Potential application of hot rehydration alone or in combination with hydrogen peroxide to control pectin methylesterase activity and microbial load in cold-stored intermediate-moisture sun-dried figs


JOURNAL OF FOOD SCIENCE, vol.69, no.3, 2004 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 69 Issue: 3
  • Publication Date: 2004
  • Doi Number: 10.2165/00002018-199309050-00005
  • Title of Journal : JOURNAL OF FOOD SCIENCE


Sun-dried figs contain a considerable amount of pectin methylesterase (PME) activity (22 muM COOH/min/g). The enzyme causes softening and loss of desired gummy texture in cold-stored intermediate-moisture (IM) sun-dried figs brought to a 28% to 29% moisture range. Partial reduction of PME activity (28%) delayed undesirable textural changes in IM figs rehydrated at 80 degreesC for 16 min. The heat treatment did not cause a considerable reduction in microbial load. However, the addition of 2.5% H2O2 to the rehydration medium at 80 degreesC reduced the initial total mesophilic aerobic count of figs by at least 90% and turned the figs from a brown color to a desirable and stable yellow-light brown. The in situ fig catalase remains after rehydration at 80 degreesC. Thus, by reducing the contact period of figs with H2O2 or by pureeing figs, it is possible to eliminate residual H2O2 and to obtain safe and SO2-free light-colored fig products.