Study On The Preparation Of Micro-porous Cassava Starch Microencapsulation Tilapia Oil By Spray Drying

Tilapia nilotica oil is one of deep processing of products from Tilapia nilotica, rich in unsaturated fatty acid and easily oxidized. To reduce the deterioration of Tilapia nilotica oil and broaden its use field, we focus on the preparation technologies of micro-porous cassava starch, and a simple method have been suggested to evaluate the properties of the micro-porous starch, and the preparation technique of micro-porous cassava starch micro-encapsulation tilapia oil with the self-made micro-porous cassava starch and the collagen protein from tilapia skin as wall materials, and the tilapia oil as core materials by spray drying. The addition of composite vitamins and active matter can prepare high-quality powdered Tilapia nilotica oil of eutrophy and facilitate to transport and storage.First, the preparation technologies of micro-porous cassava starch and its oil adsorption capacity were studied in this paper, respectively. The main influence factors including reaction temperature, reaction time, enzyme addition, enzyme combination, and substance concentration and reaction pH were studied for oil adsorption capacity by L9(34)orthogonal test. The results showed the optimum conditions were as follows:substance concentration 60%, enzyme addition 2.5%, enzyme combination ratio 1:5, pH 6.0, reaction temperature 60℃and reaction time 7 h. Under these conditions, the capacity of oil adsorption was increased by 53%.Showed by SEM, there are clear traces and observed the structure of inner granule on the cassava starch treated with the complex enzyme. Under the best conditions, the BET surface area was increased by 54%.Based on the grey relational grade theory a simple method has been suggested to evaluate the properties of the microporous starch. Using this method, the changing of porous starch’s specific surface could be characterized with the hydrolysis rate.The preparation technique of micro-encapsulation tilapia oil with the self-made micro-porous cassava starch and the collagen protein from tilapia skin as wall materials, and L16 (45)orthogonal test to optimize the conditions of the tilapia oil micro-encapsulation process by spray drying were studied in this paper. The results showed the optimum conditions were as follows:emulsifying temperature 55℃, pH 6.0, homogenization duration 6 min, proportion of core material and wall material 1:1.5, the collagen protein 1.1%, solid substance concentration 20%, air inlet temperature 180℃, and emulsifier 0.15%. Under those conditions, the encapsu-lation ratio of tilapia was up to 92.1%.From the SEM photos, the surface of microcapsule kernel is compact, round and no cracking which further proved the perfect formulation. It was conformed that the shelf-life of microencapsulation was more than 12 months by peroxide value analysis.