Pulsed UV-C radiation of beef loin steaks: Effects on microbial inactivation, quality attributes and volatile compounds

Abstract

The aim of this study was to investigate the effect of pulsed light treatment at fluences of 0.525, 1.05, 2.1 and 4.2 J/cm2 on the chemical composition, microbiological quality and volatile compounds of beef loin steaks. Pulsed light treatment did not affect total moisture, total protein, total lipid and ash content of samples significantly (P > 0.05). The a* and b* values of the pulsed light treated samples significantly decreased compared to control samples with maximum difference of 2.11 and 1.33 unit, respectively (P < 0.05). The highest reduction (3.49 ± 0.67 log CFU/g) in total aerobic mesophilic bacterial counts (compared to naturally occuring microbiota in control group) was achieved for samples treated with 4.2 J/cm2 of UV-C fluence level. A total of 14 volatiles, mainly aldehydes, alcohols, ketones and terpen compounds were identified in the raw samples and pulsed light treatment caused an increase in the amounts of some volatile compounds, including hexanal (from 33.41 μg/kg to 69.67 μg/kg), 2-heptenal (from 0.60 μg/kg to 1.52 μg/kg), 2-octenal (from 0.39 μg/kg to 1.58 μg/kg), 2,4-nonadienal (from 0.05 μg/kg to 0.24 μg/kg), 2,4-decadienal (from 0.04 μg/kg to 0.26 μg/kg), 3-octen-2-one (from 0.37 μg/kg to 2.53 μg/kg), limonene (from 2.06 μg/kg to 18.42 μg/kg). Otherwise, pulsed light decreased the levels of some compounds coming from microbial metabolism such as 1-heptanol (from 0.57 μg/kg to 0.39 μg/kg), 1-octen-3-ol (from 1.83 μg/kg to 1.12 μg/kg), 2-octen-1-ol (from 0.28 μg/kg to 0.09 μg/kg). In conclusion, pulsed light treatment can enhance the microbial safety of meat and has potential for use in the meat industry.