Establishment of control of microbes system for fresk-cut vegetables during processing and distribution

鲜切蔬菜上的细菌数量因蔬菜而异，从鲜切蔬菜中分离的优势细菌是革兰氏阴性杆菌，主要是假单胞菌属等植物病原菌。电解水处理（20-50 ppm有效氯）减少了鲜切蔬菜表面的微生物种群。含50 ppm有效氯的电解水比含15或30 ppm有效氯的水具有更强的杀菌效果，并且与含50至200 ppm有效氯的次氯酸钠溶液一样有效。电解水处理的鲜切肉中维生素C和钾的含量高于次氯酸钠处理的鲜切肉。0.5%~ 2%O_2和3%~ 10%CO_2的气调贮藏有利于降低鲜切菠菜的微生物生长和呼吸速率，但高CO_2气调贮藏的鲜切菠菜维生素C含量低于10 ℃和20 ℃气调贮藏的鲜切菠菜。电解水处理的鲜切肉在气调贮藏和气调贮藏条件下，其细菌数量的增加明显低于水处理和气调贮藏。电解水对鲜切蔬菜贮藏过程中的组织pH值、表面颜色、口感、外观和呼吸速率无影响。

Bacterial count on fresh-cut vegetables differed among vegetables, and the predominant bacteria isolated from fresh-cuts were Gram-negative-rod-forms that are mainly plant pathogenic bacteria such as the genera Pseudomonas. Electrolyzed water treatment (20-50 ppm available chlorine) reduced the microbial population on the surface of fresh-cut vegetables. Electrolyzed water containing 50 ppm available chlorine had a stronger bactericidal effect than water containg 15 or 30 ppm chlorine, and was as effective as sodium hypochlorite solution containing 50 to 200 ppm available chlorine. Vitamin C and potassium contents were higher in fresh-cuts treated with electrolyzed water than with sodium hypochlorite solution. Controlled atmosphere (CA) of 0.5 to 2% O2 and/or 3 to 10% CO2 was beneficial in reducing microbial growth and respiration rate of fresh-cut vegetables, but fresh-cut spinach stored in high CO2 atmosphere had lower vitamin C content than those stored in air at 10 and 20C. When fresh-cuts were treated with electrolyzed water and stored in CA or modified atmosphere (MA), the increasing count of bacteria was restricted when compared with the water-treated or air-stored control. Electrolyzed water did not affect tissue pH, surface color, taste, general appearance and respiration rate of fresh-cut vegetables during storage.