Development Of The Paste Of Dissolvability Pumpkin Seed Powder And Research On The Technology Of Granulation

In this paper, it is aimed to study of pumpkin seed powder, and glutinous rice starch, rice starch, potato starch are excipients. The paste of dissolvability pumpkin seed powder was mixed. By studying the gel mechanism of the mixed pumpkin seed powder, the optimum combinations are determined by D-optimization design, the fluidized bed agglomeration granulation process, brewing, moisture adsorption characters and its stability during storage are studied, conclusions are obtained as follows:Different amounts of glutinous rice starch, rice starch and potato starch influenced the pasting properties of pumpkin seed powder, and the pasting properties of pumpkin seed powder with potato starch had a significance. Twenty groups of raw materials combinations were designed by means of a trial of mixture design, and the viscosity textural and sensory properties were studied. The optimum combinations of pumpkin seed powder, glutinous rice starch, rice starch and potato starch were25.02%,30.00%,23.94%,21.04%. Different ingredient on pumpkin seed powder of gel pasting, rheological properties and mechanism were studied. Soy lecithin could reduce the solubility and the swelling, and soy lecithin combined into starch, fat and protein. The gel system excluded the gas and formed a fine network structure. Maltodextrin contained more amylase starch to form hydrogen bonds with the hydroxyl group, the starch molecules changed from disorder to order sorting. Xanthan gum bonded the hydrogen with the starch. It served to strengthen pumpkin seed powder of the network structure, enhanced its visco elasticity and flexibility. Excess sugar or sodium chloride decreased the water of activity, weakened the gel system of water and pumpkin seed powder.Five factors (rotate rate, pump rate, atomization air pressure, bed temperature and binder) influenced average particle size, moisture content of the granulation pumpkin seed powder. Rotate rate, atomization air pressure and bed temperature significantly influenced pumpkin seed powder of average particle size, moisture content. Through rotate rate(XI), atomization air pressure(X2) and bed temperature(X3)3factors BBD experiment optimization, the average particle diameter (Y1) and sensory property (Y2) of the secondary response surface regression model were comed out. The optimal granulation process parameters of pumpkin seed powder by fluidized bed was obtained as follows:rotate rate1769r/min, atomization air pressure0.lOMPa, bed temperature79.3℃, pump rate8mL/min,7.5%maltodextrin. The average particle diameter of pumpkin seed powder was685.2±6.33μm, sensory score was90.50±0.4which was close to the theoretical predictions. Tap density and bulk density were reduced to0.32g/mL,0.25g/mL, and CI Index was21.88through the tap density and bulk density. The angle of repose increased after granulation, the agglomerated powder formed better sensory quality. The wetting time was only3.52±0.67s when water was at85℃. Pumpkin seed powder’s color, shape, texture, solubility and sensory score were improved except flavor. Pumpkin seed powder was like big spherical particle, surface wrinkled after granulation. The moisture of the granulationed pumpkin seed powder after graluation and pumpkin seed powder raw materials were increased with relative humidity. Both of them decreased when temperature was increasing. The Henderson model fitted pumpkin seed powder raw materials when stored at20℃, and fitted model was EMC=[-ln(1-aw)/0.117]1/0.865, R2was0.9974. The Smith model fitted pumkin seed powder raw materials when stored at40℃, and fitted model was EMC=-0.965-10.6171n(1-aw), R2was0.9677. The Smith model fitted pumkin seed powder after graluation when stored at20℃, and fitted model was EMC=-1.244-12.765ln(1-aw), R2was0.9890. The Henderson model fitted pumkin seed powder after graluation when stored at40℃, and fitted model was EMC=[-ln(1-aw)/0.149]1/0.872, R2was0.9897.The peroxide value and acid value of pumpkin seed powder significantly increased during storage. The peroxide value and acid value of pumpkin seed powder increased faster when the temperature get higher, and the peroxide value and acid value of pumpkin seed powder raw materials were higher than pumpkin seed powder after granulation. The antioxidants (TBHQ, tocopherol) can effectively delay the peroxide value and acid value of pumpkin seed powder. DPPH radical scavenging rates decreased during20℃and40℃storage, the rate of the decline got faster when the temperature got higher. Antioxidants (TBHQ, tocopherol) significantly slowed down DPPH radical scavenging rate, especially TBHQ. L*declined, a*had little change, b*deepened during storage. During stored at20℃RH20%condition, the equilibrium moisture content of pumpkin seed powder changed little, and during stored at20℃RH44%, RH66%condition, the moisture content of pumpkin seed powder increased sharply especially RH66%condition. T he moisture content of pumpkin seed powder increased to8.83%after30d. The sensory score of pumpkin seed powder showed a clear downward trend under the rise of relative humidity. Relative humidity and storage time both influenced the quality of pumpkin seed powder, the condition of high relative humidity extremely unfavorable kept the quality of pumpkin seed powder.