Laboratory of Microbial Processes in Foods, Dept. of Food Engineering, Technology Center, Federal Univ. of Paraíba, João Pessoa, Paraíba, Brazil.
Depto. de Producción Animal y Ciencia de los Alimentos, Facultad de Veterinaria, Inst. Agroalimentario de Aragón-IA2 (Univ. de Zaragoza-CITA), Zaragoza, Spain.
J Food Sci. 2019 Apr;84(4):848-858. doi: 10.1111/1750-3841.14474. Epub 2019 Mar 13.
This study assessed the compromised acceptance threshold (CAT) and rejection threshold (RT) of Citrus lemon (CLEO) and Citrus reticulata essential oil (CREO) in apple and orange juices. The efficacy of CLEO and CREO concentrations below the RT were evaluated alone and combined with mild heat treatment (MHT) (54 °C, up to 12 min) to inactivate the autochthonous spoilage bacteria Lactobacillus brevis, Lactobacillus plantarum, and Leuconostoc mesenteroides in apple and orange juices. The CAT of CLEO and CREO varied from 0.15 to 0.17 μL/mL in orange and apple juices. The RT of CLEO was approximately 0.58 μL/mL in apple and orange juices, and the RT of CREO was 0.68 μL/mL in both juices. When CLEO and CREO were assayed alone, the highest concentration (0.50 μL/mL) decreased counts of all strains approximately 2 log CFU/mL after 12 min of exposure to 54 °C. All concentrations of CLEO or CREO in combination with MHT acted synergistically against L. brevis, L. plantarum, and L. mesenteroides. Decreases in counts varied with the strain, CLEO and CREO concentrations, juice type, and exposure time to the combined treatment. CREO was more effective than CLEO in combination with MHT against the strains in apple and orange juices. Effective combinations of CLEO or CREO with MHT to control the autochthonous spoilage bacteria did not compromise the quality parameters (°Brix, pH, and titratable acidity) that characterize unsweetened juices. These results indicate CLEO or CREO at concentrations below the sensory RT in combination with MHT as a feasible technology to control autochthonous spoilage bacteria in fresh fruit juices. PRACTICAL APPLICATION: The present study provides novel information concerning the efficacy of sensorially accepted doses of CLEO and CREO combined with MHT against autochthonous spoilers in fruit juice. The valuable synergistic effects that can be observed when combining CLEO and CREO with MHT reveal a feasible preservation technology and alternative to traditional treatments that are successful because they help reduce treatment intensity, thereby avoiding adverse effects on the sensory, physicochemical, and nutritional properties of these products.
本研究评估了柠檬（CLEO）和柑橘酸橙（CREO）精油在苹果和橙汁中的可接受妥协阈值（CAT）和拒绝阈值（RT）。评估了 RT 以下的 CLEO 和 CREO 浓度单独使用以及与温和热处理（MHT）（54°C，长达 12 分钟）联合使用对苹果和橙汁中原生腐败细菌短乳杆菌、植物乳杆菌和肠膜明串珠菌的效果。CLEO 和 CREO 在橙汁和苹果汁中的 CAT 从 0.15 到 0.17μL/mL 不等。CLEO 在苹果和橙汁中的 RT 约为 0.58μL/mL，CREO 的 RT 为 0.68μL/mL。当单独检测 CLEO 和 CREO 时，最高浓度（0.50μL/mL）在 54°C 暴露 12 分钟后，使所有菌株的计数减少了约 2 个对数 CFU/mL。MHT 联合使用的 CLEO 或 CREO 的所有浓度均对 L. brevis、L. plantarum 和 L. mesenteroides 表现出协同作用。菌株、CLEO 和 CREO 浓度、果汁类型以及暴露于联合处理的时间不同，计数的减少也不同。在苹果和橙汁中，MHT 联合使用 CREO 比 CLEO 更有效。MHT 联合使用 CLEO 或 CREO 控制原生腐败菌不会影响特征为非加糖果汁的质量参数（°Brix、pH 和可滴定酸度）。这些结果表明，在 MHT 联合使用下，低于感官 RT 的 CLEO 或 CREO 浓度可以作为控制新鲜果汁中原生腐败菌的可行技术。实际应用：本研究提供了有关在感官可接受剂量下的 CLEO 和 CREO 与 MHT 联合使用对果汁中本地腐败菌的功效的新信息。当 CLEO 和 CREO 与 MHT 结合使用时，可以观察到有价值的协同作用，这揭示了一种可行的保存技术和替代传统处理的方法，因为它们有助于降低处理强度，从而避免对这些产品的感官、物理化学和营养特性产生不利影响。
