Laboratoire Eau, Molécules Actives, Macromolécules, Activité, Université de Bourgogne, Dijon, France.
Int J Food Microbiol. 2010 Aug 15;142(1-2):106-13. doi: 10.1016/j.ijfoodmicro.2010.06.009. Epub 2010 Jun 19.
The objective of this study was to develop and to validate a model for predicting the combined effect of temperature and a(w) on the radial growth rate, mu, of Botrytis cinerea and Penicillium expansum on grape berries. The proposed strategy was based on the gamma-concept developed previously [Zwietering, M.H., Wijtzes, T., de Wit, J.C., van't Riet, K. 1992. A decision support system for prediction of the microbial spoilage in foods. Journal of Food Protection. 12, 973-979]: mu=mu(opt).gamma(T).gamma(a(w)), where the gamma functions were cardinal models with inflection (CMI), mu(opt) the radial growth rate on grape berries. Firstly, the cardinal temperatures and a(w)'s were estimated independently from experiments carried out on Potato Dextrose Agar. Secondly, the gamma concept was validated i/ on a synthetic grape juice medium (SGJ) and ii/ on a grape juice agar (GJA). Accuracy and bias factors were closer to 1 with the latter analogue, thus suggesting that GJA should be preferred to SGJ. Thirdly, an experimental protocol taken into account the isotropic nature of fungal growth was developed for estimating mu(opt) on grape berries. This study demonstrated that CMI's can be validated on agri-food products over a wide range of temperature and a(w) using the described methodology.
本研究的目的是开发和验证一个模型，以预测温度和 a(w) 对葡萄浆果上 Botrytis cinerea 和 Penicillium expansum 的径向生长速率 μ 的综合影响。所提出的策略基于先前开发的γ概念[Zwietering，M.H.，Wijtzes，T.，de Wit，J.C.，van't Riet，K. 1992. 用于预测食品中微生物腐败的决策支持系统。食品保护杂志。12，973-979]：μ=μ(opt).γ(T).γ(a(w))，其中γ函数是具有拐点的基数模型（CMI），μ(opt)是在葡萄浆果上的径向生长速率。首先，从在马铃薯葡萄糖琼脂上进行的实验中独立估计基数温度和 a(w)。其次，在合成葡萄汁培养基（SGJ）和葡萄汁琼脂（GJA）上验证了γ概念。后者类似物的准确性和偏差因子更接近 1，因此表明 GJA 应该优于 SGJ。第三，开发了一种考虑真菌生长各向同性的实验方案，用于估计葡萄浆果上的 μ(opt)。本研究表明，使用描述的方法，CMI 可以在农业食品产品上验证温度和 a(w)范围很宽的情况。
