Uso de diferentes protocolos de aspersão de água fria sobre carcaças bovinas durante o resfriamento e seus efeitos sobre a qualidade de carne

Abstract

This study was designed to evaluate the use of different protocols for spraying cold water on bovine carcasses during cooling and its effects on meat quality. Four protocols were carried out. In protocols I, II and III, 60-second spraying cycles were performed, 10 minutes apart, with every cycle lasting 13, 15 and 17 hours respectively. In protocol IV a software-controlled refrigeration unit was used, recording the carcass weight in real time and determining the interval and the duration of spray cycles. In all treatments the temperature of the water sprayed on the carcasses was 2°C. For each spray protocol, 10 Nelore female cattle, aged up to 24 months, fat thickness ranging 3 to 6 mm and carcass weight ranging 180 to 210 kg were used. Each protocol was repeated in triplicate for a total of 120 animals. Data evaluated by counting colony forming units before the cooling period and after 24 hours of carcass cooling was: carcass features, such as body weight at slaughter, warm and cold carcass weight, weight losses on cooling, pH, temperature and microbiological quality. Meat samples were collected evaluating musculus longissimus thoracis for color, fat thickness, losses on cooking, losses on exudation and shearing force, shortly after boning and after 14 days of maturation. The study was structured in a completely randomized design, with 4 treatments and 3 replicates for each. The spraying protocols evaluated were effective in controlling weight loss during cooling. The 13- and 15-hour protocols differed from each other and presented weight loss of 0.512% and 0.388%, respectively. The 17-hour protocol presented weight loss similar to the software-controlled protocol (0.189% and 0.182%, respectively). No significant difference was observed between the treatments for shearing force (kgF) evaluated in the same maturation period. The protocols tested did not create a favorable environment for the growth of psychrotrophic and enterobacteria in the evaluated carcasses. The use of the spray contributes to the reduction (P>0.05) of mesophiles after 24 hours of cooling. Differences between the results of the protocols for losses on exudation, losses on cooking, and color were observed, and the software-controlled protocol presented the highest loss values due to exudation, cooking and luminosity.