Comparison of results of sensory and chemical and physico-chemical investigations of fresh chilled beef packaged in vacuum during storage in retail conditions

Abstract

Vacuum packaging of fresh meat can contribute to prolonged shelf-life, slower chemical changes in meat, and maintaining of desirable sensoric properties. The main goal of this work was the comparative examination of sensory and chemical properties relevant for oxidative and hidrolytic changes of cooled fresh beef cuts (m.quadriceps femoris) in vacuum packaging, and the determination of interdependence of hydrolytical and oxidative changes regarding to sensory characteristics. The beef flank cuts taken from primal cuts (quarters) of 3 Simmental steers (average weight of 400 kg; one steer per testing cycle) after slaughtering, dressing and cooling were taken for the experiment. Cutting and packaging in vacuum thermo-shrinkable multilayered bags was performed in the industrial meat establishment, within 40 hours after slaughtering. The vacuum packaged beef cut samples were stored under controlled temperature conditions (0-2°C) in refrigerated retail show case. During the night, samples were removed from show case and stored in cold storage room in the same establishment (0-4°C). This method was repeated as daily routine during examination period. Sensory and chemical examination dynamics was set as: day 1 (immediately after packaging), days 15, 21 and 28 in each particular testing cycle (3). Sensory properties were evaluated by using quantitative-descriptive test, on a scale of 1 to 5. The following properties were evaluated: appearance of meat, the colour of meat surface, the colour of meat intersection, structure, texture, smell of the fresh meat, smell of the meat after cooking, taste of the meat after cooking and roasting. The examined chemical properties indicating oxidative and hydrolytic changes were: acid value, peroxide number, TBA test (test with thiobarbituric acid to determinate malonaldehide content), TVB-N (total volatile basic nitrogen), aw (water activity value) and pH. Sensory and chemical qualities of vacuum packaged beef flank under established storage conditions were acceptable in all three testing cycles, ending with the 21st day. In the first and second cycle, in most cases, there were confirmed medium to strong correlations of all examined chemical parameters with the sensoric characteristics of beef. In the third cycle, the registered above mentioned correlations between chemical parameters and sensory properties were classified as negative weak correlations.