Avaliação da qualidade dos queijos Minas Frescal e tipo Mussarela produzidos com leite contendo diferentes níveis de células somáticas / Evaluation of Minas Frescal and Mozzarella type cheeses manufactured from milk containing different somatic cell counts

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

The aim of the present study was to evaluate the effect of somatic cells counts (SCC) in raw milk (at levels of 100-200,000, 400-500,000 and 800,000 cells./mL) on physical, chemical, microbiological, sensorial and functional characteristics of Minas frescal and Mozzarella type cheeses. A completely randomized block design was used, considering SCC as the main effect, the days of analysis as sub parcels and the processing batches as the blocks. Each type of milk was obtained from cows previously selected according to its individual SCC. The manufacture of cheeses included: pasteurization of milk (65ºC, 30 minutes), addition of calcium chloride, starter culture (for Mozzarella) and rennet, coagulation and separation of the curd, whey drainage, salting (for Minas cheese), stretching of the curd, kneading and salting in brine (for Mozzarella), and packing the products. The cheeses were stored in a B.O.D. oven at 4ºC and evaluated on days 2, 9, 16 23 and 30 after the manufacture. The sequence of elaboration of the Minas frescal and Mozzarella cheeses was repeated 5 and 3 times, respectively, for each treatment. The analyses carried out in the cheeses were: pH, acidity, percentages of fat, dry matter (DM), ashes, total nitrogen (NT), non-protein-nitrogen (NPN), non-casein nitrogen (NCN), proteolysis, free fatty acids (FFA), texture, sensorial evaluation, functional properties (melting capacity the 107 ºC and percentage of free oil - only in the cheese Mozzarella), mesophile and psychrotrophic counts and the most probable number at 30 and 45ºC. For Minas frescal cheese, no interaction was found between SCC and days of storage when considering the data on chemical, physical, microbiological, functional and lipolysis index. However, a significant effect (P<0.05) was observed for proteolysis and depth of proteolysis. For mesophiles, psychrotrophics, acidity, dry matter, firmness and free fatty acids, there was a significant effect (P<0.05) for days of storage. The sensorial evaluation made on the first day of analysis did not present significant differences for all attributes. However, the Minas cheese made with high SCC (800,000 cells/mL) differed on day 30, when it received worse grades for all the attributes. For the Mozzarella cheese, an interaction between SCC and days of storage was observed only for the melting capacity, which resulted in an increment of the melting along the time of storage. The parameters of pH, free fatty acid, proteolysis, extension and depth of proteolysis, springiness and elasticity had significant effect (P<0.05) for days of storage. Amongst the attributes evaluated in the sensorial, only the appearance presented difference between treatments. The yield of Minas frescal and Mozzarella cheese was not influenced by the amount of somatic cells in the original milk. Results indicated that milk used for the manufacture of Minas frescal and Mozzarella cheeses should present SCC up to 400-500,000 cells/mL, in order to avoid quality changes in those products during storage.

ASSUNTO(S)

analysis stretched curd cheese análises scc ccs mastite queijo fresco fresh cheese mastitis queijo de massa filada

ACESSO AO ARTIGO

Documentos Relacionados