| High-temperature-air fluidized brown rice(HFBR),as a whole grain product,has advantages of easy cooking,better taste and flavor quality.The storage stability of brown rice was reduced by the high-temperature air fluidization,and HFBR was easy to produce a bad smell during storage,which limits its development and circulation in market.The reasons of high temperature air fluidization treatment on the storage stability of brown rice were preliminarily explored in this study,and the effects of different methods on the storage quality of brown rice were studied.The complex active packaging method of ethanol emitter(EE)combined with oxygen absorber(OA)was finally applied as the optimal storage method to improve the shelf life of HFBR.Firstly,the change of storage stability of brown rice reduced after high temperature air fluidization was studied.The results showed that the change of the fatty acid value of HFBR was significantly lower than that of the untreated brown rice(UBR)during storage,but it exceeded the national standard of 35 mg/100 g.The increase of the fatty acid value was mainly caused by the action of residual lipase in the HFBR.Compared with UBR,the content of aldehydes and ketones of the HFBR’ volatile gas components increased significantly during storage,and the HFBR had a bad flavor as the content of hexanal exceeded 1.98 μg/g.While the content of hexanal of HFBR was significantly higher than UBR and exceeded 1.98 μg/g,which was related to the increase of free radical content and the enhancement of lipid oxidation reaction in brown rice after high temperature fluidized treatment.Secondly,the effects of different storage methods on the storage stability of HFBR were studied.The results showed that stored at 55,37°C and room temperature respectively,the complex active packaged HFBR of EE combined with OA could limited the fatty acid value and the hexanal content below 35 mg/100 g and 1.98 μg/g,respectively,which effectively improved the storage stability and prolonged the shelf life of HFBR.The complex active packaging method of EE-200 combined with OA-100 can maintain the shelf life of HFBR over 180 days stored at room temperature.Then,the reasons for improving the storage stability of HFBR with complex active packaging were investigated.The results showed that the lipase activity of the complex active packaged HFBR was significantly lower than that of the control group,and they were about 68% of the control group,and the decrease of lipase activity of complex active packaged HFBR increased with increasing ethanol content.The free radical signal intensity of the complex active packaged samples were about 50% of the control group,the relative content of the unsaturated fatty acids were increased,and the aldehydes and ketones were increased during storage,which indicates that the oxidation reaction of the lipid in HFBR the complex active packaging was inhibited.Finally,the effect of complex active packaging on the content of antioxidant components,the gelatinization properties and cooking quality of HFBR was studied at room temperature for 180 days.The results showed that:(1)the total phenolic content and flavonoid content of the complex active packaging HFBR were approximately 112% and 156% of the control group after 180 days of storage,respectively,which were significantly higher than the control group(p<0.05).(2)Compared with the control group,there were no significant difference in peak viscosity and disintegration value during storage of HFBR in complex active packaging,and the final viscosity and retrogradation value were lower.(3)The water absorption rate of composite active packaging HFBR were significantly lower than those of the control group during storage,and the volume expansion ratio,iodine blue value and texture characteristics were similar to those of the control group,the sensory score of HFBR with the complex active packaging were higher than 70 points and significantly higher than that of the control group(p<0.05),the method can maintain the better eating quality of HFBR. |
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