Submitted to: Postharvest Biology and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 17, 2011
Publication Date: September 15, 2011
Citation: Xiao, Z., Luo, Y., Luo, Y., Wang, Q. 2011. Combined effects of sodium chlorite dip treatment and chitosan coatings on the quality of fresh-cut d’Anjou pears. Postharvest Biology and Technology. 62:319-326.
Interpretive Summary: Increased demand by modern consumers for natural, fresh, and healthy foods has stimulated rapid expansion of the fresh-cut fruit and vegetable market over the past twenty years. However, tissue injury encountered during minimal processing renders a rapid enzymatic browning reaction and the loss of product quality. In this study, the researchers developed a combination treatment of sodium chlorite and edible chitosen coatings that significantly reduced quality deterioration and the browning reaction of fresh-cut d’Anjou pears. This information is important to the fresh-cut produce industry to control browning and maintain fruit quality.
This study evaluated the effects of sodium chlorite (SC) alone and its sequential treatment with edible coatings on browning inhibition and quality maintenance of fresh-cut d’Anjou pears. Edible coatings were prepared from chitosan (CH) and its water soluble derivative: carboxymethyl chitosan (CMCH), separately. Pear wedges were immersed in SC solution, followed by coating with CH or CMCH solutions. The samples were packaged in gas permeable bags and stored at 4°C for subsequent color, firmness, and weight loss measurement. The effects of the SC and coating treatments on PPO inhibition and microbial inactivation were also evaluated. Results indicated that SC significantly (P < 0.05) inhibited browning reaction of fresh-cut pears and PPO activities. The SC treatment also displayed strong efficacy in inactivating E. coli O157:H7 on pear slices. Coating the SC treated pear slices with CH adversely affected the quality of pear slices as shown in accelerating the discoloration of cut surface and increasing the PPO activity. On the contrary, coating SC-treated samples with CMCH significantly prevented the browning reaction and inhibited PPO activity. In addition, SC and CH/CMCH coatings maintained tissue firmness and did not affect weight loss. Our study may provide a scientific basis for the use of SC+CMCH treatment for inhibiting enzymatic browning and improving quality of fresh-cut pears.