Variations in Phytic Acid Content and Their Relationship with Protein Content and Kernel Morphological Characters of Chinese Winter Wheat Cultivars

[Objective] The aim of this study was to determine the variation of phytic acid content （PAC） and its frequency distribution, as well as the relationship between PAC and protein content, kernel characteristics in 161 Chinese winter wheat cultivars from four regions. [Method] One hundred and sixty-one winter wheat varieties from China Wheat Zones I, II, III and IV （Table 1） were grown in a randomized block de- sign, in the 2009-2011 cropping season; and then the indexes for describing the grain morphological characteristics such as the thousand kernel weight （TKW）, kernel length （KL）, kernel width （KW） and kernel thickness （KT） were measured; the phytic acid content （PAC）, protein content and sedimentation value were also determined; finally, the relationship between PAC and protein content, kernel characteristics were analyzed. [Result] The PAC in the cultivars tested ranged from 0.92% to 1.95% with a mean value of 1.41%. Protein content ranged from 12.60% to 19.20%, with a mean of 15.24%. Most （53.4%） of the wheat genotypes had a PAC value in the range of 1.25% to 1.55%. No significant correlation was found between PAC and protein content, sedimentation value, while protein content and SDS sedimentation value was significant correlated, which suggested the possibility of breeding wheat cultivars that have a low PAC but a high protein content and good gluten quality. There was a high correlation between TKW and KW （,.=0.79）, KL （r=0.50） and KT （r=0.64）. PAC was found having no significant correlation with TKW, KW, KL and KT. [Conclusion] The result suggests the possibility of breeding wheat cultivars that have a low PAC but high kernel weight.

pH Influence on Performance of Phytic Acid Conversion Coatings on AZ31 Magnesium Alloy in Simulated Body Fluid

Phytic acid （PA） conversion coating on AZ31 magnesium alloy is prepared by a deposition method. pH influences on the formation process, microstructure and properties of the conversion coating are investigated. Electrochemical tests including polarization curve and electrochemical impedance spectroscopy are used to examine the corrosion resistance, and scanning electron microscopy is used to observe the microstructure. The chemical nature of conversion coating is investigated by energy dispersive spectroscopy. And thermodynamic method is used to analyze the optimum pH. The results show that PA conversion coating can improve the corrosion resistance of AZ31 Mg alloy. The maximum efficiency achieves 89.19% when the AZ31 Mg alloy is treated by PA solution with pH=5. It makes the corrosion potential of sample shift positively about 156 mV and corrosion current density is nearly an order of magnitude less than that of the untreated sample. The thermodynamic analysis shows that the corrosion resistance of PA coatings is affected by not only the concentration of PA ion and Mg2＋ but also the release rate of hydrogen.

Phytic Acid Contents of Wheat Flours from Different Mill Streams

The phytic acid contents of eight fractions of wheat flours from different mill streams and those in wheat brans, which were separated by different sieves into various sizes, were determined and analyzed. A rapid method for phytic acid assay by adding thioglycolic acid （mercapto acetic acid） with 2,2-bipyridine was used, with an acidic iron-Ⅲ-solution of known iron content. The amount ofphytate was indicated by the decrease in iron in the supernatant. Significant differences were observed in phytic acid content among different milling streams and different cultivars （P〈0.05）. On an average, coarse bran had the highest phytic acid content （53.85 mg g^-1）, and the shorts had 28.48 mg g^-1. The B5 break flour had a higher phytic acid content （4.8 mg g^-1） than the B7 （2.75 mg g^-1） and B8 （2.03 mg g^-1） reduction flours. Lower values were found in the B3, B6 and B7 flours （1.07, 0.79, and 0.76 mg g^-1, respectively）. The phytic acid contents of bran decreased with smaller bran sizes, ranging from 54 to 5.09 mg g^-1.

Enhanced corrosion resistance of phytic acid coated magnesium by stearic acid treatment

A green chemical conversion coating for magnesium was obtained with a phytic acid solution. The microstructure and corrosion properties of phytic acid conversion coated magnesium were further improved by soaking in stearic acid solution. The phytic acid conversion coated magnesium after soaking in the stearic acid showed no micro-cracks and the surface became very smooth. The corrosion behavior of the uncoated and coated magnesium samples was studied by electrochemical methods. The corrosion resistance of the stearic acid treated sample was much higher than that of phytic acid conversion coated magnesium or uncoated magnesium. The electrochemical results indicated that the stearic acid treated coating provided effective corrosion protection to the magnesium sample.

RNAi-Mediated Silencing of ITPK Gene Reduces Phytic Acid Content,Alters Transcripts of Phytic Acid Biosynthetic Genes,and Modulates Mineral Distribution in Rice Seeds

Phytic acid is the principal storage form of phosphorus in plant seeds and an essential signalling molecule in several regulatory processes of plant development.However,it is known as an anti-nutrient compound owing to its potent chelating property.Thus,reducing the phytic acid content in crops is desirable.Studies involving regulation of MIPS and IPK1 genes to generate low phytate rice have been reported earlier.However,the functional significance of OsITPK and the effect of its down-regulation on phytic acid content and the associated pleiotropic effects on rice have not yet been investigated.In this study,tissue specific RNA interference(RNAi)-mediated down-regulation of a major ITPK homolog(OsITP5/6K-1)resulted in 46.2%decrease in phytic acid content of T2 transgenic seeds with a subsequent 3-fold enhancement in the inorganic phosphorus content.Silencing of OsITP5/6K-1 altered the transcript levels of essential phytic acid pathway genes,without significantly affecting the transcript levels of other OsITPK homologs.Furthermore,the mapping of elements through X-ray microfluorescence analysis revealed significant changes in the spatial distribution pattern and translocation of elements in low phytate seeds.Additionally,low phytate polished seeds exhibited 1.3-fold and 1.6-fold enhancement in iron and zinc content in the grain endosperm,respectively.Silencing of OsITP5/6K-1 also altered the amino acid and myo-inositol content of the transgenic seeds.Our results successfully established that RNAi-mediated silencing of OsITP5/6K-1 gene significantly reduced the phytate levels in seeds without hampering the germination potential of seeds and plant growth.The present study provided an insight into the mechanism of phytic acid biosynthesis pathway.

Identification of Quantitative Trait Loci for Phytic Acid Concentration in Maize Grain Under Two Nitrogen Conditions

Phytic acid （PA） is the main storage form of phosphorus （P） in seeds. It can form insoluble complexes with microelements, thereby reducing their bioavailability for animals. Identification of quantitative trait loci （QTLs） associated with grain PA concentration （PAC） is essential to improve this trait without affecting other aspects of grain nutrition such as protein content. Using a recombinant inbred line （RIL） population, we mapped QTL for grain PAC, as well as grain nitrogen concentration （NC） and P concentration （PC） in maize under two N conditions in 2 yr. We detected six QTLs for PAC. The QTL for PAC on chromosome 4 （phi072-umc 1276） was identified under both low-N and high-N treatments, and explained 13.2 and 15.4% of the phenotypic variance, respectively. We identified three QTLs for grain NC, none of which were in the same region as the QTLs for PAC. We identified two QTLs for PC in the low-N treatment, one of which （umc1710-umc2197） was in the same interval as the QTL for PAC under high-N conditions. These results suggested that grain PAC can be improved without affecting grain NC and inorganic PC.

Gastric digestion of pea ferritin and modulation of its iron bioavailability by ascorbic and phytic acids in caco-2 cells

AIM： To understand the digestive stability and mechanism of release and intestinal uptake of pea ferritin iron in caco-2 cell line model.METHODS： Pea seed ferritin was purified using salt fractionation followed by gel filtration chromatography.The bioavailability of ferritin iron was assessed using coupled in vitro digestion/Caco-2 cell model in the presence or absence of ascorbic acid and phytic acid.Caco-2 cell ferritin formation was used as a surrogate marker of iron uptake. Structural changes of pea ferritin under simulated gastric pH were characterized using electrophoresis, gel filtration and circular dichroism spectroscopy.RESULTS： The caco-2 cell ferritin formation was significantly increased （P 〈 0.001） with FeSO4 （19.3±9.8 ng/mg protein） and pea ferritin （13.9 ± 6.19 ng/mg protein） compared to the blank digest （3.7 ± 1.8 ng/mg protein）. Ascorbic acid enhanced while phytic acid decreased the pea ferritin iron bioavailability. However,either in the presence or absence of ascorbic acid, the ferritin content of caco-2 cells was significantly less with pea ferritin than with FeSO4. At gastric pH, no band corresponding to ferritin was observed in the presence of pepsin either on native PAGE or SDS-PAGE. Gel filtration chromatography and circular dichroism spectroscopy revealed a pH dependent loss of quaternary and secondary structure.CONCLUSION： Under gastric conditions, the iron core of pea ferritin is released into the digestive medium due to acid induced structural alterations and dissociation of protein. The released iron interacts with dietary factors leading to modulation of pea ferritin iron bioavailability,resembling the typical characteristics of non-heme iron.

Comparison of Properties between Phytic Acid and RE-phytic Conversion Coatings of Mg-Li Alloy

The properties among of phytic acid conversion coatings,RE-phytic conversion coatings,rare earth conversion coatings and chromate conversion coatings were compared.The surface micrograph and the corrosion morphology of matrix and various coatings were observed,and the polarization curve,amount of hydrogen evolution and coating binding force were tested.The infrared spectra of phytic acid solution,phytic acid conversion coatings and RE-phytic conversion coatings were compared.The results indicated that the phytic acid coating and RE-phytic acid coating have better corrosion resistance and the RE-phytic acid coating is much better.The infrared spectra indicated that the characteristic peak of phytic acid conversion coatings shift left compared to that of phytic acid.The characteristic peak of RE-phytic conversion coating is similar with that of the phytic acid conversion coating.The di-hydrogen phosphate group of phytic acid reacted with metal matrix or rare earth conversion coating to generate hydrophosphate or phosphate.Phytic acid conversion coating consists of magnesium salt,aluminum salt,zinc salt and ferrous salt.The RE-phytic coating contains cerium salt besides those salts.

Difference of Phytic Acid Content and its Relation to Four Protein Composition Contents in Grains of Twenty-nine japonica Rice Varieties from Jiangsu and Zhejiang Provinces,China

Twenty-nine japonica rice varieties collected from Jiangsu and Zhejiang Provinces, China were planted in Hangzhou, China, to investigate the phytic acid content in brown rice and its frequency distribution as well as the correlation among the contents of phytic acid, total protein and four protein compositions in brown rice. The phytic acid content in brown rice ranged from 0.699% to 1.034%, with a mean of 0.868% for the 29 tested rice varieties. Xiushui series rice varieties generally exhibited lower phytic acid level than Wuyujing and Huai series rice varieties. A rough normal distribution, with a mean of 8.722%, was observed for the total protein contents in the tested varieties. Of the four protein compositions, the glutelin, globulin and albumin contents had larger coefficient of variation than the prolamin content, although the difference in prolamin content was genotype-dependent. No significant correlation was found between the phytic acid and four protein composition contents, whereas the total protein content was significantly and positively related to the glutelin content in brown rice.

Study on Phytic Acid Conversion Coating on Mg-Li Alloy

The impact of phytic acid concentration,immersion time and soaking temperature on phytic acid conversion coating of the Mg-Li alloy are studied.The surface morphology and the corrosion of the phytic acid conversion coating are tested by using scanning electron microscopy and the electrochemical analyzer.The results show that phytic acid concentration and immersion time,soaking temperature affects the microstructure and corrosion resistance of the phytic acid conversion coating.There is a passivation interval with a smaller capacitor and larger resistor in the phytic acid conversion coating.The phytic acid conversion coating is made up of white particle and flake film.

Effects of Dietary Soybean Stachyose and Phytic Acid on Gene Expressions of Serine Proteases in Japanese Flounder(Paralichthys olivaceus)

Soybean stachyose (SBS) and phytic acid (PA) are anti-nutritional factors (ANF) which have deleterious effects on the growth and digestibility in fish. The present research studied the effects of dietary SBS and PA on the expression of three serine protease genes in the liver of Japanese flounder (Paralichthys olivaceus). These genes are trypsinogen 1 (poTRY), elastase 1 (poEL) and chymotrypsinogen 1 (poCTRY). Eight artificial diets with graded levels of supplemented ANFs were formulated to 4 levels of SBS (0.00, 0.40, 0.80 and 1.50%), 4 levels of PA (0.00, 0.20, 0.40 and 0.80), respectively.Japanese flounder (initial weight 2.45 g ± 0.01 g) were fed with these diets for 10 weeks with three replications per treatment. At the end of 10 weeks, supplementation of 0.40% of dietary SBS or PA significantly increased the gene expression of poTRY and poCTRY (P<0.05). The same level of dietary SBS significantly decreased the gene expression of poEL. In comparison with the control group (ANF-free),dietary PA (0.2% and 0.8%) significantly decreased the gene expression of poTRY, poCTRY and poEL (P<0.05). However, excessive supplement of dietary SBS (1.5%) has no significant effects on these gene expressions (P>0.05). These results suggested that dietary SBS and dietary PA could directly affect the serine protease genes at the transcriptional level in Japanese flounder, and these genes'expression was more sensitive to dietary PA than to SBS under the current experimental conditions.

Phytic acid-derived fabrication of ultra-small MoP nanoparticles for efficient CO methanation: Effects of P/Mo ratios

Molybdenum phosphide(MoP) catalyst has been widely applied in hydrogenation reactions, while the preparation of unsupported MoP catalysts with ultra-small size and large specific surface area(SBET) is still challenging. Herein, we have provided a facile method for preparing a series of MoP-x(x=P/Mo ratios ranging from 1 to 5) catalysts by pyrolyzing phytic acid(PA)-derived Mo complexes in a H2 atmosphere. The physicochemical properties and the catalytic activity of MoP catalysts were investigated. The results showed that the obtained MoP-5 catalyst had the largest SBETand exhibited ultra-small nanoparticle diameter of 3.6 nm, which ascribed to the chelation of PA and the confinement of deposited products.As the content of PA increased, the synthetic mechanism of MoP was also affected, which led to the difference in the valence of surface Mo species. The characterization results further confirmed that Moδ+ sites in MoP catalysts are active sites for methanation reaction and its content on the surface of MoP-x catalysts determines the catalytic activity.

The Genetic Variances for the Phytic Acid and Inorganic Phosphorus Contents of Elite Inbred Lines in Tropical Maize

The study aimed to determine the genetic variances of phytic acid （myo-inositol 1,2,3,4,5,6 hexakis-dihydrogen phosphate） （PA） and inorganic phosphorus contents （InP） in grains of tropical maize （Zea mays L.）. The understanding of genetic variances in PA and InP in tropical maize would be useful for breeding management in tropical region. A total of 16 Ki inbred lines and 26 new inbred lines of tropical maize were planted in Completely Randomized Design （CRD） on the dry season 2008 at lnseechandrastitya Institute for Crops Research and Development, Thailand. The results showed that genotypic differences were highly significant （P 〈 0.01） for InP in both sources of germplasm, but genotype effect only was found significant in new inbred lines for PA content. The values for broad sense heritability （h2b） was generally lower on PA in maize grains compared with InP both in Ki and new inbred lines [h^2b of PA： 2.42 （Ki）, 14.18 （commercial hybrid extracted）; h^2b of InP： 32 （Ki） and 29.53 （commercial hybrid extracted）].

Variability of Phytic Acid and Inorganic Phosphorus Contents in Seeds of Tropical Maize （Zea mays L.）

The correlation coefficients and scattering were studied in Ki and new inbred lines for phytic acid （PA） and inorganic phosphorus content （InP） content in seeds of tropical maize （Zea mays L.）. The understanding of the variability in PA and InP characters would be useful in a breeding program. A total of 16 Ki and 25 new inbred lines of tropical maize were planted in Completely Randomized Design （CRD） during late rainy season, 2007 to early rainy season, 2009 at Inseechandrastitya Institute for Crops Research and Development, Thailand. The result showed low correlation with no statistical significant between PA and InP contents in corn seeds performed either in different sources of inbred lines or years. For PA content, most of inbred lines were skewed toward high PA （〉 900 mg/100 g） both in Ki and new inbred lines in every year. The lowest PA value found in Ki inbred lines both in two years were Ki10, Ki15, Ki20, and Ki52.30A10-S11-43-1-3 was the lowest PA inbred lines observing in two years in new germplasm.

Genetic variation for phytic acid content in mungbean(Vigna radiata L. Wilczek)

Mungbean(Vigna radiata L. Wilczek) is a short-duration legume crop cultivated for seeds that are rich in protein and carbohydrates. Mungbeans contain phytic acid(PA), an anti-nutritional factor that is the main storage form of organic phosphorus in seeds. It is a strong inhibitor against the absorption of nutrients including iron, zinc, calcium and magnesium in monogastric animals. Genotypes with low phytic acid(lpa) in seed may show increased assimilation of nutrients and be useful in breeding lpa cultivars. The present study was conducted to identify lpa sources, genetic variation, heritability, and association with seed coat color, inorganic phosphorus(IP), and seed size in 102 mungbean genotypes including released varieties, land races, mutants, and wild species grown in two seasons: summer 2011 and rabi 2012. PA and IP in dry seeds were estimated by modified colorimetric method and Chen's modified method,respectively. PA, IP, and 100-seed weight differed significantly in the two seasons. PA content in102 genotypes ranged from 5.74 to 18.98 mg g-1and 5.85 to 20.02 mg g-1in summer 2011 and rabi 2012, respectively. High heritability was found for PA(0.87 and 0.86) and seed size(0.82 and0.83) but low heritability for IP(0.61 and 0.60). A negative correlation was found between PA and seed size(r =-0.183 and-0.267). Yellow and green seed coat genotypes contained significantly less PA than black seed coat genotypes. Cluster analysis revealed the distinctness of wild species, land races and cultivated varieties on the basis of PA content. The genotypes YBSM(6.001 mg g-1) and JL-781(6.179 mg g-1) showed lowest PA. These lpa sources can be used to develop high-yielding mungbean cultivars with low phytic acid.

Inaccuracies in Phytic Acid Measurement: Implications for Mineral Biofortification and Bioavailability

Biofortification of commonly eaten staple food crops with essential mineral micronutrients is a potential sustainable solution to global micronutrient malnutrition. Because phytic acid (PA;1,2,3,4,5,6-hexakis myo-inositol) reduces mineral micronutrient bioavailability, reduction of PA levels could increase the bioavailability of biofortified iron (Fe), zinc (Zn), calcium (Ca), and magnesium (Mg). PA is viewed as an anti-nutrient, yet PA and other inositol phosphates have also demonstrated positive health benefits. Phytic acid analysis in the agricultural, food, and nutritional sciences is typically carried out by colorimetry and chromatographic techniques. In addition, advanced techniques such as nuclear magnetic resonance and synchrotron X-ray absorption spectroscopy have also been used in phytic acid analysis. The colorimetric analysis may overestimate PA levels and synchrotron X-ray absorption techniques may not detect very low levels of inositol phosphates. This short communication discusses the advantages and disadvantages of each widely used phytic acid analysis method, and suggests high performance anion exchange (HPAE) chromatography with conductivity detection (CD) based analysis can achieve greater accuracy for the identification and quantification of inositol phosphates. Accurate characterization and quantification of PA and inositol phosphates will inform PA reduction and biofortification efforts, allowing retention of the benefits of non-phytic inositol phosphates for both plants and humans.

Changes in Inositol Phosphates in Low Phytic Acid Field Pea (<i>Pisum sativum</i>L.) Lines during Germination and in Response to Fertilization

Inositol phosphates are the main form of phosphorous (P) storage in legume seeds. Mutants low in inositol hexaphosphate (IP6), also known as phytic acid (PA), have been developed to increase iron (Fe) bioavailability and reduce P waste to the environment. The objectives of this study were to determine 1) inositol-P form changes during germination, and 2) the effect of P fertilizer application on seed PA, total P, and Fe concentration of three field pea (Pisum sativum L.) cultivars and two low-PA lines grown under greenhouse conditions. Low-PA field pea lines clearly had lower PA (1.3 - 1.4 mg·g-1) than cultivars (3.1 - 3.7 mg·g-1). Phytic acid concentration in both cultivars and low-PA lines decreased during germination, but tended to increase seven days after germination. Levels of inositol-3-phosphate-phosphate (IP3-P;0.6 mg·g-1) and inorganic P (1.8 - 2.0 mg·g-1) were higher in low-PA lines than in the field pea cultivars. Reduction of PA in low-PA line seeds may reduce seed Fe and total P concentrations, as levels in the low-PA lines (37 - 42 mg·kg-1 Fe;4003 - 4473 mg·kg-1 total P) were typically less than in field pea cultivars (37 - 55 mg·kg-1 Fe;3208 - 4985 mg·kg-1 total P) at different P fertilizer rates. Overall, IP3 is the major form of P present in low-PA field pea lines during germination;however IP6 is the major form of P present in field pea cultivars. Therefore, low-PA field pea lines could be a potential solution to increase Fe bioavailability, feed P utilization, and reduce P waste to the environment.

Determination and inheritance of phytic acid as marker in diverse genetic group of bread wheat

Phytic acid (Myo-inositol 1,2,3,4,5,6 hexa-kisphophate) is a storage form of phosphorus and can accumulate to the levels as high as 35% in the wheat kernel. Phytic acid acts as an inhibitor for macronutrients as well as micronutrients and located in the bran of wheat kernel. Due to its inhibitory role, a high concentration of phytic acid is undesirable as it hinders the bio-availability of some essential nutrients such as Fe, Mg, Ca, Zn and Cu, etc. In order to check the inheritance of phytic acid in wheat kernels, phytic acid concentration was initially determined in kernels of 10 wheat genotypes to identify two contrasting genetic groups for diallel analysis. Based on pre-screening results of 10 wheat genotypes, five wheat genotypes (3 with high and 2 with low phytic acid concentration) were crossed in all possible combinations during 2007-2008 by 5 × 5 full diallel mating fashion to insight the inheritance of phytic acid and other yield contributing traits. All 20 F1 hybrids and five parental genotypes revealed significant differences statistically, except plant maturity. The narrow and broad sense heritability estimates varied widely among traits for spike length (0.17, 0.62), spikelets spike-1 (0.35, 0.74), tillers plant-1 (0.05, 0.52) and phytic acid concentration (0.01, 0.86). The values for phytic acid concentration ranged from 0.56% to 3.43% among F1 hybrids and 1.06 to 3.67% for parental genotypes. F1 hybrids, Ps-2005 × Ghaznavi (0.56%), AUP-4006 × Ps-2004 (0.74%), Janbaz × Ps-2004 (0.89%) and Janbaz × Ps-2005 (1.01%), had the lowest concentration of phytic acid. The study concluded that F1 hybrids with low phytic acid concentration could yield desirable segregants.

Formation Process and Properties of Phytic Acid Conversion Coatings on Magnesium

A chromium-free conversion coating treatment for magnesium by phytic acid solution was studied. The formation process of phytic acid conversion coating was studied through measuring the open circuit potential (OCP) and weight change of the pure magnesium in the different conversion treatment time. The morphologies and compositions of the coatings were determined by SEM and EDS respectively. The conversion coating has the multideck structure with netlike morphology which is similar to the chromate conversion coating, and is mainly composed of Mg, P, O and C. The contents of C and P and the size of the cracks in different layers decrease from the external layer to the inner layer. The hydroxyl groups and phosphate carboxyl groups in the coating which have the similar properties to organic paintcoat are beneficial to the combination of substrate and organic paintcoat. The formation mechanism and thickness variation of the conversion coatings are also discussed.

<i>In Vitro</i>Corrosion and Bioactivity Study of Surface Phytic Acid Modified AZ31 Magnesium Alloy

The purpose of the present work was to examine in vitro corrosion and bioactivity of surface phytic acid treatment AZ31 magnesium alloys. Untreated AZ31 magnesium alloys were used as control. The surface morphologies of magnesium alloys were observed by SEM. EDS was used to analyze the surface chemical elemental compositions and elemental concentration distribution. Corrosion properties were evaluated by electrochemical tests. Human osteosarcoma MG-63 cells were used to examine cell viability and proliferation. The results showed that surface phytic acid treatment resulted in a surface coating formation, which did not significantly improve the corrosion resistance of the alloys. The corrosion potential of AZ31 magnesium alloy positive shifted only about 0.04 V (from -1.50 V to -1.46 V);and the corrosion current decreased only 0.354 mA/cm2 (from 2.547 × 10-3 mA/cm2 to 2.193 × 10-3 mA/cm2). However, the cell analysis showed that this coating induced obviously higher MG-63 cell viability and proliferation, and displayed good surface bioactivity.