PHYTOCHEMICAL AND NUTRITIONAL COMPOSITION, IN VITRO ANTIOXIDANT CAPACITY AND ALPHA- AMYLASE INHIBITORY ACTIVITY OF OIL PALM (Elaeis guineensis Jacq) SYRUP, KOLA NUT (Cola acuminata Scott) AQUEOUS EXTRACT, AND THEIR MIXTURES.

ABSTRACT

In this study, the nutritional composition and chemical characteristics of oil palm (Elaeis guineensis Jacq) syrup aqueous solutions, aqueous extracts of kola nut (Cola acuminata) and their mixtures were determined using standard biochemical methods. The pH values for the aqueous solutions of oil palm syrup ranged from 3.53 for the 40g / 100 ml, to 3.63 for the 5 g/100 ml solutions. Values for the aqueous extracts of C. acuminata seeds varied from 6.48 for the 3.0g/100ml to6.70 for the 0.1g/100ml solutions and 4.57 to 4.83 respectively for 0.1g and 3.0g combination of both extracts in 20g/100ml syrup in distilled water. The titrable acidity for the palm syrup ranged from 2.70g/L for the 5g/100ml to 4.01g/L for the 40g/100ml solution. Total phenolic content (TPC) for oil palm syrup ranged from 420.6µg GAE/L for 40g/100ml to 112.7 µg GAE/L for 5g/100ml, 307.1µg GAE/L for 3.0g/100ml to 129.0µg GAE/L for 0.1g/100ml of distilled water for Cola acuminata and 476.9µg GAE/L to 200.0 µg GAE/L respectively for 0.1g and 3.0g mixtures of both C. acuminata/palm syrup extracts in 20g/100ml syrup in distilled water. The vitamin C content of oil palm syrup ranged 5.99mg/L for 40g/100ml to 2.80mg/L for 5g/100ml,6.55mg/L for 3.0g/100ml to 0.78g/L for 0.1g/100ml of distilled water for Cola acuminata and 21.1mg/L to 8.45mg/L respectively for 0.05g and 1.5g combination of both C. acuminata/palm syrup extracts in 20g/100ml syrup in distilled water. The reducing power of palm syrup ranged from 0.384 for the 40g/100ml to 0.236 for 5g/100ml, 0.914 for 3.0g/100ml to 0.284 for 0.1g/100ml of distilled water for Cola acuminata and 2.047 to 1.042 respectively for 0.1g and 3.0g mixtures of both C. acuminata/palm syrup extracts in 20g/100ml syrup in distilled water. The IC₅₀values for α-amylase inhibitory activity of oil palm syrup, C. acuminata and C. acuminata/palm syrup mixtures were 0.51%, 4.50% and 12.10% respectively. 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of oil palm syrup, C. acuminata and C. acuminata/palm syrup mixtures showed that the IC₅₀ values were 8.44%, 3.29% and 6.60% respectively. The nutritional and functional implications of the results are discussed.