The influence of tempeh fermentation and conventional cooking on anti‐nutrient level and protein bioavailability (in vitro test) of grass‐pea seeds

BACKGROUND: The solid state fermentation tempeh type is known to result in the decomposition of anti‐nutrients and the improvement of nutritional value of legume seeds. The aim of the research was to study the influence of tempeh fermentation and conventional cooking on (1) levels of 3‐ N ‐oxalyl‐ L ‐2,3‐diaminopropionic acid (ODAP), soluble phenols, trypsin inhibitors and inositol phosphates; and (2) the in vitro bioavailability of proteins in grass‐pea seeds. RESULTS: Tempeh fermentation reduced the level of ODAP, trypsin inhibitors and phytates by 93, 99 and 22%, respectively, and increased protein bioavailability by about 25%. Protein bioavailability from conventionally cooked seeds was higher than from fermented seeds. However, during the in vitro test more soluble protein (approx. 10%) was released from 100 g tempeh product than from cooked seeds. CONCLUSIONS: Solid state fermentation and cooking resulted in seeds of comparable quality but the tempeh contained much less ODAP, which is very promising in the context of popularising grass pea.