不同二氧化碳比例气调对冷鲜鸡肉中荧光假单胞菌的抑制作用

为研究不同体积分数二氧化碳气调包装对冷鲜鸡保鲜效果的影响,以辐照灭菌后接种荧光假单胞菌为103 CFU/g左右的冷鲜鸡胸肉为原料,设置各组气调比例:M1组(V(CO_2)∶V(N_2)=0∶100)、M2组(V(CO_2)∶V(N_2)=20∶80)、M3组(V(CO_2)∶V(N_2)=40∶60)、M4组(V(CO_2)∶V(N_2)=60∶40),以托盘包装作为对照,在(4±1)℃贮藏条件下测定气调包装盒的凹陷程度、荧光假单胞菌总数、p H值、挥发性盐基氮和腐胺含量的变化。结果表明:荧光假单胞菌总数、挥发性盐基氮和腐胺含量随着贮藏时间延长而上升,随二氧化碳体积分数的升高而下降;凹陷程度随着贮藏时间的延长及二氧化碳体积分数的升高而升高,即M4组气调包装盒的凹陷程度显著高于其他3组(P0.05),影响产品的外观。M2组的气调包装盒的凹陷程度和腐胺含量与M3组无显著性差异(P0.05),在贮藏9~12 d之间,挥发性盐基氮含量也与M3组无显著差异(P0.05),能达到同样的保鲜效果。此外,同体积的二氧化碳的成本高于氮气。整体来看,在(4±1)℃贮藏条件下,20%~40%体积分数的二氧化碳气调包装能抑制冷鲜鸡胸肉中荧光假单胞菌的生长繁殖。

Inhibitory Effect of Modified Atmosphere Packaging with Different Carbon Dioxide Concentrations on Pseudomonas fluorescens in Chilled Chicken

In order to investigate the effect of modified atmospheres with varying carbon dioxide levels on the preservation of chilled chicken, chilled chicken was inoculated with 103 CFU/g Pseudomonas fluorescent after sterilization by irradiation, packaged in different modified atmospheres: M1 group ((V(CO2):V(N2) = 20:80), M2 group ((V(CO2):V(N2) = 20:80), M3 group ((V(CO2):V(N2) = 40:60) and M4 group ((V(CO2):V(N2) = 60:40) and then stored at (4 ± 1) ℃. Normal air package was used as control. Changes in the degree of concavity, P. fluorescent count, pH, total volatile basic nitrogen (TVB-N) and putrescine content were measured during storage. Results showed that P. fluorescent count, TVB-N and putrescine content increased with increasing storage time, whereas they decreased with increasing CO2 level. The degree of concavity increased with increasing storage time or CO2 level; the degree of concavity in group M4 was significantly higher than that in other groups (P < 0.05), impacting the visual appearance of chicken. No difference in the degree of concavity or putrescine content was observed comparing groups M2 and M3 (P > 0.05). Similarly, no difference in TVB-N content was found from the ninth day to the twelfth day of storage (P > 0.05). Thus, an identical preservation effect was achieved. However, CO2 is more expensive than N2 of the same volume. Overall, we concluded that modified atmospheres containing 20%–40% of CO2 could strongly inhibit the growth of P. fluorescent in chilled chicken under the storage of (4 ± 1) ℃.