SUSSLE - Enhancing sustainability of chilled prepared foods (AFM266)

在过去的十年里，冷藏即食餐的销售有了相当大的增长。这些食品被加热(通常在70摄氏度-90摄氏度)，然后由生产商、零售商和在家冷藏。保质期取决于污染原材料的细菌的数量(和类型)、加热过程的致命性、加工后的污染以及冷藏期间的生长控制。冷冻食品行业提供大量经过低强度热处理(&gt；70C/2min但&lt；90C/10min)的产品，以及有限数量的经过高强度热处理(90C/10min)以延长保质期的食品。非蛋白水解性肉毒梭菌是肉毒杆菌中毒的危险食源性致病菌，是一种病死率很高的严重疾病。食源性肉毒杆菌中毒是由于食用肉毒杆菌生长并形成其剧毒毒素的食物引起的。肉毒杆菌毒素是已知的最有毒的物质，只要一茶匙就足以杀死英国所有人。确保肉毒杆菌不会在任何食物中生长并形成毒素是至关重要的。非蛋白水解性肉毒杆菌已被确定为这些最低限度加热的冷藏即食餐的主要安全隐患。该项目旨在定义和实现对一种新的和严格的方法的认可，以确定这些最低加热的冷藏即食餐的安全保质期。新的方法将使用一种数学方法(特别是风险评估技术)，将原材料中非蛋白水解性肉毒杆菌的装载量和明确的加热过程与安全的保质期(定义为保质期结束时在食品中检测不到肉毒杆菌毒素)联系起来。为了实现项目目标，我们将开发数学(风险评估)方法和微生物技术(使用前沿孢子回收和计数技术)。第一个目标是确定各种原料(如鱼、肉)中非蛋白水解性肉毒杆菌孢子浓度的变异性分布。这将以文献数据和新数据为基础。然后将使用数学(基于风险评估的统计)方法来合并这些分布，以便为在最低限度加热的冷藏方便餐中的非蛋白水解性肉毒杆菌孢子建立适当的保护因子(减少生长和毒素产生的可能性)。第二个目标是确定经过低强度热处理(75℃/10分钟)的最低加热冷藏即食餐的非蛋白水解性肉毒杆菌的保质期，第三个目标是确定这些经过中等强度热处理(80C-95C)的冷藏食品的非蛋白水解性肉毒杆菌的保质期。这两个目标将通过以下方式实现：建立风险评估模型，确定商业食品的保质期，接种实际孢子浓度(根据上文确定的保护系数)，给予适当的热处理，并确定毒素形成的时间。

Over the last decade there has been a considerable increase in sales of refrigerated ready meals. These foods are heated (typically in the range 70C-90C) and are then stored under refrigeration by the producer, retailer and at home. Shelf life depends on the number (and type) of bacteria contaminating the raw materials, lethality of the heat process delivered, post-process contamination, and control of growth during refrigerated storage. The chilled food industry supplies large volumes of products given a low intensity heat treatment (>70C/2min but <90C/10min), plus a limited amount of food that receives a high intensity heat treatment (90C/10min) for extended shelf life. Non-proteolytic Clostridium botulinum is a dangerous foodborne pathogen responsible for botulism, a severe disease with high fatality rate. Foodborne botulism results from consumption of food in which C. botulinum has grown and formed its highly poisonous toxin. The botulinum toxin is the most poisonous substance known, with as little as one teaspoon sufficient to kill everyone in the UK. It is essential to ensure that C. botulinum does not grow and form toxin in any food. Non-proteolytic C. botulinum has been identified as the principal safety hazard in these minimally heated refrigerated ready meals. This project aims to define and achieve recognition for a novel and rigorous approach to determine the safe shelf life for these minimally heated refrigerated ready meals. The new approach will use a mathematical approach (specifically risk assessment techniques) to link the loading of non-proteolytic C. botulinum in the raw materials and a defined heat process to a safe shelf life (defined as no detectable botulinum toxin in food at the end of shelf life). In order to achieve the project aims, we will develop mathematical (risk assessment) methods and microbiological techniques (use of leading edge spore recovery and enumeration techniques). The first objective is to establish variability distributions for the concentration of non-proteolytic C. botulinum spores in various classes of raw materials (e.g. fish, meat). This will be based on literature data and new data. A mathematical (risk assessment based statistical) approach will then be used to combine these distributions in order to establish an appropriate protection factor (level of reduction in the probability of growth and toxin production) for spores of non-proteolytic C. botulinum in minimally heated refrigerated ready meals. The second objective is to establish shelf life with respect to non-proteolytic C. botulinum of minimally heated refrigerated ready meals that are given a low intensity heat treatment (75C/10min), and the third objective is to establish shelf life with respect to non-proteolytic C. botulinum of these chilled foods that are given a medium intensity heat treatment (80C-95C). These two objectives will be achieved by building on the risk assessment models, and determining the shelf life for commercial food products, inoculated with realistic spore concentrations (based on the protection factor identified above), given the appropriate heat treatment, and determining time to toxin formation.