Optimization of fermentation conditions for dry-aged sirloins with probiotic bacteria added

Abstract

The objective of the research conducted was to optimize the fermentation conditions of pork sirloins and to assess the impact thereof on the sensory quality of dry-aged raw meat products with the addition of probiotic bacteria. The research material consisted of dry-aged pork sirloins and a probiotic strain of Lactobacillus casei LOCK 0900 (Patent Claim No.: P-382760). Two sirloin variants were studied: a control sample with the glucose added and a sample with the probiotic strain and glucose added. The samples of those two variants were aged in three temperature ranges (16, 20, and 24 °C). During the 21-day aging period, the aging meat samples were taken every 7 days in order to analyze them microbiologically. A sensory analysis was performed upon the completion of the aging process of the product. The number of lactic acid bacteria (LAB) was determined using a Tempo ® (bioMérieux, France) apparatus, which counted the number of micro-organisms, whereas the sensory evaluation was carried out by a Quantitative Descriptive Analysis (QDA) method. The highest LAB growth of bacteria, including the Lb. casei ŁOCK 0900 probiotic strain, was found in the pork sirloins during the 21-day aging period at 20 °C (from 107 to 108 log CFU/g). A high number of LAB was also found in the meat samples that aged at 24 °C (from 106 to 107 log CFU/g). The lowest growth of LAB, including the probiotic strain, was determined in the sirloin samples that aged at 16 °C (from 104 to 106 log CFU/g). The product samples that aged at 16 and 20 °C were characterized by the highest overall quality. As regards the microbiological and sensory quality, the optimal fermentation conditions of the dry aged raw sirloins with probiotic bacteria added are: aging temperature of 20°C and aging time of 21 days.