Processing Effect on Phytic Acid and Inorganic Phosphorus Content of Soybean (Glycine max, Brown var.)

Abstract

The objective of this research was to study the effect of some processing methods on phytic acid (a prominent anti-nutritive substance) and inorganic phosphorous content of the king legume soybean. The processing treatments viz. soaking and subsequent germination; kinema fermentation and heating were applied. It was observed that soaking for 12 hrs at room temperature under citric acid solution, distilled water and sodium bicarbonate solution significantly (p <0.05) lowered the phytic acid content of soybean by 7.99%, 6.38% and 7.20% respectively and also correspondingly lowered the inorganic phosphorous by 21.8%, 27.55% and 30.75% . Maximum destruction of phytic acid (35.1% reduction) occurred during germination for 120 hrs in 0.1% citric acid solution. This was further confirmed by increase of inorganic phosphorous content (196.22%) in corresponding treatments. A 46.07% significant reduction (p < 0.05) of phytic acid content over the control was noticed after 72 hrs of kinema fermentation. On the same interval, inorganic phosphorous content also significantly increased by 180%. Autoclaving was found more effective than dry heating and boiling also could reduce the phytic acid content of soybean. Autoclaving (121ºC for 15 min), dry heating (200ºC for 5 min) and boiling (100ºC for 30 min) significantly lowered (p< 0.05) soybean phytate by 20.76%, 12.84% and 14.84% respectively. In other hand, inorganic phosphorous content were increased significantly by 80.56%, 43.8% and 63.55% at the same time. DOI: http://dx.doi.org/10.3126/jfstn.v7i0.11208   J. Food Sci. Technol. Nepal, Vol. 7 (102-106), 2012