Effect of processing method on quality characteristics of harit soybean (glycine max): in vitro protein digestibility, hplc, ftir analysis

Abstract

Purpose Soybean is potentially a rich source of protein and lipids along with isoflavone. However, the use of soybean is limited due to presence of anti-nutritional factors such as trypsin inhibitor, phytic acid, etc. The present study aimed at evaluation of Harit soya seeds of different treatments such as soaking, dehulling, germination, soaking+roasting and roasting in order to enhance its quality. Design/methodology/approach Harit soya seeds were utilized were soaked overnight and subjected for dehulling, germination for 3 days as well as roasting followed by drying to obtain fine powder for quality evaluation. Findings Dehulling and germination produce significant (p < 0.01) increase in protein, crude fiber, total chlorophyll, ascorbic acid, total phenolics, flavonoids and isoflavones while fat was decreased non-significantly. The highest value of 12.4 mg/100g, 5.3 mgGAE/g and 6.6 mg/g for ascorbic acid, total phenolics and isoflavones was found in germinated seeds. Also, the effect of soaking, roasting and their combination lead to significant decrease in the functional properties of the seeds. Anti-nutritional factors were significantly (p < 0.01) reduced in all forms of treated seeds while pepsin and trysin digestibility was enhanced during soaking, dehulling and germination with maximum value of 72.6 and 25.8%, respectively in germinated seeds. Originality/value Improvement in quality of evergreen variety of soybean using cost effective traditional methods