Phytic Acid Levels Research Articles

Evaluation of soybean meal from different sources as an ingredient in practical diets for Pacific white shrimp Litopenaeus vannamei

Solvent extracted soybean meal (SBM) is generated using different varieties of soybeans grown under a range of conditions and then processed at different crushing plants. Due to its competitive cost and availability, it is a popular plant-based protein source for shrimp feed formulations. However, there is limited information about effects of variations in the nutritional composition of soybean meal have on performances of shrimp. Hence, the present study was designed to determine the effects of different soybean sources on the growth performances of Litopenaeus vannamei. Two growth trials were conducted with iso-nitrogenous and iso-lipidic (350 g/kg protein and 80 g/kg lipid) test diets formulated with 25 sources of soybean meal. Trial one incorporated 14 treatments including a soy-based diet containing 517 g/kg SBM (eight replicates) and this soy source was then replaced with 13 different soybean sources (four replicates per treatment). The second trial used the same basal diet and 11 different sources of soybean meal (Total 12 diets) with five replicates per treatment. Both growth trials were conducted with a stocking density of 10 shrimps/aquarium in a semi-closed recirculating system and the initial weight of shrimps for trials 1 and 2 were 0.23 g ± 0.02 and 0.67 g ± 0.02 respectively. During the two trials, shrimp were fed four times/day assuming a FCR of 1.8, over 42 days for trial 1 and 35 days for trial 2. Results indicated that there are differences among sources of soybean meal for standardized percentage TGC. Diet 21 that contained SBM4550 had the largest value for TGC whereas the lowest value for TGC was observed for shrimp fed diet 17 that contained SBM45536. According to the statistical analysis that was used to interpret the growth performance data from the complete chemical profile of the SBM, phosphorous, phytate-phosphorous and total phytic acid levels had positive correlations (p < 0.005) with TGC whereas raffinose (p = 0.086) had a negative correlation with TGC. Results of this work indicates phosphorous, phosphorous in phytic acid and total phytic acid and raffinose are important components in SBM that may have significant effects on the growth performances of pacific white shrimp.

The Utilization of Phytase Enzymes and SEM Analysis in order to increase the Quality of Rice Bran as a Layer and Fish Feed

Phytase is one of the enzymes belonging to the group phosphatase, which is capable of hydrolyzing the phytic compounds in the form of myo-inositol (1.2.3.4.5.6) into myo-inositol phosphatase and organic phosphate. In the digestive tract of non-ruminant livestock (poultry) and fish, there are no phytase enzymes. This causes the content of the rice bran phytate compounds to be difficult to digest because of the strong chelating properties. Restrictions on the use of rice bran in the fish’s diet are because of the fiber content and the high level of phytic acid. One alternative to reduce the phytate content of the feed is to use the phytase enzyme, which is expected to hydrolyze the phytic acid (myo-inositol 1.2.3.4.5.6) in the rice bran orthophosphate in organic produce. All of the minerals, such as P and Ca, are important minerals to release and it is used for the growth of both layers and fish. The result showed that: 1. The scanning Elektron Microscope (SEM) analysis of the surface with the addition of rice bran phytase enzymes caused the bond breaking force with the inositol phosphate acid groups. These showed changes in the structure of the phytic irregular bond and 2. The addition of the phytase enzymes to degrade phytic acid increases the availability of minerals such as phosphorus and calcium and crude protein, and decreases the crude fiber in the rice bran.

Phytic acid content and starch properties of maize (Zea mays L.): Effects of irrigation process and nitrogen fertilizer

In the present study, the effects of different irrigation levels (I50: 50%; I75: 75%; and I100: 100% of depleted water from field capacity) and nitrogen fertilizer concentrations (N1:100, N2:200 and N3:300 kg ha−1N) on starch properties (total, resistant and nonresistant starch, amylose-amylopectin ratios) and phytic acid content of maize were investigated. The single and interaction effects of the treatments and also influence of harvesting year were evaluated. Total starch accumulation changed with the treatments and the highest values were obtained from I50 and N3 combination and the lowest levels were recorded for I100-N1 and I100-N2 treatments. Amylopectin increased with the effect of irrigation, while the amylose decreased with the irrigation treatment in parallel to amylopectin content. Besides, the lowest phytic acid level was also obtained from the treatments of I100 and N1. This study would provide some valuable information for agricultural and nutritional applications of maize.

Apparent availability of zinc, selenium and manganese as inorganic metal salts or organic forms in plant-based diets for Atlantic salmon (Salmo salar)

The composition of salmonid diets has changed from the use of mainly marine ingredients to increased use of plant ingredients, and this has an impact on the mineral content and availability. Minerals, like zinc (Zn), selenium (Se) and manganese (Mn), are supplemented to diets as inorganic or organic forms to cover the nutritional requirements of fish. This study compared the apparent availability (AA) of Zn, Se and Mn from inorganic metal salts and their organic forms in Atlantic salmon. Sixteen diets were prepared based on a two-level factorial design (24). The tested factors were Zn additive source (A), Se additive source (B), Mn additive source (C) and phytic acid level (D). The diets were fed to Atlantic salmon for 11 days, faeces were collected by stripping, and the total content of mineral and yttrium in diets and faeces were determined by inductively coupled plasma mass spectrometry. Data obtained were used to estimate the AA for the minerals. Zinc additive source had no significant effect on the AA of Zn. However, the Se and Mn additive source had significant effects on the AA of Se and Mn, respectively. Higher AA of Se was achieved with selenomethionine than with selenite, and Mn sulphate was more available than Mn chelate of glycine. The phytic acid level did not significantly affect the AA of Zn, Se or Mn. However, several interactions between mineral additive sources and the phytic acid level significantly affected the AA of Zn, Se and Mn.

Studies on genetic parameters and combining ability in maize for the production of hybrids with low phytic acid

Phytic acid is a major constraint in affecting the nutritional concerns of the people feeding on maize. Being a strong negatively charged chelator, this compound binds all the positively charged minerals like iron and zinc. It also acts as a major storage compound of phosphorous. Thus monogastric animals lacking phytase, fails to absorb these minerals and is considered as a antinutritional factor. This experiment was conducted to identify the potential donors for low phytic acid to produce hybrids with moderate phytic acid content. With this objective a reference set for phytate (2-16 mg/g) formed from a base population was screened. A D2 analysis in the reference set was done and this classified the genotypes into eight clusters. The genotypes with low phytate were grouped in cluster 4. Highest significant variability was observed for all the traits including phytic acid. Cob weight followed by phytic acid had a highest heritability with high genetic advance as percent of mean indicating the effectiveness of selection for these traits due to the presence of additive gene action. Among the six low phytate lines observed, UMI-113 had lowest phytate content of 2.77 mg/g. These six low phytate genotypes classified in cluster 4 were then selected as testers and were crossed to four elite lines. Among the 24 hybrids produced, three hybrids., UMI 1200 x UMI 1099, UMI 1201 x UMI 1099 and UMI 1210 x UMI 1099 yielded higher than the standard check with medium levels of phytic acid ranging from 10.23-10.46 mg/g. The line UMI-1099 was found be a good general combiner for yield related traits with a negative combining ability for phytic acid. Hence this line could be successfully used in low phytate breeding programs and these identified hybrids could be further used in poultry testing trials for analyzing the bioavailability of nutrients.

Effect of Processing Methods on Phytic Acid Content of Peanut and Wheat

The effects of processing methods (roasting, fermentation, baking and germination) on phytic acid of cereal grains were studied based on the decoloration of Fe3+- sulfosalicylate complex by using Latta and Eskin method. Phytic acid solution was also standardize for using to validation of the previous colorimetric method. The samples screened were peanut, whole wheat and white wheat flour. Phytate content ranged between 13.5 - 20.6 mg/g for peanut, 15.07 - 15.75 mg/g for whole wheat and 2.71 - 5.44 mg/g for white wheat flour. During roasting for peanut, the level of phytic acid reduced between 3.64 - 5.78%, 12.18 - 22.6% and 14.25 - 25.76% for 10, 20 and 30 min, respectively. During germination for whole wheat, the level of phytic acid reduced between 9.09 - 14.98%. During fermentation and baking for white wheat flour, , the level of phytic acid reduced between 15.22 - 37.56% for dough, 18.58 - 39.38% for dough with baking, 38.94 - 47.43% for dough with fermentation and 39.65 - 48.19% for dough with fermentation and baking. Based on these results, the processing methods used reduced phytic acid at different rates.

Impact of plant extract on the gastrointestinal fate of nutraceutical-loaded nanoemulsions: phytic acid inhibits lipid digestion but enhances curcumin bioaccessibility.

The impact of phytic acid on lipid digestion and curcumin bioaccessibility in oil-in-water nanoemulsions was investigated using a simulated gastrointestinal tract (GIT). The size, charge, and structural organization of the colloidal particles in the system were measured as the curcumin-loaded emulsions (7 mg curcumin per g lipid) were passed through simulated mouth (pH 6.8, 2 min), stomach (pH 2.5, 2 hours), and small intestine (pH 7.0, 2 hours) stages. After the small intestine stage, the level of free fatty acids (FFAs) generated and the bioaccessibility of curcumin were measured. The total amount of FFAs released significantly decreased with increasing phytic acid level, from 105.7 ± 5.9% (control) to 78.4 ± 6.4% (0.5% phytic acid). Conversely, curcumin bioaccessibility significantly increased from 39.4 ± 3.5% (control) to 74.7 ± 2.6% (0.5% phytic acid). The inverse relationship between lipolysis and curcumin bioaccessibility was ascribed to the impact of phytic acid on droplet flocculation and the level of free calcium ions present, which affected the production of mixed micelles capable of solubilizing the nutraceutical. The knowledge obtained here might prove beneficial for the employment of phytic acid as a multifunctional ingredient that inhibits lipid digestion while boosting nutraceutical bioavailability.

Chemical Composition, Nutritional Quality and Anti-Nutritional Factors of Weaning Food Prepared From Maize and Legumes

Weaning is a gradual process of introducing solid foods to infant’s diet, alongside breast milk from the age of six months, since the breast feeding along cannot meet the infant nutritional requirement. This study aims to prepared high quality weaning foods from locally available raw materials at low cost. Weaning food was produced from the blends of yellow maize flour with some legumes (soybean, chickpeas and peanut). blends were prepared in a mixed ratio 70:30 using traditional techniques like milling, roasting and drying were evaluated. In samples, chemical composition, anti-nutritional factors, protein digestibility, amino acid content and sensory evaluation were determined. Results showed that the formulated weaning food. The maize used in this experiment were yellow maize of local variety. The results revealed that, the protein content ranged from 12.26% -17.68% of the weaning food blends from yellow maize is similarly close to the recommended daily intake for infants (6 month to 2 year) compared to the raw maize without legumes. The low moisture contents (4.10%), (4.89 %) and 4.72% in maize/ soybean, maize/chickpea and maize/peanut exhibited by the weaning food blends might give a good storage stability. The results of anti-nutrition factors ranges phytic acid (4.81 mg/100 g – 6.25 mg/100 g), Trypsin inhibitor (0.46 TIU/100 g – 0.52 TIU/100 g) and tannins (55.75 mg/100 g – 63.89 mg /100 g) Heat treatment of grains resulted in low levels of phytic acid and higher in vitro protein digestibility ranged from 75.43% to 81.76% of the weaning feed mixtures,. Results on sensory evaluation showed that the best blend was contained maize/chickpeas then maize peanut but maize soybean and control lower acceptability.

Development and Evaluation of Low Phytic Acid Soybean by siRNA Triggered Seed Specific Silencing of Inositol Polyphosphate 6-/3-/5-Kinase Gene.

Soybean is one of the leading oilseed crop in the world and is showing a remarkable surge in its utilization in formulating animal feeds and supplements. Its dietary consumption, however, is incongruent with its existing industrial demand due to the presence of anti-nutritional factors in sufficiently large amounts. Phytic acid in particular raises concern as it causes a concomitant loss of indigestible complexed minerals and charged proteins in the waste and results in reduced mineral bioavailability in both livestock and humans. Reducing the seed phytate level thus seems indispensable to overcome the nutritional menace associated with soy grain consumption. In order to conceive our objective we designed and expressed a inositol polyphosphate 6-/3-/5-kinase gene-specific RNAi construct in the seeds of Pusa-16 soybean cultivar. We subsequently conducted a genotypic, phenotypic and biochemical analysis of the developed putative transgenic populations and found very low phytic acid levels, moderate accumulation of inorganic phosphate and elevated mineral content in some lines. These low phytic acid lines did not show any reduction in seedling emergence and displayed an overall good agronomic performance.

The stage of seed development influences iron bioavailability in pea (Pisum sativum L.)

Pea seeds are widely consumed in their immature form, known as garden peas and petit pois, mostly after preservation by freezing or canning. Mature dry peas are rich in iron in the form of ferritin, but little is known about the content, form or bioavailability of iron in immature stages of seed development. Using specific antibodies and in-gel iron staining, we show that ferritin loaded with iron accumulated gradually during seed development. Immunolocalization and high-resolution secondary ion mass spectrometry (NanoSIMS) revealed that iron-loaded ferritin was located at the surface of starch-containing plastids. Standard cooking procedures destabilized monomeric ferritin and the iron-loaded form. Iron uptake studies using Caco-2 cells showed that the iron in microwaved immature peas was more bioavailable than in boiled mature peas, despite similar levels of soluble iron in the digestates. By manipulating the levels of phytic acid in the digestates we demonstrate that phytic acid is the main inhibitor of iron uptake from mature peas in vitro. Taken together, our data show that immature peas and mature dry peas contain similar levels of ferritin-iron, which is destabilized during cooking. However, iron from immature peas is more bioavailable because of lower phytic acid levels compared to mature peas.

Changes in levels of phytic acid, lectins and oxalates during soaking and cooking of Canadian pulses

Raw and processed (soaked or cooked) seeds of peas, lentils, chickpeas, fava beans and common beans were studied for their contents of antinutritional factors (lectins, phytic acid, total and soluble oxalates), along with soybean as a control. Analysis of variance indicated that legume type, treatment and their interactive effects were significant on these antinutrients. The raw soybean seed was found to contain the highest levels of lectins (692.8 HU/mg), phytic acid (22.91 mg/g), total oxalate (370.5 mg/100 g) and soluble oxalate (200.7 mg/100 g) among all investigated seeds. Relatively high contents of lectins were detected in beans (87.69–88.59 HU/mg) and other pulses ranging from 2.73–11.07 HU/mg. Phytic acid in Canadian pulses varied slightly from 8.55–22.85 mg/g. Total oxalates were variable, ranging from 244.7–294.0 mg/100 g in peas, 168.6–289.1 mg/100 g in lentils, 241.5–291.4 mg/100 g in fava beans, 92.2–214.0 mg/100 g in chickpeas and 98.86–117.0 mg/100 g in common beans. Approximately 24–72% of total oxalate appeared to be soluble in all investigated pulses. Soaking the seeds in distilled water significantly decreased the contents of lectins (0.11–5.18%), total oxalate (17.40–51.89%) and soluble oxalate (26.66–56.29%), but had no impact on phytic acid. The cooking process was found to be more effective in reducing levels of all the investigated antinutritional factors, except phytic acid in common beans and soybean.

Use of phytase active yeasts and lactic acid bacteria isolated from sourdough in the production of whole wheat bread

In this study, sourdough samples were collected from different locations and lactic acid bacteria (LAB) and yeasts were isolated, identified and their phytic acid degradation capabilities were investigated. The isolated phytase positive LAB and yeast strains were identified by FTIR (Fourier Transform Infrared Spectroscopy) and LAB's 16s rRNA gene and yeast's 26s rRNA gene sequencings. Phytase positive strains were used as a starter culture in whole wheat bread production. In order to determine the culture effect on the quality parameters of whole wheat bread samples, some physicochemical, nutritional, sensory, and textural properties were characterized. The spectrophotometric phytase activity was calculated as 703.1–1153.8 U/mL for LAB isolates, and 352.2–943.4 U/mL for yeast isolates. Two different yeast species (Saccharomyces cerevisiae, Pichia membranifaciens) and five different LAB species (Weissella viridescens, Pediococcus pentosaceus, Pediococcus acidilactici, Lactobacillus brevis, Lactobacillus parabuchneri) were identified based on the FTIR-based identification and molecular subtyping methods. The phytic acid content significantly decreased in culture added whole wheat breads compared to control one produced with only commercial baker's yeast. The greatest reduction in phytic acid level (43.4%) was observed in the bread produced by S. cerevisiae + Pediococcus pentosaceus culture combination.

Phenotypic diversity of nutrients and anti-nutrients in bean grains grown in different locations

The growing environments can influence grain yield and could also to influence the nutritional value of common bean grains. The objective of this study was to determine the levels of minerals, phytic acid and total protein in common bean, and to the relationship of these with grain yield, under the influence of different growing environments. The experiment was conducted with 26 genotypes in three Santa Catarina places of cropping (Anchieta/SC, Joacaba/SC and Lages/SC, Brazil). Were determined the levels of phosphorus, potassium, iron, zinc, protein and phytic acid into grains. The levels of phytate, iron and potassium, considering each genotype were influenced by the environment of cropping while for zinc, phosphorus and crude protein there was no interaction of genotypes by environments effects. In addition, there was variability for all nutrients and phytic acid in at least one cropping place. Genotypes with high grain yield had lower concentrations of nutrients, particularly phosphorus and crude protein, although this relationship is dependent of the cropping place. Concomitant choice for two minerals was possible; however, there was a positive correlation between mineral and phytate which was not favorable because the nutrients complexes with phytic acid, characterizing phytic acid as an important grains anti-nutrient.

Inference of Transcription Regulatory Network in Low Phytic Acid Soybean Seeds.

A dominant loss of function mutation in myo-inositol phosphate synthase (MIPS) gene and recessive loss of function mutations in two multidrug resistant protein type-ABC transporter genes not only reduce the seed phytic acid levels in soybean, but also affect the pathways associated with seed development, ultimately resulting in low emergence. To understand the regulatory mechanisms and identify key genes that intervene in the seed development process in low phytic acid crops, we performed computational inference of gene regulatory networks in low and normal phytic acid soybeans using a time course transcriptomic data and multiple network inference algorithms. We identified a set of putative candidate transcription factors and their regulatory interactions with genes that have functions in myo-inositol biosynthesis, auxin-ABA signaling, and seed dormancy. We evaluated the performance of our unsupervised network inference method by comparing the predicted regulatory network with published regulatory interactions in Arabidopsis. Some contrasting regulatory interactions were observed in low phytic acid mutants compared to non-mutant lines. These findings provide important hypotheses on expression regulation of myo-inositol metabolism and phytohormone signaling in developing low phytic acid soybeans. The computational pipeline used for unsupervised network learning in this study is provided as open source software and is freely available at https://lilabatvt.github.io/LPANetwork/.

Physical characteristics, proximate composition and anti-nutritional factors in grains of lablab bean (&lt;i&gt;Lablab purpureus&lt;/i&gt;) genotypes from Kenya

Objectives: The objectives of this study were to determine the physical characteristics, nutritional composition and anti-nutritional factors of grains from three lablab bean varieties with different colours and size developed by The Kenya Agricultural and Livestock Research Organisation (KALRO) Methodology and results: The length, thickness and width were determined using Vernier callipers. Dry matter, protein, fat and ash were determined using standard association of official analytical chemists (AOAC) methods. Phytates were determined using high performance liquid chromatography (HPLC), while the tannins and trypsin inhibition were determined by UV spectrophotometry. The mean 100 seed weight was significantly different among the three varieties, and ranged from 26.1 g to 29.2 g. The length, thickness and width ranged from 9.7 for KAT/DL-3 to 10.7 mm for KAT/DL-1, 5.2 (KAT/DL-1) to 5.6 mm (KAT/DL-2) and 6.8 (KAT/DL-3) to 7.4 mm (KAT/DL-1), respectively. The hydration and swelling coefficients of the beans ranged from 130.7 in KAT/DL-2 to 147.2 in KAT/DL-1, and 125.1 in KAT/DL-2 to 153.3 (KAT/DL-1), respectively. The mean crude protein and energy contents varied from 22.5(KAT/DL-3) to 25.4 %,( KAT/DL-1) and 347.4 (KAT/DL-3) to 353.7 KCal/100g in KAT/DL-1, respectively, and differed significantly (p<0.05) among the varieties. There were significant differences (p<0.05) in the phytic acid and tannin levels, where KAT/DL-2 recorded the highest levels of 723.6 mg/100 g, and 0.33%CE, respectively. Conclusion and application of findings: These results indicate that KAT/DL-1 has the best physical characteristics in respect to cooking and nutrition quality. This variety had the highest protein and energy content with low anti-nutritional factors, thus could offer better nutritive value in comparison to KATDL-2 and KAT/DL-3 Keywords: Lablab beans, varieties, proximate composition, physical parameters, anti-nutritional factors

Effects of supplemental phytic acid on the apparent digestibility and utilization of dietary amino acids and minerals in juvenile grass carp (Ctenopharyngodon idellus )

A feeding trial was conducted for 8 weeks to evaluate the effects of supplemental phytic acid (PA) on the apparent digestibility and utilization of dietary amino acids (AAs) and minerals in juvenile grass carp. Five experimental diets consisted of graded levels of PA (0.2, 4.7, 9.5, 19.1 and 38.3 g kg−1, named as P0, P5, P10, P20 and P40). Triplicate groups of fish (initial weight, 22.37 ± 0.16 g) were fed twice daily (08:00 and 16:00 h). The crude protein content in whole body significantly (p 4.7 g kg−1) significantly reduced the apparent digestibility coefficient (ADC) of AAs (Asp, Thr, Ser, Glu, Gly, Ala, Cys, Val, Met, Ile, Leu, Phe, Lys, Pro, His and Arg) and the ADC of minerals (P, Ca, Mg, Zn, Cu, Fe and Mn) in grass carp. The contents of minerals (P, Ca, Mg and Zn) in whole body and bone were also found to be significantly reduced in dietary PA > 4.7 g kg−1, while the bone ash, serum Alkp and Zn contents were found to be significantly decreased when the PA supplementation level was above 9.5 g kg−1, and the contents of serum Ca and Mg were found to be markedly altered in higher PA-supplemented groups. The results indicated that supplemental PA decreased the apparent digestibility and utilization of AAs and minerals, and thus reduced the feed utilization of grass carp, suggesting that the level of total PA should be below 4.7 g kg−1 in grass carp diet.

Growth performance, nutrient utilisation and body composition of Macrobrachium rosenbergii fed graded levels of phytic acid

Information relating to the effects of phytic acid (PA), an anti-nutritional factor (ANF) commonly found in plant protein ingredients, on the growth performance, feed conversion ratio (FCR), nutrient utilisation and whole proximate composition in the Malaysian giant freshwater prawn, Macrobrachium rosenbergii, is lacking. Replicate groups of M. rosenbergii (mean initial carapace length of 6.03±0.30mm; mean initial weight of 0.29±0.02 g; n=20 per replicate group) were fed graded levels of PA for 140days. The basal diet, to which different levels of PA were added to obtain 0.26 (control), 6.48, 11.28, 16.53, 21.45 and 26.16gPAkg−1, contained fishmeal, soy protein concentrate and wheat meal. Terminal sampling indicated that the growth performance, FCR and survival did not differ significantly between the groups receiving the different inclusions of PA within their diets. The apparent protein, lipid and energy utilisation responded negatively, decreasing significantly (p<0.05) with an increasing inclusion of PA, particularly within the groups of prawns fed diets with the highest inclusions of PA (i.e. 21.45–26.16gPAkg−1). The whole body composition of protein (p<0.04), lipid (p<0.01) and gross energy (p<0.05) also decreased significantly with an increasing supplementation of PA, while the ash content significantly increased (p<0.01), most notably in the groups of prawns receiving the highest levels of dietary PA (26.16gPAkg−1). In conclusion, inclusions of up to 11.28gPAkg−1 appear safe but levels above this have negative impacts. The results show that PA had significant effects on the nutrient utilisation and body compositions (p<0.05) but not on growth performance and FCR (p>0.05) on the M. rosenbergii reared under the experimental conditions that were employed here.

The Potential of Fermentation and Contamination of Teff by Soil to Influence Iron Intake and Bioavailability from Injera Flatbread.

The high phytic acid (PA) concentration in the diet based on teff injera is a likely contributing cause of iron deficiency in Ethiopia. We monitored PA during teff injera fermentation in 30 households in Debre Zeyit, Ethiopia and evaluated its influence on iron bioavailability, considering contaminant soil iron in teff flour. After fermentation (48h), mean PA concentration in injera batter decreased from 0.87 to 0.58 g/100 g dm (P < 0.001). Low phytase activity in teff flour (0.44 μmol phosphate/min/g) and a rapid drop in pH, indicated that PA degradation was driven by microbial phytases. The iron concentration in injera batter among the households ranged widely from 14.5-160.4 mg/100 g dm (mean: 34.7 mg/100 g dm) principally due to contamination with soil. Estimated intrinsic iron concentration of teff based on the strong correlation between total iron and aluminium concentrations (P < 0.001; aluminium concentrations in injera batter: 28.7-184.9 mg/100 g dm) was 4.4 mg/100 g dm, indicating that 86-97 % is extrinsic iron from soil. The median daily iron intakes from 3-day weighed food records in 10 young children were 18.9 mg/day including soil iron vs. 4.9 mg/day without soil iron (P < 0.01). The PA:iron molar ratios indicated low iron bioavailability from teff injera, particularly when soil iron was excluded. Traditional fermentation thus has a modest influence on PA levels and more complete degradation is needed to improve iron bioavailability. There is an urgent need to better understand the bioavailability of contamination iron from soil before considering national fortification or biofortification strategies in Ethiopia.

Evaluation of Simple and Inexpensive High‐Throughput Methods for Phytic Acid Determination

AbstractHigh‐throughput/low‐cost/low‐tech methods for phytic acid determination that are sufficiently accurate and reproducible would be of value in plant genetics, crop breeding and in the food and feed industries. Variants of two candidate methods, those described by Vaintraub and Lapteva (Anal Biochem 175:227–24, 1988; “VL” methods) and Huang and Lantzsch (J Sci Food Agric 34:1423–1426, 1983; “HL” methods), were evaluated. The primary concern with these methods is that, due to interference of matrix constituents including inorganic P, they can overestimate phytic acid and are ineffective at low levels of phytic acid. Twelve seed flours, representing lines of soybean, maize, barley and dry bean, containing a wide range of phytic acid levels, were analyzed by a minimum of eight cooperating laboratories using three variants of the VL method and two variants of the HL method. No method had consistently acceptable (˂2.0”) “Horwitz ratios”, a measure of reproducibility, although some treatments approached that. For example, one variant of the VL method when used to assay a soybean flour with a “standard” level of phytic acid had a Horwitz ratio of 2.15. Some variants of the VL method were adequate for analyses of cereal grains regardless of phytic acid level but none accurately measured phytic acid when at low levels in soybean flours. One variant of the HL method in which the 0.2 N HCl extraction media is modified to contain 10% Na2SO4, did accurately measure phytic acid levels in both cereal and legume flours regardless of endogenous phytic acid levels or matrix constituents.

Solid-State Fermentation Reduces Phytic Acid Level, Improves the Profile of Myo-Inositol Phosphates and Enhances the Availability of Selected Minerals in Flaxseed Oil Cake.

Flaxseed oil cake was subjected to fermentation with Rhizopus oligosporus (DSM 1964 and ATCC 64063), and the phytate (InsP6) content, myo-inositol phosphate profile and in vitro bioavailability of essential minerals were studied. Flaxseed oil cake had a phytate mass fraction of 13.9 mg/g. A 96-hour fermentation of flaxseed oil cake by R. oligosporus DSM 1964 and R. oligosporus ATCC 64063 decreased the InsP6 content by 48 and 33%, respectively. The strains had different phytate-degrading activities: fermentation of flaxseed oil cake with R. oligosporus DSM 1964 was more advantageous, yielding InsP3-5 as a predominating myo-inositol compound, while fermentation with R. oligosporus ATCC 64603 produced predominantly InsP5-6. Solid-state fermentation of flaxseed oil cake enhanced in vitro bioavailability of calcium by 14, magnesium by 3.3 and phosphorus by 2-4%.