Dipartimento di Scienze degli Alimenti, Università degli Studi di Bologna, Sede di Cesena, Piazza G. Goidanich 60, 47023 Cesena, Italy.
Int J Food Microbiol. 2010 Jan 1;136(3):283-9. doi: 10.1016/j.ijfoodmicro.2009.10.030. Epub 2009 Nov 6.
The aim of this work was to evaluate the antimicrobial activity of three terpenes (citral, linalool and beta-pinene), in combination with a mild heat treatment (55 degrees C, 15 min). The study has been carried out on an orange based soft drink inoculated using a wild strain of Saccharomyces cerevisiae. The results, expressed as growth/no-growth data, were analyzed with the logistic regression. A model comprising only of significant individual parameters (p < or = 0.05) and describing the relationships between terpene concentrations and the probability of having stable beverages was obtained. When citral and beta-pinene were combined, the citral concentration required to achieve a 50% probability of having stable bottles (P=0.5) dropped from 100.9 microL/L in the absence of beta-pinene to 49.3 microL/L in the presence of 20 microL/L of beta-pinene. The mixture of citral and linalool was less effective, in fact, the same probability (P=0.5) was obtained combining 60 microL/L of linalool with 35.1 microL/L of citral. The addition of 20 microL/L of linalool and beta-pinene reinforced citral bioactivity and the concentration of citral needed to reach P=0.5 fell from 100.9 microL/L in the presence of citral alone to 42.0 microL/L. The presence of both linalool and beta-pinene at a concentration of 40 or 60 microL/L in the absence of citral led to a lower spoilage probability (P=0.58 and P=0.93, respectively). It can be concluded that the antimicrobial potential of the three terpenes alone can be strengthened combining appropriate concentrations of each of them. This study confirmed also the potentiating effect of a mild temperature treatment on the antimicrobial efficacy of the molecules. Neither the thermal treatment alone nor the presence of the terpenes at their maximum concentrations (without thermal treatment) were able to guarantee the microbial stability of the beverages.
本研究旨在评估三种萜烯（柠檬醛、芳樟醇和β-蒎烯）与温和热处理（55°C，15 分钟）联合使用时的抗菌活性。该研究以接种野生酿酒酵母的橙汁软饮料为研究对象。使用逻辑回归对表示生长/不生长数据的结果进行分析。得到一个仅包含显著个体参数（p<0.05）的模型，该模型描述了萜烯浓度与饮料稳定性概率之间的关系。当柠檬醛和β-蒎烯联合使用时，在不存在β-蒎烯的情况下，达到 50%稳定瓶数的柠檬醛浓度（P=0.5）从 100.9 μL/L 降低至存在 20 μL/Lβ-蒎烯时的 49.3 μL/L。柠檬醛和芳樟醇的混合物效果较差，实际上，当 60 μL/L 芳樟醇与 35.1 μL/L 柠檬醛组合时，获得相同的概率（P=0.5）。添加 20 μL/L 芳樟醇和β-蒎烯增强了柠檬醛的生物活性，单独添加柠檬醛时达到 P=0.5 所需的柠檬醛浓度从 100.9 μL/L 降低至 42.0 μL/L。在不存在柠檬醛的情况下，当芳樟醇和β-蒎烯的浓度分别为 40 或 60 μL/L 时，导致变质概率降低（分别为 P=0.58 和 P=0.93）。综上所述，通过组合适当浓度的三种萜烯，可以增强它们各自的抗菌潜力。本研究还证实了温和热处理对分子抗菌效果的增强作用。单独的热处理或萜烯在其最大浓度下（未经热处理）都不能保证饮料的微生物稳定性。
