| 摘要: |
| 【目的】研究基于代谢组学技术的核桃内种皮苦涩味形成机理，为相关研究和苦涩味改良提供参考。【方法】以极具苦涩味内种皮和无苦涩味内种皮的核桃无性系为材料，利用超高效液相色谱和串联质谱（UPLC-MS/MS）技术，从其内种皮提取物质，通过自建数据库MVDB和代谢信息公共数据库对2种核桃无性系内种皮苦涩味的差异代谢物进行主成分分析、正交偏最小二乘判别分析、样本重复相关性评估和聚类等分析，再通过KEGG数据库注释差异代谢物参与的代谢途径，从中筛选出差异显著代谢物以及苦涩味标志物。【结果】从2种核桃内种皮中共检测到12大类263种差异代谢物，其中147种显著上调，116种显著下调，包括61种酚酸类、55种黄酮、43种脂质、20种其他类、19种鞣质、16种氨基酸及其衍生物、13种核苷酸及其衍生物、12种有机酸、11种生物碱、8种萜类、3种木脂素和香豆素及2种醌类，共注释到66条代谢途径，富集代谢物多且显著的前6条通路分别是类黄酮代谢、甘油酯代谢、糖基磷脂酰肌醇(GPI)锚定生物合成、抗坏血酸和aldarate代谢、苯丙烷类代谢、戊糖和葡萄糖醛酸的相互转化。自行构建了柚皮素代谢途径，并筛选出4个（柚皮素、圣草酚、圣草酚7-O-葡糖苷、矢车菊素3-O-葡萄糖苷）含量显著上调的代谢物，可将其作为核桃内种皮苦涩味形成的标志物。【结论】发现了2种无性系核桃内种皮代谢物差异以及苦涩味标志物。 |
| 关键词: 核桃内种皮 苦涩味物质 代谢组学 差异代谢物 代谢通路 |
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| 基金项目:四川省科技计划项目（2016NYZ0035）；农业农村部杂粮加工重点实验室开放基金项目（2017Y0012）；国家级创新训练项目（CDU_CX_2019279） |
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| Metabonomics of bitter taste quality of walnut kernel pellicle |
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SHI Yujie,WU Xiaoyong,MI Jiaxuan,et al
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| Abstract: |
| 【Objective】The formation mechanism of bitter taste in walnut kernel pellicle was studied based on metabonomics to provide reference for related research and bitter taste improvement.【Method】The extremely bitter walnut kernel pellicle (BI) and non bitter walnut kernel pellicle (SW) were selected for analysis using UPLC-MS/MS technique.The substances were extracted from walnut kernel pellicle,and then the differential metabolites of BI and SW of walnut clones were analyzed by principal component analysis,orthogonal partial least square discriminant analysis,sample correlation and clustering by self-built database MVDB and metabolic information public database.The metabolic pathways involved in differential metabolites were also annotated by KEGG database and significant metabolites and bitter taste makers were selected.【Result】A total of 263 differential metabolites of 12 classes were detected from the kernel pellicle of two walnut species,of which 147 were significantly up regulated and 116 significantly down regulated,including 61 phenolic acids,55 flavonoids,43 lipids,20 other classes,19 tannins,16 amino acids and their derivatives,13 nucleotides and their derivatives,12 organic acids,11 alkaloids,8 terpenes,3 lignans and coumarins and 2 quinones.A total of 66 metabolic pathways were annotated,and the top six pathways for metabolites enrichment were flavonoid metabolism,glycerolipid metabolism,biosynthesis of glycosylphosphatidylinositol (GPI) anchors,ascorbate and aldarate metabolism,phenylpropane metabolism,as well as pentose and glucuronate interconversions.According to related literature,the metabolic pathway of naringin was constructed,and four metabolites (naringin,eriodictyol,eriodictyol 7-O-glucoside and cyanidin 3-O-glucoside) with significantly up-regulated contents were selected to be used as markers for formation of bitter taste in walnut kernel pellicle.【Conclusion】The differences of kernel pellicle metabolites and bitter taste markers in two kinds of walnut clones were found. |
| Key words: walnut kernel pellicle bitter metabolite metabonomics differential metabolites metabolic pathway |
