Fish Oil Lab Report

Summary
Fish oil is very susceptible to oxidative degradation offering lipid peroxides, secondary and tertiary oxidation products. These products pose health risks, cause fishy odour and taste and reduce shelf-life stability. Microencapsulation techniques such as spray drying and coacervation were used to encapsulate fish oil to resolve these problems.

Introduction
The global production of fish oil is about one million ton yearly obtained from the reduction process of raw fish material. Reduction of 100 kg of fish material produces on average 5 kg fish oil and 20 kg of fish meal. Fish body is extracted with food-grade ethanol, and the crude fish oil obtained is subjected to purification using molecular distillation techniques to remove various

The oxidation products are known to be health hazards and are linked to aging, cancer and heart disease. The double bonds of -3 fatty acids are highly prone to oxidation due to their large number and position in the fatty acid chains. Initiators such as light, heat, oxygen and transitional metals produce lipid radicals and lipid peroxides leading to formation of conjugated dienes and trienes through cis-trans isomerization processes and shifts in the double bonds. [3] The unstable lipid peroxides further degrade to form more harmful secondary oxidation products such as carboxylic acids, ketones and aldehydes (e.g. cis-4-heptenal, (Z,Z)-3,6-nonadienal, (E,Z)-2,6-nonadienal) which cause the undesirable odor and taste associated with rancid oil. Further degradation results in tertiary oxidation products such as short-chain free fatty acids and unsaturated fatty esters. The total oxidation is estimated from the peroxide value which quantifies the concentration of the peroxide groups and from the anisidine value which quantifies the concentration of secondary oxidation products. Gas-chromatography coupled with mass-spectrometry are used for more accurate measurement of lipid peroxides and oxidation

It is used to encapsulate fish oil to offer effective protection against physical and chemical degradations, prevent or slow volatilization, mask unpleasant odors, extend shelf-life and provide sustained and prolonged release characteristics [4]. Microencapsulation of fish oil inhibits photooxidation and free radical autoxidation of EPA and DHA by protecting it from light and oxygen, leading to sensory stabilization of the oil. Fish oil microencapsulation was achieved using polymers such as chitosan, gelatin, maltodextrin, starch, whey proteins and plant gums via spray drying, coacervation, ultrasonication and membrane emulsification techniques. Various techniques for microencapsulation of fish oil are listed in Figure