Perspectives of lupine wholemeal protein and protein isolates biodegradation. (22nd July 2018) - Bartkiene, Elena
Summary: Lupine ( Lupinus angustifolius L.) protein (in wholemeal and protein isolates) was biodegraded using Pediococcus acidilactici in submerged and solid‐state fermentation conditions. The changes in the molecular weight of lupine protein fractions, amino acid (AA) profile, biogenic amine formation, antimicrobial and antioxidant properties, and protein digestibility in vitro and in vivo (in Wistar rats) were evaluated. After biotreatment, lower molecular weight peptides (from 10 to 20 kDa) were established, and the free AA content increased. Biodegradation improved the antioxidant properties, modulated the antimicrobial properties, and led to higher in vitro and in vivo digestibility and functionality of the lupine in treated rats (significant increase in body weight of Wistar rats, and increased acetic acid concentration and lowered Escherichia coli count in the caecum). Overall, the biodegradation of lupine protein can transform the plant protein, producing enhanced functionality and bioavailable products. Abstract : Pediococcus acidilactici strain is a suitable starter for lupine protein biodegradation, lowering the molecular weight of the protein (peptides from 10 to 20 kDa) in SMF and SSF samples. Also, enhanced protein digestibility of SSF (7.7%) and SMF protein isolates (11.2%), respectively, can be obtained, compared to nonfermented samples. The biodegradation of lupine protein endows new features to the plant protein, producing higher functionality and bioavailable products: increased TPC content, improved antioxidant properties and modulation of new antimicrobial properties (protein isolates showed antimicrobial activity against Salmonella enterica, Pseudomonas aeruginosa, Acinetobacter baumanni, Bacillus cereus and Enterococcus faecalis ). Biodegraded lupine products significantly increased the BW of Wistar rats, and also led to a higher acetic acid concentration and significantly lower Escherichia coli count in the caecum of treated rats. Finally, biodegradation improves the nutritional value of proteinaceous plants, and results in the formation of lower molecular weight compounds leads to higher bioavailability of the product.