CONICET | Buscador de Institutos y Recursos Humanos

Galactooligosaccharides (GOS) are non-digestible oligosaccharides withrecognized prebiotic role. The present study aims to evaluate a β-galactosidasefrom K. lactis during soft cheesemaking and to analyse the impact on carbohydrates metabolism, proteolysis, andvolatile compounds production, physicochemical and microbiologicalcharacteristics of the product. The enzyme was added to cheese milk (fluid milkplus whey powder) before (40 min.) or simultaneously of the starter addition (Epand E treatments, respectively); cheese without enzyme addition was also made(C treatment). Also, we characterized fresh and soft commercial cheeses fromthe point of view of carbohydrate fraction, highlighting GOS, and organic acidprofiles.Theinclusion of the enzyme in soft cheese making produced a delay in reaching the targetpH (~ 5.2). Carbohydrate fermentation profiles differed among treatments duringcheese making and ripening. GOS were only detected in Ep and E cheeses (0.88and 0.51 g/100 g, respectively). Lactose content was lower, and glucose andgalactose levels were higher in E and Ep than C. No differences in physicochemicaland microbial composition and organic acids profiles among samples wereobserved. Bioformation of volatile compounds belonging to the chemical familiesof aldehydes, ketones, alcohols, esters and acids, was not substantiallyaffected by the modification in the carbohydrate profile. GOS were not detectedin any of the commercial cheeses; great variations in the carbohydrate contentsand organic acids were found. The results obtained demonstrate the feasibilityof obtaining cheeses with GOS. Although the GOS values achieved are notadequate enough for the desired effect, the proposed technological approachturned out to be satisfying and original. Cheeses with prebiotic fiber are not stillwidespread in the market.

enviar mensaje