Studies on the Occurrence of Non-enzymatic Browning during the Storage of Cloudy Apple Juice

Abstract 120 day storage experiment at 4°C, 22°C and 40°C of cloudy apple juice without AA added or juice with 0.006% or 0.024% (w/w) AA added was conducted. The content of polyphenols, 5-(hydroxymethyl)furaldehyde (5-HMF), ascorbic acid, and the color were assessed by HPLC and other analysis techniques. The formation of new particles in juice during storage was studied by electronic scan microscope and mastersizer. During the storage period of juice, the L value decreased and the a-value increased with prolonged storage time and increased temperature. The color change of the juice was acute during the initial 45 day storage period and then remained constant. The degree of non-enzymatic browning as well as the loss of tannin, epicatechin, chlorogenic acid, ascorbic acid and the mean polymerization degree of proanthocyanidins in the juice increased as the storage time was prolonged and temperature was increased.