贮藏期间菠菜微生物生长动力学模型的研究

The Kinetics Model of Microorganism Growth on Storage of Spinach

目的研究贮藏期内不同温度下菠菜上的微生物生长趋势。方法将用保鲜膜封装好的菠菜分别置于3℃、15℃、25℃、35℃四个温度下贮藏,定期对菌落总数进行测定。首先,使用修正的Compertz方程建立不同温度下微生物生长的初级模型,其次,结合Belehradek方程讨论微生物的μmax(最大比生长速率)和λ(延滞时间)与温度的关系,并建立微生物生长的二级模型和货架期模型。结果研究认为,修正的Compertz方程能够较好地拟合不同温度下菠菜微生物生长的一级模型,R2均大于0.90;微生物的Nmax随着温度的变化波动不大,平均值为(9.4704±1.1472)lg(CFU/g);μmax随着温度的上升而变大,λ随温度的增加而减小,二级模型为(μmax)1/2=0.0215×[T-(-26.5286)]、(1/λ)1/2=0.0226×[T-(-34.0620)],R2分别为0.9967、0.9461。结论建立了具有较高的拟合度的微生物生长的初级模型、二级模型,也确立了菠菜的微生物货架期模型。

The objective of this thesis is to research microorganism growth of spinach at different tempera- tures during storage period. In the research, aerobic bacterial count was determined during storing period while the spinach was stored at four different temperatures （3~C, 15~C, 25~C, 35~C ） respectively after cling film packing treatment. Firstly, the primary level models of microorganism growth had been set up by modified Compertz equation. Secondly, the relationship between temperature and μmax （maximum specific growth rate）, K （lag time） was discussed combined with Belehradek equation, the secondary level models of microorganism growth and the shelf - life prediction model were established. The result indicated that the growth cruves of microorganism growth on spinach at above four temperatures could be well described by the modified Compertz equation （ R2 〉 0.90）. The temperature had no significant effect on N and the average value of Nmax was investigated to be （9. 4704 ±1. 1472） lg（CFU/g） at those four temperatares. It was observed that μmax increased with increasing temperaturewhile k decreased with increasing temperature. Secondary level models were both √μmax=0.0215×[T-（-26.5286）]、√1/λ=0.0226 × [T-（-34.0620）]（,R2were O. 9967, O. 9461 respectively）. In conclusion, levelmodel of primary and secondary were establi：shed that has high fitting degree, and the shelf - life prediction model were also built in our research.