Design of two different technologies for the production of argentinean sheep cheeses

BERGAMINI, CARINA V.; MEINARDI, CARLOS A.; BERNAL, SUSANA M.; WOLF, VERÓNICA I.; BUSETTI, M.; ZALAZAR, CARLOS A

Alghero, Italia

Simposio; 5th International Symposium, on The Challenge to Sheep and Goats Milk Sectors; 2007

Fédération Internationale de Latierie – International Dairy Federation (FIL-IDF)

Presentación en formato póster y publicación del resumen. The production of sheep cheeses in Argentina is very limited and recently, and consequently there are not standardized making technologies. In the present work, two different ways for the production of cheeses from Argentinean Pampinta bred milk were designed. One way allows to obtain a product of light flavour and low proteolysis. The second way, allows to obtain a product of very intense flavour, with a high proteolysis and extra ripened. With this scope cheeses S were produced employing a starter of S. thermophilus, corn size grains in curd, 43ºC of cooking temperature and curd washing. On the other hand, cheeses L were produced with a mixture of S. thermophilus (60%), L. bulgaricus (20%) and L. helveticus (20%) as starter, rice size grains in curd, 47ºC of cooking temperature and without washing. Cheeses were ripened during 180 days and analysed for gross composition, starter population and proteolysis. Fat matter, humidity and total proteins were not significantly different between L and S cheeses. Values of pH at 3 and 180 days were significantly lower for cheeses L. For both cheeses S. thermophilus from starter had an initial count of 109 CFU g-1. This population falls one and two logarithm orders at 90 and 180 days respectively. Lactobacilli population from starter in L cheeses falls significantly from the beginning (108 CFU g-1) to 90 days (104 CFU g-1). At 180 days lactobacilli were not detected. L cheeses showed a more extended and deep proteolysis than S cheeses. Differences in proteolysis were detected both in the nitrogen fractions and in the electrophoretic profiles. In L cheeses αs1 casein was totally proteolysed at 90 days, while β casein showed some hydrolysis between 90 and 180 days. In S cheeses a fraction of αs1 casein remained not proteolysed at the end of ripening, while β casein was not hydrolysed. The important decrease in lactobacilli population and the deep proteolysis in L cheeses suggest a high autolysis degree in these bacteria with liberation of intracellular protease. This hypothesis agrees with the high ripening index and the more intense sensorial characteristics of L cheeses. On the contrary, the technology and the starter employed in S cheeses allow the production of a cheese with a low level of proteolysis, sensorial characteristics not very intense and with a short ripening time.