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Phytase‐mediated mineral solubilization from cereals under in vitro gastric conditions
Author(s) -
Nielsen Anne VF,
Meyer Anne S
Publication year - 2016
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.7564
Subject(s) - phytase , phytic acid , bran , food science , bioavailability , chemistry , citric acid , biochemistry , dephosphorylation , enzyme , biology , phosphatase , raw material , bioinformatics , organic chemistry
BACKGROUND Enzymatic dephosphorylation of phytic acid (inositol hexakisphosphate) in cereals may improve mineral bioavailability in humans. This study quantified enzymatic dephosphorylation of phytic acid by measuring inositol tri‐ to hexakisphosphate ( InsP3 –6) degradation and iron and zinc release during microbial phytase action on wheat bran, rice bran and sorghum under simulated gastric conditions. RESULTS InsP3 –6 was depleted within 15–30 min of incubation using an Aspergillus niger phytase or Escherichia coli phytase under simulated gastric conditions, with the two enzymes dephosphorylating cereal phytic acid at similar rates and to similar extents. Microbial phytase‐catalyzed phytate dephosphorylation was accompanied by increased iron and zinc release from the cereal substrates. However, for wheat bran at pH 5, the endogenous wheat phytase activity produced mineral release equal to or better than that of the microbial phytases. No increases in soluble cadmium, lead or arsenic were observed with microbial phytase‐catalyzed phytate dephosphorylation. CONCLUSION Microbial phytase treatment abated phytate chelation hence enhanced the release of iron and zinc from phytate‐rich cereals under simulated gastric conditions. The data infer that acid‐stable microbial phytases can help improve iron bioavailability from phytate‐rich cereal substrates via post‐ingestion activity. © 2015 Society of Chemical Industry