Effect of pulsed magnetic field on microbiological quality and lipid oxidation of minced beef meat during refrigerated storage

摘要

This study was conducted to investigate the effect of pulsed magnetic field (PMF) on the microbiological quality and lipid oxidation of minced beef meat during refrigerated storage at 4°C. Fresh minced samples (Supraspinatus muscles) were exposed to 1 Hz PMF with intensity about 10 mT for 2 hours at 4°C. Treated and non treated (control) samples were stored at refrigeration temperature (4±1) °C during 12 days. Their microbiological quality was assessed before the exposure and at 6ht and 12th day of storage by counting the number of total aerobic mesophilic bacteria. The lipid oxidation was determined by thiobarbituric acid reactive substances (TBARS) every 2 days of storage. Five experiments were conducted and data were evaluated by Student's t-test. Analysis of variance (ANOVA) and Duncan's Multiple Range Tests, at the 0.05 level of significance, were used for comparing the means to find out the effect of storage period. The mesophilic count did not change until the 6th day of storage for both groups. But at the 12th day the mesophilic count significantly increased by 2 logs and 0.7 logs for control and treated samples, respectively. The TBARS number of both groups increased during 12 days of refrigerated storage. However, PMF treatment had no significant effect on the TBARS number of samples at any particular storage time. PMF can be a potential technology for meat preservation since the exposure of minced beef meat to PMF in this study conditions reduced the microbial growth and did not affect the lipid oxidation stability.