Validation of di-electric heating as a potential food safety intervention
Luvanda, Maureen K.
MetadataShow full item record
Food and water borne diseases are leading causes of illness and death in less developed countries killing approximately 7.2 million people annually, 1.9 million of whom are children. WHO has estimated that each year 2.2 million people, including 1.9 million children, die because of diarrheal diseases. This study was intended to experimentally analyze if di-electric heating has any indirect impact on the control, management and prevention of food borne disease outbreaks in terms of reduction of bacteria infective doses and increase in antibiotic susceptibility. This included investigating the effects on bacterial colony forming unit counts before and after exposure to microwave radiation as well as investigating changes in antibiotic susceptibility patterns. Surviving colonies were also investigated for viability, growth and multiplication ability. The aim of the study was to determine if microwave radiation can be used as a food safety intervention; whereas other objectives included evaluating its effects on growth and multiplication of bacteria. reduction of bacterial infective doses, measuring appropriate time (in minutes) required for radiation to achieve the desired results, recording the most effective power at which radiation was most likely to achieve the desired results and lastly observing if there are any significant changes as a result of exposure to microwave radiation when it comes to antibiotic susceptibility patterns. Various food samples (n=73) were artificially contaminated by food borne disease pathogens (Escherichia coli, Staphylococcus aureus, Shigella flexneri and Salmonella paratyphi) and were exposed to microwave radiation at different powers (P-OO, P-20. P-40, P-60, P-80) and time periods (2 rnin, 4 min, 6 min, 8 min).The degree of inactivation was estimated by measuring the colony forming units formed in culture before and after exposure of samples to radiation (Pre-test Post-test experimental design). The laboratory methods used were mainly culture techniques and biochemical tests. Data entry was done in Microsoft Excel after which data analysis was carried out using Statistical Package for Social Science (SPSS V 13) software. The results showed that generally microwave radiation produced a 1-2 log reduction when artificially contaminated food samples were processed. Initial seeded bacterial numbers (>3.0 x 104 ) were reduced significantly I' (P<0.05) however, this was not the same case when it came to antibiotic susceptibility patterns. The most effective time-power combination for bacteria inactivation was 8 minutes at P-80 where bacteria numbers were very low «1.0 x 10\ whereas the least effective time-power combination for bacteria inactivation was 2 minutes at P-20 where bacteria numbers remained at (>3.0 x 104).The study shows that microwave radiation reduces infective doses of bacteria by 96.67% but does not affect their antibiotic susceptibility patterns. Indications of any other effects of microwave radiation on the microbial agents were als noted. This study will serve as a guide to policies implemented on management and control of food and water borne infections. Traditional methods for improvements in food safety are still being utilized however the number of food and water borne disease incidences and antibiotic-resistance cases continue to rise. This therefore means that prevention rather than cure is important now more than ever and so modern methods or practices such as the microwave radiation that promote food hygiene should be explored and encouraged.