Jujube preservation using chitosan film with nano-silicon dioxide

The effect of 1% chitosan film with 0.04% nano-silicon dioxide on the qualitative properties of harvested jujube under ambient temperature was investigated. After 32 d, the red index, decay incidence, weight loss, and respiration rate of the coated jujubes were lower compared with those of the control. The lower phenylalnine ammonialyase activity and higher activities of scavenger antioxidant enzymes (i.e., superoxide dismutase, peroxidase, and catalase) of the coated jujubes can be attributed to the compound coating. Increased malonaldehyde in the coated jujubes was restrained. Composite coating had shown to be superior in preserving total flavonoid than chitosan coating alone. But no differences were observed in terms of vitamin C loss and total polyphenol content between composite coating and control. Coating jujubes with chitosan + nano-silicon dioxide will be a promising alternative if nano-silicon dioxide is allowed for food use. (C) 2012 Elsevier Ltd. All rights reserved.