Department of Food Science, Faculty of Food Science and Technology, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
Department of Food Technology, Faculty of Food Science and Technology, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
Int J Food Microbiol. 2025 Jan 2;426:110926. doi: 10.1016/j.ijfoodmicro.2024.110926. Epub 2024 Oct 2.
This study aims to evaluate the effect of high-pressure processing (HPP) (500 and 600 MPa for 3 min and 5 min) on the microbial changes of Murrah buffalo milk in comparison to heat treatment (72 °C for 15 s of holding time) during refrigerated storage of 28 days. The results indicated that the total plate count (TPC) of raw milk at day 0 was 5.5 ± 0.6 log CFU/mL. At day 0, heat treatment lowered TPC to 3.9 ± 0.6, while HPP treatment was in the range of 4.1 ± 0.3 to 4.8 ± 0.6 log CFU/mL. Similarly, lowered yeast and mold count and lactic acid bacteria were noted in heat- and HPP-treated milk samples compared to the control sample during refrigerated storage. There were no Staphylococcus aureus and Escherichia coli detected in heat and HPP-treated samples. Heat or HPP treatment at 600 MPa for 5 min significantly extended the shelf-life of Murrah buffalo milk for three weeks at the refrigerated storage. In addition, HPP treatment did not alter the pH, lightness (L* value), protein, or fat content of Murrah buffalo milk during refrigerated storage. Hence HPP at 600 MPa for 5 min could be a suitable alternative to conventional heat treatment.
本研究旨在评估高压处理（HPP）（500 和 600 MPa 处理 3 分钟和 5 分钟）对穆拉水牛奶微生物变化的影响，并与冷藏储存 28 天期间的热处理（72°C 保持 15 秒）进行比较。结果表明，原料奶的总平板计数（TPC）在第 0 天为 5.5±0.6 log CFU/mL。在第 0 天，热处理将 TPC 降低至 3.9±0.6，而 HPP 处理的范围为 4.1±0.3 至 4.8±0.6 log CFU/mL。类似地，与对照样品相比，在冷藏储存期间，热处理和 HPP 处理的牛奶样品中酵母和霉菌计数以及乳酸菌数量均降低。在热处理和 HPP 处理的样品中均未检测到金黄色葡萄球菌和大肠杆菌。600 MPa 处理 5 分钟的热处理或 HPP 显著延长了穆拉水牛奶在冷藏条件下的保质期至三周。此外，HPP 处理在冷藏过程中不会改变穆拉水牛奶的 pH 值、亮度（L*值）、蛋白质或脂肪含量。因此，HPP 在 600 MPa 下处理 5 分钟可以替代传统的热处理。
