Abstract:
This research was conducted to investigate the effect of edible coating on qualities of fresh-cut mangosteen during cold storage. Mangosteen fruit at color stage 5 was in ascorbic acid followed by alginate coating, especially reducing respiration rate, preventing firmness loss, inhibition of polygalacturonase activity, and retarding losses of total vitamin C, total phenolic compounds and antioxidant capacity of the fresh-cut mangosteen during the storage. In addition, application of alginate coating in combination with ascorbic acid resulted in acceptable organoleptic quality and inhibition of microbial growth of the fresh-cut mangosteen for 12 days half-peeled and immersed in distilled water (control) or coated with 1% alginate or 1% pectin. The fruit were then put in polystyrene tray (4 fruits per tray), prior to packaging in sealed polypropylene bag and storage at 10oC for 15 days. It was found that in-package O2 level of all treatments decreased whereas an increase of CO2 level was detected. Similar pattern of ethylene production was observed in all treatments. Firmness, total soluble solids, pH and titratable acidity of all treatments tended to be constant during the storage. Fresh-cut mangosteen coated with alginate exhibited better overall qualities, especially the decreased respiration rate and higher whiteness index, total vitamin C, total phenolic compounds and antioxidant capacity, compared with fresh-cut mangosteen coated with pectin or the control. A subsequently study was conducted to assess qualities of fresh-cut mangosteen in response to application of ascorbic acid in combination with alginate coating during cold storage for 15 days. Half-peeled mangosteen was subjected to various treatments including immersing in distilled water (control 1), alginate coating (control 2), immersing in 0.5% ascorbic acid before alginate coating using 2% calcium chloride solution containing 0.5% ascorbic acid. It was found that using alginate coating in combination with ascorbic acid was more effective in maintaining physical, chemical and microbiological qualities of freshcut mangosteen during storage, compared with alginate coating or immersing in distilled water. Furthermore, ascorbic acid-incorporated alginate coating tended to better retain overall qualities of the fresh-cut mangosteen, compared with immersing in ascorbic acid followed by alginate coating, especially reducing respiration rate, preventing firmness loss, inhibition of polygalacturonase activity, and retarding losses of total vitamin C, total phenolic compounds and antioxidant capacity of the fresh-cut mangosteen during the storage. In addition, application of alginate coating in combination with ascorbic acid resulted in acceptable organoleptic quality and inhibition of microbial growth of the fresh-cut mangosteen for 12 days
WALAILAK UNIVERSITY. CENTER FOR LIBRARY RESOURCES AND EDUCATIONAL MEDIA