Research Group on Quality, Safety and Bioactivity of Plant Foods, Department of Food Science and Technology, CEBAS-CSIC, Campus Universitario de Espinardo, 25, 30100, Murcia, Spain.
Research Group on Quality, Safety and Bioactivity of Plant Foods, Department of Food Science and Technology, CEBAS-CSIC, Campus Universitario de Espinardo, 25, 30100, Murcia, Spain.
Food Microbiol. 2019 Dec;84:103271. doi: 10.1016/j.fm.2019.103271. Epub 2019 Jul 15.
Fresh produce causes most foodborne outbreaks in the USA, and it is also considered a hazardous food product in other areas of the world such as Europe. The outbreaks attributed to fresh produce increase the focus of producers on hygiene to minimize exposure to food hazards. The fresh produce industry has the urgent need to detect if there are production lots contaminated with pathogenic microorganisms before distribution. Although the industry is mostly using end-product testing for the detection of target microorganisms, previous studies have evaluated the suitability of different sampling points within the production line of a fresh-cut processing plant. In the present study, the centrifuge effluent water was assessed as an alternative sampling point to end-product testing. E. coli was selected as an index microorganism of the presence of pathogens. The presence of E. coli was assessed in centrifuge effluent water, and fresh-cut lettuce from a commercial fresh-cut produce processing line (n = 95). The rate of false positives and negatives, as well as the specificity, sensitivity, and efficiency of the alternative method were calculated. The mean population of E. coli in positive water samples was 0.86 log cfu/100 mL, while the mean population of E. coli in positive fresh-cut lettuce samples was 0.23 log cfu/g. The proportion of positive samples in centrifuge effluent water and lettuce was similar (≈20%), and most of the results in both matrices were coincident (81.1%). However, the alternative method was not reliable due to its low sensitivity, as only 47.6% of the lettuce samples positive for E. coli could be matched with positive water samples.
新鲜农产品是美国大多数食源性疾病暴发的源头，在世界其他地区（如欧洲）也被视为危险食品。与新鲜农产品相关的疾病暴发促使生产者更加关注卫生，以最大程度地减少食源危害。新鲜农产品行业迫切需要在产品分发之前，检测生产批次是否受到致病微生物的污染。尽管该行业主要使用最终产品测试来检测目标微生物，但之前的研究已经评估了在新鲜切割加工厂的生产线中不同采样点的适用性。在本研究中，离心废液被评估为替代最终产品测试的采样点。大肠杆菌被选为病原体存在的指示微生物。评估了离心废液和商业新鲜切割农产品加工线的新鲜切割生菜（n=95）中大肠杆菌的存在情况。计算了替代方法的假阳性和假阴性率以及特异性、敏感性和效率。阳性水样中大肠杆菌的平均种群数为 0.86 log cfu/100 mL，而阳性新鲜切割生菜样本中大肠杆菌的平均种群数为 0.23 log cfu/g。离心废液和生菜中的阳性样本比例相似（约 20%），并且两种基质中的大多数结果都一致（81.1%）。然而，由于其敏感性较低，该替代方法不可靠，因为只有 47.6%的大肠杆菌阳性生菜样本与阳性水样匹配。
