Fermentos de lactobacilos mesófilos para quesería

DIEGO MERCANTI; MARÍA MERCEDES MILESI; ERICA HYNES

Porto Alegre

Congreso; 9º Congresso Pan-americano do Leite; 2006

FEPALE

Adjunct cultures of mesophilic lactobacilli can improve cheese quality by increasing flavor, preventing the proliferation of non starter lactic acid bacteria and providing probiotic potential to the food product. In this work, a strain of Lactobacillus plantarum was assayed as adjunct culture by in situ experiments, using a miniature soft cheese model obtained under controlled microbiological conditions. The tested culture rapidly increased up to 10exp8 CFU g-1 and remained constant over 60 days of ripening, while the starter culture population was over10exp9 CFU gexp-1, coliform bacteria diminished, and moulds and yeasts slightly augmented. Adventitious lactobacilli in control cheeses (without an adjunct culture) were always below 10exp4 CFU gexp-1. Proteolysis of the cheeses significantly increased with ripening time, as evidenced by electrophoresis, nitrogen fractions, peptide mapping and free amino acids profiles. Cheeses with and without added lactobacilli had similar proteolysis patterns, xcept for free amino acids profiles. Those showed an increase in the individual amount of several amino acids,such as Asp, Arg, Ala, Pro, Leu and Phe, and a global augmentation in the total content of free amino acids in cheeses with the adjunct culture. The aroma of the cheeses with and without lactobacilli, assessed by a triangular sniffing test, significantly differed.