Lobacz Adriana, Zulewska Justyna
Department of Dairy Science and Quality Management, Faculty of Food Sciences, University of Warmia and Mazury, Oczapowskiego 7 Street, 10-719 Olsztyn, Poland.
Microorganisms. 2021 Apr 27;9(5):938. doi: 10.3390/microorganisms9050938.
The aim of this study was to determine the survival kinetics of spp. in unripened, fresh raw milk cheese during storage at 5, 15 and 25 °C. Microbiological (coliforms and , , sp., total microbial count and ) and physicochemical (pH and a) characteristics were also determined. Two primary models were used to estimate the kinetic parameters of spp., namely Weibull and Baranyi and Roberts (no lag) models. Additionally, goodness-of-fit of the primary models was assessed by calculating the R-Square and mean square error. spp. growth in the unripened raw milk cheese was inhibited during storage, but nevertheless bacteria survived at 5 °C for 33 days (2.5 log cfu/g) and 15 °C for 18 days (1.8 log cfu/g). A decrease in the number of spp. populations from an initial concentration 6.6 log cfu/g to below a detection limit was observed at 25 °C after 7 days of storage of contaminated cheese samples. It was concluded that the storage temperature significantly influenced the inactivation rate of spp. in fresh raw milk cheese and proceeded faster at 25 °C compared to remaining storage temperatures.
本研究的目的是确定在5、15和25℃储存期间，未成熟的新鲜生乳奶酪中[具体菌种]的存活动力学。还测定了微生物学（大肠菌群和[其他菌种]、[其他菌种]、[其他菌种]、总微生物计数和[其他指标]）和理化特性（pH值和a值）。使用了两个主要模型来估计[具体菌种]的动力学参数，即威布尔模型以及巴拉尼和罗伯茨（无滞后）模型。此外，通过计算决定系数（R方）和均方误差来评估主要模型的拟合优度。在储存期间，未成熟生乳奶酪中[具体菌种]的生长受到抑制，但细菌在5℃下存活了33天（2.5 log cfu/g），在15℃下存活了18天（1.8 log cfu/g）。在25℃下，受污染的奶酪样品储存7天后，观察到[具体菌种]数量从初始浓度6.6 log cfu/g降至检测限以下。得出的结论是，储存温度显著影响新鲜生乳奶酪中[具体菌种]的失活速率，与其他储存温度相比，在25℃下失活速率更快。
