基于机器学习的代谢组学解析腊八蒜储藏过程中代谢物差异

本研究采用气相色谱-质谱法对不同储藏时间的腊八蒜进行非靶向代谢组学研究，利用多元统计分析，筛选出不同储藏时间腊八蒜的显著性代谢物，进一步利用深度学习支持向量机递归特征消除（SVM-RFE）算法确定其标志性代谢物，并对其标志性代谢物的途径进行富集分析。结果表明，基于偏最小二乘-判别分析（PLS-DA）为标准进行筛选，共筛选出57种差异代谢物（VIP≥1,P<0.05,FDR<0.05），包括酸类（6种）、醇类（12种）、胺类（6种）、糖苷类（1种）、酯类（3种）、醚类（4种）、芳香类（13种）、烯烃类（2种）、其他（10种）。进一步地基于SVM-RFE过程筛选出6个标志性代谢物，其中5-己炔-1-醇是区别大蒜和腊八蒜的关键因素，而有机活性小分子肌醇、9-十八碳烯酰胺、硬脂酸、棕榈酸、苯甲酸是区分腊八蒜储藏的第35和85 d的关键因素。KEGG富集分析表明，在腊八蒜储藏过程中较为重要的代谢通路为不饱和脂肪酸生物合成途径，脂肪酸生物合成，角质、亚伯碱和蜡的生物合成，抗坏血酸和醛糖酸代谢，脂肪酸链伸长系统，磷脂酰肌醇信号系统，半乳糖代谢，磷酸肌醇代谢，脂肪酸降解。本研究解析出的腊八...

Metabolomics Analysis of Metabolite Differences during the Storage Process of Laba Garlic Based on Machine Learning

In this study, non-targeted metabolomic research was conducted using gas chromatography-mass spectrometry (GC-MS) on Laba garlic at different storage times to explore the signature metabolite changes during storage. Multivariate statistical analysis was used to screen out the significant metabolites of Laba garlic at different storage times. Further, the deep learning support vector machine recursive feature elimination (SVM-RFE) algorithm was used to determine its landmark metabolites, and enrichment analysis of the pathways of its landmark metabolites was carried out. A total of 57 different metabolites were screened out (VIP≥1, P<0.05, FDR<0.05) based on partial least squares-discriminant analysis (PLS-DA) as a criterion for screening, including acids (6), alcohols (12), amines (6), glycosides (1), esters (3), ethers (4), aromatics (13), olefins (2), and others (10). Further, 6 landmark metabolites were screened based on the SVM-RFE process, among which 5-hexyn-1-ol was the key factor to distinguish garlic and Laba garlic, while the organic active small molecule including inositol, 9-octadecenamide, stearic acid, palmitic acid and benzoic acid were the key factors to distinguish the 35th and 85th days of Laba garlic storage. KEGG enrichment analysis indicated that the more important metabolic pathways during storage were biosynthesis of unsaturated fatty acid, fatty acid biosynthesis, cutin, suberine and wax biosynthesis, ascorbate aldarate metabbolism, fatty acid elongation, phosphatidylinositol signaling system, galactose metabolism, inositol phosphate metabolism and fatty acid degradation. The six landmark metabolites in the storage process of Laba garlic analyzed in this study would provide a theoretical basis for the storage and evaluation of Laba garlic.