| Castanea henryi,as a potential source of high quality of starch and the future food resources,its processing property and application of starch is of great significance to develop.Taking Fujian Castanea henryi as the main raw material,the thesis using the shearing machine to deal with Castanea henryi seeds for wet grinding,and the physical and chemical properties of processed Castanea henryi starch were studied.In addition,on the basis of shear,wet grinding,combined with the double enzymatic preparation,the main preparation process of Castanea henryi beverage were studied.The results of the study are as follows:1.Study on color-protecting-Pretreatment of shearing on Castanea henryi starchThrough the orthogonal test,the effect of EDTA-2Na,sodium isoascorbate,salt and sugar’s dosage on Castanea henryi juice’ s browning inhibition was studied.Take the browning degree as index,this research obtained the optimal combination,which is as bellow:the EDTA-2Na dosage was 0.003%,sodium isoascorbate 0.025%,salt 0.4%and sugar 8.5%.After exploring,a polynomial relationship between browning degree and pulping time was found,which is as bellow:y=0.2263x2-2.14x+8.5087,the correlation coefficient R2=0.9995.2.Research on Castanea henryi starch shearing technologyBy single factor test and the quadratic general rotary combination test,take the grain under 74μ m ’s yield as index,the research obtained the relationship during shearing frequency,shearing time and material liquid ratio.In addition,After the DPS data processing software ’s analysis,the quadratic regression model during the three factors was obtained,which is as bellow:Y=87.51436+0.18136X1-0.16309X3-0.55644X12-1.84868X22-1.59412X32+0.21500X1X2+0.93750X2X3After optimal portfolio analysis,prioritization scheme,which yield was greater than 84.78%of grain under 74μm,is as bellow:shearing frequency was 32.16～36.43HZ,shearing time 10.418～11.65min,and material liquid ratio 1:10.65～1:9.562.The regression equation,ideal yield is 87.51%.Experiments proved that the model under the scheme is feasible.When the shearing frequency was 35HZ,shearing time is 11 min,material liquid ratio is 1:10,the experiment can receive the best shearing result.3.The properties of Castanea henryi starch after shearing treatment(1)Compared the sheared Castanea henryi starch with original starch,the sheared Castanea henryi starch has the following features:① Shearing process basically kept the smooth surface of the starch,and haven’t appeared the collapse surface or ravines fracture,but could reach the grinding result as other crushing method.②After shearing,the tap density of sheared starch was greater than not sheared starch.③The solubility and retention ability of sheared starch was slightly smaller than the original starch,the swelling capacity was much smaller than the original starch.④The light transmittance of sheared starch was smaller than the original starch.From the light transmittance decline,aging of sheared starch was slower.⑤Sheared under 1%concentration,the coagulation sink performance of starch was better than the original starch,also the sedimentation rate was higher.⑥Freeze-thaw stability of sheared starch is better than the original starch.⑦Digestion efficiency of sheared starch was higher than the original starch.⑧The peak viscosity of sheared starch was much higher than the original starch.But the heat-resisting performance was less,so the breakdown value was greater than the original starch;sheared under 8%concentration,the coagulation sink is far less than the original starch,it can be seen that,under temperature change,form of sheared starch was much better than the original starch,the processing performance was better as well.⑨ After shearing,content of resistant starch was slightly more than the original starch,which has a guiding significance on the infants,young children,and the elderly’s digestible food.(2)Under different shear condition,properties of Castanea henryi starch are as follows:① Castanea henryi starch got the minimum termination viscosity when Shear frequency was under 35HZ,the terminate viscosity would increase when above or below 35HZ,.②The longer shearing time was,the less time needed for Castanea henryi starch’s peak viscosity,the greater the peak viscosity.③The smaller Material liquid ratio was,the more time needed for Castanea henryi starch’s peak viscosity,in addition,the rate of sheared starch peak viscosity is faster than the original starch.4.Research on Castanea henryi beverage preparation technologyExperimental set gelatinization time,double enzyme amount,enzymolysis pH value,enzymolysis time and temperature for five factors,adopts the L16(45)orthogonal table,and makes sugar,light transmittance and centrifugal sedimentation rate as indexs for comprehensive evaluation.After research on the optimal process of enzymolysis,the Castanea henryi liquid could get the best enzymolysis result when the gelatinization time was 30min,double enzyme added amount was fungalα-amylase:glucoamylase=0.4:0.4,enzymolysis pH value was 4.0,enzyme solution temperature was 50℃,enzymatic hydrolysis time was 80min.Meantime,the solution system has the highest sugar degree and transmittance,but least centrifugal sedimentation rate.It suggests that in this condition,precipitation was not easy to happen and kept the Castanea henryi special aroma,taste is sweet and refreshing.When stabilizer was added into beverage,shearing time had a great effect on dissolution and stability of stabilizing agent.When the shearing time was 11 min,Castanea henryi beverage had the minimal centrifugal sedimentation rate,and the longest storage period. |
PDF Full Text Request