. However, these parameters drastically decreased as fermentation progressed. These results provide scientific knowledge for producing lentil- or quinoa-based ingredients with low antinutrient content enriched with protein fungal biomass.

Achieving nutritional security in India through iron and zinc biofortification in pearl millet (Pennisetum glaucum (L.) R. Br.)

The health problems caused by iron (Fe) and zinc (Zn) deficiency plague developing and underdeveloped countries. A vegetarian person mainly depends on cereal based diet with low quantity of Fe and Zn. Biofortification is an economical and sustainable approach to challenge the micronutrient malnutrition problem globally. Pearl millet (Pennisetum glaucum (L.) R. Br.) is one of the nutri-cereals and mostly grown under hot, dry conditions on infertile soils of low water-holding capacity, where other crops generally fail. It contains anti-nutrient compounds like phytic acid and polyphenols which reduce the mineral bioavailability because of their chelating properties. Biofortification of pearl millet is like a double-edged sword which cuts down the economic burden and simultaneously supplies required nutrition to the poor, offering a great scope for food security as well as nutritional security. With this background, this review focus on biofortification of grain Fe and Zn content in pearl millet. Genetic research on Fe and Zn uptake and accumulation in pearl millet grain is crucial in identifying the 'bottlenecks' in biofortification. The review also reveals the need and strategies for increasing bioavailability of Fe and Zn in humans by increasing promoters and decreasing anti-nutritional factors in pearl millet.

Exploration of the relationship between anemia and iron and zinc deficiencies in children under 5 years of age living in the malaria endemic area of South Kivu/Democratic Republic of Congo

The aim of this study was to explore the relationship of iron and zinc deficiencies and anemia in children aged under 5 years living in malaria endemic area of South Kivu/DRC. We conducted a cross-sectional study in the health zone of Miti Murhesa in South Kivu/DRC. A total of 1088 children in good general health were included in this study. Almost 40% of children were anemic. The prevalence of iron deficiency (ID) was found in 34.9% and 49.1% children based on ferritin or free erythrocyte protoporphyrin (FEP), respectively. If anemia is present, we found iron deficiency anemia (IDA) according to the WHO-criteria (ferritin) in 31%, and according to FEP in 66% of children. The overall prevalence of zinc deficiency was 17.6%. If anemia is present, zinc deficiency was found in 24.4% of children. Inflammation/infection, based upon CRP, was present in 39.7% children. The independent factors associated with anemia were recent illness, middle upper arm circumference, weight-for-height, ID according to FEP, zinc deficiency, and submicroscopic Plasmodium infection. A high prevalence of ID was observed in children in South Kivu according to FEP. Ferritin as acute phase protein was less suited in this population due to a high frequency of infection/inflammation. Iron and zinc deficiencies were found to be significantly associated with anemia in this population.

Oxidative stability of tocochromanols, carotenoids, and fatty acids in maize (Zea mays L.) porridges with varying phytate concentrations during cooking and in vitro digestion

Phytic acid, the main storage form of phosphate in maize (Zea mays L.) grains, is known as antinutrient due to its chelating properties but may also prevent oxidation. Thus, the impact of phytic acid on the degradation of tocochromanols, carotenoids, fatty acids, and oxidation products in maize during cooking and subsequent in vitro digestion was examined. Maize porridges from low phytic acid maize flour with or without admixed phytate, or from high phytic acid maize flour were prepared, and digestion experiments conducted. HPLC-(MS) or GC-MS analyses revealed a significant decrease in tocochromanols, carotenoids, and unsaturated fatty acids in the digesta compared to the maize porridges while α-tocopherylquinone and malondialdehyde concentrations increased. The addition of phytic acid did not affect the digestive stabilities of total tocochromanols and carotenoids, but increased micellarisation efficiencies of carotenoids. In conclusion, phytate did not exert antioxidant effects in maize porridge during cooking or simulated digestion.

Iron Bioavailability from Infant Cereals Containing Whole Grains and Pulses: A Stable Isotope Study in Malawian Children

BACKGROUND

Compared with infant cereals based on refined grains, an infant cereal containing whole grains (WGs) and pulses with adequate amounts of ascorbic acid to protect against absorption inhibitors could be a healthier source of well-absorbed iron. However, iron absorption from such cereals is uncertain.

OBJECTIVE

We measured iron bioavailability from ferrous fumarate (Fefum) added to commercial infant cereals containing 1) refined wheat flour (reference meal), 2) WG wheat and lentil flour (WG-wheat-lentil), 3) WG wheat and chickpea flour (WG-wheat-chickpeas), and 4) WG oat flour (WG-oat) and from ferrous bisglycinate (FeBG) added to the same oat-based cereal (WG-oat-FeBG).

METHODS

In a prospective, single-blinded randomized crossover study, 6- to 14-mo-old Malawian children (n = 30) consumed 25-g servings of all 5 test meals containing 2.25 mg stable isotope-labeled iron and 13.5 mg ascorbic acid. Fractional iron absorption (FIA) was assessed by erythrocyte incorporation of isotopes after 14 d. Comparisons were made using linear mixed models.

RESULTS

Seventy percent of the children were anemic and 67% were iron deficient. Geometric mean FIA percentages (-SD, +SD) from the cereals were as follows: 1) refined wheat, 12.1 (4.8, 30.6); 2) WG-wheat-lentil, 15.8 (6.6, 37.6); 3) WG-wheat-chickpeas, 12.8 (5.5, 29.8); and 4) WG-oat, 9.2 (3.9, 21.5) and 7.4 (2.9, 18.9) from WG-oat-FeBG. Meal predicted FIA (P ≤ 0.001), whereas in pairwise comparisons, only WG-oat-FeBG was significantly different compared with the refined wheat meal (P = 0.02). In addition, FIAs from WG-wheat-lentil and WG-wheat-chickpeas were significantly higher than from WG-oat (P = 0.002 and P = 0.04, respectively) and WG-oat-FeBG (P < 0.001 and P = 0.004, respectively).

CONCLUSION

In Malawian children, when given with ascorbic acid at a molar ratio of 2:1, iron bioavailability from Fefum-fortified infant cereals containing WG wheat and pulses is ≈13-15%, whereas that from FeBG- and Fefum-fortified infant cereals based on WG oats is ≈7-9%.

Phytic Acid and Whole Grains for Health Controversy

Phytate (PA) serves as a phosphate storage molecule in cereals and other plant foods. In food and in the human body, PA has a high affinity to chelate Zn²⁺ and Fe²⁺, Mg²⁺, Ca²⁺, K⁺, Mn²⁺ and Cu²⁺. As a consequence, minerals chelated in PA are not bio-available, which is a concern for public health in conditions of poor food availability and low mineral intakes, ultimately leading to an impaired micronutrient status, growth, development and increased mortality. For low-income countries this has resulted in communications on how to reduce the content of PA in food, by appropriate at home food processing. However, claims that a reduction in PA in food by processing per definition leads to a measurable improvement in mineral status and that the consumption of grains rich in PA impairs mineral status requires nuance. Frequently observed decreases of PA and increases in soluble minerals in in vitro food digestion (increased bio-accessibility) are used to promote food benefits. However, these do not necessarily translate into an increased bioavailability and mineral status in vivo. In vitro essays have limitations, such as the absence of blood flow, hormonal responses, neural regulation, gut epithelium associated factors and the presence of microbiota, which mutually influence the in vivo effects and should be considered. In Western countries, increased consumption of whole grain foods is associated with improved health outcomes, which does not justify advice to refrain from grain-based foods because they contain PA. The present commentary aims to clarify these seemingly controversial aspects.

Small Intestinal Phosphate Absorption: Novel Therapeutic Implications

BACKGROUND

Chronic kidney disease (CKD) affects approximately 15% of adults in the USA. As CKD progresses, urinary phosphate excretion decreases and results in phosphate retention and, eventually, hyperphosphatemia. As hyperphosphatemia is associated with numerous adverse outcomes, including increased cardiovascular mortality, reduction in phosphorus concentrations is a guideline-recommended, established clinical practice. Dietary phosphate restriction, dialysis, and phosphate binders are currently the only options for phosphate management. However, many patients with hyperphosphatemia have phosphorus concentrations >5.5 mg/dL, despite treatment.

SUMMARY

This review pre-sents recent advances in the understanding of intestinal phosphate absorption and therapeutic implications. Dietary phosphate is absorbed in the intestine through two distinct pathways, paracellular absorption and transcellular transport. Recent evidence indicates that the paracellular route accounts for 65-80% of total phosphate absorbed. Thus, the paracellular pathway is the dominant mechanism of phosphate absorption. Tenapanor is a first-in-class, non-phosphate binder that inhibits the sodium-hydrogen exchanger 3 or solute carrier family 9 member 3 (SLC9A3) encoded by the SLC9A3 gene, and blocks paracellular phosphate absorption. Key Messages: Targeted inhibition of sodium-hydrogen exchanger 3 effectively reduces paracellular permeability of phosphate. Novel therapies that target the paracellular pathway may improve phosphate control in chronic kidney disease.

How postharvest variables in the pulse value chain affect nutrient digestibility and bioaccessibility

Pulses are increasingly being put forward as part of healthy diets because they are rich in protein, (slowly digestible) starch, dietary fiber, minerals, and vitamins. In pulses, nutrients are bioencapsulated by a cell wall, which mostly survives cooking followed by mechanical disintegration (e.g., mastication). In this review, we describe how different steps in the postharvest pulse value chain affect starch and protein digestion and the mineral bioaccessibility of pulses by influencing both their nutritional composition and structural integrity. Processing conditions that influence structural characteristics, and thus potentially the starch and protein digestive properties of (fresh and hard-to-cook [HTC]) pulses, have been reported in literature and are summarized in this review. The effect of thermal treatment on the pulse microstructure seems highly dependent on pulse type-specific cell wall properties and postharvest storage, which requires further investigation. In contrast to starch and protein digestion, the bioaccessibility of minerals is not dependent on the integrity of the pulse (cellular) tissue, but is affected by the presence of mineral antinutrients (chelators). Although pulses have a high overall mineral content, the presence of mineral antinutrients makes them rather poorly accessible for absorption. The negative effect of HTC on mineral bioaccessibility cannot be counteracted by thermal processing. This review also summarizes lessons learned on the use of pulses for the preparation of foods, from the traditional use of raw-milled pulse flours, to purified pulse ingredients (e.g., protein), to more innovative pulse ingredients in which cellular arrangement and bioencapsulation of macronutrients are (partially) preserved.

Source-Sink Manipulation Affects Accumulation of Zinc and Other Nutrient Elements in Wheat Grains

To better understand the source–sink flow and its relationships with zinc (Zn) and other nutrients in wheat (Triticum aestivum L.) plants for biofortification and improving grain nutritional quality, the effects of reducing the photoassimilate source (through the flag leaf removal and spike shading) or sink (through the removal of all spikelets from one side of the spike, i.e., 50% spikelets removal) in the field of the accumulation of Zn and other nutrients in grains of two wheat cultivars (Jimai 22 and Jimai 44) were investigated at two soil Zn application levels. The kernel number per spike (KNPS), single panicle weight (SPW), thousand kernel weight (TKW), total grain weight (TGW) sampled, concentrations and yields of various nutrient elements including Zn, iron (Fe), manganese (Mn), copper (Cu), nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg), phytate phosphorus (phytate-P), phytic acid (PA) and phytohormones (ABA: abscisic acid, and the ethylene precursor ACC: 1-aminocylopropane-1-carboxylic acid), and carbon/N ratios were determined. Soil Zn application significantly increased the concentrations of grain Zn, N and K. Cultivars showing higher grain yields had lower grain protein and micronutrient nutritional quality. SPW, KNPS, TKW (with the exception of TKW in the removal of half of the spikelets), TGW, and nutrient yields in wheat grains were most severely reduced by half spikelet removal, secondly by spike shading, and slightly by flag leaf removal. Grain concentrations of Zn, N and Mg consistently showed negative correlations with SPW, KNPS and TGW, but positive correlations with TKW. There were general positive correlations among grain concentrations of Zn, Fe, Mn, Cu, N and Mg, and the bioavailability of Zn and Fe (estimated by molar ratios of PA/Zn, PA/Fe, PA × Ca/Zn, or PA × Ca/Fe). Although Zn and Fe concentrations were increased and Ca was decreased in treatments of half spikelet removal and spike shading, the treatments simultaneously increased PA and limited the increase in bioavailability of Zn and Fe. In general, different nutrient elements interact with each other and are affected to different degrees by source–sink manipulation. Elevated endogenous ABA levels and ABA/ACC ratios were associated with increased TKW and grain-filling of Zn, Mn, Ca and Mg, and inhibited K in wheat grains. However, the effects of ACC were diametrically opposite. These results provide a basis for wheat grain biofortification to alleviate human malnutrition.

Phytase Mediated Beneficial Impact on Nutritional Quality of Biofortified Wheat Genotypes

Background:

Biofortification has been proposed as an intervention towards alleviation of micronutrient deficiency in the population of developing countries. However, the presence of anti- nutritional factor phytic acid in staple cereals chelates divalent cations and decreases their bioavailability for monogastric animals. Thus, the use of phytase enzyme for hydrolysing phytate-P and enhancing the amount of free divalent cations is of great importance.

Methods :

In this study, two phytases i.e. APF1 phytase from fungal source and commercial wheat phytase were supplemented with flours of biofortified wheat genotypes and their impact on food quality parameters was accessed. Since commercial wheat phytase is costly, it was used as known phytase to compare the application of APF1 phytase. The phytic acid content was reduced in the range of 70 to 84% with APF1 phytase and 79 to 89% with the wheat phytase as compared to untreated samples, respectively. In contrast to phytate, the dialyzability of important micronutrients Fe and Zn enhanced in the range of 21.9 to 48% and 39.5 to 96% with APF1 phytase and, 6.10 to 30% and 23.2 to 81% with wheat phytase, over untreated samples, respectively.

Results and Discussion:

A decrease in tannin content was observed in the range of 8 to 23% and 7 to 23% after treatment with APF1 and wheat phytase, respectively. The phytase treatment has resulted in increased soluble protein content and inorganic phosphate content to different level over untreated samples.

Conclusion:

The study revealed that APF1 phytase was comparatively more effective for enhanced nutritional quality of wheat flour through phytase supplementation for its food based applications.

The Role of Oat Nutrients in the Immune System: A Narrative Review

Optimal nutrition is the foundation for the development and maintenance of a healthy immune system. An optimal supply of nutrients is required for biosynthesis of immune factors and immune cell proliferation. Nutrient deficiency/inadequacy and hidden hunger, which manifests as depleted nutrients reserves, increase the risk of infectious diseases and aggravate disease severity. Therefore, an adequate and balanced diet containing an abundant diversity of foods, nutrients, and non-nutrient chemicals is paramount for an optimal immune defense against infectious diseases, including cold/flu and non-communicable diseases. Some nutrients and foods play a larger role than others in the support of the immune system. Oats are a nutritious whole grain and contain several immunomodulating nutrients. In this narrative review, we discuss the contribution of oat nutrients, including dietary fiber (β-glucans), copper, iron, selenium, and zinc, polyphenolics (ferulic acid and avenanthramides), and proteins (glutamine) in optimizing the innate and adaptive immune system's response to infections directly by modulating the innate and adaptive immunity and indirectly by eliciting changes in the gut microbiota and related metabolites.

Iron Fortification Practices and Implications for Iron Addition to Salt

This introductory article provides an in-depth technical background for iron fortification, and thus introduces a series of articles in this supplement designed to present the current evidence on the fortification of salt with both iodine and iron, that is, double-fortified salt (DFS). This article reviews our current knowledge of the causes and consequences of iron deficiency and anemia and then, with the aim of assisting the comparison between DFS and other common iron-fortified staple foods, discusses the factors influencing the efficacy of iron-fortified foods. This includes the dietary and physiological factors influencing iron absorption; the choice of an iron compound and the fortification technology that will ensure the necessary iron absorption with no sensory changes; encapsulation of iron fortification compounds to prevent unacceptable sensory changes; the addition of iron absorption enhancers; the estimation of the iron fortification level for each vehicle based on iron requirements and consumption patterns; and the iron status biomarkers that are needed to demonstrate improved iron status in populations regularly consuming the iron-fortified food. The supplement is designed to provide a summary of evidence to date that can help advise policy makers considering DFS as an intervention to address the difficult public health issue of iron deficiency anemia, while at the same time using DFS to target iodine deficiency.

Dietary patterns of Australian pre-schoolers and associations with haem and non-haem iron intakes

PURPOSE

To describe Australian pre-schooler dietary patterns and examine their associations with dietary iron intakes.

METHODS

Dietary data of children (n = 812, 2 to < 6 years old) from the 2011-12 National Nutrition and Physical Activity Survey were collected via two non-consecutive 24-h recalls and analysed using AUSNUT 2011-13. Usual food and nutrient intakes were estimated via Multiple Source Method. Principal component analysis was used to extract dietary patterns from 32 food groups. Associations between dietary patterns and energy-adjusted iron intakes were assessed using linear regression, accounting for the complex survey design.

RESULTS

Mean (SD) usual total dietary and haem iron intakes were 6.3 (1.9) and 0.5 (0.3) mg/day, respectively. Three dietary patterns were identified, explaining 14% of the variance. Pattern 1 (positive loadings for cheese, breads, fats and oils, and water) was positively associated with total dietary iron intakes (β = 0.08, 95% CI 0.01, 0.15). Pattern 3 (positive loadings for red meat, fortified fruit and vegetable products, and sauces and spreads) was negatively associated with total dietary iron (β = - 0.08, 95% CI - 0.14, - 0.01) and non-haem iron (β = - 0.09, 95% CI - 0.15, - 0.02) intakes. No dietary patterns were associated with haem iron intakes.

CONCLUSIONS

Three main patterns characterise Australian pre-schooler diets. The pattern with which dietary iron is positively associated is predominately characterised by non-haem iron sources and non-iron-fortified foods. Future research is required to estimate the iron bioavailability of Australian pre-schooler diets.

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

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.

Microbial consortium increases maize productivity and reduces grain phosphorus concentration under field conditions

BACKGROUND

The use of microbes that improve plant phosphorus (P) use efficiency is an avenue to boost crop yields while alleviating environmental impacts. We tested three microbial inoculants (Rhizoglomus irregulare alone - designated AMF; Pseudomonas putida alone - designated PSB; and R. irregulare and P. putida in consortium - designated AMF+PSB), combined with chemical fertilizers, in an intensive maize agricultural system.

RESULTS

As hypothesized: (i) despite the native soil microbial community and the application of P fertilizer, the microbial inoculants enhanced plant P uptake from the soil by 14-60%, and consequently improved P acquisition efficiency; (ii) PSB and AMF+PSB plants produced ±50% more biomass per unit of P taken up, and consequently enhanced plant internal P use efficiency (i.e. the biomass produced per unit of P); and (iii) the combined inoculation of AMF and PSB provided the best results in terms of productivity and P use efficiency. Further, the microbial inoculants altered P allocation within the plant, reducing grain P concentration.

CONCLUSION

By testing the microbial inoculants under field conditions, our study clearly shows that the microbial consortium (AMF+PSB) increased maize productivity, and at the same time improved P use efficiency. Further, the use of these microbial inoculants was shown to be compatible with conventional agricultural management practices.

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.

Salivary cystatin SN is a factor predicting iron bioavailability after phytic acid rich meals in female participants

Phytic acid is an inhibitor of iron bioavailability, but it has been suggested that individuals may adapt to phytic acid over time, and that the salivary protein, cystatin SN, may be involved. This study evaluated the relationship between human cystatin SN levels and iron bioavailability after a phytic acid rich meal. Three groups of ten women consumed meals with: (1) 500 mg phytate sprinkles, (2) 500 mg phytate capsules, or (3) no phytic acid. Iron bioavailability was measured by the mealtime percentage of maximum iron recovery; cystatin SN was measured pre-and post-meal by enzyme-linked immunosorbent assay. Pre-to-post meal cystatin SN was positively correlated with improved iron bioavailability in group 1. Pre-to-post meal cystatin SN was correlated with improved iron absorption in groups 1 and 2. Cystatin SN recovery after phytic acid rich meals may be a physiological factor predicting iron bioavailability.

Addition of Whole Wheat Flour During Injera Fermentation Degrades Phytic Acid and Triples Iron Absorption from Fortified Tef in Young Women

BACKGROUND

Iron deficiency is a major public health concern in Ethiopia, where the traditional diet is based on tef injera. Iron absorption from injera is low due to its high phytic acid (PA) content.

OBJECTIVES

We investigated ways to increase iron absorption from FeSO4-fortified tef injera in normal-weight healthy women (aged 21-29 y).

METHODS

Study A (n = 22) investigated the influence on fractional iron absorption (FIA) from FeSO4-fortified injera of 1) replacing 10% tef flour with whole wheat flour (a source of wheat phytase), or 2) adding an isolated phytase from Aspergillus niger. Study B (n = 18) investigated the influence on FIA of replacing FeSO4 in tef injera with different amounts of NaFeEDTA. In both studies, the iron fortificants were labeled with stable isotopes and FIA was calculated from erythrocyte incorporation of stable iron isotopes 14 d after administration.

RESULTS

In study A, the median (IQR) FIA from the 100% tef injera meal was 1.5% (0.7-2.8%). This increased significantly (P < 0.05) to 5.3% (2.4-7.1%) on addition of 10% whole wheat flour, and to 3.6% (1.6-6.2%) on addition of A. niger phytase. PA content of the 3 meals was 0.62, 0.20, and 0.02 g/meal, respectively. In study B, the median (IQR) FIA from the 100% tef injera meal was 3.3% (1.1-4.4%) and did not change significantly (P > 0.05) on replacing 50% or 75% of FeSO4 with NaFeEDTA.

CONCLUSIONS

FIA from tef injera by young women was very low. NaFeEDTA was ineffective at increasing iron absorption, presumably due to the relatively low EDTA:Fe molar ratios. Phytate degradation, however, greatly increased during tef fermentation on addition of native or isolated phytases. Replacing 10% tef with whole wheat flour during injera fermentation tripled FIA in young women and should be considered as a potential strategy to improve iron status in Ethiopia.

Nutritional, Microbial, and Sensory Evaluation of Complementary Foods Made from Blends of Orange-Fleshed Sweet Potato and Edible Insects

Improved formulations of complementary foods (CFs) with animal-source foods (ASFs) is an important strategy to improve infant and young child feeding (IYCF). However, ASFs are expensive in many food-insecure settings where edible insects abound. CFs were developed from flours of orange-fleshed sweet potato (OFSP) and cricket (OFSCri) or palm weevil larvae (OFSPal) or soybean (OFSSoy) in the ratio 7:3. Nutritional and microbial quality of the novel CFs were determined and compared with Weanimix (recommended maize-peanut-soybean blend). Sensory evaluation of porridges was rated on a five-point hedonic scale among 170 Ghanaian mothers. OFSCri (20.33 ± 0.58 g/100 g) and Weanimix (16.08 ± 0.13 g/100 g) met the protein requirement of 15 g/100 g from CFs. Although Fe content was significantly higher for OFSCri (1.17 ± 0.03 mg/100 g), none of the CFs met the recommended levels for Fe. All the CFs were free from Salmonella, and aerobic plate count was significantly below permissible levels. All the CFs were ranked above the minimum threshold (hedonic scale = 3; neither like nor dislike) of likeness for the sensory attributes. Crickets and palm weevil larvae can be blended with OFSP and could be sustainable, culturally appropriate alternative ASFs for IYCF, but long-term studies are needed to evaluate their efficacy.

Zinc in Wheat Grain, Processing, and Food

Improving zinc (Zn) content in wheat and its processed foods is an effective way to solve human Zn deficiency, which can cause a variety of diseases. This article summarizes the works on Zn in wheat grain, wheat processing, and wheat-derived foods. Grain Zn content in wheat was 31.84 mg·kg-1 globally but varied across continents, for example, 25.10 mg·kg-1 in Europe, 29.00 mg·kg-1 in Africa, 33.63 mg·kg-1 in Asia, and 33.91 mg·kg-1 in North America. Grain Zn content in wheat improved from 28.96 to 36.61 mg·kg-1 and that in flour increased from 10.51 to 14.82 mg·kg-1 after Zn fortification. Furthermore, Zn content varied in the different processed components of wheat; that is, Zn content was 12.58 mg·kg-1 in flour, 70.49 mg·kg-1 in shorts, and 86.45 mg·kg-1 in bran. Zinc content was also different in wheat-derived foods, such as 13.65 mg·kg-1 in baked food, 10.65 mg·kg-1 in fried food, and 8.03 mg·kg-1 in cooking food. Therefore, the suitable Zn fortification, appropriate processing, and food type of wheat are important to meet people's Zn requirement through wheat.

Genetic Manipulation for Improved Nutritional Quality in Rice

Food with higher nutritional value is always desired for human health. Rice is the prime staple food in more than thirty developing countries, providing at least 20% of dietary protein, 3% of dietary fat and other essential nutrients. Several factors influence the nutrient content of rice which includes agricultural practices, post-harvest processing, cultivar type as well as manipulations followed by selection through breeding and genetic means. In addition to mutation breeding, genetic engineering approach also contributed significantly for the generation of nutrition added varieties of rice in the last decade or so. In the present review, we summarize the research update on improving the nutritional characteristics of rice by using genetic engineering and mutation breeding approach. We also compare the conventional breeding techniques of rice with modern molecular breeding techniques toward the generation of nutritionally improved rice variety as compared to other cereals in areas of micronutrients and availability of essential nutrients such as folate and iron. In addition to biofortification, our focus will be on the efforts to generate low phytate in seeds, increase in essential fatty acids or addition of vitamins (as in golden rice) all leading to the achievements in rice nutrition science. The superiority of biotechnology over conventional breeding being already established, it is essential to ascertain that there are no serious negative agronomic consequences for consumers with any difference in grain size or color or texture, when a nutritionally improved variety of rice is generated through genetic engineering technology.

Food Pattern Modeling as an Alternative Assessment Method to Multiday Dietary Recalls for Iron-Related Nutrients: A Proof-of-Concept Study

There are barriers to in-depth memory-based dietary assessment techniques in community-based research. Food pattern modeling may be an alternative method to traditional assessment techniques. The objective of this study was to pilot a comparison of food pattern modeling to 24 h diet recalls for predicting hematological outcomes of iron status. Data from 3-24 h dietary recalls in 27 women were analyzed by two methods: mean dietary intake estimates or food pattern modeling. Food pattern modeling was used to determine the total inventory of foods consumed with iron, phytate, or ascorbic acid or iron-phytate ratios. Each variable was analyzed for its relationship to hemoglobin, ferritin, and acute iron absorption from a meal challenge study by creating receiver operating characteristic (ROC) curves. There were no differences in ROC curves or diagnostic accuracies between food pattern modeling or mean dietary intake estimates for iron, vitamin C, phytate, or phytate-iron ratios for estimating hemoglobin or ferritin values (p > 0.05). Food pattern modeling was inferior to mean dietary estimates for acute iron absorption, suggesting that more detailed methods may be necessary for studies with sensitive or acute dietary measurement outcomes. Food pattern modeling for total iron, vitamin C, phytate, and phytate-iron ratios may be comparable to detailed memory-based recalls for larger studies assessing the impact of foods on iron status.

Cataloging of Cd Allocation in Late Rice Cultivars Grown in Polluted Gleysol: Implications for Selection of Cultivars with Minimal Risk to Human Health

Cadmium (Cd) is a toxic trace metal that has polluted 20% of agricultural land in China where its concentration exceeds the standards for Chinese farmland. Plants are capable of accumulating Cd and other trace metals, but this capacity varies with species and cultivars within a species. Rice is a staple food consumed by half of the global population. In order to select safe late rice cultivars that are suitable late rice cultivars that can be cultivated in for growing in slightly contaminated soil, a two-year field experiment was conducted with 27 in the first year and 9 late rice cultivars in the second year. The results showed that plant Cd concentrations varied among the cultivars, with high magnitudes of variation occurred in straw and grains. Five genotypes including LR-12, LR-17, LR-24, LR-25 and LR-26 were identified as low accumulators for the first year while LR-15 and LR-17 were identified as promising cultivars based on Cd concentration in the polished rice grains (<0.02 mg kg⁻¹ DW). In addition, these cultivars had favorable traits, including mineral nutrition and grain yield. Therefore, these genotypes should be considered for cultivation in slightly or moderately Cd contaminated soils.

Potential contribution of cereal and milk based fermented foods to dietary nutrient intake of 1-5 years old children in Central province in Zambia

Zambia is still facing undernutrition and micronutrient deficiencies despite fortification and supplementation programmes stressing the need for additional solutions. Fermented foods have the potential to improve nutrient intake and, therefore, could have an important role in food based recommendations (FBRs) to ensure adequate intake of nutrients for optimal health of populations. Secondary dietary intake data was used in Optifood, a linear programming software to develop FBRs, for children aged 1-3 and 4-5 years in Mkushi district of Zambia. Three scenarios per age group were modeled to determine FBRs based on: (1) FBRs based on local available foods (2) FBR and Mabisi, a fermented milk beverage, and (3) FBR with Munkoyo, a cereal fermented beverage. The scenarios were compared to assess whether addition of Mabisi or Munkoyo achieved a better nutrient intake. FBRs based on only locally available non-fermented foods did not meet ≥70% of recommended nutrient intake (RNI) for calcium, fat, iron and zinc, so-called problem nutrients. The addition of Munkoyo to the FBRs did not reduce the number of problem nutrients, but after adding Mabisi to the FBR's only iron (67% of RNI) in the 1-3 year age group and only zinc (67% of RNI) in the 4-5 year age group remained problem nutrients. Mabisi, a fermented milk product in combination with the local food pattern is a good additional source of nutrients for these age groups. However, additional nutrition sensitive and cost-effective measures would still be needed to improve nutrient intake, especially that of iron and zinc.

Foliage application of selenium and silicon nanoparticles alleviates Cd and Pb toxicity in rice (Oryza sativa L.)

Direct discharge of untreated industrial waste water in water bodies and then irrigation from these sources has increased trace metals contamination in paddy fields of southern China. Among trace metals, cadmium (Cd) and lead (Pb) are classified as most harmful contaminants in farmland to many organisms including plants, animals and humans. Rice is a staple food which is consumed by half population of the world; due to longer growth period it can easily absorb and accumulate the trace metals from soil. The objective of study was to check the efficacy of Se and Si NPs (nanoparticles) alone or in combination on metals accumulation and Se-fortified rice (Oryzasativa L.) production as their efficiency remained untested. Alone as well as combined application of Se- and Si-NPs (5, 10 and 20 mg L^-1) was achieved along with CK. All the treatments significantly reduced the Cd and Pb contents in brown rice, except CK, Se3, Si1 and Se1Si3. Combined application of Se and Si (Se3Si2) was more effective in reducing the Cd and Pb contents by 62 and 52%, respectively. In addition, foliar application of both NPs improved the rice growth and quality by increasing the grain yield, rice biomass, and Se contents in brown rice. Highest concentration of Se (1.35 mg kg^-1) in brown rice was observed with combined application of Se- and Si-Nps (Se3Si2). Selenium speciation revealed the presence of organic species (74%) in brown rice. The combinations of different doses of Se- and Si-Nps are the main determining factor for total concentration of metals in grains. These results demonstrate that foliage supplementation of Se and Si-Nps alleviate the Cd and Pb toxicity by reducing the metals' concentration in brown rice. Additionally foliage supplementation improved the nutritional quality by reducing the phytic acid contents in rice grains.

Ageing, dehulling and cooking of Bambara groundnuts: consequences for mineral retention and in vitro bioaccessibility

Postharvest storage of legumes is a strategy to ensure food security. However, the hard-to-cook phenomenon, partly explained by pectin-cation-phytate theory, may develop during storage. Based on this theory, minerals could be redistributed within the matrix, affecting the concentration of free/bound minerals and hence their bioaccessibility. Therefore, this study investigated the influence of storage-induced ageing and subsequent dehulling, soaking and cooking treatments on the concentration and in vitro bioaccessibility of Ca, Mg, Fe and Zn in Bambara groundnuts. ICP-OES was performed to determine Ca, Mg, Fe and Zn concentrations after applying different treatments and after simulated digestion in the context of bioaccessibility determination. This study illustrates that while the seed coat is rich in Ca (51%), it contains only less than 15% of Mg, Fe or Zn. Hence, dehulling negatively influenced Ca, but not Mg, Fe or Zn concentration. During soaking, up to 10% or 56% of the initial Mg concentration leaches into whole or dehulled seeds, respectively. Prolonging the cooking time (300 min) of whole aged Bambara groundnuts (32 weeks), necessary for obtaining palatable textures, decreased the overall Mg, Fe and Zn concentrations by 72%, 57% and 48%, respectively. Storage-induced ageing significantly decreased Ca solubility and bioaccessibility. Bioaccessibility of trace minerals in Bambara groundnuts is low, especially for Fe, and cannot be improved by dehulling or cooking treatments. Ageing did not influence Fe and Zn bioaccessibility. Populations relying on both fresh and aged Bambara groundnuts may still be at risk for mineral deficiencies.

Prevention of dental caries by grape seed extract supplementation: A systematic review

BACKGROUND

Dental caries are the most prominent chronic disease of children and adults worldwide, and facilitating evidence-based, preventative care for their prevention is critical. Caries are traditionally and successfully prevented by regular fluoride use, but there are opportunities to halt and restore caries with alternative agents in addition to fluoride use. Grape seed extract (GSE) is a readily available plant-based supplement that, due to its concentrated levels of proanthocyanidins, has promising characteristics that may assist in dental caries prevention.

AIM

The goal of this review was to investigate whether current research supports use of grape seed extract to prevent dental caries formation.

METHODS

A systematic review of articles related to grape seed extract, prevention of dental caries, inhibition of Streptococcus mutans, and remineralization was conducted. Articles were first chosen by inclusion of dental models that used grape seed extract as an intervention, and then by strength of study design.

RESULTS

Twenty articles were reviewed. Studies overall supported three unique grape seed extract properties facilitating dental caries prevention. In the first articles reviewed, grape seed extract inhibited proliferation of bacterial biofilms on tooth surfaces. In addition, studies reviewed indicated that grape seed extract promoted dental remineralization.

CONCLUSIONS

Caries prevention by grape seed extract may be unique compared with fluoride, and is linked to grape seed extract's bacteriostatic and collagen crosslinking properties. Future research should investigate potential delivery methods, and benefits of combined grape seed extract use with known caries preventative agents, in human participants.

Vitamin D fortification of foods in India: present and past scenario

India is a densely populated country known for its traditional, cultural and lingual diversity. In India Deficiency of vitamin D is seen in both the genders and among all the age groups. Micronutrient deficiencies are steadily adding to the increasing burden of health related co-morbidities with low dietary calcium and magnesium intake in Indian population. Despite lots of sunshine, vitamin D insufficiency is widespread in India according to the age and regions (50-90%). In order to increase vitamin D intake with normal diet, the food industry will have to find a more effective strategy to improve general health conditions. The breadth of widely used foods, including milk, cheese, margarine, dairy products, and various breakfast drinks, can improve the condition of vitamin D deficiency in Asian countries such as India. The requirements for calculating the necessary micronutrients and vitamin D fortification of foods and drinks, successful strategies should be developed and emphasized. There is need to improve the effectiveness of various fruit drinks through fortification of vitamin D, which can reduce vitamin D deficiency in the general population as well as in different age groups.

Role of Dietary Flavonoids in Iron Homeostasis

Balancing systemic iron levels within narrow limits is critical for human health, as both iron deficiency and overload lead to serious disorders. There are no known physiologically controlled pathways to eliminate iron from the body and therefore iron homeostasis is maintained by modifying dietary iron absorption. Several dietary factors, such as flavonoids, are known to greatly affect iron absorption. Recent evidence suggests that flavonoids can affect iron status by regulating expression and activity of proteins involved the systemic regulation of iron metabolism and iron absorption. We provide an overview of the links between different dietary flavonoids and iron homeostasis together with the mechanism of flavonoids effect on iron metabolism. In addition, we also discuss the clinical relevance of state-of-the-art knowledge regarding therapeutic potential that flavonoids may have for conditions that are low in iron such as anaemia or iron overload diseases.

Salivary Cystatin SN Binds to Phytic Acid In Vitro and Is a Predictor of Nonheme Iron Bioavailability with Phytic Acid Supplementation in a Proof of Concept Pilot Study

BACKGROUND

Acute phytic acid intake has been found to decrease iron bioavailability; however, repeated phytic acid consumption leads to iron absorption adaptation. Salivary proline-rich proteins (PRPs) have been shown to inhibit iron chelation to tannins and may mediate similar iron absorption adaptation with phytic acid intake.

OBJECTIVES

The objectives of this study were to determine whether salivary proteins bind to phytic acid in vitro, and to explore a proof of concept in a pilot study that examined the impact of 4-wk, daily phytic acid supplementation on individuals' iron status, bioavailability, and salivary PRP concentrations.

METHODS

High-performance liquid chromatography (HPLC) and matrix-assisted laser desorption/ionization-time of flight were used to characterize in vitro salivary protein-phytic acid interactions. Nonanemic women (n = 7) consumed 350 mg phytic acid supplements 3 times daily for 4 wk, and meal challenges were employed to determine iron bioavailability, iron status, and salivary protein concentrations before and after supplementation periods. Enzyme-linked immunosorbent assay (ELISA) analysis of purified protein fractions and participant saliva identified proteins bound to phytic acid.

RESULTS

In vitro salivary protein-phytic acid interaction identified cystatin SN, a non-proline rich salivary protein, as the specific bound protein to phytic acid. Iron bioavailability (P = 0.32), hemoglobin (P = 0.72), and serum ferritin (P = 0.08) concentrations were not reduced from week 0 to week 4 after phytic acid supplementation. Basic PRPs and cystatin SN concentrations were positively correlated with iron bioavailability at week 4.

CONCLUSIONS

Overall, results suggest that phytic acid binds to the non-PRP cystatin SN and that salivary protein production may improve iron bioavailability with phytic acid consumption.

Bioavailability of Selected Micronutrients in Teff-based Complementary Infant Foods

Background:

The problem of micronutrient malnutrition is affecting millions of infants in the developing countries. One of the major issues that aggravates the problem is lack of appropriately processed complementary foods in which the bioavailability of the major micronutrients is improved.

Methods:

Teff, soybean and orange-fleshed sweet potato were separately processed into their respective flours and blended in a ratio of 70:20:10, respectively, to prepare household- and industrial-level complementary foods. The ingredients and developed complementary foods were analysed for their vitamin A, calcium, iron, zinc and phytate contents. Moreover, phytate: mineral molar ratios of calcium, iron and zinc in the complementary foods were calculated to determine their bioavailability.

Results:

The vitamin A values obtained in the complementary foods were appreciable; they were in the range of 91.89 to 160.97 µgRE/100 g. Phytate content of teff and soybean was significantly (p ≤ 0.05) reduced by the household practices employed for processing them. However, the reduction was not significant (p > 0.05) in the household-level complementary foods because of the small quantity of germinated teff flours used. Calcium, iron and zinc compositions of all complementary foods closely met the recommended levels for 6 to 8 month-old infants. Phytate: mineral molar ratios for calcium and zinc in all complementary foods were below maximum recommended limits indicating their good bioavailability. In case of iron, these ratios were above the critical limit except that of the industriallevel complementary foods.

Conclusion:

Generally, complementary foods with improved compositions and bioavailability of the micronutrients analysed were developed from the teff-soybean-orange-fleshed sweet potato formulations.