Optimization of Pretreatment Technique for the Vacuum Fried Apple Chips

In order to optimize pretreatment technology of the vacuum fried apple chips. The single factor test and uniform design method were used,and crushing force,oil content,L^* value,sensory score,comprehensive score and electronic nose detection of volatile components as indicators were analyzed by multiple regression analysis. The results showed that after the secondary stepwise regression analysis,the crushing force reached extremely significant(P<0.01),the correlation coefficient reached 0.960,and the model fit was good. Sensory score,L^* value and comprehensive score reached a significant level(P<0.05)and the oil content reached an extremely significant level(P<0.01)in a stepwise regression analysis. The impregnation concentration and blanching temperature influenced sensory score and L^* value of the product. The impregnation concentration,blanching temperature and time,and freezing time affected the oil content and comprehensive score of the product. Partial least squares regression analysis predicted that the best process parameters were as follows:maltose 14%,sucrose 5%,maltodextrin 15.7%,blanching temperature 98℃,blanching time 2 min,freezing time 3 h. Under the conditions of process,the crushing force was 53.1 N,the sensory score was 83.0,the oil content was 17.2%,L^* was 89.9,the comprehensive score was 89.6,and the flavor quality was best.