Estudo do efeito do congelamento e do tempo de armazenagem sog refrigeração apos o descongelamento nas propriedades funcionais, textura e proteolise do queijo mussarela

AUTOR(ES)
DATA DE PUBLICAÇÃO

1997

RESUMO

The effect of storage time (T=6-8°C) after thawing on proteolysis, melting edacity, free oil formation, the color before and after melting, the separation of water, water activity, ease of cutting, and texture attributes TPA [texture profile analysis} of Mozzarela cheese was evaluated. Three batches of cheese were produced under Industrial conditions on three separate days, using a mesofilic starter. Each batch consisted of 10 blocks of cheese of approximately 3.5Kg. Each batch was divided into 2 parts at random, one being submitted to slow freezing (T=-20°C) in a cold chamber during 15 days, and other maintained refrigerated (T=6-8°C} as a control. After thawing, the previously frozen part was maintained refrigerated for a further month treatment referred to as tempering. After 0, 1, 2, 3 and 4 weeks of storage the samples were analysed for their functional properties, ease of cutting, texture attributes TPA and proteolysis elefroforeses as well as for the soluble M content in both, acetate buffer pH 4,6 and in 12% TCA. Only slight proteolysis was noted, electrophoresis showed a breakdown of α1-casein to α2i-casein and a slight breakdown of p-casein probably due to the activity of plasmin resulting in the appearance of γ1, γ2 and γ3-caseins bands. The low level of proteolysis was probably associated with high stretching temperature, which may have inactivated a considerable part of the coagulating agent and probably inactivated the mesofilie starter resulting in low-acid cheese. With respect to the texture profile analysis, in general great differences were noted initially which diminished with time, being practically insignificant after 2 weeks of tempering. The previously frozen cheeses were easier to cut due to their low TPA cohesivity and TPA hardness. Separation of wafer was observed up to the second week of storage. Free oil formation increased with storage time significantly for both treatments and it was superior in the tempered cheese. The melting capacity of ail the samples was generally low due to the low levels of proteolysis. Recently thawed samples showed greater melting capacity than the other samples. After two weeks of tempering, the melting capacity, ease of cutting, and the majority of texture parameters of the frozen cheese were similar to the controls. Thus after this period of tempering, the freezing process only negatively affected the separation of free oil.

ASSUNTO(S)

alimentos - textura alimentos congelados descongelamento queijo

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