Antioxidant peptides released from soybean by lactic acid bacteria with proteolytic activity

QUIROGA, MARÍA; ARGAÑARAZ MARTINEZ, ELOY; BERTANI, MILENA SABRINA; BABOT, JAIME DANIEL; PEREZ CHAIA, ADRIANA

Congreso; SAIB - SAMIGE; 2021

Biopeptides are fragments encrypted in a precursor protein. They possess a particular amino acid sequence and specificbiofunctional attributes that can influence the main systems of an organism when released by proteolysis. Glycinin and βconglycinin are the main proteins in soybean (which in turn is the main protein source in poultry feeds), and many aminoacidic sequences with different features, such as antioxidant properties, are included in them. On the other hand,microorganisms are an important source of proteolytic enzymes. They could act on soybean proteins and release biofunctionalpeptides that may possess antioxidant properties. Therefore, the aim of this work was the study of the antioxidant activity ofthe biopeptides released from soybean protein isolate (SPI, which contains only glycinin and β-conglycinin) by three lacticacid bacteria (Enterococcus italicus LET 302, E. faecium LET 303 and Lactobacillus brevis LET 216) previously isolatedfrom soybean flour. To this end, each strain was incubated for 16 h in broth with SPI as the sole protein source. Then, thesupernatants were recovered by centrifugation and sterilized by filtration with 0.22 µm pore membranes. In order to obtaindifferent peptidic fractions, the supernatants were centrifuged with 10 kDa filters, and the filtrates were centrifuged again with3 kDa filters. This way, three fractions were obtained for each strain: M1 (peptides >10 kDa), M2 (3 kDa < peptides < 10kDa),and M3 (peptides