Comparative Metabolomics Reveals Key Determinants in the Flavor and Nutritional Value of Coconut by HS-SPME/GC-MS and UHPLC-MS/MS

Hao Guo; Jun Lai; Chun Li; Haihong Zhou; Chao Wang; Weizhen Ye; Yue Zhong; Xuecheng Zhao; Feng Zhang; Jun Yang; Shouchuang Wang

doi:10.3390/metabo12080691

Comparative Metabolomics Reveals Key Determinants in the Flavor and Nutritional Value of Coconut by HS-SPME/GC-MS and UHPLC-MS/MS

Metabolites. 2022 Jul 26;12(8):691. doi: 10.3390/metabo12080691.

Authors

Hao Guo¹, Jun Lai¹, Chun Li¹, Haihong Zhou¹, Chao Wang¹, Weizhen Ye¹, Yue Zhong¹, Xuecheng Zhao², Feng Zhang³, Jun Yang^{1

2}, Shouchuang Wang^{1

2}

Affiliations

¹ College of Tropical Crops, Hainan University, Haikou 570228, China.
² Sanya Nanfan Research Institute of Hainan University, Hainan Yazhou Bay Seed Laboratory, Sanya 572025, China.
³ National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China.

Abstract

Coconut is a tropical fruit whose flesh has high flavor quality and nutritional value; however, the differences between coconut varieties are still unclear. Here, volatiles and non-volatiles were profiled at three ripening stages by HS-SPME/GC-MS and UHPLC-MS/MS in two coconut varieties (Hainan Tall, HT and Green Dwarf, GD). Four metabolite classes of volatiles were associated with good aroma including hydrocarbons, benzenoids, alcohols and esters, and these volatiles were generally higher in GD, especially at 7 and 9 months of coconut growth. Pathway-based metabolomics revealed that flavonols and their derivatives were significantly enriched in HT, and some of these metabolites were key determinants of HT flesh bitterness, including kaempferol 7-O-glucoside, a known bitter metabolite. Despite the overall accumulation of amino acids, including L-alanine, L-serine and L-methionine in GD, comparative metabolomics revealed that HT flesh provides a higher content of vitamins than GD. This study sheds light on the metabolic pathways and key metabolites differentiating the flesh flavor quality and nutritional value among coconut varieties, and reveals the possible mechanisms of flavor formation and regulation in coconut fruits.

Keywords: HS-SPME/GC-MS; UHPLC-MS/MS; coconut; flavor; nutritional value.

Grants and funding

This work was supported by the National Natural Science Foundation of China (No. 31960213), the Young Elite Scientists Sponsorship Program by CAST (No. 2019QNRC001), the Hainan Provincial Academician Innovation Platform Project (No. HD-YSZX-202004), and the Hainan University Startup Fund (No. KYQD(ZR) 1916 and KYQD(ZR) 21025).