超声波处理对生鲜鸡肉表面假单胞菌生物被膜的去污染作用

Effects of ultrasonic treatment on decontamination of Pseudomonas biofilm on fresh chicken surface

探讨了超声波处理、超声波与10%的磷酸三钠联合处理对生鲜鸡肉表面假单胞菌生物被膜的去污染效果。取生鲜鸡肉(约100 g)浸入20%双氧水浸泡后冲洗后,于无菌条件下去除表层肉,切成大小约为3 cm×3 cm×1 cm。将其无菌条件下浸入106 cfu/mL的假单胞菌菌悬液浸泡1min,30℃条件下培养24 h后放入无菌自封袋,置于超声波清洗仪(40 kHz,300 W)中处理不同时间,测定自封袋溶液中及生鲜肉表面的假单胞菌数目,并结合扫描电镜观察鸡肉表面假单胞菌生物被膜的去除程度。结果发现超声波处理单独作用30 min组鸡肉表面的假单胞菌数目降至最少,鸡肉表面的假单胞菌数目最多减少了0.80个对数;而超声波与10%的磷酸三钠联合处理时,最多可减少2.85个对数。并且扫描电镜观察到经10%的磷酸三钠处理的假单胞菌的大小与形态发生改变,部分假单胞菌表面有破损、内含物外渗。因此,超声波处理对假单胞菌生物被膜有去污染作用,与10%的磷酸三钠联合处理能增强超声波对假单胞菌生物被膜的去污染能力;且随着处理时间的延长对鸡肉表面的去污染效果也越明显,对假单胞菌生物被膜的剥离程度也逐渐增大。

This paper mainly studied the decontamination effects of ultrasonic treatment, ultrasonic combined with 10% trisodium phosphate treatment on pseudomonas biofilm of fresh chicken surface. After immersed in 20% hydrogen peroxide and washed down with distilled water, the surface of the fresh chicken （about 100 g） was cut off in sterile conditions to keep the meat surface sterilized, then it was cut into the size of about 3 cm×3 cm×1 cm. The pseudomonas biofilm was established through immersing the meat in pseudomonas bacterial suspension （106 cfu/mL） for 1 min in sterile conditions and cultivated for 24 h in the temperature of 30℃. Then, the pseudomonas biofilm on the fresh chicken surface was treated in the ultrasonic cleaning device （40 kHz, 300 W） for different time after put into the sterile ziplock bag. The contamination effects were determined by the measurement of colony number of pseudomonas in the ziplock solution and on the fresh chicken surface combined with scanning electron microscope of chicken surface. The results showed that the pseudomonas population on the chicken surface of the sample fell to the minimum when was treated with ultrasound for 30 min; ultrasonic treatment alone can reduce a numbers of 0.80 logarithm; but when treated combined with 10% trisodium phosphate, the number was 2.85 logarithm. Through scanning electron microscope, it showed that the size and shape of pseudomonas treated with ultrasonic and 10% trisodium phosphate were changed, some pseudomonas surface even were damaged, inclusions extravasation. Therefore, the decontamination effect of ultrasonic treatment on pseudomonas biofilm was obvious, ultrasonic combined with 10% trisodium phosphate treatment can enhanced the decontamination capability of the ultrasonic treatment. And with the extension of the processing time, the decontamination effect of ultrasonic increased.