398 Chilled foods or skin, have been dealt with under personal hygiene( Chapter 13). In this context. surface sanitation is undertaken to remove microorganisms, or material conductive to microbial growth. This reduces the chance of contamination by pathogens and, by reducing spoilage organisms, may extend the shelf-life of some products remove materials that could lead to foreign body contam provide food or shelter for pests. This also improves the quality of product by removing food materials left on lines that may deteriorate and re-enter subsequent production runs extend the life of, and prevent damage to equipment and services, provide a safe and clean working environment for employees and boost morale and present a favourable image to customers and the public. On audit, the initial perception of an untidy'or 'dirty' processing area, and hence a poorly managed operation is subsequently difficult to overcome 14.2 Sanitation principles Sanitation is undertaken primarily to remove all undesirable material (food esidues, microorganisms, foreign bodies and cleaning chemicals) from surfaces in an economical manner, to a level at which any residues remaining are of minimal risk to the quality or safety of the product. Such undesirable materia generally referred to assoil,, can be derived from normal production, spillages, line-jams, equipment maintenance, packaging or general environmental contamination (dust and dirt). To undertake an adequate and economic sanitation programme, it is essential to characterise the nature of the soil to be removed The product residues are readily observed and may be characterised by their chemical composition, e.g. carbohydrate, fat, protein or starch. It is also important to be aware of processing and/or environmental factors, however, the same product soil may lead to a variety of cleaning problems dependent primarily on moisture levels and temperature. Generally, the higher the product oil temperature(especially if the soil has been baked) and the greater the time period before the sanitation programme is initiated (i.e. the drier the soil becomes), the more difficult the soil is to remove e Microorganisms can either be incorporated into the soil or can attach to urfaces and form layers or biofilms. There are a number of factors that have been shown to affect attachment and biofilm formation such as the level and type of microorganisms present, surface conditioning layer, substratum nature and roughness, temperature, pH, nutrient availabil ity and time available. Several reviews of biofilm formation in the food industry have been published including Pontefract (1991), Holah and Kearney(1992), Mattila-Sandholm and Wirtanen (1992), Carpentier and Cerf (1993), Zottola and Sasahara(1994), Gibson et al.or skin, have been dealt with under personal hygiene (Chapter 13). In this context, surface sanitation is undertaken to: • remove microorganisms, or material conductive to microbial growth. This reduces the chance of contamination by pathogens and, by reducing spoilage organisms, may extend the shelf-life of some products. • remove materials that could lead to foreign body contamination or could provide food or shelter for pests. This also improves the appearance and quality of product by removing food materials left on lines that may deteriorate and re-enter subsequent production runs. • extend the life of, and prevent damage to equipment and services, provide a safe and clean working environment for employees and boost morale and productivity. • present a favourable image to customers and the public. On audit, the initial perception of an ‘untidy’ or ‘dirty’ processing area, and hence a ‘poorly managed operation’ is subsequently difficult to overcome. 14.2 Sanitation principles Sanitation is undertaken primarily to remove all undesirable material (food residues, microorganisms, foreign bodies and cleaning chemicals) from surfaces in an economical manner, to a level at which any residues remaining are of minimal risk to the quality or safety of the product. Such undesirable material, generally referred to as ‘soil’, can be derived from normal production, spillages, line-jams, equipment maintenance, packaging or general environmental contamination (dust and dirt). To undertake an adequate and economic sanitation programme, it is essential to characterise the nature of the soil to be removed. The product residues are readily observed and may be characterised by their chemical composition, e.g. carbohydrate, fat, protein or starch. It is also important to be aware of processing and/or environmental factors, however, as the same product soil may lead to a variety of cleaning problems dependent primarily on moisture levels and temperature. Generally, the higher the product soil temperature (especially if the soil has been baked) and the greater the time period before the sanitation programme is initiated (i.e. the drier the soil becomes), the more difficult the soil is to remove. Microorganisms can either be incorporated into the soil or can attach to surfaces and form layers or biofilms. There are a number of factors that have been shown to affect attachment and biofilm formation such as the level and type of microorganisms present, surface conditioning layer, substratum nature and roughness, temperature, pH, nutrient availability and time available. Several reviews of biofilm formation in the food industry have been published including Pontefract (1991), Holah and Kearney (1992), Mattila-Sandholm and Wirtanen (1992), Carpentier and Cerf (1993), Zottola and Sasahara (1994), Gibson et al. 398 Chilled foods