Enzymatic Extraction Of Lotus Germ Oil And Preparation Of Its Powdered Oil

Today,nutrition and health is becoming a theme for human consumption.Therefore,the research on food with good nutritional value and physiological functions is bound to become an important direction of food industry.Lotus germ oil contains large amounts of unsaturated fatty acids and functional fat-soluble substances,thus having important physiological functions and high nutritional value.In this paper,the process route of enzymatic extraction of lotus germ oil was studied,and the extracted oil was made into powered oil.The appropriate formula of powered lotus germ oil was optimized.And the storage stability and quality of powered lotus germ oil were analyzed.The main results were as follows:1.The reasonable route of enzymatic extraction of lotus germs oil was worked out by orthogonal tests.After cleanup,40 ? drying for 12 h and 60-mesh crush,lotus germ was mixed uniformly with water as 1:5(w/v).After enzyme destruction for 15 min by boiling water,pH was adjusted to 4.8 when cooling down to room temperature.Then,lotus germ was hydrolyzed by 1.2%(w/w)of cellulase(specific activity:50 OOOU/g)at 50 ? with shaking speed at 120 r/min for 2.5 h,followed by the use of 1.5%(w/w)of acid protease(specific activity:800 000U/g)at 45 ?,pH 3.0 for 2.5 h with the same shaking speed.The system was then put in boiling water for 10 min.Extration at 60 ? for 2 h was followed after n-hexane was added to the reaction system,the concentration of lotus germ to n-hexane as 1:2(w/v).After 4800 g centrifugation for 15 min,87.83%of lotus germ oil was finally obtained.2.Preparation of powered lotus germ oil by vacuum freeze-drying method was studied.The optimal working parameters were determined by orthogonal test:27.5%of total solid concentration,the mass radio of core material and wall material as 1:5,3 min of homogenization time,-20 ? pre-frozen for 24 h and freeze-dried for 24 h.The powered lotus germ oil with an embedding ratio of 77.36%was obtained.3.The quality of powered lotus germ oil prepared under optimal conditions was analyzed.The moisture content and density of powdered lotus germ oil was 1.11%and 0.47 g/mL.With good dispersion,the powered oil should be stored in a dry environment.SEM results showed that the particles of powdered lotus germ oil had smooth and round surface with no cracks.The wall material had good integrity and compactness.Particle diameter was about 13 ?m.Infrared spectroscopy showed that lotus germ oil was indeed embedded after freeze-drying.The results of GC-MS indicated that the content and composition in oil and powered oil were almost sameness.Accelerated oxidation experiments further confirmed that the storage stability of lotus germ oil was greatly improved after embedding and the shelf life of powdered lotus germ oil was estimated to be 153 days.