Valorization of byproducts from meat and dairy industries through fermentation to produce peptides

Abstract

The escalating global issue of waste streams, particularly within the food industry, necessitates a sustainable approach to valorizing food wastes and incorporating these valorized compounds into new products. This study addresses the limitations of existing protein extraction methods by proposing an innovative bioprocessing technology to effectively recover them from waste streams. The primary objective is to regulate protein hydrolysis through a fermentation procedure applied to waste streams from the meat and dairy industries. Sodium-citrated whole blood from cattle and pre-sterilized acid whey from cottage cheese production were blended, followed by the addition of Lactobacillus rhamnosus (OSU-PECh-69) due to its high proteolytic activity. The fermentation process, conducted at 37 °C for 5 days, revealed that L. rhamnosus maintained viability at ∼9 log CFU g⁻¹, while coliforms remained below the detection limit of 250 CFU g⁻¹. The acidity in the acid whey favored the growth of lactic acid bacteria over other pathogens, resulting in a decline in pH, which limited coliform growth. The fermentation mixture with the addition of L. rhamnosus achieved a degree of hydrolysis of 6%. SDS-PAGE analysis confirmed the modification of proteins into smaller fragments during fermentation. This biotechnological process demonstrates the potential to valorize nutrient-dense byproducts through fermentative hydrolysis, offering a promising avenue for creating economically viable and sustainable processing solutions to make better use of the food industry byproducts.