Preparation And Purification Of Natural Apple Essence

China is the world's apple juice concentrate production and export of the first big country,In order to improve the use of agricultural and sideline products in the production process of concentrated fruit juice,This paper studied the recovery and purification of natural apple essence In this paper,red Fuji apple was used as raw material,and the volatile aroma components were recovered by vacuum distillation.At the same time,the natural apple flavor was obtained by secondary distillation.The chemical composition analysis was carried out by gas phase mass spectrometry.The main contents and results are as follows:(1)To apple juice as raw material,with vacuum distillation method to recover aroma components,The results showed that the total aroma components of alcohols,aldehydes,esters,other(ketones,acids,hydrocarbons,phenols,etc.)showed a tendency to decrease the total peak area with the increase of the temperature of the water bath and the distillation time.Taking the aroma quantity and peak area of various substances as the evaluation index,the comprehensive evaluation model of aroma was established,The optimum parameters for the preparation of natural apple flavors were as follows:distillation temperature was 60 ? and distillation time was 10 min.(2)The reaction surface method was used to study the purification process of natural apple flavor,Based on the single factor experiment,the equation of the second regression model was established between the total content of aroma and the distillation time,rotational speed and water bath temperature.The results show that the distillation time is 12 min,the rotation speed is 50 r/min and the water bath temperature is 59 ?.Under this experimental condition,the natural apple fragrance is purely tested,and the relative content of aroma components is 3.5918 mg/m L,There is no significant difference between the experimental results and the model predictions,indicating that the quadratic regression model equation can be used to analyze the prediction.(3)The chemical composition of natural apple essence was analyzed by SPME and GC-MS,The natural apple fragrance obtained from the experiment was compared with the commercial natural apple essence.It was found that the natural apple flavor was difficult to be purified by vacuum distillation and secondary distillation.The final aroma components were mainly alcoholic substances,Such as ethanol,butanol,2-methyl butanol,n-hexanol,etc.there are some aldehydes,almost no esters,esters in the distillation of vacuum distillation and secondary distillation process is serious,almost difficult to recover Purified.Commercial fragrance is mainly some of esters,Such as isoamyl acetate,ethyl acetate,butyl acetate,hexyl acetate,capillate acetate,ethyl caproate,geranyl acetate,and etc.By comparing the aroma components of the apple stock,some aroma ingredients were found and this experiment was not detected.