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Aim: The effects of gaseous ozone and open air factor (OAF) on environmental Listeria monocytogenes attached to three common food contact surfaces were investigated. Methods and Results: Listeria monocytogenes on different food contact surfaces was treated with ozone and OAF. Microbiological counts, scanning electron microscopy (SEM) and atomic force microscopy (AFM) were performed. Ozone at 10 ppm gave <1-log reduction when L. monocytogenes was attached to stainless steel, while 45 ppm gave a log reduction of 3Á41. OAF gave better log reductions than 10 ppm ozone, but lower log reductions than 45 ppm. Significant differences were found between surfaces. Biofilm organisms were significantly more resistant than those surface attached on stainless steel. SEM and AFM demonstrated different membrane and cell surface modifications following ozone or OAF treatment. Conclusions:The strain used demonstrated higher resistance to ozone than previous studies. This may be due to the fact that it was isolated from a food manufacturing premises that used oxidizing disinfectants. OAF was more effective at reducing the levels of the organism than an ozone concentration of 10 ppm. Significance and Impact of the Study: Pathogen management strategies must account for resistance of environmental strains when validating cleaning and disinfection. OAF has shown potential for surface decontamination compared with ozone. SEM and AFM are valuable tools for determining mechanisms of action of antimicrobial agents.

To reduce foodborne illnesses, hazard and risk-based quality management systems are essential. Small and medium sized companies (SMEs) tend to have a poor understanding of such systems and limited adoption of the Hazard Analysis Critical Control Point system (HACCP). The requirement for full HACCP implementation by 2006 will place an even greater burden on these businesses. The aim of this project is to assess the current levels of understanding of hazards and risks in SMEs in the manufacturing sector. A questionnaire survey was made of 850 SMEs, including microbusinesses. This determined the industry sector and processes carried out, whether the company operated hazard-based quality management and the knowledge of the technical manager regarding the associated hazards and risks. Follow-up visits to the manufacturing plant observed the processes and the operatives to determine their level of understanding. A benchmarking audit was carried out and each company was rated. The results show that the majority of respondents stated that they operated hazard analysis-based quality management. The ability of the respondents to correctly define a hazard or risk or identify different types of hazard was, however, poor. There was no correlation between business type and audit score. The microbusinesses did, however, perform significantly less well than the larger SMEs.

Peanuts are increasingly being used as nibbed ingredients in cereal bars, confectionery and breakfast cereals. However, studies on their oxidative stability in this format are limited. Storage trials to determine the stability to oxidation were carried out on whole and nibbed kernels of conventional (CP) and high oleic (HOP) peanuts, with respect to temperature and modified atmosphere packaging. HOP exhibited the highest oxidative stability, with a lag phase in whole kernels of 12-15 weeks before significant oxidation occurred. HOP also showed higher levels of intrinsic antioxidants, a Trolox Equivalent Antioxidant Capacity (TEAC) of 70 mMol equivalence and radical scavenging percentage (RSP) of 99.8% at the beginning of storage trials, whereas CP showed values of 40 mMol and 81.2%, respectively. The intrinsic antioxidants at the beginning of these storage trials were shown to affect the peroxide value (PV), where RSP and TEAC decreased, PV increased. Therefore in peanuts the processing format (nibbed or whole) had the highest influence on susceptibility of lipid oxidation, highest to lowest importance; processing format > temperature > atmospheric conditions.

In order to understand the development of the microbial population within a hot-drinks vending machine a new machine was placed in a staff area of a university campus vending only hot chocolate. The machine was cleaned weekly using a detergent based protocol. Samples from the mixing bowl, dispense area, and drink were taken over a 19-wk period and enumerated using plate count agar. Bacillus cereus was identified using biochemical methods. Vended drinks were sampled at 0, 3, 6, and 9 min after vending; the hot chocolate powder was also sampled. Over the 1st 8 wk, a significant increase in the microbial load of the machine components was observed. By the end of the study, levels within the vended drink had also increased significantly. Inactivation of the automatic flush over a subsequent 5-wk period led to a statistically but not operationally significant increase in the microbial load of the dispense area and vended drink. The simple weekly clean had a significant impact on the microbial load of the machine components and the vended drink. This study demonstrated that a weekly, detergent-based cleaning protocol was sufficient to maintain the microbial population of the mixing bowl and dispense point in a quasi-steady state below 3.5 log CFU/cm2 ensuring that the microbial load of the vended drinks was maintained below 3.4 log CFU/mL. The microbial load of the drinks showed no significant changes over 9 min after vending, suggesting only spores are present in the final product.