Avaliação da taxa de congelamento e do tempo de armazenamento congelado na qualidade de contrafilés bovinos maturados após descongelamento

Abstract

The effects of different freezing rates (slow, (-20 ° C, static air; and fast, -25 ° C, forced air) and frozen storage times (1, 14 and 28 days at - 18 ºC) prior to aging time (2 ºC, 14 days) on meat quality characteristics (Longissimus thoracis muscle) of Nellore beef. The slow freezing increased (P < 0.05) the pH, purge, drip and cooking loss. The fragmentation index (IF) and shear force (FC) had a aging time effect (P < 0.05). The IF was not affected (P > 0.05) by the freezing method and storage time. For FC the fast freezing stored for one day showed lower values (P < 0.05). Freezing decreased (P < 0.05) the rate of oxygen consumption and the proportion of oxymyoglobin and increased (P < 0.05) the formation of metmyoglobin. regardless of type and storage time, presented less (P < 0.05) brightness values (L *), red (a *), yellow (b *), saturation (C *) and higher (P < 0.05) shade values (h *). In the psychrotrophic count, the samples frozen and stored for 14 and 28 days, obtained lower counts (P < 0.05) than in the count immediately after thawing (day zero). Freezing prior to maturation can be an alternative to improve meat tenderization, especially at the rapid freezing rate under storage for one day, as it presents less losses and favors the tenderness of the samples, leaving less time stored.