本文主要探究热压结合处理(50℃,350 MPa保压10 min)对低温火腿中绿色魏斯菌和肠膜明串珠菌的抑制作用。通过薄层平板计数法对热压结合处理的杀菌效果进行判断,使用流式细胞技术判断细胞的生理状态,通过扫描电镜(scanning electron micr...本文主要探究热压结合处理(50℃,350 MPa保压10 min)对低温火腿中绿色魏斯菌和肠膜明串珠菌的抑制作用。通过薄层平板计数法对热压结合处理的杀菌效果进行判断,使用流式细胞技术判断细胞的生理状态,通过扫描电镜(scanning electron microscope,SEM)和透射电镜(transmission electron microscope,TEM)观察细胞形态结构的变化,利用紫外分光光度法测定热压结合处理对细菌细胞膜通透性的影响。结果表明:经热压结合处理后,绿色魏斯菌和肠膜明串珠菌的存活率分别为-4.74和-6.61lg(CFU/m L),其生长变得迟缓,对数期生长速率降低。扫描电镜结果显示热压结合处理对两种菌的形态造成明显的变形,透射电镜结果显示细胞内部出现团状聚集和透电子区。热压结合处理对细胞膜产生损伤,细胞膜通透性变大,导致细胞外紫外吸收物质也极显著增加(p <0.001),细胞处于亚致死状态。热压结合处理会对细胞膜产生一定的形变及损坏,使得细胞内核酸和蛋白质流出,同时细胞内部也会发生蛋白变性和细胞质皱缩,达到抑制耐压菌生长繁殖的目的。展开更多
Pale, soft, exudative-like （PSE-like） broiler muscle is a growing problem for meat industry all over the world. However, limited studies have been made to assess broiler meat quality in China. The aim of this study ...Pale, soft, exudative-like （PSE-like） broiler muscle is a growing problem for meat industry all over the world. However, limited studies have been made to assess broiler meat quality in China. The aim of this study was to investigate the characteristics and incidence of PSE-like broiler muscle commercially produced in China. A total of 1 274 Pectoralis muscles of Arbor Acre broiler were randomly obtained from the processing line to determine the commercial incidence of PSE-like muscle based on color. Furthermore, broiler Pectoralis muscles selected from the 1 274 muscle samples were classified as PSE-like muscle （L＊〉53, n=33） and normal muscle （L＊〉48 and L＊=53, n=33） to assess meat quality. It was determined that PSE-like muscle had lower muscle pH values, lower water-holding capacity （WHC）, lower sarcoplasmic protein solubility, and lower total protein solubility than the normal muscle did. SDS-PAGE profile also showed that bands of approximate 96 and 24 kDa in sarcoplasmic protein and myofibrillar protein varied between these two groups, suggesting partial denaturation of sarcoplasmic proteins and precipitation on myofillarments. Correlation analysis showed that L＊ values have significant correlation with WHC and protein solubility. Furthermore, the distribution of L＊ values exhibited a normal curve with range varying from 42.70 to 58.37. It was considered that approximately 23.39% of the population was PSE-like muscle. These results suggest that PSE-like meat can represent a significant portion of commercially processed broiler breast meat in China and that the L＊ value measurement could be used to sort broiler meat quality using a cut-off point.展开更多
文摘本文主要探究热压结合处理(50℃,350 MPa保压10 min)对低温火腿中绿色魏斯菌和肠膜明串珠菌的抑制作用。通过薄层平板计数法对热压结合处理的杀菌效果进行判断,使用流式细胞技术判断细胞的生理状态,通过扫描电镜(scanning electron microscope,SEM)和透射电镜(transmission electron microscope,TEM)观察细胞形态结构的变化,利用紫外分光光度法测定热压结合处理对细菌细胞膜通透性的影响。结果表明:经热压结合处理后,绿色魏斯菌和肠膜明串珠菌的存活率分别为-4.74和-6.61lg(CFU/m L),其生长变得迟缓,对数期生长速率降低。扫描电镜结果显示热压结合处理对两种菌的形态造成明显的变形,透射电镜结果显示细胞内部出现团状聚集和透电子区。热压结合处理对细胞膜产生损伤,细胞膜通透性变大,导致细胞外紫外吸收物质也极显著增加(p <0.001),细胞处于亚致死状态。热压结合处理会对细胞膜产生一定的形变及损坏,使得细胞内核酸和蛋白质流出,同时细胞内部也会发生蛋白变性和细胞质皱缩,达到抑制耐压菌生长繁殖的目的。
基金supported by China Agriculture Research System (CARS-42)
文摘Pale, soft, exudative-like （PSE-like） broiler muscle is a growing problem for meat industry all over the world. However, limited studies have been made to assess broiler meat quality in China. The aim of this study was to investigate the characteristics and incidence of PSE-like broiler muscle commercially produced in China. A total of 1 274 Pectoralis muscles of Arbor Acre broiler were randomly obtained from the processing line to determine the commercial incidence of PSE-like muscle based on color. Furthermore, broiler Pectoralis muscles selected from the 1 274 muscle samples were classified as PSE-like muscle （L＊〉53, n=33） and normal muscle （L＊〉48 and L＊=53, n=33） to assess meat quality. It was determined that PSE-like muscle had lower muscle pH values, lower water-holding capacity （WHC）, lower sarcoplasmic protein solubility, and lower total protein solubility than the normal muscle did. SDS-PAGE profile also showed that bands of approximate 96 and 24 kDa in sarcoplasmic protein and myofibrillar protein varied between these two groups, suggesting partial denaturation of sarcoplasmic proteins and precipitation on myofillarments. Correlation analysis showed that L＊ values have significant correlation with WHC and protein solubility. Furthermore, the distribution of L＊ values exhibited a normal curve with range varying from 42.70 to 58.37. It was considered that approximately 23.39% of the population was PSE-like muscle. These results suggest that PSE-like meat can represent a significant portion of commercially processed broiler breast meat in China and that the L＊ value measurement could be used to sort broiler meat quality using a cut-off point.
