Impact of Sprouting on the Oxalate Load of Proteinaceous Plant Based Foods

Abstract

Total oxalate content of plant-based foods has a prominent impact on renal calculi formation in animals and man. The present study was aimed to estimate total oxalate in six selected whole dry seed samples namely Chick pea - Cicer arietinum (S1), Red cowpea – Vigna unguiculata (S2), Green pea – Pisum sativum (S3), Mung bean – Vigna radiata (S4), Almond- Prunus dulcis (S5) and Soybean – Glycine max (S6) and their seed coats used as protein rich foods at 0 hrs., 24 hrs. And 48 hrs. Post soaking in distilled water. Total oxalate (TO) levels were found to be decreased in all the sprouted whole seeds at 24 hrs. And 48 hrs. Than 0 hrs. Post soaking. Whole seeds of S2 contained maximum TO (400mg/100g sample) prior to sprouting which on soaking for 48 hrs. Reduced TO (122mg/100g). Maximum reduction in TO after 48 hrs. Was in S4 (292mg-25mg/100g). S1, S3, S5 and S6 exhibited lowering of TO by (243mg-80mg, 93mg-35mg, 343mg-133mg, 232mg-85mg per 100g sample) respectively. Sprouting induced more than 60% reduction of TO in whole seeds. Seed coat analysis of S4 (259mg-404mg/100g sample) and S5 (280mg-134mg/100g sample) projected an increase in TO post 24 hrs. Soaking, but further soaking till 48 hrs. Decreased the oxalate load to 261 mg and102 mg respectively. Seed coats of S1 and S3 shows lowering of TO from 30mg/100g sample and 33mg/100g sample to12mg/100g and 13 mg/100gsample. Sprouting, regulated oxalate levels in plant-based foods and exclusion of seed coats could reduce oxalate intake. Total Oxalate analysis of plant-based foods need to be addressed for safety of renal patients in choosing low oxalate diet.