Food Engineering / Gıda Mühendisliği

Permanent URI for this collectionhttps://hdl.handle.net/11147/12

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2016 - 20182

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Author: search.filters.author.Boyacı, DeryaPublisher: search.filters.publisher.Elsevier Ltd.

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  • Article
    Citation - WoS: 14
    Citation - Scopus: 23
    Expanding Horizons of Active Packaging: Design of Consumer-Controlled Release Systems Helps Risk Management of Susceptible Individuals
    (Elsevier Ltd., 2018) Boyacı, Derya; Yemenicioğlu, Ahmet
    The objective of this study was the development of zein based antilisterial films that contain a consumer-controlled and pH-triggered release mechanism for lysozyme (LYS). For this purpose, composite films were formed by mixing hydrophobic zein with hydrophilic soy protein isolate (SPI) or lentil protein isolate (LPI). Active property of films was formed by maintaining 30 to 50% of total LYS in free form (LYSfree). On the other hand, the pH-triggered release mechanism was formed by exploiting attractive charge-charge interactions between LYS (pI: 11.4) and SPI or LPI (pI values ≈ 4.5), and binding remaining LYS (LYSbound) in film matrix. The pH-triggered release mechanism of composite films worked in buffers that had pHs varying between 4.3 and 7.3. The composite films bound majority of LYS between pH 5.3 and 7.3, but they released LYS at pH ≤ 4.5. The pH-triggered release of LYS was achieved with zein-LPI films activated by acidification in packed cold-stored beef, lamb and smoked salmon. The zein-SPI films performed pH-triggered LYS release in packed food with the exception of packed smoked salmon. The LYSfree and LYSbound released from pH-triggered films showed antimicrobial activity on Listeria innocua. Consumer-controlled release mechanisms enable increasing antimicrobial stress over pathogens during transfer from market to home and cold storage at home. Thus, such films could initiate personalized packaged food to help risk management of susceptible individuals.
  • Article
    Citation - WoS: 36
    Citation - Scopus: 50
    Development of Activate-At Edible Antimicrobial Films: an Example Ph-Triggering Mechanism Formed for Smoked Salmon Slices Using Lysozyme in Whey Protein Films
    (Elsevier Ltd., 2016) Boyacı, Derya; Korel, Figen; Yemencioğlu, Ahmet
    The aim of the present study was to develop the first generation of a novel natural antimicrobial packaging system which could be activated by consumers at home. For this purpose, antimicrobial films having a pH-triggering mechanism which could be activated by acidification were developed by exploiting isoelectric properties and pH induced charge-charge interactions between whey proteins (WP) and lysozyme (LYS). The release tests of films in buffers and on coated smoked salmon slices at 4 °C showed the immobilization of positively charged LYS by the negatively charged WP films at pHs ≥ 5.5. The LYS release initiated when pH was reduced below 5.5 where WP started to gain positive charges. The amount of LYS released and LYS release rate increased as pH reduced gradually from 5.5 to 3.0. The preparation of composite films of WP with beeswax (BW) and oleic acid (OLE) increased the total released LYS from films. WP, WP-OLE and WP-BW films showed antimicrobial activity against Listeria innocua in laboratory media. The smoked salmon slices coated by activated LYS containing WP-OLE films showed significantly lower (almost 0.6 decimal) L. innocua counts than controls after 1 week at 4 °C. This study clearly showed that the antimicrobial films could be activated by consumers to improve safety of opened packed food stored in home type refrigerators.