The Study On The Stability Of Numb-taste Of Zanthoxylum And Its Product In Different Treatments And Storage Conditions

Zanthoxylum is a spice plant of the genus of Zanthoxylum.As an important characteristic condiment in our country,numb-taste is an important flavor characteristic and also an important index to evaluate its quality.Zanthoxylum contains a lot of numb-taste,which mainly is chain unsaturated fatty acid amide substances.Numb-taste can easily be oxidized,which resulting in more stable derivatives,so that the loss of material.However,there is no systematic study on the stability of the numb-taste of Zanthoxylum and its products.In this paper,the effects of drying methods,different storage methods and adding different antioxidants on the stability of the material were studied by using fresh Zanthoxylum,dried Zanthoxylum,Zanthoxylum oil and its oleoresin as raw materials.The results were as follows:1.Comparing the numb-taste of fresh green and red Zanthoxylum,we found that there was significant difference between the different origin and cultivars(P <0.05).The effects of different drying methods on the fresh Zanthoxylum in different areas were compared.The natural drying was significantly higher than that of oven drying.The numb-taste rate of fresh green Zanthoxylum in the natural drying was over 90%,and the volatile oil rate was more than 93%;The fresh red Zanthoxylum in the natural drying was over 98%,and the volatile oil rate was more than 93%.2.The effects of different degree of crushing,packaging and storage temperature on the numb-taste of red Zanthoxylum were studied.The changes of the numb-taste in the conventional packaging were significant(P < 0.05)in low temperature,which the loss of the Zanthoxylum powder was the most serious,the crushed Zanthoxylum was inferior,and the whole Zanthoxylum was the best.The vacuum packing of aluminum foil bag and the inflating packaging of the pot filled with the contents of the material content of the three kinds of crushed prickly ash have protective effect,which can reduce the loss of numb-taste.To study the whole Zanthoxylum stored at low temperature and at room temperature in twelve months with six kinds of packaging whose changes of numb-taste.The results showed that the temperature had a significant effect on the loss of numb-taste of the whole Zanthoxylum.Under low temperature conditions,the loss of numb-taste is lower;at both temperatures,vacuum packaging andinflatable packaging significantly reduce the loss of numb-taste of the whole Zanthoxylum.3.The effects of different antioxidants on the stability of Zanthoxylum oil and its oleoresin were studied.Tea polyphenols,VC and VE are respectively added into Zanthoxylum oleoresin.With numb taste loss rate as the evaluation index and through the low temperature oxidation test and thermal stability test,it is found that the best antioxidant is tea polyphenols whose the optimum adding amount is 0.5%;Tea polyphenols,VE,VC,TBHQ,rosemary,L-ascorbic acid palmitate and compound antioxidant are respectively added into Zanthoxylum oil.With peroxide value as the evaluation index and through accelerated oxidation test,it is discovered that the best antioxidant is L-ascorbic acid palmitate whose the optimum adding amount is 0.2 g/kg.