Effect of Maturation on the Chemical Composition, Nutritional Value, Biological Activities In Vitro and Volatile Organic Compounds in the Coconut Meat of Wenye No. 3 Variety

Coconut meat (solid endosperm) is a valuable oilseed product with significant nutritional and functional properties, yet the quality changes during maturation remain unclear. This study investigated the effects of maturity on nutrients, antioxidant and α-amylase inhibitory activities, and volatile organic compounds in coconut meat of the Wenye No. 3 variety at 8, 10, and 12 months after pollination (named CM-8, CM-10 and CM-12, respectively). Results showed that moisture content decreased from 81.15% to 61.73%, while fat (8.61% to 17.53%), protein (0.60% to 1.29%), and total soluble sugars (2.13% to 4.84%) increased from CM-8 to CM-12. Total phenolic content declined with maturity, whereas ABTS scavenging activity was significantly higher at CM-12 than at CM-10, and hydroxyl radical scavenging activity was similarly elevated at CM-10 and CM-12. α-Amylase inhibitory activity peaked at CM-10 (20.4%). Phosphorus, magnesium, zinc, and copper peaked at CM-12. Lauric acid predominated at all stages, with unsaturated fatty acids transiently increasing at CM-10. GC-IMS identified 31 volatile compounds, with esters and alcohols dominating in CM-8 and CM-10, while aldehydes accumulated in CM-12. These findings provide theoretical guidance for staged harvesting and graded utilization of coconut in the processing industry.