406 Chilled foods Table 14.3 Characteristics of some universal disinfectants Property Chlorine QAC Amphoteric Peracetic M Spores Developed microbial resistance Inactivation by organic matter er Detergency properties Surface activity Corrosion Potential environmental impact Cost no effect(or problem) ++large effect Within the chilled food industry, particularly for mid-shift cleaning and disinfection in high-risk areas, alcohol based products are commonly used. This is primarily to restrict the use of water for cleaning during production as a control measure to prevent the growth and spread of any food pathogens that penetrate the high-risk area barrier controls. Ethyl alcohol (ethanol) and isopropyl alcohol(isopropanol)have bactericidal and virucidal(but not poricidal) properties(Hugo and Russell 1999), though they are only active in he absence of organic matter i.e. the surfaces need to be wiped clean and then alcohol reapplied. Alcohols are most active in the 60-70% range, and can be formulated into wipe and spray based products. Alcohol products are used on a small, local scale because of their well recognised health and safety issues The efficacy of disinfectants is generally controlled by five factors nterfering substances(primarily organic matter), pH, temperature, concentra- tion and contact time. To some extent, and particularly for the oxidative biocides, the efficiency of all disinfectants is reduced in the presence of organic matter. Organic material may react chemically with the disinfectant such that it oses its biocidal potency, or spatially such that microorganisms are protected from its effect. Other interfering substances, e.g. cleaning chemicals, may reactWithin the chilled food industry, particularly for mid-shift cleaning and disinfection in high-risk areas, alcohol based products are commonly used. This is primarily to restrict the use of water for cleaning during production as a control measure to prevent the growth and spread of any food pathogens that penetrate the high-risk area barrier controls. Ethyl alcohol (ethanol) and isopropyl alcohol (isopropanol) have bactericidal and virucidal (but not sporicidal) properties (Hugo and Russell 1999), though they are only active in the absence of organic matter i.e. the surfaces need to be wiped clean and then alcohol reapplied. Alcohols are most active in the 60–70% range, and can be formulated into wipe and spray based products. Alcohol products are used on a small, local scale because of their well recognised health and safety issues. The efficacy of disinfectants is generally controlled by five factors: interfering substances (primarily organic matter), pH, temperature, concentra￾tion and contact time. To some extent, and particularly for the oxidative biocides, the efficiency of all disinfectants is reduced in the presence of organic matter. Organic material may react chemically with the disinfectant such that it loses its biocidal potency, or spatially such that microorganisms are protected from its effect. Other interfering substances, e.g. cleaning chemicals, may react Table 14.3 Characteristics of some universal disinfectants Property Chlorine QAC Amphoteric Peracetic acid Microorganism control Gram-positive + + + + + + + + Gram-negative + + + + + + + Spores + + + Yeast + + + + + + + + Developed microbial resistance + + Inactivation by organic matter + + + + + water hardness + Detergency properties ++ + Surface activity ++ ++ Foaming potential ++ ++ Problems with taints +/ +/ Stability +/ +/ Corrosion + Safety + + + Other chemicals + Potential environmental impact + + /+ /+ Cost ++ ++ + no effect (or problem). + effect. + + large effect. 406 Chilled foods