CONICET | Buscador de Institutos y Recursos Humanos

Whey is a by-product of the cheese industry often disposed as waste causing environmental contamination problems. To solve this concern, numerous approaches have been taken to add value to whey. Since this product has high nutritional value it might be used as substrate for the development of fermented whey-based beverages or foods. The aim of this work was to evaluate the growth and proteolytic activity of sixty-five strains of lactic acid bacteria (LAB) in whey to further formulate a starter culture for the development of fermented whey-based beverages. Fermentations were performed at 37°C for 24 h in 1.0 and 1.6 g∙L reconstituted whey powder (RW). Growth (CFU∙mL-1), pH, and proteolytic activity (o-phthaldihaldehyde test) were determined at 6 and 24 h of incubation. Hydrolysis of whey proteins was analyzed by Tricine SDS-PAGE. Principle component analyses (PCA) was applied to evaluate the growth and proteolytic activity of the different LAB strains in RW. Results showed that all the assayed strains could grow and degrade whey proteins albeit at different extent. The Lactobacillus casei group was the most proteolytic while the streptococci were the most acidifying strains. Statistical PCA analysis is a simple method for selecting appropriate strains for starter culture formulation.