Adrian C. Peters

Evaluation of two methods for monitoring surface cleanliness—ATP bioluminescence and traditional hygiene swabbing

The minimum bacterial detection limits and operator reproducibility of the Biotrace Clean-Tracetrade mark Rapid Cleanliness Test and traditional hygiene swabbing were determined. Areas (100 cm2) of food grade stainless steel were separately inoculated with known levels of Staphylococcus aureus (NCTC 6571) and Escherichia coli (ATCC 25922). Surfaces were sampled either immediately after inoculation while still wet, or after 60 min when completely dry. For both organisms the minimum detection limit of the ATP Clean-Tracetrade mark Rapid Cleanliness Test was 10(4) cfu/100 cm2 (p < 0.05) and was the same for wet and dry surfaces. Both organism type and surface status (i.e. wet or dry) influenced the minimum detection limits of hygiene swabbing, which ranged from 10(2) cfu/100 cm2 to >10(7) cfu/100 cm2. Hygiene swabbing percentage recovery rates for both organisms were less than 0.1% for dried surfaces but ranged from 0.33% to 8.8% for wet surfaces. When assessed by six technically qualified operators, the Biotrace Clean-Tracetrade mark Rapid Cleanliness Test gave superior reproducibility for both clean and inoculated surfaces, giving mean coefficients of variation of 24% and 32%, respectively. Hygiene swabbing of inoculated surfaces gave a mean CV of 130%. The results are discussed in the context of hygiene monitoring within the food industry.

Incidence of Campylobacter and Salmonella isolated from retail chicken and associated packaging in South Wales

Aims: To investigate the incidence of Campylobacter and Salmonella contamination associated with supermarket and butchers’ shop chicken and related packaging.

Bactericidal Properties of Ozone and Its Potential Application as a Terminal Disinfectant

The efficacy of ozone as a terminal disinfectant was evaluated under laboratory conditions. Different microorganisms of importance to the food industry were inoculated onto stainless steel squares and incubated at various temperatures and relative humidities for up to 4 h. Survival of microorganisms from these controls was compared with identically incubated squares exposed to ozone. Exposure of the contaminated surfaces to ozone (2 ppm for 4 h) resulted in a reduction in microbial viability that ranged, depending on organism type, from 7.56 to 2.41 log values. For all the microorganisms tested, this loss in viability was significantly greater (P < 0.05) than that observed in the absence of ozone. Gram-negative bacteria were more sensitive to ozone than gram-positive organisms; bacteria were more sensitive than the yeast strain tested. Exposure to ozone (2 ppm for 4 h) in the presence of ultra-high temperature (UHT) milk resulted in a reduction in bacterial viability that ranged from 5.64 to 1.65 log values. In most cases, this reduction was significantly less (P < 0.05) than that achieved in the absence of organic material, although still significantly greater (P < 0.05) than that observed in the absence of ozone. The presence of a meat-based broth reduced the effectiveness of ozone to a greater extent, although the number of surviving gram-negative organisms was still significantly less (P < 0.05) than in the absence of ozone. Less than 1 log unit of yeast cells was destroyed when exposed to ozone in the presence of UHT milk or meat-based broth. Results of this investigation suggest that if applied after adequate cleaning ozone could be used as an effective disinfectant.

Food Hygiene and Hazard Analysis Critical Control Point in the United Kingdom Food Industry: Practices, Perceptions, and Attitudes

A mail survey was designed and distributed to 1,650 managers of food businesses across the manufacturing, retail, and catering sectors of the United Kingdom food industry. Respondents were asked about the food hygiene practices of their business, their use of systems such as hazard analysis critical control point (HACCP), and their attitudes toward a range of food hygiene-related issues. Complete responses were received from 254 businesses, a response rate of 15.3%. The results showed that 69% of manufacturers were using HACCP systems, significantly more than the 13% and 15% in the retail and catering sectors, respectively (P < 0.05); 53% of manufacturing, 59% of retail, and 48% of catering managers thought that their business represented a low risk to food safety. Among businesses using HACCP, specific training in the system was significantly related to the likelihood that businesses had adopted all seven of the HACCP principles (P < 0.05). Business size was a significant factor in the use of HACCP in both the manufacturing and retail sectors. Higher levels of food hygiene qualifications among business managers, business status, and higher perceptions among managers of the risk to food safety of the business were also significantly related to HACCP use in all sectors (P < 0.05). The results from this survey have implications for the future development of HACCP, particularly within the UK retail and catering sectors. Risk communication and training are highlighted as areas of concern for marketing HACCP within these industry sectors.

A national survey of food hygiene training and qualification levels in the UK food industry

The food hygiene training received and qualifications held by four different grades of food handlers were compared by means of a postal survey of 1650 businesses in the manufacturing, retail and catering sectors of the UK food industry. Significant differences ( p < 0.05) were identified between the methods of training delivery to, and qualifications held by different grades of food handlers across the three industry sectors. Business status, personnel characteristics and risk perceptions of managers all had significant effects on the methods of training used and qualification levels achieved within each industry sector. Positive attitudes towards training were expressed by most managers although follow-up face-to-face interviews revealed their concerns about the cost, time and relevancy of the training their staff received. Whilst both the uptake of training and level of food hygiene qualifications may have improved in recent years, this study highlighted the need to develop training methods that are proven to change workplace behaviour as well as imparting knowledge. This may be best achieved by consolidating food hygiene training as a fundamental part of a wider approach to food safety control based on HACCP.

An evaluation of HACCP implementation status in UK small and medium enterprises in food manufacturing

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.

Growth of Listeria monocytogenes and Yersinia enterocolitica colonies under modified atmospheres at 4 and 8 °C using a model food system

W.A. HARRISON, A.C. PETERS and L.M. FIELDING.2000. The growth of Listeria monocytogenes and Yersinia enterocolitica colonies was studied on solid media at 4 and 8 °C under modified atmospheres (MAs) of 5% O2 : 10% CO2 : 85% N2 (MA1), 30% CO2 : 70% N2 (MA2) and air (control). Colony radius, determined using computer image analysis, allowed specific growth rates (μ) and the time taken to detect bacterial colonies to be estimated, after colonies became visible. At 4 °C both MAs decreased the growth rates of L. monocytogenes by 1·5‐ and 3·0‐fold under MA1 (μ = 0·02 h−1) and MA2 (μ = 0·01 h−1), respectively, as compared with the control (μ = 0·03 h−1). The time to detection of bacterial colonies was increased from 15 d (control) to 24 (MA1) and 29 d (MA2). At 8 °C MA2 decreased the growth rate by 1·5‐fold (μ = 0·04 h−1) as compared with the control (μ = 0·06 h−1) and detection of colonies increased from 7 (control) to 9 d (MA2). At 4 °C both MAs decreased the growth rates of Y. enterocolitica by 1·5‐ and 2·5‐fold under MA1 (μ = 0·03 h−1) and MA2 (μ = 0·02 h−1), respectively, as compared with the control (μ = 0·05 h−1). At 8 °C identical growth rates were obtained under MA1 and the control (μ = 0·07 h−1) whilst a decrease in the growth rate was obtained under MA2 (μ = 0·04 h−1). The detection of colonies varied from 6 (8 °C, aerobic) to 19 d (4 °C, MA2). Refrigerated modified atmosphere packaged foods should be maintained at 4 °C and below to ensure product safety.

Investigation on whey proteins profile of commercially available milk‐based probiotics health drinks using fast protein liquid chromatography (FPLC)

Purpose – The main aim of this study is to investigate the whey protein profiles of different commercially available fermented milk drinks that might have been influenced by the growth of probiotics bacteria that have been added according to the claims made by the manufacturer.Design/methodology/approach – The growth and the subsequent effect of probiotics on whey proteins were investigated through the peptide profiles of the hydrolysed whey protein. The profiles of whey proteins in skimmed milk and the four other probiotic fermented milk drinks were obtained by using the FPLC technique. Changes in whey proteins profiles in fermented milks were evaluated by comparing them with those of unfermented skimmed milk (control). The four samples were those of Yakult, Actimel, Muller and Tesco probiotic cranberry drinks.Findings – This work has shown that all samples demonstrated a degree of protein hydrolysis. The high level of hydrolysis in “Yakult” and “Actimel” drink samples might have been due to the nature o...