摘要：The levels of polyphenol and activities of polyphenol oxidases in some Nigerian kolanuts were investigated. Garcina cola had the least polyphenol content of 15.60±1.70 (mg/g), while Cola nitida (red) recorded the highest value of 33.50±2.51mg/g. Polyphenol oxidase from Garcina cola had its optimum pH of activity in the acidic region (pH 3), but the white and red species of Cola nitida had a neutral (pH 7) optimum pH. With catechol as substrate, polyphenol oxidase activity was highest in Cola nitida (white) (55.70±2.60) and lowest in Garcina cola (2.22 ± 0.04). Whilst the values of polyphenol obtained may explain the high incidence of enzymatic browning in some Nigeria kolanuts, the white cultivar of Cola nitida could be further explored as a good source of polyphenol oxidase.
