404 Chilled foods Acids have little detergency properties, although they are very useful in making soluble carbonate and mineral scales, including hard water salts and proteinaceous deposits. As with alkalis, the stronger the acid the more effective it is; though, in addition, the more corrosive to plant and operatives. Acids are not used as frequently as alkalis in chilled food operations and tend to be used Sequestering agents(sequestrants or chelating agents) are employed to prevent mineral ions precipitating by forming soluble complexes with them Their primary use is in the control of water hardness ions and they are added to surfactants to aid their dispersion capacity and rinsability. Sequestrants are most commonly based on ethylene diamine tetracetic acid (EDTA), which is expensive. Although cheaper alternatives are available, these are usually polyphosphates which are environmentally unfriendly A general-purpose food detergent may, therefore, contain a strong alkali to saponify fats, weaker alkali"builders'or" agents, surfactants to improve wetting, dispersion and rinsability and sequestrants to control hard water ions. In addition, the detergent should ideally be safe, non-tainting, non-corrosive, stable, environmentally friendly and cheap. The choice of cleaning agent will depend on the soil to be removed and on its solubility characteristics, and these are summar- ised for a range of chilled products in Table 14.2(modified from Elliot 1980 Because of the wide range of food soils likely to be encountered and fluence of the food manufacturing site(temperature, humidity, type of equipment, time before cleaning, etc. ) there are currently no recognised laboratory methods for assessing the efficacy of cleaning compounds. Food manufacturers have to be satisfied that cleaning chemicals are working appropriately, by conducting suitable field trials. Although the majority of the microbial contamination is removed by the cleaning phase of the sanitation Table 14.2 Solubility characteristics and cleaning procedures recommended for a rang of soil types Soil type Solubility characteristics Cleaning procedure Sugars, organic Mildly alkaline detergent High protein food Water-soluble Chlorinated alkaline detergent poultry, fish) Alkali-soluble Slightly acid-soluble Starchy foods, tomatoes, Partly water-soluble Mildly alkaline detergent fruits Alkali-soluble Fatty foods(fat, butter, Water-insoluble Alkaline-soluble Heat-precipitated water Water-insoluble Acid cleaner used on a hardness. milk stone Alkaline-insoluble protein scale Acid-solubleAcids have little detergency properties, although they are very useful in making soluble carbonate and mineral scales, including hard water salts and proteinaceous deposits. As with alkalis, the stronger the acid the more effective it is; though, in addition, the more corrosive to plant and operatives. Acids are not used as frequently as alkalis in chilled food operations and tend to be used for periodic cleans. Sequestering agents (sequestrants or chelating agents) are employed to prevent mineral ions precipitating by forming soluble complexes with them. Their primary use is in the control of water hardness ions and they are added to surfactants to aid their dispersion capacity and rinsability. Sequestrants are most commonly based on ethylene diamine tetracetic acid (EDTA), which is expensive. Although cheaper alternatives are available, these are usually polyphosphates which are environmentally unfriendly. A general-purpose food detergent may, therefore, contain a strong alkali to saponify fats, weaker alkali ‘builders’ or ‘bulking’ agents, surfactants to improve wetting, dispersion and rinsability and sequestrants to control hard water ions. In addition, the detergent should ideally be safe, non-tainting, non-corrosive, stable, environmentally friendly and cheap. The choice of cleaning agent will depend on the soil to be removed and on its solubility characteristics, and these are summar￾ised for a range of chilled products in Table 14.2 (modified from Elliot 1980). Because of the wide range of food soils likely to be encountered and the influence of the food manufacturing site (temperature, humidity, type of equipment, time before cleaning, etc.), there are currently no recognised laboratory methods for assessing the efficacy of cleaning compounds. Food manufacturers have to be satisfied that cleaning chemicals are working appropriately, by conducting suitable field trials. Although the majority of the microbial contamination is removed by the cleaning phase of the sanitation Table 14.2 Solubility characteristics and cleaning procedures recommended for a range of soil types Soil type Solubility characteristics Cleaning procedure recommended Sugars, organic acids, salt Water-soluble Mildly alkaline detergent High protein foods (meat, Water-soluble Chlorinated alkaline detergent poultry, fish) Alkali-soluble Slightly acid-soluble Starchy foods, tomatoes, Partly water-soluble Mildly alkaline detergent fruits Alkali-soluble Fatty foods (fat, butter, Water-insoluble Mildly alkaline detergent; if margarine, oils) Alkaline-soluble ineffective, use strong alkali Heat-precipitated water Water-insoluble Acid cleaner, used on a hardness, milk stone, Alkaline-insoluble periodic basis protein scale Acid-soluble 404 Chilled foods