College of Food Science and Engineering, Ningxia University, Yinchuan, 750021, PR China.
College of Food Science and Engineering, Ningxia University, Yinchuan, 750021, PR China.
Food Microbiol. 2023 Oct;115:104345. doi: 10.1016/j.fm.2023.104345. Epub 2023 Jul 29.
Combining High-pressure Thermal Treatment (HPTT) and Potassium Sorbate (PS) may have a stronger spore inactivation effect. Spores of Bacillus subtilis were subjected to HPTT at 600 MPa-65 °C/75 °C and a combination of HPTT and PS of 0.1% and 0.2% concentrations. After these treatments, different procedures and techniques were employed to investigate the spore's inactivation. The results revealed that 4.92 ± 0.05 log spores were inactivated after treatment at 600 MPa-75 °C, while 5.97 ± 0.09 log spores were inactivated when the HPTT treatment was combined with 0.2% PS. Changes in permeability of the spore's inner membrane were characterized by OD value and release rates of nucleic acids, protein, and dipicolinic acid (DPA). Compared with HPTT treatment at 600 MPa-75 °C, the OD value of spores decreased further by about 50% after treatment with a combination of HPTT and 0.2% PS. Additionally, the combined treatments resulted in a significant increase in the OD and OD values, as well as the DPA release. The spore size analysis indicated a significant decrease in the size of spores treated with a combination of HPTT at 600 MPa-75 °C and PS of 0.2% concentration. Furthermore, the flow cytometry analysis and confocal laser scanning microscopy (CLSM) analysis indicated that the inner membrane damage of spores was higher after combined treatments than that after HPTT treatment alone. A significant reduction was also found in the Na/K-ATPase activity after the combined treatments. Also, the FTIR analysis revealed that the combined treatments resulted in significant adverse changes in the spores' inner membrane, cell wall, cortex, and nucleic acid. Therefore, the combination of HPTT and PS has a stronger inactivation effect and can be suggested as a promising strategy for the inactivation of Bacillus subtilis spores.
高压热处理（HPTT）与山梨酸钾（PS）联合使用可能具有更强的孢子灭活效果。将枯草芽孢杆菌孢子进行 600 MPa-65°C/75°C 的 HPTT 处理，以及 0.1%和 0.2%浓度的 HPTT 和 PS 的联合处理。采用不同的程序和技术对处理后的孢子进行灭活效果检测。结果表明，600 MPa-75°C 的 HPTT 处理可使 4.92±0.05 log 个孢子失活，而 HPTT 联合 0.2% PS 处理可使 5.97±0.09 log 个孢子失活。通过 OD 值和核酸、蛋白质和二吡啶酸（DPA）的释放率来表征孢子内膜通透性的变化。与 600 MPa-75°C 的 HPTT 处理相比，HPTT 联合 0.2% PS 处理后孢子的 OD 值进一步降低约 50%。此外，联合处理导致 OD 和 OD 值显著增加，DPA 释放也显著增加。孢子大小分析表明，经 600 MPa-75°C 的 HPTT 与 0.2% PS 联合处理后，孢子的大小显著减小。此外，流式细胞术分析和共聚焦激光扫描显微镜（CLSM）分析表明，联合处理后孢子的内膜损伤比单独 HPTT 处理更高。联合处理后 Na/K-ATPase 活性也显著降低。FTIR 分析还表明，联合处理导致孢子内膜、细胞壁、皮层和核酸的显著不良变化。因此，HPTT 与 PS 的联合使用具有更强的灭活效果，可以作为枯草芽孢杆菌孢子灭活的一种有前途的策略。
