二氧化碳联合益生菌对猪肉中单增李斯特菌抑制模型的建立

Modeling for the inhibition of CO2 combined with probiotic on Listeria monocytogenes in pork

摘要:

【背景】由单增李斯特菌导致的猪肉食用安全问题不仅给消费者带来极大的食用风险，也给食品加工业造成巨大的经济损失。加强对猪肉制品中单增李斯特菌致病力的控制可有效遏制社会公共卫生问题的发生。【目的】基于预测微生物学方法研究二氧化碳(CO₂)联合植物乳杆菌(Lactobacillus plantarum) (CO₂-LP)对猪肉中单增李斯特菌生长特性的影响，筛选出CO₂-LP抑制单增李斯特菌生长的最优组合。【方法】应用Jameson-effect模型描述CO₂-LP对猪肉中单增李斯特菌的抑制影响，并且分析该联合处理对单增李斯特菌生长动力学参数迟滞时间(λ)、最大比生长速率(μ_max)和最大污染浓度(N_max)的影响。【结果】构建的Jameson-effect模型能够很好地描述CO₂-LP对单增李斯特菌的抑制作用。CO₂-LP处理可延长单增李斯特菌的λ，同时降低μ_max和N_max；并且CO₂浓度越高，抑制作用越强。与对照组相比，80% CO₂-LP处理可将猪肉中单增李斯特菌的λ延长0.87倍，μ_max降低47%，N_max降低2.05 lg (CFU/g)。虽然80% CO₂-LP的抑菌效果最好，但考虑到需要在气调包装中充入N₂以维持包装结构稳定，研究选择60% CO₂-LP为最优组合。与对照组相比，60% CO₂-LP可将单增李斯特菌的λ延长0.81倍，μ_max降低33%，N_max降低1.83 lg (CFU/g)。【结论】CO₂-LP处理能够从不同方面抑制单增李斯特菌的生长，体现了栅栏技术的优势。

关键词:CO₂;益生菌;联合;抑制模型;单增李斯特菌

Abstract:

[Background] The pork safety problem caused by Listeria monocytogenes not only brings great consumption risks to consumers but also causes huge economic losses to the food processing industry. The virulence of Listeria monocytogenes in pork products should be controlled to curb the occurrence of public health events.[Objective] To explore the inhibitory effect of CO₂ combined with the probiotic Lactobacillus plantarum (CO₂-LP) on L. monocytogenes in pork by the method of predictive microbiology and determine the optimal combination of CO₂-LP. [Methods] The Jameson-effect model was employed to establish the growth curves of L. monocytogenes in pork samples treated with CO₂-LP, and the kinetic parameters including lag phase (λ), maximal growth rate (μ_max), and maximum population density (N_max) were determined. [Results] The inhibitory effect of CO₂-LP was well fitted by the Jameson-effect model. CO₂-LP treatment prolonged the λ and reduced the μ_max and N_max of L. monocytogenes. Moreover, the inhibitory effect of CO₂-LP enhanced as the CO₂ concentration increased. Compared with the control group, the 80% CO₂-LP treatment increased the λ by 0.87 fold and decreased the μ_maxand N_max by 47% and 2.05 lg (CFU/g), respectively. Although 80% CO₂-LP had the best inhibitory effect, the 60% CO₂-LP was selected as the optimal treatment, because the presence of N₂ could prevent pack collapse in modified atmosphere packaging. Compared with the control group, 60% CO₂-LP treatment increased the λ by 0.81 fold and decreased the μ_maxand N_maxby 33% and 1.83 lg (CFU/g), respectively.[Conclusion] CO₂-LP treatment inhibited the growth of L. monocytogenes in pork from different aspects, which reflected the advantages of hurdle technology.

Key words:CO₂;probiotic;combination;model of inhibition;Listeria monocytogenes