| Zanthoxylum bungeanum Maxim.(ZB)is a kind of traditional edible spice,which is deeply loved by consumers because of its unique hemp flavor and rich nutrients.However,the traditional drying and storage methods o used resulted in serious quality loss.Moreover,the effects of different storage methods(packaging,temperature)on the quality indexescomtents,such as total alkylamides,volatile oil and anthocyanin were rarely reported during the long-term storage periods of more than 12 months.In this study,’Dahongpao’ ZB of Fengxian was used to inquiry the effects of different drying and storage methods on its quality indexes,explore the change rules of each index,and screen the appropriate processing,storage methods and storage period,so as to provide theoretical basis and application technology for the ZB industry and market.The main results are as follows:(1)Vacuum freeze drying provides new possibilities for the drying of ZB.Among the four treatments of shade drying,hot air drying,far-infrared drying and vacuum freeze drying,the quality indexes contents of vacuum freeze drying ZB were the second and only next to those of fresh samples,which had a good effect on maintaining the quality of ZB.Vacuum freeze-drying had poor retention effect on volatile oils,and the score of principal components was only-3.01.The shade drying was beneficial to the retention of volatile oils with the principal components score of3.76,which is higher than that of fresh samples(2.70),but the loss of color,hemp flavor and antioxidation were serious.(2)The correlation analysis of anthocyanin,total phenol and total flavonoids contents and antioxidant indexes(DPPH free radical scavenging activity,FRAP)of ZB under different drying treatments showed that the contents of anthocyanin,total phenol and total flavonoids were significantly positively correlated with antioxidant activity.The correlation between total phenol content and antioxidant activity was the strongest,showing the total phenol may play an important role in the regulation of antioxidant activity of ZB.(3)ZB was packaged in three types: fresh-keeping bags,vacuum bags and glass bottles.The vacuum packaging significantly inhibited the decrease of the contents of total alkylamides,anthocyanin,total phenols,total flavonoids and antioxidant activity of ZB during storage and showed a better effect.The recommended storage period was 18 months.The glass bottle packaging was conducive to the preservation of volatile oil and the retention for other indicators were better than that of PE packaging,but the loss was still high,therefore the recommended storage period was 12 months.The quality indicators of ZB packaged in PE bags had the fastest decline and the most losses during storage And the recommended storage period was 12 months.(4)ZB was stored at room temperature of 20 °C and low temperature of 4 °C,in which 4 °C significantly maintained the quality of ZB during storage.The content of volatile oil,total alkylamides,anthocyanin and antioxidant properties of ZB at °C were significantly higher than those stored at 20 °C.The storage period could reach18 months with the decrease rates of volatile oil,total alkylamides and anthocyanin were 10.71%,35.60% and 34.97%,respectively.(5)The kinetic analysis of quality indicators of ZB with different storage methods showed that each indicator conformed to the zero-order or first-order kinetic model and the fitting effect was well,which could predict the decline rate of each indicator and provide a reference for the selection of storage period.In summary,in different processing and storage methods,vacuum freeze-drying,vacuum packaging and low temperature storage at 4 °C can better maintain the quality of ZB during the processing/storage period.The kinetic model can predict the storage period and provide theoretical basis and application technology for the ZB industry and market. |
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