Phytase-mediated mineral solubilization from cereals under in vitro gastric conditions

Characteristics of Selected Bioactive Compounds and Malting Parameters of Hemp (Cannabis sativa L.) Seeds and Malt

Hemp (Cannabis sativa L.) seeds are an interesting raw material for malting regarding its relatively high bioactive compounds concentration and proven advantageous properties in different food products and dietary supplements. In the first stage of the study, important seeds properties relevant to the malting process including moisture content, seed viability, and water absorption capacity were determined. However, a few parameters determining the seeds' usability for malt preparation, such as germination ability and water sensitivity, are different in comparison to typical malting raw materials such as barley or wheat. However, they make it possible to obtain high-quality hemp malt. In the next stage of research, spectroscopic and chromatographic analyses, including measurements of antioxidant activity and protein separation by SEC-HPLC, were conducted. The results showed that the malting process improved the total antioxidant potential of hemp seeds by 15%, leading to an increase in the concentration of lower molecular weight proteins and oligopeptides-below molecular mass of 10 kDa-responsible for this high antioxidant activity. The processing of hemp seeds reduced the phytate content while increasing phosphate fractions with fewer phosphate groups, which may have a beneficial effect on nutritional value. These results suggest that malting hemp seeds needs optimalization of the process but can increase its nutritional value as a promising raw material in the food industry.

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

BACKGROUND

Soymilk is a high-quality source of protein and minerals, such as calcium (Ca), iron (Fe), and zinc (Zn). However, phytic acid in soymilk restricts mineral and protein availability. We here investigated the effects of removing phytic acid on the physicochemical properties, mineral (Ca, Fe, and Zn) bioaccessibility, and protein digestibility of soymilk.

RESULTS

Physicochemical property analysis revealed that the removal of phytic acid reduced protein accumulation at the gastric stage, thereby facilitating soymilk matrix digestion. The removal of phytic acid significantly increased Zn bioaccessibility by 18.19% in low-protein soymilk and Ca and Fe bioaccessibility by 31.20% and 30.03%, respectively, in high-protein soymilk.

CONCLUSION

Removing phytic acid was beneficial for the hydrolysis of high-molecular-weight proteins and increased the soluble protein content in soymilk, which was conducive to protein digestion. This study offers a feasible guide for developing plant-based milk with high nutrient bioaccessibility. © 2024 Society of Chemical Industry.

Phytic acid accumulation in plants: Biosynthesis pathway regulation and role in human diet

Phytate or phytic acid (PA), is a phosphorus (P) containing compound generated by the stepwise phosphorylation of myo-inositol. It forms complexes with some nutrient cations, such as Ca, Fe and Zn, compromising their absorption and thus acting as an anti-nutrient in the digestive tract of humans and monogastric animals. Conversely, PAs are an important form of P storage in seeds, making up to 90% of total seed P. Phytates also play a role in germination and are related to the synthesis of abscisic acid and gibberellins, the hormones involved in seed germination. Decreasing PA content in plants is desirable for human dietary. Therefore, low phytic acid (lpa) mutants might present some negative pleiotropic effects, which could impair germination and seed viability. In the present study, we review current knowledge of the genes encoding enzymes that function in different stages of PA synthesis, from the first phosphorylation of myo-inositol to PA transport into seed reserve tissues, and the application of this knowledge to reduce PA concentrations in edible crops to enhance human diet. Finally, phylogenetic data for PA concentrations in different plant families and distributed across several countries under different environmental conditions are compiled. The results of the present study help explain the importance of PA accumulation in different plant families and the distribution of PA accumulation in different foods.

In vitro assays for evaluating phytate degradation in non-ruminants: chances and limitations

The positive effects of phytases on the environment, animal welfare and animal feed costs have resulted in the continuous development and improvement of these enzymes in the non-ruminant feed market. To test the efficacy of these phytases, a large number of experimental animals are necessary, antagonising the animal welfare aspect of these enzymes. In the present review, we summarise the most prominent available in vitro assays for evaluating phytase enzymes and how far they can reduce the number of in vivo experiments. Several in vitro assays exist that differ in their setup, extent and conditions depending on the animal of interest and the research question. With the in vitro assays described, it is not possible to fully replace in vivo trials. However, for the investigation of phytase effects in feedstuffs, the use of an in vitro assay has several advantages. In vitro assays have the potential to be used for ranking feed enzymes and as screening tools. Applying in vitro protocols will result in a reduction in the number of animals or treatments usually necessary for an in vivo trial, thus acting towards the three Rs. © 2020 Society of Chemical Industry.

Effect of phytase treatment of sorghum flour, an alternative for gluten free foods and bioaccessibility of essential minerals

This study evaluated the effect of phytase treatment on the bioavailability of iron (Fe), calcium (Ca), zinc (Zn), and myo-inositol phosphate fractions in sorghum flour; and characterized its macronutrients and minerals. The proximate composition and mineral content indicated that, sorghum flour has a nutritional potential superior to wheat and maize. The results obtained in the solubility and dialysis assays indicated that, naturally occurring minerals (without phytase treatment) in sorghum flour, presented considerable bioaccessibility; reaching 32, 47 and 67% of dialyzable Fe, Zn, and Ca respectively. The use of phytase had a positive influence on the reduction of myo-inositol phosphates, mainly the IP6 fraction, present in sorghum flour samples, and an increase in the soluble percentage (Fe 52% for one sample, for Zn higher than 266%) and dialyzed minerals (Fe 7.8-150%; Zn 19.7 for one sample; and Ca 5-205%) for most samples. Therefore, the essential minerals naturally occurring in sorghum have an absorption potential; and the use of phytase reduced the IP6 fraction and improved the availability of the minerals evaluated.

Characteristics of an Acidic Phytase from Aspergillus aculeatus APF1 for Dephytinization of Biofortified Wheat Genotypes

Phytases are the special class of enzymes which have excellent application potential for enhancing the quality of food by decreasing its inherent anti-nutrient components. In current study, a protease-resistant, acidic phytase from Aspergillus aculeatus APF1 was partially purified by ammonium sulfate fractionation followed by chromatography techniques. The molecular weight of partially purified phytase was in range of 25-35 kDa. The purified APF1 phytase was biochemically characterized and found catalytically active at pH 3.0 and 50 °C. The K_m and V_max values of APF1 phytase for calcium phytate were 3.21 mM and 3.78 U/mg protein, respectively. Variable activity was observed with metal ions and among inhibitors, chaotropic agents and organic solvents; phenyl glyoxal, potassium iodide, and butanol inhibited enzyme activity, respectively, while the enzyme activity was not majorly influenced by EDTA, urea, ethanol, and hexane. APF1 phytase treatment was found effective in dephytinization of flour biofortified wheat genotypes. Maximum decrease in phytic acid content was noticed in genotype MB-16-1-4 (89.98%) followed by PRH₃-30-3 (82.32%) and PRH₃-43-1 (81.47%). Overall, the study revealed that phytase from Aspergillus aculeatus APF1 could be effectively used in food and feed processing industry for enhancing nutritional value of food.

Microbial degradation of myo-inositol hexakisphosphate (IP6): specificity, kinetics, and simulation

Microbial degradation of myo-inositol hexakisphosphate (IP6) is crucial to deal with nutritional problems in monogastric animals as well as to prevent environmental phosphate pollution. The present study deals with the degradation of IP6 by microorganisms such as Sporosarcina spp. pasteurii, globiospora, psychrophila, Streptococcus thermophilus and Saccharomyces boulardii. These microbes were screened for phytase production under laboratory conditions. The specificity of the enzyme was tested for various phosphorylated substrates such as sodium phytate (IP6), sodium hexametaphosphate, phenyl phosphate, α-d-glucose-6 phosphate, inosine 5' monophosphate and pyridoxal 5' phosphate. These enzymes were highly specific to IP6. The influence of modulators such as phytochemicals and metal ions on the enzymatic activity was assessed. These modulators in different concentrations had varying effect on microbial phytases. Calcium (in optimal concentration of 0.5 M) played an important role in enzyme activation. The enzymes were then characterized based on their molecular weight 41~43 kDa. The phytase-producing microbes were assessed for IP6 degradation in a simulated intestinal setup. Among the selected microbes, Sporosarcina globiospora hydrolyzed IP6 effectively, as confirmed by colorimetric time-based analysis.

A novel protein tyrosine phosphatase like phytase from Lactobacillus fermentum NKN51: Cloning, characterization and application in mineral release for food technology applications

A novel protein tyrosine phosphatase like phytase (PTPLP), designated as PhyLf from probiotic bacterium Lactobacillus fermentum NKN51 was identified, cloned, expressed and characterized. The recombinant PhyLf showed specific activity of 174.5 U/mg. PhyLf exhibited strict specificity towards phytate and optimum temperature at 60 °C, pH 5.0 and ionic strength of 100 mM. K_m and K_cat of PhyLf for phytate were 0.773 mM and 84.31 s^-1, respectively. PhyLf exhibited high resistance against oxidative inactivation. PhyLf shares no homology, sans the active site with reported PTLPs, warranting classification as a new subclass. Dephytinization of durum wheat and finger millet under in vitro gastrointestinal conditions using PhyLf enhanced the bioaccessibility of mineral ions. Probiotic origin, phytate specificity, resistance to oxidative environment and gastric milieu coupled with ability to release micronutrients are unique properties of PhyLf which present a strong case for its use in ameliorating nutritional value of cereals and animal feed.