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Fish oil is rich in docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA) and other polyunsaturated fatty acids, which have a variety of physiological functions, prevention of cardiovascular and cerebrovascular diseases, brain puzzle, inhibit inflammation and enhance human immunity and anti-cancer and other functions. However, EPA and DHA are highly unsaturation, oxygen, light and heat, are extremely sensitive, so that fish oil is easily oxidized and lose its physiological function and nutritional value. The rich in EPA and DHA fish oil microencapsulation, thereby isolated from the outside environment, prevent oxidative deterioration, maintaining the physiological function of EPA and DHA, disguise the smell of fish oil, increasing consumer acceptability, powdered fish oil, As used in various food nutrition fortifier, expanding the scope of application of fish oil, fish oil to improve the use value. This consists of two proteins, casein, soy protein isolate, respectively, with a reducing sugar (glucose: lactose = 1:1) the reaction product of the Maillard reaction as the wall material, the microcapsules prepared by spray drying fish oil, a preparation of formula and processes and storage stability, and further oxidation of the wall material and the physical and chemical properties, the microencapsulation of fish oil to provide a theoretical basis for the storage stability. First studied the different reaction conditions on casein, soy protein isolate and sugar Maillard reaction products affect and improve the initial pH of the reaction help accelerate the Maillard reaction speed. As the reaction time and reactant concentration, Maillard browning reaction product was intensified obvious color change of the reaction product, the performance value of a *, b * value increases, L value decreases, indicating that the product increase the degree of browning. By measuring two kinds of Maillard reaction products reducing power, anti-oxidation ability of lecithin liposomes and DPPH ·, · OH scavenging. The results showed that the two reaction products emerged better antioxidant capacity, the reaction time and reactant concentration increases, the reduction of Maillard reaction products first increases and then decreases force on DPPH ·, · OH all have scavenging and scavenging as the reaction time increases, the scavenging capacity enhancement, the initial concentration of the reactant dose-effect relationship. At the same concentration of reactants, the Maillard reaction products with antioxidant capacity increased with the increase of reaction time. Under the same reaction time, the preparation of soy protein isolate with a reducing sugar Maillard reaction products reducing power, the inhibition of lipid peroxidation capacity, free radical scavenging and reducing sugars lower than the reaction of casein Merah German reaction product. Preliminary analysis by GC-MS of Maillard reaction products headspace volatile components, including alcohols, acids, esters, aldehydes, ketones, phenols, and other heterocyclic compounds. Among them, the Maillard reaction products larger contribution antioxidant compounds, mainly thiazole, furan and pyrazine containing S, N-containing heterocyclic compound and a hydroxyl number. With the Maillard reaction, the reaction product of lysine (Lys), arginine (Arg) and proline (Pro) and a number of hydrophobic amino acids has increased significantly. Among them, the most active of the Maillard reaction products are mainly amino acid residue aspartic acid (Asp), glutamic acid (Glu), glycine (Gly), lysine (Lys) and proline (Pro). Determined by orthogonal experiments with isolated soy protein and sugar Maillard reaction products prepared microcapsule wall material of the best fish oil microencapsulation process conditions: reaction time 5h, the reaction temperature is 80 ℃, pH value 7.5, ratio of the core wall 0.3 (w / w), microencapsulation efficiency of 94.53% yield of microencapsulated 96.97%, peroxide value (POV) was 73.23 (meq / Kg). Casein and sugar Maillard reaction products as wall material microencapsulated fish oil preparation optimum conditions for the Maillard reaction time 3h, the reaction temperature is 105 ℃, pH value of 8.5, the core wall ratio of 0.4 (w / w), microencapsulation efficiency and productivity rates were 93.19%, 87.56%, POV was 46.21 (meq / Kg). Determining the spray drying conditions: inlet air temperature of the spray 180 ℃, homogenization pressure of 35 MPa, homogeneous 2 times, the yield of microcapsules, the efficiency reached 90%. SEM shows the Maillard reaction products as wall material of fish oil microcapsules embedded in the surface structure, spherical, surface wrinkles, but no cracks and holes, so that Maillard reaction products of fish oil has a better embedding microencapsulation efficiency. Differential scanning calorimetry analysis of the microcapsules of the glass transition temperature, casein Maillard reaction with reducing sugars as wall material of the microcapsules fish glass transition temperature of 33.24 ℃. Soy protein isolate with a reducing sugar in the Maillard reaction products of fish oil microcapsule wall material has a glass transition temperature of 43.07 ℃. The glass transition temperature of microcapsules fish indicate storage temperature. The effect of temperature on fish oil storage stability of microcapsules. The results showed that the appearance of the product and the high temperature core material retention rates have a big impact. Gelatin and sucrose with the complex of the wall material of microcapsules prepared fish oil compared to the Maillard reaction product microcapsule wall material as poor storage stability of fish oil products. This is because the wall material and the matrix density is poor, high oxygen permeability and moisture caused. By adding 0.12% pectin, Maillard reaction products to improve the permeability of the walls of the matrix, the effective protection of the core material composition, the rate of increase peroxide value was decreased, thereby improving microencapsulated fish oil product storage stability.
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