Characterization of Rigor Mortis Process in Longissimus Dorsi of Crossbred Calves

Characterization of rigor mortis process in Longissimus dorsi of crossbred calves
Annelise AG Lobo¹, Anna CF Rocha², Mario L Chizzotti², Ana CB Menezes², Aline S Trece², Marcelo MD Castro², Juliana Dias², Victorio R Vardiero² and Marcos I Marcondes², (1) University of São Paulo (USP), Pirassununga, Brazil, (2) University of Viçosa (UFV), Viçosa, Brazil

This study, conducted at the University of Viçosa, Brazil, aimed to characterize the process of conversion of muscle into meat of crossbred Holstein x Gir veals. This study aimed to characterize the process of conversion of muscle into meat of crossbred veals. Was used 35 calves with an initial mean body weight (35±5 kg). We used 35 carcasses of crossbred calves Holstein-Gir subject to two treatments: 1)fed only milk (L) and 2) milk plus concentrated (LC).The animals were slaughtered at 44 days old. It was accompanied the temperature, pH and sarcomere length at different intervals of time after slaughter (0200, 0400, 0600, 0800, 1000, 1200 and 2400). The temperature of the cold chamber was adjusted by decreasing 2°C every two hours, starting at 16°C. For all parameters we used a 5% of significance. The carcasses were kept for 24 hours in the cold chamber at 4°C and after that period the Longissimus dorsi muscle was removed from each half carcass. The muscle was vacuum packed and frozen. The pH variation was significant for hour and diet (P < 0.05). Over time the pH decreased, presenting a mean of 6.71 at time 0 and 5.51 at time 2400. The carcasses of the animals submitted to LC treatment had a lower mean (5.98) than the carcasses of the L treatment (6.06). The monitoring of the pH drop is an important tool to analyze the quality of the meat. Depending on your speed of decrease and the level of glycogen available the quality may vary, leading to a softer or harder meat. The temperature variation was not significant between treatments (P > 0.05). Statistical analysis did not show a significant difference (P > 0.05) regarding the length of sarcomere values in time, diet and time and diet intervals. Thus, carcasses of animals submitted to the diet with or without concentrate do not presente length of sarcomere and temperature during the process of rigor mortis. The decrease in pH is observed to act faster in calves fed with concentrate during its development phase.

Keywords: pH, sarcomere length, temperature