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1 PROCESS FOR PURIFICATION AND DECOLORIZATION OF FATTY ACID ALKYL ESTER Owners and Authors Novonesis Martin Rushworth Yee Hon Seng Shalin Phoon Chong Soke Yan Procter and Gamble Karunakaran Narasimhan Rajesh Balasubramanian Jovina Tan Monash University Chan Eng Seng Wail Gourich Natural Bleach Patrick Howes 5 REFERENCE TO A SEQUENCE LISTING This application contains a Sequence Listing in computer readable form, which is incorporated herein by reference. 10 FIELD OF INNOVATIVE DEVELOPMENT This innovative development relates to the field of oil purification treatment, and specifically relates to decolorization treatment of fatty acid alkyl ester. This innovative development relates to a process for decolorization of fatty acid alkyl ester by enzymatic esterification and/or transesterification, caustic polishing and hot water acid washing followed 15 by treating with an adsorbent. BACKGROUND OF DEVELOPMENT Methyl esters are widely used in the oleochemical industry as feedstock for fatty alcohol production, whereby a process involving the reaction of methyl ester with hydrogen in 20 the presence of an inorganic catalyst is used to produce the fatty alcohol. Coconut oil and palm derived oils such as kernel oil are commonly used feedstocks for fatty alcohol due to desirable high content of C12 and C14 fatty acid chains. Other vegetable oils such as palm oil, soy, rapeseed could also be used. The oil is converted to fatty acid methyl esters that could be converted subsequently to fatty alcohol and certain carbon chain lengths such as the C16 25 C18 fractions of the methyl esters could be used as biodiesel. One of the processes is to convert crude coconut oil and crude palm kernel oil feedstocks to fatty acid methyl ester. As a prework towards the methyl ester process, residual fatty acid from the oil has to be pre-stripped and removed, before the transesterification of the oil to methyl ester by reaction with methanol in the presence of sodium methoxide catalyst. 2 The by-product of the pre-stripping, which usually takes place in a continuous deodorizer, is fatty acid distillate (FAD) typically representing around 3% to 6% of the feedstock. Theoretically, the fatty acid distillate by-product could be esterified with methanol and fed back into the main fatty acid methyl ester process thus avoiding a yield loss. Such a 5 process would involve the esterification of the fatty acid content of the FAD with methanol to methyl ester using catalysts such as sulfuric acid, methane sulfonic acid (MSA), or para- toluene sulfonic acid (PTSA) or other catalysts followed by transesterification of the remaining glycerides with methanol to produce methyl ester using sodium methoxide catalyst. However, this is not commercially feasible because the impurities in the methyl ester would make the 10 material color increase beyond customer acceptance. The impurities in the coconut or palm kernel fatty acid methyl esters are signaled by a dark color due to the presence of unsaponifiable components such as oil soluble phenolics and polyphenols, aromatic and polyaromatic hydrocarbons, squalene’s, tocotrienols, tocopherols, carotenes, aldehydes and ketones, and contaminants such as polymerized lipids. These impurities in the dark colored 15 coconut fatty acid distillates are not suitable to remain in the fatty acid methyl ester since they cannot be removed by distillation. Thus, there is a need for the development of an improved process for the production of high-quality alkyl esters from coconut fatty acid distillate whereby the process removes the unwanted contaminants, and the high-quality alkyl ester is accompanied by a significant 20 reduction in colour. SUMMARY OF THE INNOVATIVE DEVELOPMENT This innovative development relates to a process for decolorization of fatty acid alkyl ester comprising steps of: 25 I. providing a fatty acid distillate feedstock substrate comprising triglycerides, diglycerides, monoglycerides, free fatty acids, fatty acid alkyl esters, or any combination thereof: II. reacting said substrate with alcohol in the presence of one or more lipase to produce fatty acid alkyl esters; 30 III. separating the reaction mixture of step (II) into light phase comprising fatty acid alkyl ester, free fatty acids and optionally, unreacted fatty acid feedstock; and a heavy phase comprising lipase, glycerol, short chain alcohol and water; IV. subjecting the light phase of step (III) to polishing in presence of sodium hydroxide; 35 V. washing the light phase alkyl ester from step (IV) with citric acid and water; 3 VI. treating the washed alkyl ester with one or more adsorbent wherein the adsorbent is selected from a group consisting of a mixture of activated clay, activated carbon, acid activated bleaching earth, acid activated carbon or any combination thereof. 5 DEFINITIONS Before particular embodiments of this innovative development are disclosed and described, it is to be understood that this innovative development invention is not limited to the particular process and materials disclosed herein as such may vary to some degree. It is also to be understood that the terminolog...