Discrimination and characterization of different coconut water (CW) by their phenolic composition and volatile organic compounds (VOCs) using LC-MS/MS, HS-SPME-GC-MS, and HS-GC-IMS.

Abstract

Three varieties of coconut (Cocos nucifera L.) water (CW) at two maturity stages were investigated for physicochemical and nutritional properties. The profile of phenolic compounds and volatile organic compounds (VOCs) was determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS), headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS), and headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS). Most of the properties of CW changed significantly with maturity rather than variety. The five most relevant phenolic compounds in CW were chlorogenic acid, 4-hydroxy-3,5-dimethoxycinnamic acid, L-epicatechin, and procyanidins B2 and B1. Variety played a more important role in phenolic composition than maturity, and Wenye No. 4 can be distinguished from other two varieties. Alcohols and esters were the main VOCs in CW identified by HS-GC-IMS and HS-SPME-GC-MS, respectively. Five and four compounds (VIP scores>1) were characteristic compounds for CW by HS-GC-IMS and HS-SPME-GC-MS, respectively. The VOCs of Wenye Nos. 2 and 3 were more similar than those of Wenye No. 4. These findings could provide useful information for the selection of raw materials of CW used for different industrial purposes.