Analysis Of Functional Components Of Sichuan Pepper And Study On Dynamic Changes Of Drying Process

Sichuan pepper(Zanthoxylum bungeanum Maxim.)is a dicotyledonous plant in the Rutaceae family,which has both medicinal and edible functions.This study firstly compared Sichuan pepper shoots,leaves,seeds and shells from the perspective of functional components,and studied the difference of these four materials in volatile components,hydroxy-α-sanshool,polyphenols,alkaloids,and antioxidant activity.Secondly,based on the drying of Sichuan pepper,compare the effects of five drying methods on the color,hydroxy-α-sanshool,polyphenols,alkaloids,and antioxidant activity.Finally,the most common hot air drying method was used to evaluate the dynamics of volatile components,hydroxy-α-sanshool,polyphenols,alkaloids,and antioxidant activity of Sichuan pepper during the drying process at different drying temperatures.The main findings are as follows:1.Study on the components of Sichuan pepper and its different partsThe order of polyphenol content of Sichuan pepper and its different parts is leaf >shoots > shell > seed;the order of total alkaloid content is shoots > shell > leaf > seed;the order of antioxidant activity is shoots > shell > leaf> seed.Hydroxy-α-sanshool is distributed in Sichuan pepper shell,shoot,leaves and seeds,and the content in the shell is the highest;A total of 78 volatile components were identified from Sichuan pepper and its different parts,including 39 alkenes,13 esters,and 15 alcohols.Shell has 60 volatile components,the shoots have 57 volatile components,and the leaves have 56 volatile components,all containing the characteristic components of Sichuan pepper such as linalool,germacrene D,D-limonene and β-myrcene.2.Research on the quality of Sichuan pepper shell by different drying methods.Compared with the color of fresh pepper,the color of the cold air drying is the best;Different drying methods have great effects on the polyphenols,total organisms and antioxidant capacity of Sichuan pepper,the results showed that the contents of polyphenols and total alkaloids were relatively high after cold air drying and vacuum freeze drying,which showed better DPPH,ABTS free radical scavenging ability and FRAP reduction ability.Drying would reduce the content of hydroxyl-α-sanshool,and temperature was one of the important factors affecting the content of hydroxy-α-sanshool.It was found that the functional components of the sample obtained by cold-air drying are close to that of fresh Sichuan pepper by principal component analysis method.3.Research on the dynamic change of quality of Sichuan pepper shell during hot air drying.The model of the moisture content of fresh Sichuan pepper with drying time at different drying temperatures conforms to the Henderson and Pabis model.When the hot air drying temperature was greater than 55 °C,the drying rate of Sichuan pepper can be quickly increased.During the hot air drying process,the degradation of polyphenols and antioxidant capacity has a certain regularity,which can be described by a fitted model.Temperature has a significant effect on functional components.Increasing the drying temperature can significantly accelerate the degradation of polyphenols and hydroxy-α-sanshool.Compared with the 33 kinds of volatile components in fresh pepper,the peak areas of 33 kinds of volatile compounds after 60 ℃ hot air drying were all significantly reduced,and the peak areas of 30 kinds of volatile compounds after 55 ℃ hot air drying were reduced,the peak area of L-4-terpineol is equivalent,the peak areas ofα-muurolene and(4E,6Z)-alloocimene were increased,and the peak areas of 30 volatile components are reduced after hot air drying at 50 °C.