| The optimal formula of Royal Jelly Milk Powder, which composed of fresh milk and Royal Jelly by vacuum freeze drying or spray drying, was determined by orthogonal experiment. The vacuum freeze drying and spray drying processing technology of Royal Jelly Milk Powder was also studied. The major results were summarized as follows:1. The initial formula of Royal Jelly Milk Powder by freeze dryingThe initial formula of Royal Jelly Milk Powder was determined by the single factor experiments, including the selection of the drying adjuvant, the adding content of drying adjuvant and liquor concentration. The results showed that drying adjuvant was maltodextrin, the adding content of drying adjuvant was25%and liquor concentration was20%.2. The vacuum freeze drying processing technology of Royal Jelly Milk PowderAccording to the principle of central composite Box-Behnken experimental design and the results of initial formula studies and single factor experiments, the response surface experiments for response value were designed to optimize the freeze drying processing technology with independent variable of the sublimation temperature (X1), the desorption temperature (X2) and the liquid thickness (X1), and the dependent variable of the moisture content (Y1) and solubility (Y2). The regression equations of the moisture content and solubility were obtained as follows:Y1=10.488-0.046X1-0.33205X2-0.372X3+0.0006X1X2+0.00425X1X3-0.00875X2X3+0.002435X12+0.004235X22+0.12838X32Y2=54.3065+0.16463X1+1.6031X2+3.43337X3+0.003675X1X2-0.05325X1X3+0.000375X2X3-0.017745X12-0.01842X22-0.42362X32The weight coefficient of the moisture content and solubility of products were obtained by the optimal analysis of the regression equations, which both were50%. The optimum vacuum freeze drying conditions were the sublimation temperature (3℃), the desorption temperature (43℃) and the liquid thickness (3mm).3. The optimization of the initial formula for vacuum freeze dryingBased on the optimal vacuum freeze drying conditions and the results of single factor experiments, the orthogonal experiment L9(34) of the adding content of drying adjuvant, β-cyclodextrin, lecithin and liquor concentration were designed to detect the sensory evaluation, moisture content and solubility of Royal Jelly Milk Powder. According to the results of orthogonal experiment and taking the sensory evaluation, moisture content and solubility into consideration, the optimization of the formula were as follows:the adding content of drying adjuvant, β-cyclodextrin, lecithin and liquor concentration were25%,2%,0.3%and20%, respectively.4. The initial formula of Royal Jelly Milk Powder by spray dryingThe initial formula of Royal Jelly Milk Powder was determined by the single factor experiments, including the selection of the drying adjuvant, the adding content of drying adjuvant and liquor concentration. The results showed that drying adjuvant was maltodextrin, the adding content of drying adjuvant was35%and liquor concentration was20%.5. The spray drying processing technology of Royal Jelly Milk PowderThe initial formula of Royal Jelly Milk Powder was determined by the single factor experiments, including the selection of the main drying adjuvant, the adding content of drying adjuvant and liquor concentration. According to the principle of central composite Box-Behnken experimental design and the results of initial formula studies and single factor experiments, the response surface experiments for response value were designed to optimize the spray drying processing technology with independent variable of the inlet temperature (X1), the air flow (X2) and the feed rate (X3), and the dependent variable of the yield (Y1), moisture content (Y2) and solubility (Y3). The regression equations of the yield, moisture content and solubility were obtained as follows:Y1=-1506.6395+14.5615X1+0.92124X2+8.6826X3-0.000665X1X2+0.0012X1X3-0.00184X2X3-0.047015X12-0.00047915X2-0.11826X32Y2=198.4735-1.6625X1-0.11324X2-1.7478X3+0.00006X1X2+0.0017X1X3-0.00035X2X3+0.005195X12+0.00006995X22+0.03158X32Y3=-605.62775+6.96887X1+0.22796X2+5.71695X3-0.0001725X1X2-0.0014X1X3-0.000715X2X3-0.02258X12-0.00011005X22-0.08232X32The weight coefficient of the yield, moisture content and solubility of products were obtained by the optimal analysis of the regression equations, which was60%,20%,20%, respectively. The optimum spray drying conditions were the inlet temperature (150℃), the air flow (814L/h) and the feed rate (30mL/min).6. The optimization of the initial formula for spray dryingBased on the optimal spray drying conditions and the results of single factor experiments, the orthogonal experiment L16(45) of the adding content of drying adjuvant, whey powder, soybean protein, lecithin and liquor concentration were designed to detect the sensory evaluation, yield, moisture content and solubility of Royal Jelly Milk Powder. According to the results of orthogonal experiment and taking the sensory evaluation, yield, moisture content and solubility into consideration, the optimization of the formula were as follows:the adding content of drying adjuvant, whey powder, soybean protein, lecithin and liquor concentration were35%,10%,3%,0.2%and20%, respectively. |
