| Apple brewing can enhance the added value and increase economic benefits.Storage or delayed harvesting affects the quality of apple fruit and thus the quality of distilled wine.The quality of distilled liquor was analyzed lots of indexes by using apples as raw materials with different storage periods and delayed harvesting,which include alcohol strength,methanol content and the variety and content of volatile aroma components,etc.Using Gas chromatography mass spectrometer to determine volatile aroma components.Meanwhile,the composition of the distillate in the distillation process was determined in different time periods.It provides some theoretical basis for reasonable selection of apple storage and harvesting time and "throttling" of distillate selection.The main results of the experiment are as follows:（1）With the extension of apple storage time,the soluble solids increased,acidity decreased,hardness decreased,juiced yield and wine yield decreased.The alcohol strength of distilled liquor decreased continuously,and the methanol content was lower in the early stage and changed irregularly.While the volatile aroma substances decreased.According to the analysis of various indexes,the comprehensive quality of apple was better,which stored for120 to 180 d was more suitable for brewing of apple liquor.The yield of raw materials was5.43%-5.68%.53.7 %vol-54.1 %vol of alcohol strength.Methanol content was 0.57 g·L-10.67 g·L-1,and more than 27 kinds of volatile aroma substances were detected in liquor,the content of which was 894.64 mg·L-1-1 024.01 mg·L-1.（2）The soluble solid content of delayed harvest apples increased,acidity and hardness decreased,and raw material juice yield and wine yield decreased.While the alcohol strength of distilled liquor increased,and the content of volatile aroma substances increased,which improved the quality of distilled liquor.However,delayed harvest had adverse effects on plant growth and fruit next year.By comprehensive comparison,delay of 30 d was the optimal harvest time for the raw materials of apple liquor.The yield of raw materials was 6.30%,the alcohol strength was 53.1 %vol,and the methanol content was 0.63 g·L-1,which was relatively low.There were detected a total of 29 kinds of volatile aroma substances in distilled liquor,with the most varieties and the content of 432.12 mg·L-1.Delayed harvesting for 30 d,the fruit setting rate of the next year was 44.61%.The length of new branches was 25.1 cm,and yield per plant was 17.06 kg,and had less effect on the growth and yield of the next year.（3）The whole distillation process was divided into 10 periods.In the first time period of distillation from 0 to 12 min,alcohol strength was 67.17 %vol,and the methanol content was4.07 g ·L-1,and there were 20 volatile aroma substances.The methanol content was too high and the aroma components varieties were too few,so they should be removed as the wine head.At the 9th and 10 th time period of 96 to 120 min,5.24 L of mixture was distilled with an average alcohol strength of 36.1 %vol,and 19 kinds of volatile aroma substances(366.63mg·L-1)were detected.Because the alcohol strength and the content of volatile aroma substances in the mixed liquor was too low,few types,which were not suitable to be the main part of distilled liquor.In this experiment,all 35.16 L distillate was used,and 11.67% of the liquor in the first time period could be discarded as the wine head.The last two time periods would be discarded as the tail part,which accounting for 14.90% of the total distillate.The remaining seven time periods,a total of 25.82 L,73.44%,the average alcohol strength of55.8 %vol,the average methanol content of 0.79 g·L-1,there were 24 kinds of volatile aroma substances,the average content of 699.38 mg·L-1,with more varieties and high content,suitable to be retained as the main part of apple liquor. |
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