INTRODUCTION A top goal has always been ensuring food security because of the rising need for food as the population grows. Lipase and esterase are two of the many enzymes found in bran and germ, and they are primarily found in the outer bran portion of cereal kernels. They hydrolyze water-insoluble and soluble esters, producing free fatty acids that cause lipolytic rancidity (Doblado-Maldonado et al., 2012). High lipids content is one of the important factors responsible for development of rancidity (Goyal et al., 2015). High lipolytic enzyme esterase activity has been substantially associated with the development of hydrolytic rancidity. In moistened flour, lipoxygenase either performs non-enzymatically or enzymatically the oxidation of the free fatty acids collected during storage. By oxidising polyunsaturated fatty acids produced by lipase activity in the presence of too much moisture while the dough is being mixed, it may have a negative impact on the quality of the wheat (Delcros et al., 1998; Mann and Morrison, 1975). The secondary oxidation products, such as volatile substances like hexanal and various ketones, are produced by the rearrangement and decomposition of the hydroperoxide derivatives produced as a result of Lipoxygenase activity (Doblado-Maldonado et al., 2012). Poor bread quality is caused by hydrolytic and oxidative rancidity products (Tait and Galliard 1988), production of bitter compounds (Bin and Peterson 2016) and a decline in sensory properties (Hansen and Rose 1996). Despite being assigned different enzyme class numbers for the two distinct functions, the identical enzymes perform amidase and esterase reactions. The esterases are divided into A-, B-, and C-esterases based on how they interact with toxicologically significant organophosphates. Organophosphates are potent inhibitors of B-esterases, which accounts for their (intended selective insecticidal as well as unintentional overdose mammalian) toxicity. Organophosphates are substrates of A-esterases and are consequently detoxified by them. C-esterases do not interact with organophosphates. Since esterases can be used in a wide range of industries, including the food industry, pharmaceuticals, fine chemistry, etc., there is increasing interest in them. Numerous characteristics of esterases, including their widespread dispersion, measurement, manufacturing, synthesis target, purification, and molecular biology, have been published. The esterases are used in the synthesis of low molecular weight esters, the creation of dairy products, wine, fruit juices, beer, and alcohol (Goyal et al., 2015). Modulators as extrinsic factors, often metal ions or organic compounds of known as well as unknown function have often been employed either to identify their role as direct participation as cofactor in catalysis, identification of amino acid residues in active site, or stabilizer/de-stabilizer of intra and inter subunit interactions so as to change catalysis favourably. Negative modulation of lipids hydrolyzing or oxidizing enzymes native to grains by pre treatment of grains and/or fortification of flour with food grade additives may prove to be an effective approach for decreasing their activities in flour and thus slowing down the reactions leading to minimal production of undesirable metabolites viz., free fatty acids, hydroxyperxides, volatile aldehydes/ketone etc Barros and Macedo (2015). Gaining knowledge of its physico-chemical and kinetic properties is a pre-requisite for identifying modulator(s) of enzyme activity which necessitates purification of fatty acid esterases. Partial purification of plant Fatty acid esterases. Extraction buffers or solutions used by the investigators for preparation of crude extract of Fatty acid esterases from various plant sources along with their activities and specific activity are listed in Table 1. Barros and Macedo (2015) extracted the enzyme from soybean seeds in1 mM CaCl2 with added 5 mM EDTA, however, earlier (Barros and Macedo 2011). They used only 1 mM CaCl2, 1 mM. Chen et al. (2019) also preferred 1mM CaCl2 containing 2.5 mM DTT and 0.1% Triton X-10 for extracting the enzyme from rice bran. Therefore, mentioned researcher did not mention pH of CaCl2 solutions. Tris-HCl buffer of either 50 or 100 mM strength and pH ranging from 7.0 to 8.3 was used for extraction of esterase and 50 mM phosphate buffer of pH 7.0 or 7.5 have been used by the researchers. Invariably pearl millet fatty acid esterases have been extracted in 100 mM phosphate buffer of pH 8.0 (Sheenu et al., 2018). Activities and specific activities of FAEs in crude extracts varies depending upon plant species. Levels of fold purification and recovery of enzyme activity of different plant Fatty acid esterases by fractional precipitation with ammonium sulphate and organic solvents are presented in Table 3. Recovering 92 % of the enzyme activity purified Fatty acid esterases from Synadenium grantii. Staubmann et al. (1999) used 50-80 % alcohol for fractional precipitation of Jatropha curcas L. FAE but had not reported recovery of the activity. Physiochemical and kinetic properties of plant Fatty acid esterase. Earlier a good comparison of activities of p-nitrophenylpalmitate dependent esterases and lipase of many grasses was made by Mohamed et al. (1999). They reported high variation the level of activities not only among the genus but within species or cultivars. By conducting experiments at various temperatures in the range of 30-90°C at pH 7.0, using 0.1 M phosphate buffer, it was possible to determine the impact of temperature on the esterase activity. Most pure esterases from plants and animals were found to work best at a pH between 7.0 and 9.0. For sorghum, barley, and Mucuna seeds, a pH of 7.0 was shown to be ideal for plant esterases. Most plant esterases were stable in the pH range of 4 to 9.0. Similar to this, Caesalpania seed esterase had an optimal pH of 7, and it was stable between pH 4 and 9.0. Industrial Applications: The industrial uses of esterases provide significant contributions to environmentally friendly practises in the food, textile, agrochemical (herbicides, insecticides), and bioremediation industries (Gupta, 2016). Esterases hydrolyze ester bonds and act on a wide range of naturally occurring and synthetically produced substances, making them very helpful in the bioremediation process. It is possible to successfully determine the primary amino acid sequence and three-dimensional structure of enzymes through purification. The structure-function relationships of pure esterases may be established using X-ray investigations, which can help to better understand the kinetic mechanisms of esterase activity on the hydrolysis, synthesis, and group exchange of esters. Esterase is essential for the breakdown of hazardous compounds, polymers, and other natural and industrial contaminants such grain trash. The synthesis of optically pure chemicals, flavouring agents, fragrances, and antioxidants can all benefit from it (Panda and Gowrishankar 2005). In the oxidation and cycling of marine organic carbon, esterases play a significant role. Sea-derived halotolerant esterases might work well in high-salt industrial operations (Zhang et al., 2017). Octyl Acetate (OA) or Octyl Ethanoate is a flavour ester with a fruity orange flavour that is utilised in the food and beverage industries. It is made from octanol and acetic acid. It can be found in foods like wines, wheat bread, cedar cheese, bananas, sour cherries, and oils made from citrus peel. It is a flavouring component that serves as the foundation for synthetic orange flavouring. The purification of esterase and its usage in the manufacture of octyl acetate ester are the main topics of the current research. This is the first account of octyl acetate being synthesized using esterase.