In the early stage of fruit formation, the oil content of the fruit is very low. As the fruit approaches maturity, oil formation increases rapidly to around 50% of the palm fruit weight. In a fresh ripe, unbruised palm fruit, the oil contains less than 0.3% free fatty acids (FFA). However, in ripe fruit the exocarp becomes soft and more susceptible to attack by LPS, especially at the bottom when the fruit is detached from the bunch. Enzyme attack results in increased FFA of the oil through hydrolysis. Studies have shown that if a palm fruit is bruised, the FFA content of the damaged part of the fruit increases rapidly to 60% within an hour. Therefore, the integrity of the palm fruit bunch affects its composition and quality.
During harvesting, a bunch is cut from the tree and allowed to fall to the ground by gravity. In the process of pruning palm fronds, it is possible to damage the fruit, exposing the bottom of the bunch. The fruit took a hit when the bunch (weighing about 25kg) fell to the ground. There will also be more opportunities for fruit to be bruised during loading and unloading.
In Africa, most fresh palm fruit bunches are transported to processing sites in overhead baskets. When unloading, the contents of the basket are often dumped on the ground. This can cause more chafing. Sometimes the trucks and carts are unable to gently put the goods down, transporting the goods from the village to the processing site. Again, the tumbled fruit from the vehicle was rough, causing abrasions on the soft exocarp. In any case, the fruit should be handled with care to avoid excessive bruising.
Picking, transporting, and handling fresh palm fruit bunches can lead to fruit damage, and one of the ways to combat these problems is to handle them as early as possible after harvest, say within 48 hours. However, the authors feel it is best to let the fruit ferment for a few days before processing. Connoisseurs of good edible palm oil know that increased FFAs only add to the “mouthfeel” of the oil. At worst, oils high in FFA have a good laxative effect. Free fatty acid content is not a quality issue for direct consumers of crude oil, but it is for refiners, who have problems neutralizing palm oil with high FFA content.