Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7148

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Author: search.filters.author.Demirbüker Kavak, DilekSubject: search.filters.subject.Hydrogen peroxide

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  • Article
    Citation - WoS: 10
    Citation - Scopus: 12
    Effects of Hot Rehydration in the Presence of Hydrogen Peroxide on Microbial Quality, Texture, Color, and Antioxidant Activity of Cold-Stored Intermediate-Moisture Sun-Dried Figs
    (John Wiley and Sons Inc., 2005) Demirbüker Kavak, Dilek; Arcan, İskender; Tokatlı, Figen; Yemecioğlu, Ahmet
    Pectin methylesterase (PME) causes considerable softening in intermediate-moisture (IM) figs rehydrated at 30°C and cold stored at 28% to 29% moisture content. Rehydration of figs at 80°C for 16 min inactivated PME partially (25-30%), but this did not prevent the softening over 3 mo of cold storage. Also, heating did not reduce the microbial load of figs significantly and increased their browning. In contrast, rehydration of figs 1st in 2.5% H2O2 at 80°C for 8 min and then in water at 80°C for 8 min reduced the microbial load of IM figs significantly, turned their brown color to yellow-light brown, and maintained their desired textural properties. The residual H2O2 in IM figs decomposed in 3 or 1.5 wk by the in situ catalase or by application of the iron (II) sulfate-ascorbic acid residue elimination method, respectively. Hot rehydration did not affect the antioxidant activity of IM figs, but treatment of figs with H2O2 increased their antioxidant activity slightly. These results indicate that the hot rehydration of figs in the presence of H 2O2 and cold storage may be applied to obtain safe and SO2-free light-colored IM fig products.
  • Article
    Citation - WoS: 8
    Citation - Scopus: 7
    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
    (John Wiley and Sons Inc., 2004) Demirbüker Kavak, Dilek; Şimşek, Şebnem; Yemenicioğlu, Ahmet
    Sun-dried figs contain a considerable amount of pectin methylesterase (PME) activity (22 μM 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°C for 16 min. The heat treatment did not cause a considerable reduction in microbial load. However, the addition of 2.5% H2O2 to the rehydratlon medium at 80°C 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°C. 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.