Search

The effects of 16-androstene steroids on skatole deposition in backfat and lean pork water activity, pH and microbial flora were determined. An experimental pig population composed of 28 boars, 30 gilts and 29 barrows from commercial Duroc/Hampshire cross Yorkshire breed was used and slaughtered at an average of 105 kg. Based on the measurements of the 16-androstene steroid backfat content, meat from 3 groups composed of 4 pig loins with 16-androstene steroids levels, 0 μ g/g of fat (control), 0.5 μ g/g of fat (intermediate) and 1.0 μ g/g of fat (high), was enumerated for total mesophiles, psychotrophs, Enterobacteriaceae, pseudomonads, Micrococcaceae, lactic acid bacteria and Brochothrix thermosphacta . Results indicated that the levels of 16-androstene steroids had no significant impact on skatole level in boar backfat, lean water activity and lean pH. High levels of 16-androstene steroids did not cause bacterial population displacement nor interfere with normal bacterial growth even at elevated temperature (7°C) of storage.

Spoilage organisms isolated from retail samples of vacuum-packaged, cooked delicatessen meats were identified asLactobacillus sake,Lactobacillus curvatus,Lactobacillus sharpeaeandLeuconostoc mesenteroidesssp.mesenteroides.Lactobacillusspp. predominated and almost half of all isolates wereL sake. Treatment ofLactobacillus sakeat 53 °C to 55 °C for ≤ 12 min yielded from 15 to 98% lethality, with 82 to 99.8% of survivors injured. Lethality was greatest when thermal stress was applied to cells in phosphate buffer (pH 6.3), but the proportion of injured survivors present after heating in buffer or MRS broth did not differ. Repair of injury in lactobacilli was complete within 6 h in some trials at 34 °C, but at 4 °C withLactobacillus sake, > 10 d was required to achieve significant repair. Older cells were more resistant to thermal stress and were able to repair injury faster. The presence of catalase in the recovery medium facilitated repair byLactobacillus sake.Lactobacillus curvatuswas slightly less thermally-resistant but was also capable of repairing induced injury. Lethality was severe (>99.98 %) with theLeuconostocspp. tested at 53 °C for 8 min. Repairable injury was not demonstrated in the latter organisms following this treatment.

Ground pork and preblends containing 2% NaCl or 2% NaCl plus 200 ppm NaNO2 were prepared from hot (HB) and cold (CB) boned pork in a commercial slaughtering plant. Total aerobic mesophiles, psychrotrophs, Enterobacteriaceae , salt tolerant, and lactic acid bacteria were enumerated in freshly ground meat and in preblends stored for 1 week at 2°C. Boning method had no effect on mesophillic, psychrotrophic, and salt tolerant counts in freshly ground meat, but Enterobacteriaceae and lactic acid bacteria were found in higher numbers in CB than HB meat (P < 0.05). Addition of salt plus nitrite led to the inhibition of most bacterial groups, although lactic acid bacteria were found in higher numbers in HB preblends after one week of storage (P < 0.05). The data revealed that HB pork preblends of excellent bacteriological quality and stability can be produced in an industrial context.