Impact of ultrasound treatment on viability of Staphylococcus aureus and the human milk antioxidant activity

Abstract This study aimed to evaluate the application of thermosonication for the viability of Staphylococcus aureus and the antioxidant activity of HM. The US effect on the S. aureus was measured by counting viable cells in discarded HM immediately before and after different treatments varying time (1, 5 and 10 minutes) and temperature (20, 30, 40, 50 and 60 °C) through surface plating on standard agar. The antioxidant activity evaluation was carried out by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) scavenging method. With Regarding microbiological quality, it can be concluded that treatment with US at 60 °C for 10 minutes was the most effective in terms of reducing the viability of S. aureus, in addition to presenting a significant increase in the content of antioxidants when compared to raw and pasteurized milk samples.

摘要：本研究旨在评估热超声处理（thermosonication）对金黄色葡萄球菌（Staphylococcus aureus）存活率及HM抗氧化活性的应用效果。通过设置不同处理参数（处理时间分别为1、5、10分钟，处理温度分别为20、30、40、50、60℃），采用标准琼脂表面涂布计数法，对处理前后废弃HM中的活菌数进行计数，以探究超声处理对金黄色葡萄球菌的影响。抗氧化活性测定采用2,2-二苯基-1-苦基肼（DPPH）清除法。微生物质量分析结果表明，60℃下超声处理10分钟的方案，在降低金黄色葡萄球菌存活率方面效果最为显著，且与生乳及巴氏杀菌乳样品相比，该处理的抗氧化物质含量显著提升。