Chemical Profiling and Antioxidant Characterisation of Palm Wine Variants from Different Ecological Zones of Cross River State

Palm wine, tapped from Elaeis guineensis and Raphia hookeri palms, is a traditional fermented beverage widely consumed across Cross River State in South South Nigeria. Its nutritional and bioactive composition varies with palm species, tapping location, fermentation time, and ecological zone, factors that have not been comprehensively characterised for Cross River State variants. This study conducted chemical profiling and antioxidant characterisation of twelve palm wine samples from forest, mangrove, and highland ecological zones within Cross River State. Parameters analysed included ethanol content by GC-FID, total soluble solids by refractometry, titratable acidity, pH, total reducing sugars, vitamin C content, total phenolic content by Folin-Ciocalteu method, and antioxidant activity by DPPH and ABTS radical scavenging assays. Amino acid profiles were determined by ion-exchange chromatography. Significant differences were observed across ecological zones. Forest zone samples contained higher total phenolics and antioxidant activity than mangrove and highland variants. Vitamin C content declined significantly with fermentation time beyond 12 hours. Eighteen amino acids were identified, including essential amino acids lysine and tryptophan at nutritionally relevant concentrations. Ethanol content ranged from 2.1 to 6.8% v/v. These findings provide a comprehensive chemical characterisation database for Cross River State palm wine variants with relevance to standardisation, quality control, and nutraceutical application. Keywords: palm wine, chemical profiling, antioxidant activity, Cross River State, fermentation.