COMPARATIVE ANALYSIS OF CHANGES IN PHYSICO-CHEMICAL AND BIOCHEMICAL INDICATORS DURING CHILLED AND SLIGHTLY FROZEN MEAT* STORAGE

The aim of the study is to conduct experimental studies of the process of refrigeration storage of samples of various types of meat in vacuum packaging, depending on the method of their preliminary refrigeration treatment. Objectives: to study the effect of various temperature conditions and duration of refrigeration storage on the physicochemical and biochemical parameters of chilled and slightly frozen samples of beef and pork and their comparative analysis. The object of the study was beef and pork samples weighing (300 ± 50) g, obtained from the longissimus dorsi muscle (m. L. dorsi), packed in Caso vacuum bags measuring 16 × 23 cm. Samples for the study were collected at the beginning of the experiments and on the 7th, 14th and 21st days of the experiments. It was determined that the slightly frozen state effectively prevents an increase in the active acidity of meat. After 21 days of storage, the pH values of the frozen beef and pork samples were lower than in the chilled state by 1.05 and 1.03 times, respectively. Throughout the entire refrigerated storage period, a significantly lower accumulation of free amino acids was observed using the slightly freezing technology compared to traditional refrigeration. At the end of the experiments, this indicator was higher than the initial values for beef and pork, respectively: by 52.2 and 65.9 % for the chilled samples; and 34.8 and 17.7 % for the slightly frozen samples. During the experimental studies, an increase in acid number compared to baseline values was consistently recorded: for chilled beef and pork, by 5.63 and 5.86 times; for frozen beef and pork, by 3.38 and 3.43 times, respectively. For all studied samples stored chilled, the increase in acid number was 40–42 % higher than for frozen storage. An empirical equation was obtained describing the relationship between pH and acid number and storage duration for beef and pork samples.