Impact of native Enterococcus faecalis and Pichia kudriavzevii intracellular enzymes on ultra-filtered cheese: compositional, textural and sensory analysis

Abstract

This study aimed to expedite the ripening process of ultra-filtered (UF) cheese utilizing intracellular crude enzymes (CRE) derived from native enterococci and yeasts. Model UF cheese samples were treated with the CRE of selected strains, showcasing both proteolytic and lipolytic activities. The cheeses underwent comprehensive analysis for proteolytic, lipolytic, textural, and sensory characteristics over a 60-day storage period. From the microbial isolates obtained from Lighvan cheese, a subset of 7 Enterococcus and 7 yeast strains were chosen for further characterization. Results revealed a progressive increase in proteolysis and lipolysis indices across all groups including cheese supplemented with Enterococcus faecalis CRE (E-C), cheese supplemented with Pichia kudriavzevii CRE (P-C), cheese supplemented with a combination (1:1) of both E. faecalis and P. kudriavzevii CRE (E.P-C), cheese supplemented with commercial enzymes (CE-C) and control cheese without enzyme supplementation (C-C) during storage. Notably, cheeses inoculated with the combination of Enterococcus faecalis and Pichia kudriavzevii CRE exhibited superior sensory attributes compared to those treated with individual CRE or commercial enzymes. In conclusion, the synergistic action of E. faecalis and P. kudriavzevii CRE emerges as a promising strategy for enhancing flavor, texture, and the ripening process of UF cheese.