ABSTRACT
The antibotulinal effect of sodium propionate was evaluated by a factorial-design experiment and by an inoculated-pack study on a shelf-stable beef product. Processing of samples involved curing, cooking, vacuum packing, and gamma irradiation. The factorial-design experiment involved 240 samples treated with 0, 0.8, 2.0, and 3.3% sodium propionate, challenged with 101 to 105 spores of type A Clostridium botulinum per package, irradiated with 2.5, 5, 7.5, and 10 kGy, and stored at 28°C for up to 4 months. In the pack study, 110 samples with 2% added sodium propionate were challenged with 108 spores of C. botulinum per package, irradiated with 12.5 kGy, and stored (28°C) for 8 months. Addition of 0.8% sodium propionate resulted in a delay (compared to control samples) in toxigenesis of 18 (5 kGy), 34 (2.5 kGy), and 34 (7.5 kGy) days, while no toxin was detected in samples irradiated with 10 kGy. Samples containing 2 and 3.3% sodium propionate were not toxic at any irradiation dose assayed. A safety level, expressed as the number of decimal reductions (DR = log 1/P) for the combination 0.8% sodium propionate and 10 kGy, was estimated to be >4.4. In the inoculated pack study, 2 of 107 samples became toxic, and the safety level treatment resulted in 10.7 DR. Sodium propionate in combination with other processing factors was very effective in preventing C. botulinum toxigenesis: it can be used as a further safety hurdle in the development of shelf-stable meat products.
ABSTRACT
We determined the virucidal effectiveness against foot-and-mouth disease virus of the low-temperature long-time cooking of virus-contaminated semitendinosus muscle (ST). Of the 11 time and temperature combinations examined, over a range of 63°C to 75°C for extended periods, the respective processing conditions of 71°C for 10.66 h and 75°C for 5.75 h were virucidal. Samples cooked under these temperature-time combinations were more tender (P<0.01) and had better overall acceptability (P<0.05) than beef cuts cooked by conventional commercial processes currently used in Argentina for meat to be exported. Product yields were increased from 60% for the commercial process to 67.8% or 68.6%, respectively, for the two virucidal thermal processes.
ABSTRACT
A 2-kGy gamma (low-dose) irradiation was applied to fresh top round from beef animals slaughtered and fabricated at commercial facilities. Cuts were packed in polyethylene film and stored at 1°C. Temperature abuse (9°C/24h) was simulated during storage. Psychrotroph counts on nonirradiated samples reached 107 CFU/cm2 between 8 and 11 d of storage, while similar counts were found after 28 d of storage on low-dose irradiated samples. Pseudomonads, Enterobacteriaceae , and Brochotrix thermosphacta were strongly inhibited on irradiated samples. No changes in organoleptic attributes were observed by a trained panel on treated samples. Low-dose irradiated samples had an average of 17 more shelf life days than the nonirradiated counterparts based on psychrotroph counts status and under the experimental condition being tested in this study.
ABSTRACT
A sampling technique by which the whole carcass is rubbed with a polyurethane sponge was used to study bacterial status on 523 beef carcasses at six different slaughterhouses over four different years. Although some abattoirs were differentiated based upon the psychrotroph counts from their carcasses, effects on counts of visits and season of sample taking, as well as interaction year x abattoir found at the other plants were large enough to mask the abattoir effect. Mesophile counts were not consistent enough to discriminate abattoirs, while, Enterobacteria, total and fecal coliforms, and Staphylococcus aureus coagulase-positive organisms showed very low counts and did not set apart differences. A guideline to monitor beef carcass hygiene and indirectely the hygiene of the slaughtering practices through the psychrotroph counts is proposed. A two-kinds sampling plan is suggested with "right-incorrect" as levels of hygiene. A sample unit (n) of 10, an acceptance number of contaminated carcasses (c) of 3, and a count limit (m) of 103 CFU/cm2 are proposed. Under this guideline, a lot of carcasses will be deemed as hygiene lacking when 4 or more, out of 10 carcasses, yield counts of 103 CFU/cm2 or higher.
