Effects of postharvest irradiation and superfine grinding wall disruption treatment on the bioactive compounds, endogenous enzyme activities, and antioxidant properties of pine (Pinus yunnanensis) pollen during accelerated storage

Abstract Effects of irradiation and superfine grinding wall disruption treatment on quality parameters and antioxidant activity of pine pollen during storage at 55°C for 8 weeks were investigated. Results showed that irradiation slowed the reduction of taxifolin and ascorbic acid levels and the increase of ferric-ion reducing antioxidant power (FRAP), but accelerated the increase of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity over storage. In addition, superfine grinding wall disruption accelerated the rise of p-coumaric acid and naringenin contents and the decline of taxifolin level in pine pollen during storage. Moreover, superoxide dismutase activity, FRAP value, naringenin, malondialdehyde, total saturated and polyunsaturated fatty acids content were increased both in untreated and treated pine pollen, whereas the total spins, taxifolin, and ascorbic acid contents were decreased. The changes of parameters in endogenous antioxidant system indicated that metabolism in pine pollen was triggered in response to damage induced by processing and storage. These results would help improve the quality and commercial values of pine pollen in the food and pharmaceutical industries.