A Study On Preparation Of Microcapsulated Banana Powder Via Spray Drying

In this paper, spray drying was employed to prepare microcapsulated banana powder The inhibition of banana browning during processing banana microcapsulation by different food additives was studied and the enzymatic hydrolysis conditions of banana puree were optimized by response surface methodology (RSM). Then the effect of spray drying technological parameters on spray drying of banana juice was analyzed and the optimized parameters of spray drying of banana juice were obtained by RSM. The aromatic compounds of the fresh banana, clear banana juice, microcapsule banana powder and reconstituted banana juice were identified by GC-MS and changes in aromatic components of banana during the preparation process of juice and microcapsule powder were studied.In the study on inhibition of banana browning during processing by different food additives, citric acid, ascorbic acid, sodium chloride, tea polyphenol, cysteine and oxalic acid were studied as potential inhibitors against banana browning. Cysteine was found the most effctive inhibitor against banana browning and showed synergy with ascorbic acid. By orthogonal test, the optimized mixed solution and treatment for inhibition oagainst banana browning during processing was the dip in mixed solution of 0.2% cysteine and 0.3% ascorbic acid for 30 minutes and then treatment by 495W of the microwave for 30s.The effect of enzymatic hydrolysis of Pectinex xxl and Viscozyme L was compared by analyzing the ingredients of banana puree and the properties of banana juice. The results showed that Viscozyme L is effective for degradation of pectine and cellulose and have better enzymolysis effect. Viscozyme L and Fungalα-amylase were used for the enzymolysis of banana puree. The enzymatic hydrolysis conditions were optimized by RSM. The optimum conditions are 110.05 FGB/kg Viscozyme L, 4702.36 SKBU/kg Fungalα-amylase at 40.4℃for 151.69min. On these conditions the total soluble solid content was 23.2 oBrix and the viscosity was 2.868 mPa·s.Effects of three spray drying technological parameters, namely inlet air temperature, drying air flow rate and compressed air flow rate, as well as drying aid content, on spray drying of banana powder was analyzed by RSM.The productivity was highest and reached 44.28% under the optimal processing parameters of the inlet air temperature 170.0℃, drying air flow rate 36.08m3/h and compressed air flow rate 489.70L/h, with 60%maltodextrin and 1%gum arabic were added, and the qualities of the product were good. The aromatic compounds of the fresh banana, clear banana juice, microcapsule banana powder and reconstituted banana juice were then identified by GC-MS. Esters were found to be the decisive components of the aroma in the raw banana puree, clear banana juice and reconstituted banana juice, and of which isoamyl butyrate was the major constituent. Compounds were hardly detected from the microcapsule banana powder, which proved that the main volatile components can be effectively encapsulated and protected well via microcapsulation.