Caseinophosphopeptides Overcome Calcium Phytate Inhibition on Zinc Bioavailability by Retaining Zinc from Coprecipitation as Zinc/Calcium Phytate Nanocomplexes.

Caseinophosphopeptides have shown great potential to increase zinc bioavailability from phytate-rich diets, but the mechanism of action remains unclear. Here, caseinophosphopeptides from a sodium caseinate hydrolysate dose-dependently retained zinc in solution against calcium phytate coprecipitation under physiologically relevant conditions. The 3 kDa ultrafiltration separation unveiled no added low-molecular-weight chelates of zinc and calcium by caseinophosphopeptides. Tyndall effect, dynamic light scattering measurements, transmission electron microscopy observation, electron diffraction pattern, X-ray diffraction spectrum, and energy-dispersive X-ray analysis demonstrated the caseinophosphopeptides-mediated formation of single-crystal zinc/calcium phytate nanocomplexes (Zn/CaPA-NCs) with a size and ζ-potential of 10-30 nm and -25 mV, respectively. Caseinophosphopeptides-stabilized Zn/CaPA-NCs were found to deliver bioavailable nanoparticulate zinc in mouse jejunal loop ex vivo model and polarized Caco-2 cells, and the treatments with specific inhibitors revealed that intestinal zinc absorption from Zn/CaPA-NCs invoked macropinocytosis, lysosomal release into the cytosol, and transcytosis. Overall, our study proposes a new paradigm for the benefit of caseinophosphopeptides for zinc bioaccessibility and bioavailability in phytate-rich diets.

Differences in the nutritional quality of improved finger millet genotypes in Ethiopia.

Improved crop genotypes are constantly introduced. However, information on their nutritional quality is generally limited. The present study reports the proximate composition and the concentration and relative bioavailability of minerals of improved finger millets of different genotypes. Grains of finger millet genotypes (n = 15) grown in research station during 2019 and 2020 in Ethiopia, and replicated three times in a randomized complete block design, were analysed for proximate composition, mineral concentration (iron, zinc, calcium, selenium), and antinutritional factors (phytate, tannin and oxalate). Moreover, the antinutritional factors to mineral molar ratio method was used to estimate mineral bioavailability. The result shows a significant genotypic variation in protein, fat and fibre level, ranging from 10% to 14.6%, 1.0 to 3.8%, and 1.4 to 4.6%, respectively. Similarly, different finger millets genotypes had significantly different mineral concentrations ranging from 3762 ± 332 to 5893 ± 353 mg kg-1 for Ca, 19.9 ± 1.6 to 26.2 ± 2.7 mg kg-1 for Zn, 36.3 ± 4.6 to 52.9 ± 9.1 mg kg-1 for Fe and 36.6 ± 11 to 60.9 ± 22 µg kg-1 for Se. Phytate (308-360 µg g-1), tannin (0.15-0.51 mg g-1) and oxalate (1.26-4.41 mg g-1) concentrations were also influenced by genotype. Antinutritional factors to minerals molar ratio were also significantly different by genotypes but were below the threshold for low mineral bioavailability. Genotype significantly influenced mineral and antinutritional concentrations of finger millet grains. In addition, all finger millet genotypes possess good mineral bioavailability. Especially, the high Ca concentration in finger millet, compared to in other cereals, could play a vital role to combating Ca deficiency. The result suggests the different finger millet genotypes possess good nutrient content and may contribute to the nutrition security of the local people.

Texture classification and in situ cation measurements by SEM-EDX provide detailed quantitative insights into cell wall cation interaction changes during ageing, soaking, and cooking of red kidney beans.

Hard-to-cook (HTC) is a textural defect that delays the softening of common bean seeds during cooking. While this defect is commonly associated with conventionally stored beans, soaking/cooking of beans in CaCl2 solutions or sodium acetate buffer can also prolong the cooking time of beans due to formation of Ca2+ crosslinked pectin retarding bean softening during cooking. In this study, the role of the cell wall-bound Mg2+/Ca2+ content and the degree of pectin methyl esterification (DM) was quantified, as important factors for bean texture-related changes stipulated in the pectin-cation-phytate hypothesis, the most plausible hypothesis of HTC development. Evaluation of texture changes during cooking of conventionally aged beans (35 °C and 83% RH for up to 20 weeks), beans soaked/cooked in CaCl2 solutions (0.01 to 0.1 M) or soaked in 0.1 M sodium acetate buffer (pH 4.4) revealed large bean-to-bean variations. Therefore a texture-based classification approach was used to better capture the relation between texture characteristics and cell wall polymer, in particular pectin, related changes. While cell wall-bound Ca2+ and pectin DM did not change/were not related to the texture variation during cooking of fresh beans, increased cell wall-bound Ca2+ and decreased pectin DM were associated with prolonged conventional storage of beans and their texture changes during subsequent cooking (due to pectin cross linking, retarding its solubilization during cooking). Exogenously added Ca2+ from pre-treating beans in CaCl2 solutions promoted to a great extent the cell wall-bound Ca2+ during soaking but even more so during cooking, complementing the harder texture associated with these beans during cooking (compared to conventionally stored and fresh beans). Similarly, free Ca2+ endogenously generated by phytase-catalysed phytate hydrolysis (beans treated by acetate buffer) promoted crosslinking of pectin by Ca2+ (cell wall-bound Ca2+), delaying softening of beans during cooking.

[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.

Assessment of Protein Nutritional Quality of Novel Hairless Canary Seed in Comparison to Wheat and Oat Using In Vitro Static Digestion Models.

Hairless canary seed (Phalaris canariensis L.) is a novel true cereal that is now approved for human consumption in Canada and the United States. This true cereal grain has higher protein content (22%) than oat (13%) and wheat (16%) and represents a valuable source of plant proteins. Assessment of canary seed protein quality is therefore essential to evaluate its digestibility and ability to provide sufficient amounts of essential amino acids for human requirements. In this study, the protein nutritional quality of four hairless canary seed varieties (two brown and two yellow) were evaluated in comparison to oat and wheat. The assessment of anti-nutrients contents (phytate, trypsin inhibitor activity, and polyphenols) showed that brown canary seed varieties had the highest content in phytate and oat the highest in polyphenols. Trypsin inhibitor level was comparable among studied cereals, but slightly higher in the brown canary seed Calvi variety. In regard to protein quality, canary seed had a well-balanced amino acid profile and was particularly high in tryptophan, an essential amino acid normally lacking in cereals. The in vitro protein digestibility of canary seeds as determined by both the pH-drop and INFOGEST (international network of excellence on the fate of food in the gastrointestinal tract) protocols appears slightly lower than wheat and higher than oat. The yellow canary seed varieties showed better overall digestibility than the brown ones. For all studied cereal flours, the limiting amino acid was lysine. The calculated in vitro PDCAAS (protein digestibility corrected amino acid score) and DIAAS (digestible indispensable amino acid score) were higher for the yellow C05041 cultivar than the brown Bastia, similar to those of wheat, but lower than those of oat proteins. This study demonstrates the feasibility and utility of in vitro human digestion models for the assessment of protein quality for comparison purpose.

Novel insights into the role of the pectin-cation-phytate mechanism in ageing induced cooking texture changes of Red haricot beans through a texture-based classification and in situ cell wall associated mineral quantification.

Utilization of common beans is greatly hampered by the hard-to-cook (HTC) defect induced by ageing of the beans under adverse storage. Large bean-to-bean variations exist in a single batch of beans. Therefore, a texture-based bean classification approach was applied in this detailed study on beans with known textures, to gain in-depth insights into the role of the pectin-cation-phytate mechanism in relation to the texture changes during subsequent cooking of Red haricot fresh and aged beans. For the first time, a correlation between the texture (exhibited after cooking) of a single bean seed before ageing (fresh) and its texture after ageing was established. Furthermore, scanning electron microscopy coupled with energy dispersive spectrometry (SEM-EDS) based in situ cell wall associated mineral quantification revealed that the cell wall associated Ca concentration was significantly positively correlated with the texture of both fresh and aged cooked Red haricot bean cotyledons, with ageing resulting in a significant enrichment of Ca at the cell wall. These additional Ca cations originate from intracellular phytate hydrolysis during ageing, which was shown to affect the texture distribution of aged beans during cooking significantly. The relocation of the mineral cations from the cell interior to the cell wall occurs mainly during storage rather than subsequent soaking of the cotyledons. In addition, the pectin-cation-phytate hypothesis of HTC was further confirmed by demethylesterification of the cell wall pectin and increased pectin-Ca interactions upon ageing of the cotyledons, finally leading to HTC development of the cotyledon tissue.

Phytate and mineral profile evolutions to explain the textural hardening of common beans (Phaseolus vulgaris L.) during postharvest storage and soaking: Insights obtained through a texture-based classification approach.

During adverse postharvest storage of Red haricot beans, the inositol phosphate content, particularly InsP6, decreased significantly, along with a significant increase in InsP5. Using a texture-based classification approach, the InsP6 content in cotyledons was shown an indicator for the extent of hard-to-cook (HTC) development during bean aging. This textural defect development was predominated by storage-induced InsP6 degradation, rather than phytate interconversions during soaking. Ca cations, released during storage, did not leach out significantly during subsequent soaking, suggesting that they were bound with the cell wall pectin in cotyledons, while Mg cations were mostly leached out into the soaking water due to their weak binding capacity to the pectin, and the cell membrane damages developed during HTC. Results obtained herein provide evidence for the pectin-cation-phytate mechanism in textural hardening (and its distribution after cooking) of common beans, and call for a more detailed Ca-relocation study during postharvest storage, soaking and cooking.

Evaluation of the effects of different chelation agents on root dentin roughness.

Successful root canal treatment requires effective irrigation of the entire root canal system. While chelating agents support irrigation, they can also alter physicochemical properties of the root dentin structure. The aim of this study is to evaluate the effect of different chelation agents on root dentin roughness. Twenty-five extracted maxillary incisors were used in this study. Samples were separated longitudinally and divided into five groups: distilled water, NaOCl, ethylenediaminetetraacetic acid (EDTA), phytic acid and citric acid (CA). Atomic force microscope and energy dispersive X-ray spectroscopy analyses were used for analysing. One-way analysis of variance and Turkey tests were used in the statistical analysis of the study. EDTA, CA and phytic acid solutions increased the roughness and phytic acid and CA solutions decreased the Ca/P ratio in dentin tissue. No statistical difference was observed in the other groups. The decrease of Ca/P ratio should be taken under consideration during irrigation. The increase in surface roughness may provide clinical benefit by supporting the adhesion of the root canal filling materials to the dentin surface.

Calcium transport and phytate hydrolysis during chemical hardening of common bean seeds.

In this study, two chemical bean seed hardening methods were used to investigate the changes in cooking behavior associated with Ca2+ transport and phytate hydrolysis to better understand their role in the pectin-cation-phytate hypothesis. The texture evolution of fresh and hardened red kidney beans was evaluated, hardening being induced by soaking or in a CaCl2 solution (0.01 M, 0.05 M, 0.1 M) or sodium acetate buffer (0.1 M, pH 4.4, 41 °C). The beans soaked in a CaCl2 solution at higher concentrations or in sodium acetate buffer for a longer time exhibited a delayed cooking behavior. This study also explored the bio-chemical changes (calcium content in different bean substructures, phytate content and the pectin degree of methylesterification (DM) in the cotyledons) occurring in the beans during chemical hardening and cooking. The Ca2+ concentrations in the whole beans and cotyledons of beans soaked and cooked in CaCl2 solutions significantly increased while inositol hexaphosphate IP6 content showed no significant changes. This indicates that the delayed texture drop in this case results from the influx of exogenous Ca2+ in the cotyledons and seed coats during cooking while the IP6 was not hydrolyzed and did not release endogenous Ca2+. For beans soaked in sodium acetate buffer, phytate profiling showed increased hydrolysis of IP6 with longer soaking time, suggesting the migration of endogenous Ca2+ released from phytate hydrolysis contributing to the delayed cooking of these beans. These results indicate that both an exogenous Ca2+ influx during soaking and cooking and an endogenous Ca2+ replacement resulting from phytate hydrolysis can play an important role in the hardening of beans. In neither of the cases, a significant change in pectin DM was observed during chemical hardening, therefore limiting the delayed cooking to the role of Ca2+ transport. The outcome of both cases is inline with the basic principles of the pectin-cation-phytate hypothesis whereby pectin DM changes are hardly involved and different mechanisms of release/transport are involved.

Structure of a cereal purple acid phytase provides new insights to phytate degradation in plants.

Grain phytate, a mixed metal ion salt of inositol hexakisphosphate, accounts for 60%-80% of stored phosphorus in plants and is a potent antinutrient of non-ruminant animals including humans. Through neofunctionalization of purple acid phytases (PAPhy), some cereals such as wheat and rye have acquired particularly high mature grain phytase activity. As PAPhy activity supplies phosphate, liberates metal ions necessary for seedling emergence, and obviates antinutrient effects of phytate, its manipulation and control are targeted crop traits. Here we show the X-ray crystal structure of the b2 isoform of wheat PAPhy induced during germination. This high-resolution crystal structure suggests a model for phytate recognition that, validated by molecular dynamics simulations, implicates elements of two sequence inserts (termed PAPhy motifs) relative to a canonical metallophosphoesterase (MPE) domain in forming phytate-specific substrate specificity pockets. These motifs are well conserved in PAPhys from monocot cereals, enzymes which are characterized by high specificity for phytate. Tested by mutagenesis, residues His229 in PAPhy motif 4 and Lys410 in the MPE domain, both conserved in PAPhys, are found to strongly influence phytase activity. These results explain the observed phytase activity of cereal PAPhys and open the way to the rational engineering of phytase activity in planta.

Hydrolyzing behaviors of endogenous proteases on proteins in sesame milk and application for producing low-phytate sesame protein hydrolysate.

Endogenous proteases with high activity have been identified in sesame seeds. However, the hydrolyzing behaviors of endogenous proteases on proteins in sesame milk are not well understood. In this study, the endogenous proteases optimally hydrolyzed proteins at pH 4.5 and 50 °C for 6 h. Tricine-sodium dodecyl sulphate-polyacrylamide gel electrophoresis and liquid chromatography tandem mass spectrometry analyses revealed that endogenous proteases randomly cleaved the cleavable peptide bonds on 11S globulins, and amino acid analysis indicated that serine carboxypeptidases preferentially cleaved tryptophan, phenylalanine, methionine, tyrosine, and leucine. The hydrolyzed sesame milk was separated into cream, transparent skim, and precipitate fractions by centrifugation (3000g, 5 min). The major protein components in skim were 42% peptides (<1500 Da) and 35% free amino acids. The phytate in skim was greatly reduced by adjusting to neutral and alkaline pH. This study is meaningful at supplying a strategy for producing low-phyate sesame protein hydrolysate.

Organic dry pea (Pisum sativum L.) biofortification for better human health.

A primary criticism of organic agriculture is its lower yield and nutritional quality compared to conventional systems. Nutritionally, dry pea (Pisum sativum L.) is a rich source of low digestible carbohydrates, protein, and micronutrients. This study aimed to evaluate dry pea cultivars and advanced breeding lines using on-farm field selections to inform the development of biofortified organic cultivars with increased yield and nutritional quality. A total of 44 dry pea entries were grown in two USDA-certified organic on-farm locations in South Carolina (SC), United States of America (USA) for two years. Seed yield and protein for dry pea ranged from 61 to 3833 kg ha-1 and 12.6 to 34.2 g/100 g, respectively, with low heritability estimates. Total prebiotic carbohydrate concentration ranged from 14.7 to 26.6 g/100 g. A 100-g serving of organic dry pea provides 73.5 to 133% of the recommended daily allowance (%RDA) of prebiotic carbohydrates. Heritability estimates for individual prebiotic carbohydrates ranged from 0.27 to 0.82. Organic dry peas are rich in minerals [iron (Fe): 1.9-26.2 mg/100 g; zinc (Zn): 1.1-7.5 mg/100 g] and have low to moderate concentrations of phytic acid (PA:18.8-516 mg/100 g). The significant cultivar, location, and year effects were evident for grain yield, thousand seed weight (1000-seed weight), and protein, but results for other nutritional traits varied with genotype, environment, and interactions. "AAC Carver," "Jetset," and "Mystique" were the best-adapted cultivars with high yield, and "CDC Striker," "Fiddle," and "Hampton" had the highest protein concentration. These cultivars are the best performing cultivars that should be incorporated into organic dry pea breeding programs to develop cultivars suitable for organic production. In conclusion, organic dry pea has potential as a winter cash crop in southern climates. Still, it will require selecting diverse genetic material and location sourcing to develop improved cultivars with a higher yield, disease resistance, and nutritional quality.

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.

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].

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.

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.

A single nucleotide substitution in the SPDT transporter gene reduced phytic acid and increased mineral bioavailability from Rice grain (Oryza sativa L.).

Phosphorus (P) flow in agricultural land depends on the P taken off from harvested product, its losses through runoff and fertilizer applied to balance the removed P. Phytic acid (PA), the major storage form of phosphorus (P) in cereal grains is a key anti-nutrient for human and non-ruminants leads to eutrophication of waterways. As the natural non-renewable P reserves are limited, enhancing P use efficiency is needed for field crops. SULTR-like phosphorus distribution transporter (SPDT) is a novel rice transporter transfer P to the grain. Any alteration in transporter gene reduce grain P with concomitant rise in the leaves. A low PA (3.0 g/kg) rice Khira was identified where a single nucleotide mutation in LOC_Os06g05160 gene encoding SPDT showed low P transportation to grain. An amino acid change was detected as Valine-330 to Alanine at the 3' end of fifth exon. Highest expression of SPDT was observed in node I of rice as compared to low PA genotype. The mutation in SPDT could significantly affect P and PA accumulation in the grains with increased mineral bioavailability. PRACTICAL APPLICATIONS: Excessive P application in crop leads to higher production cost as well as rapid depletion of limited rock phosphate. Alteration of P transporter function in the rice lower PA and total P accumulation in the grains with increased mineral bioavailability. The re-distributed P in the straw can be applied as manure to the rice field. Thus, less P will be removed from the field, result in the decreased requirement for P fertilizer.

Role of ß-glucan content, molecular weight and phytate in the bile acid binding of oat ß-glucan.

There is controversy about the role of viscosity and co-migrating molecules on the bile acid binding of beta-glucan. Thus, this study aimed to investigate the impact of ß-glucan molecular weight and the content of both ß-glucan and phytate on the mobility of bile acids by modelling intestinal conditions in vitro. Two approaches were used to evaluate factors underlying this binding effect. The first studied bile acid binding capacity of soluble ß-glucan using purified compounds. Viscosity of the ß-glucan solution governed mainly the mobility of bile acid since both a decrease in ß-glucan concentration and degradation of ß-glucan by enzyme hydrolysis resulted in decreased binding. The second approach investigated the trapping of bile acids in the oat bran matrix. Results suggested trapping of bile acids by the ß-glucan gel network. Additionally, hydrolysis of phytate was shown to increase bile acid binding, probably due to better extractability of ß-glucan in this sample.