Food Engineering / Gıda Mühendisliği

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

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Author: search.filters.author.Boyacı, DeryaWoS Q: search.filters.wosQuartile.Q1

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Now showing 1 - 4 of 4
  • Article
    Citation - WoS: 64
    Citation - Scopus: 77
    Development of Flexible Antimicrobial Zein Coatings With Essential Oils for the Inhibition of Critical Pathogens on the Surface of Whole Fruits: Test of Coatings on Inoculated Melons
    (Elsevier, 2019) Boyacı, Derya; Iorio, Gianmarco; Sözbilen, Gözde Seval; Alkan, Derya; Trabattoni, Silvia; Pucillo, Flavia; Yemenicioğlu, Ahmet
    This study aimed to develop essential oil (EO)-containing antimicrobial coatings for the inhibition of pathogenic bacteria contamination on fruit peels. Incorporation of eugenol (EUG), carvacrol (CAR), and thymol (THY) into films at > 1% (w/w) eliminated the typical brittleness of zein films. However, EUG outperformed CAR and THY in terms of mechanical properties. Films with >= 2% (w/w) CAR and THY and >= 3% EUG showed clear zones against L. innocua and E. coli in agar medium at 37 degrees C. All EO-containing films also inhibited L. innocua and E. coli inoculated at their surfaces by minimum 3.9 and 2.7 decimal (D) within 1 day at 10 degrees C. Moreover, 2% EUG-containing zein coatings caused 2-3 decimal reduction in L. innocua and E. coli counts of inoculated melon surfaces at 10 degrees C. Unlike the bare zein coatings, flexible EUG-containing films on melons did not show cracking or detachment. Zein films loaded with EUG showed a highly hydrophilic surface. The best oxygen barrier performance was observed for the EUG-richest formulation (i.e., EUG at 3%), and this was attributed to a homogenizing effect of the EO that eventually led to a denser and hole-free network. This work suggested that flexible coatings of zein containing EOs could inhibit pathogens embedded in the rough peel surface of melons.
  • Article
    Citation - WoS: 5
    Citation - Scopus: 9
    Development of Gel-Based Pads Loaded With Lysozyme and Green Tea Extract: Characterization of Pads and Test of Their Antilisterial Potential on Cold-Smoked Salmon
    (Academic Press, 2020) Boyacı, Derya; Yemenicioğlu, Ahmet
    The objective of this work is to develop antilisterial gel-based pads (g-pad) for active packaging of cold-smoked salmon. Lysozyme (LYS) and/or green tea extract (GTE) (1% w/w) were incorporated into g-pads of gelatin (GEL), and its mechanically improved composite g-pads obtained by mixing GEL with rice starch (GEL/RS) or candelilla wax (GEL/CW). GEL g-pad with LYS and GEL/RS g-pad with LYS or LYS + GTE, and GEL/CW g-pad with LYS + GTE caused >= similar to 1.8 and similar to 1.7 log reduction in broth media against Listeria innocua within 11 and 15 days, respectively. All g-pads with LYS or LYS + GTE inhibited L. innocua growth, and gave cold-smoked salmon with 1.5-1.9 log lower Listeria load than controls after 15 days at +4 degrees C. GEL g-pad with LYS was the most potent on salmon surface since it achieved faster LYS release (1.3-1.8-fold) than other g-pads. Sustained release of GEL/RS g-pads for LYS, and GEL/CW g-pads for GTE was promising for extended storage. Composite g-pads were more compatible with GTE than GEL g-pads since they prevented discoloration of polyphenols. Water absorption capacities showed that GEL/RS g-pads (75%) could prevent drip-loss better than GEL (59%) and GEL/CW (57%) g-pads. Active g-pads provide alternative to active edible films to reduce listeriosis from processed high-risk food.
  • 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.