Reduction of acidity in mature oil palm (Elaeis guineensis Jacq.) fruits: stakes and oil quality improvement. A review

Introduction. Palm oil acidification determines the quality and stability of this important foodstuff. This review article analyzes the causes of acidification, and its effects on the quality and stability of palm oil. The stakes involved in the reduction of acidity in fruits and the approaches used are also analyzed, especially reduction via genetic improvement. Literature. Acidification is mainly due to the action of an endogenous lipase of the fruit's mesocarp, but it can also be caused by microbial lipase or autocatalytic hydrolysis. Many factors, particularly plant material, conditions of harvest and post-harvest bunch treatment, and conditions of oil extraction and storage have an appreciable impact on acidification. Acidification reduces the quality and market value of palm oil and causes important oil losses due to the removal of free fatty acids in the mill. The genetic background of individuals of low oil acidity has been identified. The variability of this trait makes varietal selection possible. One gene implicated in palm oil acidification has been identified, but other genes or genetic factors may also be involved. Conclusions. Such research has led to the recent commercialization of the first oil palms with low acidity. This will improve oil quality, increase yield and facilitate the management of harvest and post-harvest operations, especially for smallholder farmers. There is a need to identify all the genetic factors responsible for the degradation of triglycerides in the Elaeis genus. The validation of genomic tools would allow the marker-assisted selection of oil palm varieties with low acidity.