Effect of 60Co-γ-irradiation on the degradation of β-agonists residues and the quality of fresh pork during refrigeration

Abstract

This study aimed to investigate the degradation effects of different doses (0, 2, 4, 6, 8, and 10 kGy) of 60Co-γ-irradiation on β-agonists, and systematically research the effects of irradiation on the quality of fresh pork during refrigeration (0, 2, 4, 6, and 8 days). Both β-agonists in the aqueous solution and pork demonstrated dose-dependent degradation, however, the amount of degradation was lower in the latter than in the former. Liquid chromatography time-of-flight mass spectrometry (LC-TOF-MS/MS) identified five, three, and four irradiation degradation products of clenbuterol (CLB), salbutamol (SAL), and clorprenaline (CLO), respectively, and the luminescence toxicity assay of Vibrio fischeri preliminarily revealed that the toxicity of the three drugs was enhanced after irradiation. Throughout the refrigeration period, irradiation treatment increased the a* value of fresh pork, accelerated the rate of shear force increase, slowed the rate of increase of pH and TVB-N value, and had a good killing or controlling effect on the total plate count (TPC), coliform, Staphylococcus aureus, and Listeria monocytogenes. Meanwhile, it was also discovered that irradiation enhanced the oxidation of lipids and proteins in fresh pork. In conclusion, although irradiation technology can prolong the shelf life of meat, change the quality of meat to some extent, and have a degradation effect on β-agonists, the biotoxicity of the drug is enhanced after irradiation, so it is necessary to strictly prohibit the use of β-agonists from the source to avoid a greater risk to food safety.