Enzymatic Preparation Of Waxy Maize Juice) And Its Stability Is Studied

Wax corn, not only owned the high edible value, but also had the unique nutritional value and healthcare effects, loved by consumers. In recent years, the fresh wax corn plant area and the yield were both increased greatly. However, due to the problems in processing, wax corn was preferred being fresh food to being made in the form of other products, especially the drink. This paper studied in the method of processing wax corn juice by double enzyme hydrolysis and adding hydrocolloids,which could avoid browning and precipitation easily appeared in wax corn slurry were and improv the stability, thus off-white, fresh and stable wax corn juice was made from wax corn seeds.The influences of different enzymes for quality of wax corn juice were investigated. The combination of a-amylase and neutral protease had a more desirable effect on the quality of wax corn juice. When reaction temperature was65℃, middle temperature a-amylase concentration was7.5U/g, and hydrolysis time was30min.,the wax corn juice was best. The hydrolysis of starch into dextrin and oligosaccharides could reduce the particle size and increase the juice soluble solid content and suspension stability. The optimal parameters of neutral protease enzymatic were as follows:reaction temperature was45℃, neutral protease concentration was81U/g and hydrolysis time was42min. Neutral protease ydrolyzed the protein in the slurry h to small peptides, which could result in the increase of free amino acid in three times, the decrease of the browning level and improvement of the system stability.Different effects of different hydrocolloids on stability of wax corn juice were studied. The cloudy stability of wax corn juice was compared, and the result showed that the neutral and electronegative hydrocolloids were helpful to increase wax corn juice stability. The gums of xanthan gum, sodium alginate, guar gum and sophora bean gum had a better thickening effect, but the stabile time was short. Through blending with two hydrocolloids,it showed that the ratio of the of xanthan gum and sophora bean gum was1:4had a significant stability (the amount of addition:0.15%), And the right storage time is150d. Through the electrostatic determination to validate the further combination,it can improve the system of electrostatic repulsive force so as to improve the stability.The cloudy stability of key points during the wax corn juice processing were studied, and the result showed that the enzyme hydrolysis could puff the pulp tissue structure loose and have significant effects on the degradation of cells in the juice system. Homogenization made the pulp particles to be micro granules, which could reduce the Zeta potential value and improve the stability of wax corn juice, significantly. The optimal parameters of homogenization temperature were55, the first homogenization pressure20MPa, and the second homogenization pressure25MPa. The best sterilization effect was obtained at121℃for5min.Under this condition, electrostatic repulsion of system increased, so as to improved the stability.