16 - Chilled foods microbiology

Abstract

This chapter focuses on chilled food microbiology. Chilled foods comprise a diverse and complex group of commodities that contain a large number of ingredients. The composition and number of micro-organisms present is affected by the indigenous microflora, micro-organisms contaminating before and after processing, the growth rates and abilities of the micro-organisms, the spoilage abilities of the micro-organisms, the intrinsic properties of the food, the effects of processing and packaging, and the time and temperatures of storage. Consequently, the microbial safety and spoilage of chilled foods is very complex, but certain general principles may be applied: (i) the microbiological status of all raw materials should be known and only materials of good quality used; (ii) all stages of processing should be defined, monitored and controlled to ensure their correct operation. This is of particular significance in foods that rely on a combination of factors to ensure microbial stability; (iii) the temperatures and times of chill storage should be controlled during all stages, from raw materials through retail sale and preferably to the home. The lower the temperature throughout the process, the slower the rate of growth; and (iv) attention must be given to the hygiene of the entire process to ensure that microbial contamination is minimized.