Free Fatty Acids (FFA) is the acid which was released on the hydrolysis of fat. There are various kinds of fat, but for calculations, FFA levels of palm oil is considered as palmitic acid (molecular weight 256). Meat palm oil contains lipase which can cause damage to the oil quality when disrupted cellular structure.
Enzyme which resides in the fruit flesh tissue is inactive because of veiled by a layer of vacuoles, and so can not interact with a lot of oil contained in the fruit flesh. Still active below 15 degrees C and non-active with the temp above 50 degrees C.
CH2RCOO CH2OH
l l
CHRCOO + 3H2O <---> CHOH + рей RCOOH
l lCH2RCOO CH2OH
TAG + H2O <---> DAG + ALB
DAG + H2O <---> MAG + ALB
MAG + H2O <----> Gliserol + ALBCH2RCOO CH2OH
Fat hydrolysis reaction is reversible equilibrium reaction condition is achieved when the reaction rate of fat digestion with the reaction of the formation of fat.
Fat hydrolysis reactions take place in stages that is the formation of diacylglycerol isomers, the formation of alpha & betha monoasilgliserol and the formation of glycerol.
Before the oil extraction process carried out, first-tam fruit boiled in stelizer. One aim is to not activate the enzyme activity. In existing oil palm fruit lipase and oxidase enzymes are still working before it was stopped by means of physics and chemistry.
How physics is by heating at temperatures that can degrade proteins. Lipase acts as a catalyst in the formation of triglycerides and then break it back into free fatty acids (FFA).
Oxidase plays a role in the formation of peroxide which is then oxidized again and breaks into clusters aldehide and cations. The latter compound when oxidized again will become acidic. So FFA found in palm oil is the result of lipase and oxidase.
The higher enzyme activity when the injured fruit. To reduce the enzyme activity reached the plant cultivated for oil palm fruit is not damaged and the fruit is not rotten. Enzyme was not active anymore pad temperature of 50 degrees C. Therefore Sterilizer boiling in the temperature of 120 degrees C will stop the enzyme.
Several process variables affecting the acquisition of fatty acids such as the influence of temperature, fruit maturity, fruit wounding levels, stirring, adding water, the addition of CPO and long storage.
1. Effect of Temperature
From the research that has been done, shows that fatty acid levels highest obtained at room temperature (25 oC - 27 oC). Lipase on oil palm fruit are inactive at a temperature of 8 ° C cooling and on heating at 50 oC.
In general, temperatures were very influential in chemical reactions, where the temperature rise will increase the reaction rate. The nature of the inactivated enzyme at high temperature, the enzymatic process is no limit on the temperature so that enzymes can work optimally. Decrease in enzyme activity at high temperature effect caused by protein denaturation.
also at low temperature, enzyme activity also decreased as a result of enzyme denaturation.
2. Effect of Water Addition
Water has an influence on the reactions that occur, and this effect is basically the help of contact between the substrate with the enzyme. Lipase active at the surface (interface) between layers of oil and water, so by doing the stirring, the water content in the fruit will be able to help prevent these contacts.
In this hydrolysis process, a stoichiometric excess of water on the fruit had to produce fatty acid (water content of fruit is about 28%), but because the water is in the solid it is necessary to pelumatan fruit and then performed the stirring. In addition, to overcome / prevent water shortages.
Effect of water content in the product attained a very large, where a very large water content resulted in a reaction between fatty acids and glycerol can not happen properly.
3. Effect of wounding and Stirring Fruit
Lipase is not in oil, but is in the fiber. The level of fruit wounding and stirring affect the hydrolysis process because it will help prevent contact between the enzyme and the oil (substrate). This is because the position of the oil palm fruit lipase is not known with certainty, so to overcome this, the fruit must be crushed into powder, then mixed back oil and fiber. With such a process is evident that the fatty acid content obtained was higher than if the fruit is not crushed into powder (just crushed / injured).
Stirring speed settings on this reaction needs to be done, because in this process of stirring affects the contact time between water, substrates and enzymes. In addition, because the stirring is a mixture of fiber and oil, then the selection of the design of the mixer is very necessary to be noticed.
4 Effect of Fruit Maturity
Fruit contained on a single oil palm fruit bunches will not mature simultaneously. Fruit that is in the outer layers are usually more mature when compared to fruit that is in the deeper part. This resulted in the different percentage of oil contained in each fruit that are in a bunch.
In the oil palm fruit, the ripe fruit of the oil level will be higher. With increasing oil content in fruit then enzymatically hydrolysis process would happen faster, so the acquisition of fatty acids will be higher.
5. Effect of storage duration
Naturally, free fatty acids will be formed over time, either because microbial activities as well as hydrolysis with lipase catalyst assistance. However, free fatty acids that form is considered as a result of hydrolysis using the enzyme lipase present in oil palm fruit.
6. Effect of CPO
In this process, the reaction rate is lower when the addition levels of CPO on the mix between the fiber and oils is increasing. This can occur because the enzyme lipase which is in the fruit is saturated or limited in number, while the amount of substrate is very excessive. The speed of reaction depends on the concentration of lipase, not on substrate concentration.
The properties of the lipase enzyme is as follows:
• Optimum Temperature: 35 ° C, at a temperature of 50 C. The enzyme was most damaged.
• Optimum pH: 4.7 to 5.0
• molecular weight: 45000-50000
• Able to work in aerobic and anaerobic
• co-factor: Ca + +, Sr + +, Mg + +. Of the three co-factors are the most effective is the Ca + +
• Inhibitors: Zn2 +, Cu2 +, Hg2 +, iodine, versene
