Synergistic use of fermentation and extrusion processing to design plant protein-based sausages

The synergistic effect of lactic acid fermentation and high-moisture extrusion processing of pea protein on the microbiological and sensory properties of plant-based sausages was investigated. Plant-based sausages were formed by combining fermented pea protein concentrate (PPC) biomass with high-moisture extruded pea protein isolate (PPI). Pea protein concentrate (PPC) was fermented with Lactococcus lactis subsp. lactis and Lactiplantibacillus plantarum to improve the perceived structure, texture, and flavour (specifically via expression of glutamic acid which is connected to umami flavour) of plant-based sausages.

The sausages were prepared by stuffing the mixture of extruded PPI and fermented PPC (addition level 70:30) inside vegetarian casings followed by steam cooking. After preparation and cooking of the sausages, a trained sensory panel evaluated the intensities of ten selected attributes defining the flavour, odour, colour, and texture. In addition, dry matter content, acidification, microbial quality, and glutamate contents were analysed.

The results demonstrated that fermentation decreased the pea-like odour and improved the texture of the sausages. In addition, yeast-like odour and umami taste were observed. The study was able to demonstrate novel clean-label processing approaches by combined fermentation and extrusion to generate in-situ meat-like flavour and texture based on plant protein ingredients.