Cloud stabilization of cloudy apple juice during storage

To investigate the cloud stability of cloudy apple juice during storage, the 120 day storage experiments of cloudy apple juice at 4℃, 22℃ and 40℃ were conducted. The cloud stability of juices during storage were studied by using optical microscopy, electron microscopy, Zeta potential and size distribution analysis of particles combined with polyphenols component analysis by High Performance Liquid Chromatography(HPLC). At the beginning of storage, the turbidity of juice decreased quickly because particles of larger size in juices congregated and deposited, and with the decrease of the larger particles at the upper portion of the bottles, the depositing speed of particles decreased. The loss of total phenolic compounds, epicatechin, chlorogenic acid and tannin increased, with the increase of temperature and storage time. The addition of 0.006%(m/m) vitamine C to juices can inhibit the oxidation and polymerization of phenolic compounds to avoid the formation of new small insoluble particles, and reduce the change of turbidity of juices during the storage. The effect of particles size on cloud stabilization is more remarkable than that of particles electricity.