Abstract
In plant seeds, phytic acid acts as a storage compound of phosphorus, which can form complexes with minerals and trace elements reducing their bioavailability, thereby having a negative impact on human nutrition. Further, phosphorus in this form is unavailable for absorption in monogastric animals and humans. Dephosphorylation of phytic acid is carried out by enzymes called phytases, which in turn makes phosphorus available back for absorption. Sourdough fermentation has shown reduced amounts of phytic acid even by 70% due to the combined action of acidification process and endogenous microbial phytases. Hence, sourdough can be used to naturally reduce the amount of phytic acid in cereal (or legumes) breads and improve bioavailability with significant importance in the food industry. Determination of phytic acid in unprocessed foods and feeds has been extensively studied using diverse methods, including chromatographic separation, precipitation, and spectroscopy. However, most of these methods are laborious, costly, are of low throughput, and require specialized analysts. Here, we describe a rapid colorimetric method, which involves acid extraction of phytic acid, followed by dephosphorylation with phytase and alkaline phosphatase. The phosphate released is measured with a molybdenum-based blue assay and calculated as phytic acid or total phosphorus content in the original sample.