TY - JOUR

T1 - Proteolytic activity of selected commercial Lactobacillus helveticus strains on soy protein isolates

AU - Shirotani, Naoki

AU - Hougaard, Anni Bygvraa

AU - Lametsch, René

AU - Petersen, Mikael Agerlin

AU - Rattray, Fergal P.

AU - Ipsen, Richard

PY - 2021

Y1 - 2021

N2 - Soy protein isolates were fermented by three commercial Lactobacillus helveticus strains for a maximum of seven days to investigate the resulting proteolysis. The proteolytic activity of the most active strain (LH88) was further analyzed (LC–MS/MS and GC–MS) and it was shown that the β-conglycinin α subunit 1, β-conglycinin α’ subunit, glycinin G1, and 2S albumin were specifically degraded. Peptigram analysis and visualization of the crystal structure showed that the hydrolysis sites of β-conglycinin α subunit, α’ subunit, and the glycinin G1 were located on the surface of the molecule or at the mobile disordered region, hence being highly accessible for the proteinase of LH88. The proteins were partially further degraded to free amino acids, and subsequently catabolized to volatile compounds. However, most of the proteins remained native, even after seven days of fermentation, thus additional modification of protein structure or adjustment of fermentation conditions are required for effective generation of flavor compounds.

AB - Soy protein isolates were fermented by three commercial Lactobacillus helveticus strains for a maximum of seven days to investigate the resulting proteolysis. The proteolytic activity of the most active strain (LH88) was further analyzed (LC–MS/MS and GC–MS) and it was shown that the β-conglycinin α subunit 1, β-conglycinin α’ subunit, glycinin G1, and 2S albumin were specifically degraded. Peptigram analysis and visualization of the crystal structure showed that the hydrolysis sites of β-conglycinin α subunit, α’ subunit, and the glycinin G1 were located on the surface of the molecule or at the mobile disordered region, hence being highly accessible for the proteinase of LH88. The proteins were partially further degraded to free amino acids, and subsequently catabolized to volatile compounds. However, most of the proteins remained native, even after seven days of fermentation, thus additional modification of protein structure or adjustment of fermentation conditions are required for effective generation of flavor compounds.

KW - Fermentation

KW - Lactobacillus helveticus

KW - Proteolysis

KW - Soy protein

U2 - 10.1016/j.foodchem.2020.128152

DO - 10.1016/j.foodchem.2020.128152

M3 - Journal article

C2 - 33032150

AN - SCOPUS:85091998883

VL - 340

JO - Food Chemistry

JF - Food Chemistry

SN - 0308-8146

M1 - 128152

ER -