Utilization of electron beam irradiated almond skin powder as a natural antioxidant in ground top round beef

ABSTRACT:  Defatted Carmel variety almond skin powder (ASP) irradiated at 0, 10, 20, and 30 kGy was mixed with ground top round beef at 0.5% (w/w) and stored at 4 °C. Color stability, peroxide values (PV), conjugated dienes (CD), thiobarbituric acid reactive species (TBARS), and hexanal were determined periodically over a 2-wk period. The L values were not affected by time or treatment. Initially, the redness ( a value) was higher for both the negative control with no ASP ( a value of 21.83) and positive control with 0.01% BHT ( a value of 22.33) compared to samples that contained the ASP ( a values from 17.70 to 20.17) on day 1. This decrease in redness was attributed to the presence of the ASP. Similar to day 1, the a values were not significantly different between the 2 controls over the duration of the study. All the samples with ASP exhibited lower lipid oxidation when compared to the negative control, with greatest oxidation retardation observed at 20 and 30 kGy. Over the treatment period, a 13% to 85% reduction in PV and a 40% to 80% reduction in TBARS were observed in the sample with 30 kGy ASP compared to the negative control. Generally, PV and TBARS of samples with ASP decreased with an increase in irradiation dose. While a difference due to irradiation dose was not observed in CD and hexanal content, the values were significantly lower ( P < 0.05) than the controls over time. This study demonstrates that almond skin power could be used to extend the shelf life of refrigerated ground raw beef.