A comparison of the cooking performance of different appliances when following food manufacturers' instructions
The purpose of this research was to measure the temperature achieved in, and the microbiological count of, chicken burgers cooked following the preparation instructions given by the manufacturers. The work investigates the cooking of chicken burgers, manufactured by four different companies, cooked at different positions under a grill. Three appliances were used. Each showed uneven distribution of heat and a hot position and cool position was established for each grill. Differences in the temperature of the burgers cooked at different positions on the grills were also found. The burgers at the cool position attained a much lower cooking temperature and had a higher number of microorganisms surviving the cooking. The grill that produced the highest temperatures in the burgers had the lowest number of organisms surviving in the burgers. Only 24 out of the 72 burgers cooked to the manufacturers' instructions attained temperatures above 70°C. Some of the burgers appeared to be cooked when visibly assessed, but the core temperatures were low and had high microbial counts. The results obtained indicate that not all the cooking instructions were satisfactory and not all the appliances performed satisfactorily.
FOOD SAFETY IN THE HOME: CURRENT MICROBIOLOGICAL PERSPECTIVES
Despite the publication of two comprehensive reports (Richmond I and II) on the microbiological safety of food, together with new legislation, there has been little direct action concerning food safety in the home. Of particular relevance has been new research data which have shown that smaller numbers of bacteria are able to cause food poisoning, which stresses the importance of cross‐contamination. Doubts also have been raised about the safety of cooking raw meat in microwave ovens. Of perhaps greater impact have been the increased demands of food manufacturers and consumers on refrigeration. This has resulted, for example, from the increasing popularity of convenience foods and a reduction in the use of preservatives. Furthermore, many bacteria implicated in food poisoning are able to grow at relatively low temperatures. Recommendations include new standards by manufacturers of refrigerators and microwave ovens, together with a greater awareness and education of food safety issues.
Rapid Colorimetric Test for Alkaline Phosphatase in Dairy Products.
The Scharer rapid test for measuring alkaline phosphatase activity in milk and milk products was modified to include a photoelectric colorimeter in place of visual observation of color. Dairy products containing various amounts of added enzyme (3-15 μg phenol/ml or g) were prepared for analysis as per standard methods and analyzed by the rapid colorimetric test. A linear relationship was found between the percent of raw milk added and the enzyme activity with a correlation coefficient (r) range of 0.963 to 1.000. Hydrolysis of the substrate (disodium phenyl phosphate) by the surviving enzyme in different dairy products was similar. Recovery of the added enzyme varied, depending on the nature of the product. The method is quantitative, reproducible, and can be used as a rapid confirmatory procedure. Similarly, this method was applied to differentiating residual and reactivated enzyme in milk, cream and buttermilk. Compared to the Scharer rapid and the Rutgers visual methods, this test was more reliable in borderline cases because it eliminated the bias encountered in visual examination. A method was developed to analyze alkaline phosphatase in casein.