MANUFACTURE OF GOAT CHEESE WITH ADDITION OF AUTOCHTHONOUS STARTER AND ADJUNCT ACID LACTIC CULTURES: IMPACT ON CHEESE FLAVOUR

GUZMÁN, F.; HERRERA, V.; GONZALEZ, S.; OLISZEWSKI R.

San Miguel de Tucuman

Simposio; IV Simposio Internacional de Bacterias Lácticas; 2013

CERELA-CONICET

The use of autochthonous acid lactic bacteria cultures contribute to the typicality of the cheese and ensure food safety. The acid lactic cultures govern during cheese ripening, quality parameters such as texture, flavor and aroma, of fundamental importance in the final product. The aim of this work was to manufacture a pilot scale semi-hard goat cheese with autochthonous lactic acid bacteria starter and adjunct cultures to evaluate the performance of autochthonous adjunct strains on the sensory perception of cheeses. Two batches were made of semi-hard cheeses from 40 L of goat milk. Lb bulgaricus ETC2 was used as starter and E. faecium BM6 and BM18 as adjunct cultures. Control batch (C) was manufactures only with starter culture (1% w/v) while Experimental batch (E) with starter culture (1% w/v) and the addition of adjunct cultures (0.5% w/v). The milk was pasteurized, acid lactic cultures were added at 42 °C, then calcium chloride (0.01% w/v) and bovine liquid rennet (0.05% v/v) were added, the mass was cut corn grain size, molded and pressed up to pH 5.2 and then salted in brine (20% w/v, 12 h/K cheese). Two cheeses of 600g per batch were obtained. There were two independent trials on consecutive days, using the same milk to avoid variations in composition. Cheeses microorganisms were analyzed by plating: lactococci by LAPTg at 30° and 45°C, lactobacilli by MRS at 30° and 45°C and enterococci by KF at 45°C, all incubated 48 to 72 h, coliforms at 30°C using VRBA coliforms at 45°C by VRBGA, incubated 24 to 48 h, and fungi and yeasts at 30°C incubated 5 d. Sensory analysis was performed by triangle test. Experimental and Control batches were evaluated by 24 panelists. 3 portions cheese randomly and unidentified (2 portions for a batch and 1 portion for another) were evaluated by each judge. The choice of the different portion by each judge allows to evaluate statistically the number of positive hits of the panel, for which a minimum of 13 panelists from a total of 24 must find the different sample (significance level p<0.05). The data were analyzed by ANOVA and comparison of means by Tukey test. Results showed significantly higher values (p <0.05) of lactococci and lactobacilli 30º and 45ºC in Experimental cheeses from 1.5 to 2 units log higher compared to the Control cheeses. Enterococci showed values significantly higher (p<0.05) ​​in Experimental cheeses throughout cheese ripening. Coliforms at 30°C, 45°C and fungal and yeast showed no significant differences among batch (p<0.05). The sensory evaluation results showed significant difference between Control and Experimental batch (p<0.05). Our results suggest that the adjunct cultures evaluated enhance the development of lactic acid bacteria during ripening of cheeses and generate different flavour in cheeses.