Metabolites and nutritional variations of phenotypic diversity in Kopyor coconut (Cocos nucifera L. var. Kopyor)

Kopyor (Cocos nucifera L. var. Kopyor) is a distinct coconut variant resulting from a genetic mutation that alters the endosperm. Kopyor displays notable phenotypic diversity in terms of cultivar and endosperm quantity (EQ), which refers to the amount of flesh detached from the endocarp. Despite its distinct traits, kopyor utilization is limited because of the lack of comprehensive research on its diverse phenotypes. The aim of this study was to investigate the variations of metabolites and nutrients in kopyors by analyzing metabolomic profiles, physicochemical properties, and proximate characteristics across three cultivars with EQ levels ranging from 10 % to 50 %. The results showed that EQ influenced metabolite accumulation more significantly than the cultivar did. Elevated levels of EQ have been associated with increased concentrations of essential amino acids, which are classified as sensory-related metabolites. An increase in EQ was accompanied by the breakdown of macromolecules, particularly carbohydrates and proteins into simpler sugars and amino acids. This process potentially enhanced the bioavailability of nutrients in kopyor coconuts compared to that in normal coconuts. This study proposed potential metabolite marker for assessing the quality of kopyor coconuts. Valine, an essential amino acid, was the only compound consistently and significantly detected across all analyses, including principal component analysis (PCA), F-test, Tukey's test, Pearson correlation, and orthogonal projections to latent structures regression (OPLSR), conducted on the water and flesh of kopyor coconuts. Consequently, valine was identified as a promising biomarker candidate. This study is the first to extensively characterize the phenotypic diversity of kopyor. The findings highlight its potential for further development in the food industry.