Effect of ripening period and culture level of starter on the quality characteristics of fermented beef sausage

Abstract

This study was conducted to determine the impact of ripening period and starter culture level on physicochemical parameters, colour parameters, and total bacteria count (TBC) of fermented beef sausage under Sudanese conditions. Combination of equal portions of two strains of lactic acid bacteria (Streptococcus ssp. and Lactobacillus ssp.) were added as starter culture at two levels (level 1= 1.34 ml/kg and level 2 = 2.67 ml/kg) to formulate two batches of fermented beef sausage. Both the fermented sausages were stored for 0, 7, and 14 days under 85% relative humidity at 21 oC. Three replicates from each starter level were subjected to analysis for physicochemical parameters, colour measurements, and TBC at the three ripening periods (0, 7, and 14 days). The results revealed significant increase (P<0.01) moisture, crude protein, and fat content of fermented sausages with increasing ripening period. The pH was higher at 7 day ripening followed by 0 day ripening, whereas lower pH was observed at 7 day ripening period. Lightness (L*) increased (P<0.01) with ripening period, whereas the redness (a*) decreased sharply (P<0.01). However, yellowness (b*) value was lower (P<0.01) at 7 day ripening period followed by an increase at 14 day ripening and highest values was observed at 0 day ripening period. Furthermore, the higher values of all colour measurements were observed at lower starter level (P<0.01). Higher TBC was observed at 7 day ripening period compared to 0 day and 14 day ripening period which did not differ significantly from each other. In conclusion the 14 day ripening period and higher starter culture level results in higher values of physicochemical characteristics and colour measurements; 7 day ripening period results in higher total bacterial count of fermented beef sausages.