Fan X, Sokorai K J B
US Dept of Agriculture, Agricultural Research Service, Eastern Regional Research Center, Wyndmoor, PA 19038, USA.
J Food Sci. 2008 Sep;73(7):S367-72. doi: 10.1111/j.1750-3841.2008.00871.x. Epub 2008 Aug 8.
Improving the microbial safety while maintaining quality of fresh fruits and vegetables will increase consumer confidence in fresh produce. This study was conducted to investigate the effects of irradiation at 1 kGy, a dose that potentially inactivates E. coli O157:H7 by 5 logs, on the quality of 13 common fresh-cut vegetables: iceberg, romaine, green and red leaf lettuce, spinach, tomato, cilantro, parsley, green onion, carrot, broccoli, red cabbage, and celery. The results showed that the appearance of irradiated samples was similar to the nonirradiated ones except that irradiated carrots, celery, cilantro, and green onions had higher appearance scores than corresponding nonirradiated vegetables. There was no difference in the instrumental texture between irradiated samples and nonirradiated ones. The aroma of several irradiated vegetables was significantly better than controls after 14-d storage, because these control samples decayed or senesced. The 1 kGy irradiation did not affect vitamin C content of most vegetables; however, irradiated green and red leaf lettuce had 24% to 53% lower vitamin C contents than the controls. Our results suggest that most fresh-cut fruits and vegetables tested can tolerate up to 1 kGy irradiation without significant losses in any of the quality attributes.
在保持新鲜水果和蔬菜品质的同时提高微生物安全性,将增强消费者对新鲜农产品的信心。本研究旨在调查1千戈瑞辐照(该剂量可使大肠杆菌O157:H7的数量减少5个对数级)对13种常见鲜切蔬菜品质的影响,这些蔬菜包括:卷心莴苣、长叶莴苣、绿叶生菜和红叶生菜、菠菜、番茄、香菜、欧芹、葱、胡萝卜、西兰花、红甘蓝和芹菜。结果表明,辐照样品的外观与未辐照样品相似,只是辐照后的胡萝卜、芹菜、香菜和葱的外观评分高于相应的未辐照蔬菜。辐照样品和未辐照样品在仪器测定的质地方面没有差异。在储存14天后,几种辐照蔬菜的香气明显优于对照样品,因为这些对照样品已经腐烂或衰老。1千戈瑞的辐照对大多数蔬菜的维生素C含量没有影响;然而,辐照后的绿叶生菜和红叶生菜的维生素C含量比对照低24%至53%。我们的结果表明,大多数测试的鲜切水果和蔬菜能够耐受高达1千戈瑞的辐照,且任何品质属性都不会有显著损失。