Manipulation of the water content of foods is a classical method for food preservation and has been used by people for centuries. Salting, curing, drying, and the addition of sugars are examples of several traditional preservation methods. Of particular interest are the low moisture foods and food ingredients that are naturally low in moisture or that have been subjected to a drying process. Processed products such as milk powders, chocolate, peanut butter, infant foods, cereal and bakery products are the examples of this type of food.
Low moisture foods have received significant attention in recent years due to a number of food safety related events (e.g. peanut butter products). Many pathogens, such as Salmonella, due to its enhanced thermal residence in dry environments, are able to survive drying processes and may persist for a long time in low moisture foods, especially when stored at refrigerated temperatures. While these food products do not support the growth of Salmonella and other bacterial pathogens, many have been linked to the recent nationwide outbreaks/recalls (e.g. nuts, cereal products, and spices). This has raised awareness of low moisture foods as a vector for food foodborne illness. Salmonella and other bacterial pathogen contamination of low moisture foods has become an emerging and vexing food safety challenge for low moisture foods. Food processors should be well advised to enact highly disciplined safety control measures to address the risk of Salmonella and other pathogenic bacteria in low moisture foods.
A number of peer reviewed journal articles have explored the characteristics and food safety concerns associated with low moisture foods. However there are no books currently available which define prevalence and persistence of such pathogens and offer solution techniques for manufacturers who produce low moisture products. This book will aim to define sources and risk factors for pathogenic bacteria of concern in the manufacturing environment for low moisture/water activity products and characterize the persistence and thermal resistance of these pathogens in both the environment and the food product. A variety of foods will be discussed and multiple processing platforms evaluated from the standpoint of process validation to reach the appropriate Food Safety Objective (FSO) for the finished/packaged product prior to consumption. The book will define appropriate industry practices for the control and elimination of pathogens in these products and will provide information on current guidelines and product specific organizations that have developed such guidance and protocols (e.g. Almond Board of CA). Current Regulatory requirements will be discussed and any recommendations given will be science based on and in accordance with current rules. We will also provide a comprehensive modelling chapter to describe various aspects of pathogen detection and management. Life cycle models which describe the farm-to-fork prevalence of pathogens in low moisture foods will be combined with primary modelling concepts for growth, death and survival in both the environment and the products. Microbiological testing methods for inoculation, recovery and selection will be discussed in detail. The final chapter will explore spoilage organisms associated with these products (including yeasts and molds).
