Effect of calcium propionate on the microstructure and pectin methylesterase activity in the parenchyma of fresh-cut Fuji apples.

摘要

Effects of calcium propionate on apple microstructure and pectin methylesterase (PME; pectinesterase) activity were determined with a view to promoting structural integrity of fresh-cut produce. Fuji apples were cubed and dipped in calcium propionate solution (40 g/l) for 30 min prior to cold storage at 4 degrees C. Samples were analysed after 0,1 and 2 wk of storage for changes in parenchyma by microstructure light microscopy and cryo-SEM. Activity of PME was determined from acid release at 63 degrees C ( pH 7). Dipping in calcium propionate solution helped maintain integrity of parenchyma of fresh-cut Fuji apples during 2 wk of storage, partly due to effects of Ca on reinforcement of cell walls and preservation of cell-to-cell contact; these effects were most noticeable in surface and middle regions of the apple. Calcium propionate treatment also reduced PME activity in apple cubes both before and during storage.