Effect of debittering and solid-state fermentation processes on the nutritional content of lupine (Lupinus mutabilis Sweet)

There is a growing interest in vegetable-based sources of proteins. Despite its high nutrient content, lupine has been rarely exploited as a protein source due to the presence of high levels of non-nutritive compounds such as alkaloids, which impart a bitter taste. Here, we evaluated the effect of debittering and solid-state fermentation on the nutritional contents of three lupine varieties (Lupinus mutabilis Sweet). These processes induced significant changes (P < 0.05) in the nutritional composition of the three lupine varieties (INIAP-450, INIAP-451 and Criollo) and increased the protein levels to 644.55 g kg^?1 (Criollo variety) and the levels of several constituent amino acids such as valine (54.62 g kg^?1), methionine (42.47 g kg^?1), isoleucine (59.27 g kg^?1) and leucine (76.32 g kg^?1). The ether extract of INIAP-450 showed increased levels (up to 244.03 g kg^?1); especially, monounsaturated fatty acids (559.78 g kg^?1) and polyunsaturated fatty acids (293.17 g kg^?1) were observed. The omega-6/omega-3 ratio in the debittered grain oil reached the minimum requirement established for good-quality oils (5/1). However, the levels of other components decreased, showing levels up to 13.04 g kg^?1 (total starch) in the Criollo variety, 22.62 g kg^?1 (resistant starch) in INIAP-450, 6.53 g kg^?1 (potassium) in INIAP-451, 46 g kg^?1 (iron) in INIAP-451 and 29.75 g kg^?1 (zinc) in INIAP-450.