Lipid Oxidation, pH and Colour in Beef as Affected by Gamma Irradiation—A Meta-Analysis

A meta-analysis of the effect of gamma irradiation on the accumulation of primary and secondary products of oxidation, as well as pH and instrumental colour characteristics (lightness—L*; redness—a* and yellowness—b*) in beef stored at different temperatures and packaging was performed. A total of 15 studies were included, each concerning at least one of the examined indicators. The number of independent experiments according to the covariates (dose of irradiation, temperature of storage, and packaging) varied between 16 and 25 for the individual traits. The heterogeneity between studies determined the selection of the random effects model to be applied on the raw mean difference (effect size) in the analysis of the data. The results of the meta-analysis showed that the gamma irradiation of beef is associated with a significant increase in the peroxide value (POV) (p = 0.046) and the content of thiobarbituric acid reactive substances (TBARS) (p < 0.001) as well as a decrease in pH (p < 0.001). The colour parameters L*, a*, and b* varied insignificantly. While no effect of the dose of applied radiation and the type of packaging was found on the studied parameters, the storage conditions affected the TBARS content, which, however, remained at acceptable levels without negative influence on the high nutritional value of the meat.