Study on Clarifying Ginger Juice and Comprehensive Utilization of Byproducts
|School||Dalian University of Technology|
|Course||Of Food Science|
|Keywords||ginger clarification gingerol extraction emulsification|
Generally speaking, what we called “ginger” in our daily life is just the tender stem ofginger. Ginger is a kind of food with high nutritional and officinal value, and contains manykinds of ingredients with nutritional function or biological activity. It is a kind of perennialherb which is traditionally both edible and medicinal. It is great significance to exploit andutilize the ginger resource in China deeply. In this paper, processing technique of clear gingerjuice was studied. The ginger juice was treated by enzyme method, tannin-gelatin method,chitosan method and ultrafiltration method; comprehensive utilization of residue was alsoresearched. The results obtained were as below:1. The optimum enzymolysis condition of pectinex xxl pectinase was: amount of enzyme0.01%, at45℃for120min. Under this condition, the transmittance of ginger juice was over98%. After sterilization, few precipitations were on the bottom and the stability of ginger juicewas good; the optimum condition of tannin-gelatin method was: the addition amount ofgelatin0.04‰and tannin0.07‰, at normal temperature for1.0h. Under this condition, thetransmittance of ginger juice could research98.6%. But in the process of storage, the color ofginger became dark and brown, precipitations were on the bottom and the stability was bad;the optimum condition of chitosan method was: the addition amount of chitosan0.4%, at40℃for40min. Under this condition, the transmittance of ginger juice could research96.8%.After sterilization, the precipitations were more than xxl pectinase method, but the clarity,flavor and color were better. Therefore before the process of ultrafiltration, the ginger juicewas treated with chitosan.2. The optimum condition of ultrafiltration was membrane with MWCO10000,0.075MPa, at40-50℃. The final juice had a transmittance of99.8%. After being stored for3months, the ginger juice remained limpid with only a little precipitation. After being stored for3months at4℃, the clear ginger juice was limpid without precipitation and good stability.3. Gingerol in ginger slag was extracted by alcohol and supersonic-assisted andextraction method was optimized. Vanillin was taken as comparison standard, and UVspectrophotemetry was used to measure the content of gingerols extractive. Supersonic extraction method was better. Under the optimum condition:75%alcohol concentration,1:15material-solvent ratio,800W supersonic power for10min, the extraction rate of the gingerolin ginger slag was2.1%.4. Gingerol which was extracted by ultrasonic method was taken as raw material.Sucrose and span60were mixed up and the compound was used as emulsifier. The methodthat emulsifies the gingerol was ultrasonic and the condition of emulsification was:span60-SE HLB10, supersonic treatment time3min, the addition of gingerol3%, emulsifierconcentration0.7%, and supersonic power600W. Ke value is smaller than5at this time, andthe emulsification system stability is comparatively good.