Microbial decontamination of powdered black pepper (Piper nigrum L.) by using microwave

Powdered black pepper with varying moisture contents were subjected to intermittent or continuous microwave treatments (2450 +/- 50 MHz, 450 Watt) for 50 or 150 sec. Microwave treatment reduced microbial load in all treated samples. Higher product moisture and prolonged treatment time resulted in higher microbial reductions. The highest microbial reduction was in the groups, to which microwave treatment was applied continuously for 150 sec. Compared to the untreated samples in this group, the counts of total aerobic mesophilic microorganisms, Enterobacteriaceae, and yeast and mould were reduced by 87.8, 94.9 and 90.7%, respectively. However, in all the treated groups, the losses of volatile oil were between 3.9 and 18.7%. The results indicated that microwave treatment caused microbial reductions in the powdered black pepper, although the reductions were unsatisfactory. The levels of the reduction depended on the moisture content of the samples and exposure time. The losses of volatile oils occurred during the process were in acceptable levels

Effect of sodium lactate on the microbiological quality and shelf life of sausages

This study was performed to investigate the effects of various levels of sodium lactate on the microbiological quality and shelf life of sausages, and determine whether it can be used as a nitrite alternative. For this purpose, 0%, 0.6%, 1.2%. and 1.8% NaL and 0.125% NaNO2 were added to sausage samples. Samples were vacuum-packaged and stored at 4 degrees C for 60 days and periodically analyzed for their sensorial properties, microbial counts (aerobic plate count, lactic acid bacteria, yeast-mould, and sulphite reducing anaerobic bacteria), and pH values. Sensorial characteristics were not altered with NaL addition; the flavor of the samples was partially improved. In contrast to red-pinkish color in NaNO2 containing samples, natural meat color was preserved in the lactate containing ones. NaL delayed microbial growth depending on the concentration used. There was a significant increase in the shelf life of the samples containing NaL compared to the control group. NaL caused no change in pH values during storage that would affect the microbial quality of the samples. This study indicated that the addition of NaL to sausages improved their microbiological quality depending on the concentration used, extended their shelf life, and exhibited a better antimicrobial effect than NaNO2

Determination of growth and toxin production potential of Staphylococcus aureus and Clostridium perfringens during doner production process

Doner is a traditional meat meal that is commonly consumed in Turkey. Although it receives heat treatment during processing, some microorganisms including pathogens may remain alive. Therefore, this study was carried out to determine the changes in the number of microorganisms (total aerobic mesophilic bacteria, Enterobacteriaceae, Escherichia coli, aerobic mesophilic spore-forming bacteria, Staphylococcus- Micrococcus spp.) and survival potential of some pathogenic bacteria (Staphylococcus aureus and Clostridium perfringens) during the cooking period. Experimentally prepared doner kebabs were cooked continuously or intermittently. This process resulted in a reduction of microorganisms depending on the species and the use of low quality raw materials, and a number of bacteria survived at significant levels after cooking. The remaining bacteria multiplied and reached unacceptable levels with interrupted heat treatment over a long period of time. However, staphylococcal enterotoxins were not detected in intentionally contaminated samples that were kept at room temperature for 18 h after cooking. On the other hand, no significant microbiological changes appeared in raw sections of diner during cooking when the heat source was turned off