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

Naoki Shirotani, Anni Bygvraa Hougaard, René Lametsch, Mikael Agerlin Petersen, Fergal P. Rattray, Richard Ipsen*

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

27 Citations (Scopus)

Abstract

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.

Original languageEnglish
Article number128152
JournalFood Chemistry
Volume340
Number of pages10
ISSN0308-8146
DOIs
Publication statusPublished - 2021

Keywords

  • Fermentation
  • Lactobacillus helveticus
  • Proteolysis
  • Soy protein

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