BIOPROTECTION ON FRANKFURTER SAUSAGES

The possibility of prolonging the shelf-life of refrigerated sausages by the utilization of Lactobacillus alimentarius was studied. Frankfur ter sausages were inoculated with a suspension of Lactobacillus alimen tarius (flora meat L-2 by Chr. Hansen), by sprinkling, resulting in ap proximately 10(7) CFU cm(-2) on its surface. The sausages were then va cuum-packed and stored at +5 degrees C (+/-0.1 degrees C) and +10 degr ees C (+/-0.1 degrees C) for 8 weeks. Each week, the water activity of the sausages was recorded. Furthermore, measurements of pH and bacter ial counts for psychrotrophic microorganisms, aerobic mesophyles, Gram -negative and lactic acid bacteria were done. Simultaneously, a sensor ial analysis was conducted for taste determination, texture, colour, a roma and overall acceptability. The samples inoculated with Lactobacil lus alimentarius and kept at 10 degrees C showed a more rapid decrease in pH on day 7, whereas the rest of the samples showed a progressive pH decrease during storage. In control samples stored at 5 degrees C t he pH decrease was observed only after 5 weeks of storage. When stored at 10 degrees C the same pattern of pH decrease was observed in the t hird week. The utilization of Lactobacillus alimentarius was successfu l for microbiological control, being effective against Gram-negative m icroorganisms. Indeed, inoculated samples stored at 5 degrees C presen ted counts which were 2 logarithmic cycles lower than control samples kept at the same temperature during storage up to the 6th week. Sample s treated with Lactobacillus alimentarius and kept at 10 degrees C, pr esented a fall of one logarithmic cycle when compared to the control s amples for the same storage period. In the treated samples, the counts for psychrotrophic microorganisms and aerobic mesophyles were high at the beginning (approximately 10(6) CFU cm(-2)), due to the growth of the inoculated lactic acid bacteria. Whereas in the control samples th e counts started with a lower number (10(2) CFU cm(-2)), they increase d during storage, exceeding the microbial counts of treated samples. T he control samples, when compared to the treated ones, were considered unacceptable for consumption.