Efeito do congelamento nos processos de maturação úmida e a seco da carne de gado

Abstract

The effect of freezing before dry aging and cold storage of meat from Zebu cattle (Bos indicus) was evaluated in two treatments, control and frozen (-20 oC / 7 days), in the following aging times: 0, 14, 28 or 42 days. Thus, samples of loins (Longissimus thoracis) were analyzed to verify the technological, microbiological and sensory quality, the volatile compounds and fatty acids in beef profile. It was found that freezing can reduce (P < 0,05) the aging time from 28 to 14 days reaching the same sensory tenderness and shear force of meat aged for 42 days, however, the results of the fragmentation index suggest that this reduction in cold storage occurs due to cryogenic damage, while in dry aged this reduction is attributed to proteolysis. In general, in both cases, freezing: did not affect (P > 0,05) or reduced (P < 0,05) the sensory perception of juiciness; increased (P < 0,05) water loss; reduced (P < 0,05) the color intensity of the meat and the reducing capacity of the muscle, increasing (P < 0,05) the levels of MMb; did not influence (P > 0,05) or increased (P < 0,05) the count of mesophilic microorganisms; increased (P < 0,05) the count of lactic and psychotropic bacteria, and in the case of cold storage this increase was only observed in time zero. As for the volatile profile, a higher concentration (P <0.05) of alcohols, ketones and ester was observed in dry-aged samples, especially in frozen samples, while higher concentrations of hydrocarbons were observed (P <0.05) in wet aged and not frozen samples. The principal component analysis showed that, in wet aged samples, freezing generated a greater association with a greater number of compounds. Since, in both aged systems, freezing and higher maturation time are associated with different compounds that give desirable flavors. Freezing / thawing and maturation time had little influence on the fatty acid profile of the meat, however, dry-aged meats presented more (P <0.05) unsaturated and monounsaturated fatty acids than wet-aged. Among the characteristics analyzed, it is noted that the deleterious effects are small, making the process advantageous.