Center for Food Safety, University of Georgia, 1109 Experiment Street, Griffin, Georgia 30223-1797, USA.
J Food Prot. 2013 Jan;76(1):150-72. doi: 10.4315/0362-028X.JFP-12-211.
Foods and food ingredients with low water activity (a(w)) have been implicated with increased frequency in recent years as vehicles for pathogens that have caused outbreaks of illnesses. Some of these foodborne pathogens can survive for several months, even years, in low-a(w) foods and in dry food processing and preparation environments. Foodborne pathogens in low-a(w) foods often exhibit an increased tolerance to heat and other treatments that are lethal to cells in high-a(w) environments. It is virtually impossible to eliminate these pathogens in many dry foods or dry food ingredients without impairing organoleptic quality. Control measures should therefore focus on preventing contamination, which is often a much greater challenge than designing efficient control measures for high-a(w) foods. The most efficient approaches to prevent contamination are based on hygienic design, zoning, and implementation of efficient cleaning and sanitation procedures in the food processing environment. Methodologies to improve the sensitivity and speed of assays to resuscitate desiccated cells of foodborne pathogens and to detect them when present in dry foods in very low numbers should be developed. The goal should be to advance our knowledge of the behavior of foodborne pathogens in low-a(w) foods and food ingredients, with the ultimate aim of developing and implementing interventions that will reduce foodborne illness associated with this food category. Presented here are some observations on survival and persistence of foodborne pathogens in low-a(w) foods, selected outbreaks of illnesses associated with consumption of these foods, and approaches to minimize safety risks.
近年来，低水分活度（a(w)）的食品和食品成分被认为是导致食源性疾病爆发的病原体的载体，其出现频率有所增加。这些食源性病原体中的一些可以在低水分活度的食品以及干燥的食品加工和制备环境中存活数月甚至数年。在低水分活度食品中的食源性病原体通常对热和其他对高水分活度环境中的细胞具有致死作用的处理具有更高的耐受性。在许多干燥食品或干燥食品成分中，如果不损害感官质量，实际上几乎不可能消除这些病原体。因此，控制措施应侧重于防止污染，这通常比设计针对高水分活度食品的高效控制措施更具挑战性。预防污染最有效的方法基于卫生设计、分区以及在食品加工环境中实施高效清洁和卫生程序。应开发用于提高检测干燥细胞复苏和在干燥食品中以极低数量存在时检测食源性病原体的灵敏度和速度的方法。目标应该是提高我们对食源性病原体在低水分活度食品和食品成分中的行为的认识，最终目的是开发和实施干预措施，以降低与这类食品相关的食源性疾病。本文介绍了一些关于食源性病原体在低水分活度食品中的存活和持久性的观察结果、与食用这些食品相关的一些疾病爆发以及降低安全风险的方法。
