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The survival ability of Campylobacter jejuni in poultry has been a major public health risk because of the low infectious dose. The objective of this study was to investigate the effects of different packaging condition and temperature on the survival kinetics of C. jejuni ATCC 33291 on precooked chicken breast. Survival kinetics of C. jejuni were also compared with those of C. coli ATCC 43486. Inoculated chicken breasts with 5.0-6.0 log cfu/g were packed in three different ways (aerobic, semi-aerobic or vacuum), which were stored at 4, 10, 17, 24, 30 and 36C. Survival curves were fitted to Baranyi model to obtain the values of lag time and death rate of C. jejuni. During storage, the greatest reduction of C. jejuni (4.316 log cfu/g) was observed in aerobic packaged chicken breast at 24C, while the least reduction of C. jejuni (1.031 log cfu/g) was observed in vacuumpackaged chicken breast at 4C. Lag time was affected by packing method, temperature and strain. Similar survival behavior of C. coli to C. jejuni was observed only at 10C. At the temperatures above 24C, lag phase of C. jejuni was only observed in semi-aerobic or vacuum-packed chicken breasts, indicating that C. jejuni survived better than C. coli, for which no lag phase was observed. The results indicated that vacuum or semi-aerobic packaging on poultry product at 4C, which is the most popular method at retail markets, created the highest risk for C. jejuni survival.

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The objective of this study was to investigate the antimicrobial effects of cultured sugar/vinegar (CSV) blend and nisin to control the risk of Listeria monocytogenes in ready to cook (RTC) ravioli. Ravioli dough was prepared with 0.1, 0.3, 0.5, 1% CSV blend and 0.1, 0.2, and 0.3% nisin. Inoculated spinach or artichoke raviolis with 2.0 ± 0.5 log cfu/g of L. monocytogenes were packed aerobically or using modified atmosphere packaging (MAP), and then stored at 4, 10, 17, and 24 °C for 60 days. Growth kinetic parameters of the observed data fit well to the Baranyi equation. Ravioli with spinach filling materials yielded a higher risk than that with artichoke. L. monocytogenes was able to survive in ravioli with artichoke, but did not grow. The addition of 1% CSV blend or 0.3% nisin in spinach ravioli with the combination of MAP effectively controlled the growth of L. monocytogenes at the temperature below 10 °C. The organoleptic quality of spinach ravioli was not also affected by the application of 1% CSV blend. Therefore, the CSV blend can be recommended to improve the microbial safety and quality of natural RTC ravioli at retail market.Practical applicationsThe risk of ravioli was affected by the filling materials of ravioli at retail market. Addition of 1% cultured sugar/vinegar blend in dough substantially contributes to the extension of shelf‐life of MAP spinach raviolis. classification and regression tree analysis results indicate that refrigeration temperature is the main control factor to affect lag time and growth rate, while packaging method is critical for maximum population density.