Effect of Different Pre-Treatments on Antinutrients and Antioxidants of Rice Bean (Vigna umbellata)

Abstract Rice bean (Vigna umbellata) is a legume that belongs to Vigna genus. Native to Indo-Chinese region, it is considered to be an ‘under-utilized’ or ‘orphan’ crop. Rice bean is known to possess high nutritional potential and antioxidant activity. But the use of rice bean supplementation in routine diet is limited despite its high nutritional profile due to the presence of non-nutritional factors. Thus, various pre-treatments like soaking, germination, oven roasting, sand roasting, boiling and pressure cooking at different time and temperature were carried out to reduce the anti-nutritional content of rice bean and to study its effect on antioxidant activity and phytochemical content. All the pre-treatments were able to significantly reduce the anti-nutrient content in rice bean, but germination showed the maximum reduction. Also germinated rice bean showed the maximum antioxidant potential and maximum content of total phenols, total flavonoids, vitamin C and carotenoids. Rice bean has been underutilized so far, owing to its antinutrient content and low popularity. This experiment attempted to use low cost processing to reduce the content of antinutrients and track the antioxidant content in rice bean. The concluded processing could be adopted for commercial applications for dietary supplementation.