Effects of Various Blanching Treatments on Endogenous Enzymes and Main Qualities of Strawberry

The effects of various blanching treatments(100℃steam blanching and 100℃ boiling water blanching for 1min、1.5min,and 2min) on the enzyme inactivation and qualities of strawberry were investigated.POD showed a higher thermal stability than PPO and the inactivation effects increased with blanching time.No significant influence was observed on the total soluble solid(TSS),pH,titratable acidity(TA) of strawberry(P0.05),respectively,and the color of the blanching-treated strawberries was more brilliant.However,the content of VC significantly decreased(P0.05) while total phenols and anthocyanins significantly increased(P0.05).After blanching treatment,the type of volatile aromatic ester compositions were changeless while their relative content increased,and the relative content of trans-2-hexenal,a typical fresh strawberry aroma composition,significantly decreased after blanching(P0.05).However,the partial content of trans-2-hexenal still remained after steam blanching for 1 min and 1.5 min.The fresh grass flavor of strawberry was easily attenuated by long-time blanching.