288 Chilled foods manufacture and there was better management of retail outlets with regard to patty storage and cooking. Good m manufacturin ng practice guides are available for many sectors of the chilled food industry (e.g. IFST Guide to Food and Drink Good Manufacturing Practice: IFST 1998. UK Chilled Food Association Guidelines: CFA 1997). These guides outline responsibilities in relation to the manufacture of safe products; adherence to their principles will ensure that the product remains wholesome and safe under the expected conditions of use Product and process design will always be a compromise between the demands for safety and quality on the one hand, and cost and operational limitations on the other. Heat is the main means of ensuring product safety and the elimination of spoilage bacteria. The heating that can be applied may sometimes be limited by quality changes in the product. Usually, minimum cooking processes, either in-factory or in-home, will be designed to kill specific bacteria such as infectious pathogens or those causing spoilage. The skill of the product designer is to balance these competing demands for quality and safety and decide where an acceptable balance lies. Even so, usually more than one process step contributes to quality and safety, for example refrigerated storage is used to retard or prevent the growth of vegetative cells and spores that have survived factory heating. Hence the safety of chilled foods which have no inherent preservative properties, depends almost exclusively on suitable refrigeration temperatures being maintained throughout the supply chain including, for example, the defrosting of frozen ingredients and loading of refrigerated vehicles. Where preservation is used, for example, reduced pH/ increased acidity or vacuum packing, chilling will also contribute to the effectiveness of the preservation system and introduces the need for additional controls during processing The techniques of risk assessment, either formal or more commonly informal ay be used to guide the manufacturer in achieving a predictable and acceptabl balance between the sale of raw or undecontaminated components, cooking and the chances of pathogen survival. Successful process design must consider not only contaminants likely to be carried by the raw materials, but also the shelf- life of the food and its anticipated storage conditions with distributors, retailers or customers, CFDRA (1990). In this sense, the customer is an integral part of the safety chain and some additional level of risk attributable to consumer mishandling or mis-use is always accepted by a manufacturer when he designs products whose safety and high quality shelf-life relies on customer use(e.g cooking or chilled storage). Brackett (1992)has pointed out that chilled foods contain few, or no, antimicrobial additives to prevent growth of pathogenic micro-organisms and are susceptible to the effects of inadequate refrigeration that may allow pathogen growth. He also highlights related issues such as over reliance on shelf-life as a measure of quality and the need to consider the needs of sensitive groups(such as immunocompromised consumers)in the product design. If the product design relies on the customer carrying out a killing step to of pathogens, such as salmonellae, it is important that helpful alidated heating or cooking instructions are provided by themanufacture and there was better management of retail outlets with regard to patty storage and cooking. Good manufacturing practice guides are available for many sectors of the chilled food industry (e.g. IFST Guide to Food and Drink Good Manufacturing Practice: IFST 1998, UK Chilled Food Association Guidelines: CFA 1997). These guides outline responsibilities in relation to the manufacture of safe products; adherence to their principles will ensure that the product remains wholesome and safe under the expected conditions of use. Product and process design will always be a compromise between the demands for safety and quality on the one hand, and cost and operational limitations on the other. Heat is the main means of ensuring product safety and the elimination of spoilage bacteria. The heating that can be applied may sometimes be limited by quality changes in the product. Usually, minimum cooking processes, either in-factory or in-home, will be designed to kill specific bacteria such as infectious pathogens or those causing spoilage. The skill of the product designer is to balance these competing demands for quality and safety and decide where an acceptable balance lies. Even so, usually more than one process step contributes to quality and safety, for example refrigerated storage is used to retard or prevent the growth of vegetative cells and spores that have survived factory heating. Hence the safety of chilled foods which have no inherent preservative properties, depends almost exclusively on suitable refrigeration temperatures being maintained throughout the supply chain including, for example, the defrosting of frozen ingredients and loading of refrigerated vehicles. Where preservation is used, for example, reduced pH/ increased acidity or vacuum packing, chilling will also contribute to the effectiveness of the preservation system and introduces the need for additional controls during processing. The techniques of risk assessment, either formal or more commonly informal, may be used to guide the manufacturer in achieving a predictable and acceptable balance between the sale of raw or undecontaminated components, cooking and the chances of pathogen survival. Successful process design must consider not only contaminants likely to be carried by the raw materials, but also the shelf￾life of the food and its anticipated storage conditions with distributors, retailers or customers, CFDRA (1990). In this sense, the customer is an integral part of the safety chain and some additional level of risk attributable to consumer mishandling or mis-use is always accepted by a manufacturer when he designs products whose safety and high quality shelf-life relies on customer use (e.g. cooking or chilled storage). Brackett (1992) has pointed out that chilled foods contain few, or no, antimicrobial additives to prevent growth of pathogenic micro-organisms and are susceptible to the effects of inadequate refrigeration that may allow pathogen growth. He also highlights related issues such as over reliance on shelf-life as a measure of quality and the need to consider the needs of sensitive groups (such as immunocompromised consumers) in the product design. If the product design relies on the customer carrying out a killing step to free the product of pathogens, such as salmonellae, it is important that helpful, accurate and validated heating or cooking instructions are provided by the 288 Chilled foods