Epidemiological investigation showed that long chain (LC) ? 3 PUFAs have benefical effects on health and prevention of many disease, especialy cardiovascular types. Due to high oxidization susceptibility and undesirable aroma of these fatty acids, enrichment of foods with those sources, has an unfavovable effect on sensory properties. It has been shown that microencapsulation, protect PUFAs from oxidation. In this study, LC ? 3 PUFAs was microencapsulated using complex coaservation techique. Two numerical factors ( homogenizer rate, lactose contents and one categorial factor presence or absence of transglutaminase) was analyzed. The method of RSM design was used to determine optimuze mentioned factors to achive maximum value of microencapsulation efficiency (ME), moreover, microcapsules particel size before and after freeze-drying and P.V of surface and core oil of microcapsules was measured. Surface oil of microcapsule powder was extracted using n-hexane in order to measure ME and PV. Encapsulated Flaxseed oil was added to milk to provide 0.4 gram alpha-linolenic acid per day based on EANS recommendation for one serving per day. Physical properties, peroxide value, sensory acceptance and release of flaxseed oil from added microcapsules to milk were measured in enriched milk during 7 days storage. ME, particle size of microcapsules before and after freezedryer and PV surface and core oil of microcapsules were measured in the ranges of 44-95%, 3.2-263.12µ, 40-549.83µ, 22.43-66.5 meq/kg O 2 , 4- 9.36 meq/kg O 2 , respectively. Relative optimum points wa for homogenization rate of 10000 rpm, 2% lactose and in the presence of transglutaminase. Acidity and apparent viscosity of enriched sampels were higher than the controlled sample. The peroxide value of enriched milk sampels with free and encapsulated flaxseed oil after 7 days storage at 4 °C were increased to 206% and 76%, respectively. Sensory results showed that panelists evaluated enriched milk with flaxseed oil microencapsules as moderate like. Keywords : Alpha linolenic acide, Complex coaservation, Flaxseed oil, Microencapsulation, Milk, Sensory evaluation
