Protein recovery and quality of alfalfa extracts obtained by acid precipitation and fermentation

Alfalfa has a high potential as a novel food protein and can contribute to meet the increasing food demand. To facilitate food grade quality, protein extraction is essential. In this study, different extractions with isoelectric focusing the protein were compared; acid precipitation (citric and lactic acids) and fermentation (endogenous and Lactobacillus salivarius). Acid precipitation resulted in the highest protein recovery (30 %) compared with L. salivarius and endogenous fermentation. The protein ribulose-1.5-bisphosphate carboxylase/oxygenase (RuBisCO) was found intact and in high concentrations in acid precipitated samples. With L. salivarius, a higher content of peptides and possible cross-linked proteins were discovered. However, for both extractions, the amino acid composition showed a promising distribution meeting the recommendation of the Food and Agriculture Organization (FAO). Overall, these results indicate that protein extracts obtained with acid precipitation might be more appropriate as a food ingredient, whereas fermented products might have potential as food supplement.