Abstract:
The growth of Clostridium perfringens from spore inocula was studied in sous vide cooked ground beef with added 0 to 3% grape seed extract (GSE). C. perfringens did not grow at 4 degrees C with or without GSE present. Lag time (LT) was 95 h in control samples at 15 degrees C, whereas 1-3% GSE addition significantly (p < .05) extended LT to 244 h or longer. Generation time (GT) in 3% GSE added beef was similar to that of control (19 h, 3% GSE versus 18 h, control) at 15 degrees C. At 20 degrees C, GT was 1.5 h in samples without GSE; however, 1-3% GSE addition extended GT about 2-3 folds (p < .05). Lag time at 20 degrees C was 23 h in control samples, while LT was 40-59 h in samples containing GSE. Interestingly, GSE did not affect LT at 25 degrees C; however, significantly (p < .05) longer GT was observed in 3% GSE added samples than the other sample groups. Additionally, GSE from 1 to 3% in beef extended the period needed to reach 6 log cfu/g at 15 or 20 degrees C, while 3% GSE was required at 25 degrees C. The findings suggest that GSE exhibits concentration and temperature dependent inhibitory effect on growth of C. perfringens in sous vide cooked ground beef. Grape seed extract can be used to extend the shelf-life and ensure the microbiological safety of sous vide cooked meat products.
