| Background Dioscorea opposita Thunb.cv.Tiegun has high edible value and medicinal value,and its nutritive value is much higher than ordinary Chinese yam. It has delicate taste, distinctiveflavor, which can strengthen the spleen and boost the energy as well as improve the condition ofstomach and intestine. Chenji is located in Dingtao country, Heze city,Shandong province, which is plain area formed by the impact of Yellow River. The geographicalenvironment of this area is suitable for the growth of Chinese yam. Due to the good taste andhigh nutrition of Chenji Dioscorea opposita Thunb.cv.Tiegun, it has gradually become a regionaladvantage industry of Heze, Shandong.Because the harvest season of Dioscorea oppositaThunb.cv.Tiegun is relatively concentrated and the features of thin skin, high moisture contentand large volume, it is not conducive to the preservation and long-distance transport. Meanwhile,local yam industry make few deep processing which lead to limited use of yam resources. Somaking deep processing of it can not only improve the added value of yam and promote the useof resources, but also enrich the yam varieties of products and bring certain economic benefits tothe Chenji area and increasing farmers’ income.Purpose According to the characteristics that Chenji Dioscorea oppositaThunb.cv.Tiegun contains large amounts of starch, we launch researches on starch freeze-thawstability and aging characteristics and so forth; by the researches on starch hydrolysis andstability of yam juice, we developed Chenji Dioscorea opposita Thunb.cv.Tiegun andbanana yam beverage. Through the technology demonstration, we designed the process of yamjuice in order to provide the basis for actual production.Methods Extraction of starch in fresh Chenji Dioscorea opposita Thunb.cv.Tiegun by alcoholmethod, and studying the basic properties of yam starch part; making use of the single factorexperiment and response surface experiment to determine the optimum zymoticprocess parameters of Chenji Dioscorea opposita Thunb.cv.Tiegun juice; using the responsesurface experiment to confirm the compound stabilizer combination of Chenji Dioscorea opposita Thunb.cv.Tiegun beverage and determine the content of effective components ofexperimental product; making use the single factor experiment and the orthogonal experiment todetermine the best formula of bananas yam beverage; demonstration and material balance forthe process of Chinese yam juice to determine whether the Chinese yamjuice research has practical significance of production.Result Extracting the starch of Dioscorea opposita Thunb.cv.Tiegun by alcohol method, anddetermining the main components of starch, and the contents data are as follows: moisture12.05%, protein1.30%, fat0.28%, ash0.38%. Observing the morphology of Dioscorea oppositaThunb.cv.Tiegun by transmission electron microscopy, and the starch granule surface is smooth,mostly oval. By studying the solubility, light transmittance, the freeze-thaw stability, aging value,settling character of Dioscorea opposita Thunb.cv.Tiegun starch, we found that the yam juiceeasily appear lamination, the product quality character is not stable and not easy to frozenstorage. The conditions of separating the bark and stem of Dioscorea oppositaThunb.cv.Tiegun are7%of aqueous solution, temperature of80℃,6minutes. By the singlefactor experiment, we choose0.01%ascorbic acids as color protecting agent. To decompose yamstarch by medium temperature α-amylase, we determine the optimum enzymatic hydrolysisparameter is that enzyme dosage is1.11mg/ml,25min,62℃. Using surface experiment todetermine the result of combination of yam juice stabilizer is that CMC-Na0.06%, xanthangum0.07%, sodium alginate0.10%, and agar0.001%. Through single factor experiment, wedetermined0.2%citric acid as banana color agent. The best stabilizer of yam banana compoundbeverage is determined through orthogonal test: combination of xanthan gum0.14%, sodiumalginate0.16%, CMC-Na0.18%.Conclusion The basic physical and chemical properties of starch of Chenji Dioscorea oppositaThunb.cv.Tiegun were detrermined. We determined the juice optimumzymotic process parameters and the best composite stabilizer ratio, and found that the formula ofyam juice are yam puree97.71%, citric acid0.05%, xylitol2%, CMC-Na0.06%, xanthangum0.07%, sodium alginate0.10%, and agar0.001%. We determined the best ratio of yambanana compound beverage is72.35%yam puree,24.12%banana juice,3%xylitol,0.05%citricacid,0.14%xanthan gum,0.16%sodium alginate,0.18%CMC-Na. Through technologydemonstration and material balance, we concluded that Chenji Dioscorea opposita Thunb.cv.Tiegun juice has the significance of practical production. |
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