Study On The Main Aroma And Their Changes During Processing And Storage In Orange Juice

This paper focuses on the central topic of the main aroma constituents of orange juice and the change thereof in the processing and storage, and, with major developments orange juice varieties in Chongqing as the research objects, makes a systematic research on the main aroma constituents of the object orange juice in a series of methods such as SDE (simultaneous distillation extraction) and GC-MS (gas chromatography/mass spectrometry). This research aims to appraise and analyze the aroma constituents of orange juice of different kinds and different maturity degree, studies the corresponding change of the main aroma constituents in the processing and storage, Through the above mentioned research, the author draws the following conclusion:1. Study on the main aroma constituents of different kinds of orange juiceWithin six kinds of orange juice selected,15 kinds of alcohol,25 kinds of ester,35 kinds of hydrocarbon,9 kinds of aldehyde, and 5 kinds of ketone are detected. Jincheng orange juice contains the most alcohol, followed by 72-1 orange juice, and the other kinds of orange juice have low content of alcohol; Beibei 447 orange juice and Teluoweita orange juice is with high content of ester, and Jincheng orange juice is with the lowest; all of the six kinds of orange juice are with high content of hydrocarbon, and within which Jincheng orange juice and Zaojin orange juice are with the highest; Jincheng orange juice and 72-1 orange juice are with the highest content of aldehyde, and Zaojin orange juice is with the lowest. During the processing of orange juice, proper match of different kinds should be taken into consideration according to corresponding requirements, in order to offset the weakness and produce orange juice with high quality.2. Study on the main aroma constituents of orange juice of different maturity degreeIn four kinds of orange juice selected,17 kinds of alcohol,20 kinds of ester,38 kinds of hydrocarbon, and 8 kinds of aldehyde are detected. Among those kinds of orange juice, mature Beibei 447 orange juice is with the highest content of alcohol, followed by mature Hamulin orange juice; mature Beibei 447 orange juice and mature Hamulin orange juice are with high content of ester, and immature Hamulin orange juice is with the lowest; all of the four kinds of orange juice are with high content of hydrocarbon, and immature and mature Hamulin orange juice range first; The content of aldehyde in immature orange juice is higher than that in mature orange juice. During the processing of orange juice, the maturity degree of orange should be attached great importance to, which would have great influence on the quality of orange juice. Therefore, the harvest time should be properly controlled, and oranges have to be graded in order to produce orange juice with high quality.3. Study on the influence of different sterilization temperature on the main aroma constituentsThis experiment compared the aroma constituents before and after sterilization for 72-1 orange juice and Jicheng orange juice. It turns out that the total content of alcohol, ester and other constituents in 72-1 orange juice increases after sterilization, and that of hydrocarbon and aldehyde decreases. However, after sterilization, the content of alcohol in Jicheng orange juice is with no obvious change, the total content of ester and hydrocarbon decreases, and that of aldehyde and other constituents increases. It is shown that heat sterilization has different influence on the content of aroma constituents of different kinds of orange juice, thereby, for improving the quality of orange juice, different match of orange juice should be chosen to meet different requirements by appropriate sterilization temperature so as to enrich the aroma of finished product orange juice.4. Study on the influence of storage on the main aroma constituents of orange juiceThrough the research on the change of aroma constituents when orange juice is stored respectively under frozen storage conditions and atmosphere conditions, it is shown that the content of all of the main components of orange juice changes in the process of storage, and presents a decreasing trend. The long the storage time is, the worse the quality of the orange juice stored will be. Every factor should be taken into consideration during the processing of orange juice, and necessary strategies shall be adopted to control or slow down the changing speed or aroma constituents in order to improve the quality of orange juice.