Eze M O, Ogan U
Department of Biochemistry, University of Nigeria, Nsukka.
Plant Foods Hum Nutr. 1988;38(2):121-6. doi: 10.1007/BF01091716.
The sugar composition of the unfermented sap from oil palm (Elaeis guinensis) trees growing in the plantations of the Nigerian Institute for Oil Palm Research, Benin City, has been determined. While sucrose concentration ranges from 9.59 to 10.59% (w/v) in the pure unfermented sap, that of either glucose or fructose is much less than 1% (w/v) (0.13-0.73% w/v). Raffinose occurs in traces only (0.13-0.35 w/v). These results were derived from our improved methods which eliminate completely, or reduce to a bare minimum, fermentation of the sap during collection. The variation with time of storage of the individual sugars in the sap during fermentation to form palm wine reveals that, as sucrose steadily decreases, fructose reaches a peak at 1.51% (w/v) at the 9th hour, and thereafter declines, while glucose and raffinose remain continuously low; all sugars disappear beyond the 33rd hour. Concomittantly, pH decreases from pH 6.60 at zero time and stabilizes at pH 3.30 after 48 h, while titrable acidity increases continuously up until the 96th hour. These changes account for the variations in the quality of palm wine during storages.
对生长在贝宁城尼日利亚油棕研究所种植园中的油棕（Elaeis guinensis）树未发酵汁液的糖分组成进行了测定。在纯净的未发酵汁液中，蔗糖浓度范围为9.59%至10.59%（w/v），而葡萄糖或果糖的浓度远低于1%（w/v）（0.13 - 0.73% w/v）。棉子糖仅以痕量存在（0.13 - 0.35 w/v）。这些结果源自我们改进的方法，该方法在采集过程中能完全消除汁液发酵，或将其减少到最低限度。在汁液发酵形成棕榈酒的过程中，各糖分随储存时间的变化表明，随着蔗糖稳步减少，果糖在第9小时达到峰值1.51%（w/v），此后下降，而葡萄糖和棉子糖一直保持在低水平；在第33小时后所有糖分消失。同时，pH值从初始的6.60下降，48小时后稳定在3.30，而可滴定酸度一直持续增加直到第96小时。这些变化解释了棕榈酒在储存期间品质的变化。
