The effects of temperature and pH on the extraction of oxalate and pectin from green kiwifruit (Actinidia deliciosa L.), golden kiwifruit (Actinidia chinensis L.), kiwiberry (Actinidia arguta) and persimmon (Diospyros kaki)

作者：Ha VHong Nguyen; Savage Geoffrey Peter^*

来源：International Journal of Food Science and Technology, 2013, 48(4): 794-800.

DOI：10.1111/ijfs.12029

• Pectin
• soluble and insoluble oxalates
• total
• water and acid extraction

Oxalates and pectin were extracted from four locally grown fruits at three different pH levels, 6.9, 0.6 and 0.3, at two different temperatures, 21 and 80 degrees C. Green kiwifruit (Actinidia deliciosa L. Hayward), golden kiwifruit (Actinidia chinensis L. Hort 16A Zespri), kiwiberry (Actinidia arguta, CV. Takaka Green) and persimmon (Diospyros kaki) contained moderate levels of oxalates. Total and soluble oxalates were more efficiently extracted at 21 degrees C using 2m HCL, while the highest amounts of pectin were extracted from the fruits at 80 degrees C using 0.2m HCL. Extraction using 0.2 and 2m HCL gave the highest yields of total oxalates, which ranged from 47.1 to 220.4mg total oxalates per 100g dry matter (DM) for persimmon and kiwiberry, respectively. Extraction using water at 21 degrees C gave soluble oxalate contents ranging from 21.2mg100g1 DM, for persimmon, to 105.0mg1001 DM, for kiwiberry fruits. Extraction of pectin was not achieved efficiently using water at either temperature, while extraction using 2m HCL gave lower values; optimal extractions of pectin were achieved at 80 degrees C using 0.2m HCL.

• 出版日期2013-4