Reduction of Aqueous Chlorine by Organic Material

Abstract

Aqueous chlorine, used to reduce surface bacteria populations on carcasses of slaughter animals after evisceration, during chilling, and after transport, dissipates in the presence of organic matter. This study characterized the amount of residual chlorine present when aqueous HOCI was exposed to bovine serum albumin, bovine lean muscle, porcine adipose tissue, or Trypticase soy agar (TSA) surfaces. Test chlorine solutions, made using Ca (OCl)2, contained 0, 50, 100, 200, 400, 800, 1,600, or 3,200 ppm chlorine, the latter two concentrations being used only in the case of albumin. Chlorine depletion by albumin was almost instantaneous, but was influenced by the amount of albumin present and the initial chlorine concentration. Chlorine exposed to organic surfaces was reduced most readily by lean muscle, then by TSA, and least by adipose tissue. Available chlorine was reduced by about 62% when the volume of aqueous chlorine was 22 ml/cm2 of lean muscle and by about 89% when the volume of aqueous chlorine was 0.69 ml/cm2. With increasing exposure time, the exposure to lean and fat decreased available chlorine by an average of about 10% in 4 min, 27% in 32 min, and 45% in 96 min. Thirteen pure bacterial cultures and two mixed cultures associated with meat were exposed to aqueous chlorine to characterize the effectiveness of the chlorine. All cultures except Bacillus cereus and Enterococcus faecalis were destroyed within 15 s by 3 ppm chlorine. Based on the data, the authors conclude that (a) available chlorine reduction is dependent on exposure time, chlorine concentration, and amount/source of organic material and (b) bacterial inactivation by aqueous chlorine is species specific. These data are of value for estimating chlorine dose for carcass decontamination during washing/chilling and for confirming that bacterial resistance to HOCI is species specific.

Membrane Damage and Microbial Inactivation by Chlorine in the Absence and Presence of a Chlorine-Demanding Substrate

“…The protective effect of organic matter against chlorine has been described previously (6). This effect has been attributed to the higher chlorine demand of organic compounds, which results in a rapid decline in the available free chlorine (5,9,15). However, in experiments conducted in this investigation the residual chlorine concentration in the presence of organic matter was much higher than the chlorine concentration necessary to completely inactivate the microbial population in distilled water.…”

“…Chlorination is one of the most widely used processes for microbial control (5) in both drinking water and wastewater processing (16). Chlorine is a powerful antimicrobial substance due to its potential oxidizing capacity.…”

“…Chlorine is a powerful antimicrobial substance due to its potential oxidizing capacity. In addition to drinking water disinfection, there are a number of other commercial uses for chlorine in the food industry, including reduction of microbial populations on the surfaces of raw foods, such as fruits and vegetables, and sanitation of surfaces in food processing environments (5,7). In general, disinfectants such as chlorine are used at very high concentrations in order to attain a rapid rate of killing.…”

Isolation of Salmonella resistant to hypochlorous acid from a poultry abattoir

“…© 1998 The Society for Applied Microbiology sanitizers in the medical, water and food industries (Jaquette et al 1996;Kotula et al 1997;Leyer and Johnson 1997;Mir et al 1997). In addition, Marriot (1994) and Notermans et al (1995) reported that the implementation of sanitation programmes and Hazard Analysis Critical Control Point (HACCP) systems in food industries can lead to the production of microbially safe food products.…”

Carbon Dioxide as a Microbial Toxicity Enhancer of Some Antibacterial Agents: A New Potential Water Purification Tool

“…Chlorination is one of the most widely used processes for microbial control [3] in both drinking water and wastewater processing [4]. Chlorine is a powerful antimicrobial substance due to its potential oxidizing capacity [3].…”