壳聚糖衍生物涂膜对新疆赛买提杏香气物质代谢机制影响研究

单一壳聚糖涂膜能减少杏的腐烂率，但易造成醛类和乙醇的增加，使杏香气产生劣变。申请人前期研究发现：H202/Vc氧化还原引发的自由基反应制备壳聚糖-没食子酸衍生物膜，弥补了单一壳聚糖涂膜抗氧化及抗菌性差的缺点，且能够较好地保留杏特有的香气。但改性壳聚糖对杏保鲜过程中香气变化相关机制还未阐明。本项目以赛买提杏香气变化及代谢机制为切入点，借助HS-SPME和GC-O-MS研究涂膜前后杏香气特征代谢指纹图谱、香气生物合成前体物质代谢谱及香气生物合成中关键酶活性。在此基础上，采用线性判别效应值大小分析（LEfSe）筛选出杏涂膜前后香气变化关键物质，并采用偏最小二乘和变量投影重要性分析（PLS-VIP）揭示底物与香气物质之间的关系，从而阐明壳聚糖衍生物涂膜对赛买提杏香气成分影响机制。研究结果为杏采后保鲜提供理论指导，有望为壳聚糖衍生物涂膜材料的推广及应用提供理论支持和科学依据。

The rotten rate of apricot can be reduced by using single chitosan coating , but it is easy to increase the content of aldehydes and ethanol. It makes the aroma of apricot worse. On the base of the applicant's previous research, the chitosan gallic acid derivative film was prepared by the free radical reaction from H2O2 / VC oxidation-reduction, which make up for the shortcomings of the single chitosan coating film in anti-oxidation and anti-bacterial, and it can retain the unique aroma of apricot. However, the mechanism of aroma changes in apricot has not been clarified. It takes the aroma change and metabolic mechanism of Saimaiti Apricot as the breakthrough point, and study the characteristic metabolic fingerprint of aroma of apricot before and after coating by HS-SPME and GC-O-MS, and the metabolic spectrum of aroma biosynthetic precursors and the key enzyme activities in aroma biosynthetic. On this basis, the key aroma components were selected by linear discriminant effect size analysis (LEfSe) , and the relationship between substrate and aroma components was revealed by partial least squares and variable projection importance analysis (PLS-VIP) , the mechanism of the effect of chitosan derivative coating on aroma components of Saimaiti Apricot was elucidated. The results provide theoretical guidance for the preservation of Apricot, and may provide theoretical support and scientific basis for the popularization and application of chitosan derivative coating materials.