Histological localization of oil palm fruit lipase

Abstract

Development of free fatty acids (FFA) and subsequent deterioration of palm oil quality can be attributed to lipase, an active hydrolytic enzyme present in the mesocarp of oil palm fruit. A histochemical method was used to localize this enzyme in the mesocarp. FFA released from endogenous glycerides were precipitated as lead salt. The deposits were located on the membranes of oil bodies. Enzymatic activity in the mesocarp was also studied under different conditions of fruit storage: ambient temperature, freezing, etc. The enzyme was active after freezing but less active under ambient conditions of fruit storage. Investigations on fruit development indicated that the enzyme activity started appearing between 16–20 weeks after anthesis (WAA) which synchronized with the beginnning of lipid formation. These histochemical studies were supported wity biochemical data on FFA.

Lipase activity, mesocarp oil content, and iodine value in oil palm fruits of Elaeis guineensis, Elaeis oleifera, and the interspecific hybrid O×G (E. oleifera × E. guineensis)

“…Studies have shown that the formation of FFA in CPO is caused by the hydrolytic action of mesocarp lipase (triacylglycerol acylhydrolase, EC 3.1.1.3) . This enzyme has been associated with the membranes of oleosomes (lipid bodies) and is activated when the fruits are bruised during harvest, transportation, and storage . Different methodologies have been reported for the evaluation of lipase activity in the mesocarp of oil palm.…”

“…5,9 This enzyme has been associated with the membranes of oleosomes (lipid bodies) and is activated when the fruits are bruised during harvest, transportation, and storage. 10,11 Different methodologies have been reported for the evaluation of lipase activity in the mesocarp of oil palm. Henderson and Osborne measured the lipase activity of a powder obtained by the maceration of mesocarp tissue with liquid nitrogen and found activity between 20 and 45 • C, with glycerol tri-[1-14 C]oleate as substrate.…”

Impact of post-harvest storage and freezing of palm fruits on the extraction yield and quality of African crude palm oil extracted in the laboratory

“…They also allow the access of both endogenous and fungal lipases to triacylglycerols. Fruit storage then triggers the release of FFAs by lipases (Mohankumar et al, 1990;Morcillo et al, 2013). Freezing/thawing affects FFAs in CPO, as it causes cell membrane breakage and the rupture of oleosomes due to the growth of ice crystals.…”

“…To a lesser extent, lipases from contaminating microorganisms (Eggins and Coursey, 1968;Hiol et al, 2000), such as Lactococcus and Leuconostoc (Tagoe et al, 2012), may also be involved in CPO lipolysis. All these lipases become activated when the palm fruit is bruised during harvesting, transportation and storage (Mohankumar et al, 1990;Chong and Sambanthamurthi, 1993). This also happens when cell membranes and oil bodies are damaged by chilling and/or freezing/thawing fruits.…”

Storage lipid formation in seeds

“…For example, the storage oil-bodies found in seed tissues such as embryo and endosperm, are generally less than 1.0 \im in diameter and contain approximately 10% by weight of a class of proteins termed oleosins (Murphy, 1990). In contrast, the storage oil-bodies found in oleogenic fruits, such as avocado, oil palm and olive are often in excess of 20 \im in diameter (Platt-Aloia and Thomson, 1981;Mohankumar et al, 1990;Ross and Murphy, 1992b) and are completely lacking in oleosins (Ross and Murphy, 1992b). The difference in morphology between fruit and seed storage lipid bodies is probably due to their different functions in the plant.…”