Food Engineering / Gıda Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/12
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Article Citation - WoS: 2Citation - Scopus: 2Assessing Edible Composite Film Polymer From Potato Industry Effluent Under High Hydrostatic Pressure and Its Antimicrobial Properties(Wiley, 2022) Akdemir Evrendilek, Gülsün; Bulut, Nurullah; Uzuner, SibelDevelopment of edible film from potato industry effluent having antimicrobial properties against Salmonella enteritidis and Escherichia coli O157:H7 by addition of Citrus sinensis volatile oil (VO), and changes of its textural properties under high hydrostatic pressure (HHP) are investigated. The optimum operational conditions are determined as 500 MPa pressure, 36.97 µL VO, and 15 min processing time with the minimum force value of 372.33 × g. Textural properties are also modeled through empirical modeling, best fit Box-Behnken design, and artificial neuron network. Inhibition zones for Salmonella enteritidis and E. coli O157:H7 at the optimum HHP conditions are 1.50 ± 0.11 and 2.18 ± 0.07 cm, respectively. Textural properties of force and elongation at break of the HHP-processed films range from 2.27 ± 0.52 to 5.23 ± 0.38 N, and from 8.57 ± 1.31 to 13.36 ± 1.36 mm, respectively. Thermal transition of the edible film is observed at 87.42 °C for 7.36 min. Addition of C. sinensis VO improves the antimicrobial properties, whereas HHP improves the textural properties of the film. It is suggested that the developed film has potential to be used as an edible food packaging material.Article Citation - WoS: 39Citation - Scopus: 41Novel Edible Films of Pectins Extracted From Low-Grade Fruits and Stalk Wastes of Sun-Dried Figs: Effects of Pectin Composition and Molecular Properties on Film Characteristics(Elsevier, 2023) Çavdaroğlu, Elif; Büyüktaş, Duygu; Farris, Stefano; Yemenicioğlu, AhmetThis study aimed to explore the characteristics of novel fig pectin films. For this purpose, films of crude fig pectin (CFP) extracted from low-grade sun-dried fruits and films of crude (CSP) and purified (PSP) stalk pectins extracted from stalk waste of processed high-quality sun-dried figs were evaluated for their physicochemical properties. The properties of pristine (CFP, CSP, and PSP films) and CaCl2 cross-linked films (CFP–Ca++, CSP-Ca++and PSP-Ca++ films) of fig pectins were also compared with films of commercial citrus (CP and CP-Ca++) and apple (AP, AP-Ca++) pectins. The cross-linking improved the mechanical strength and barrier properties of most films. CP, CP-Ca++, PSP, and PSP-Ca++ films showed greater mechanical strength and stiffness than other films. PSP-Ca++, PSP and CP-Ca++ films showed the lowest water vapor permeability (6.28, 12.85, 14.96 g.mm.m−2.day−1.kPa−1, respectively) while CSP-Ca++, CP-Ca++, CP, PSP-Ca++ films showed the lowest oxygen permeability coefficients (5403, 8265, 10776, 11124 mL.μm.m−2.24h−1.atm−1, respectively). All cross-linked fig pectin films showed 2–3 fold lower degree of swelling than CP-Ca++ film. The CFP-Ca++ film showed the highest surface hydrophobicity (contact angle = 101.8°) but the lowest water solubility (32.8%) and degree of swelling. Analysis of Pearson's correlations between pectin properties and film characteristics revealed that galacturonic acid (GA) content affects the mechanical properties, while GA content, degree of esterification (DE), and acetylation affect the moisture barrier performance; finally, GA content and DE affect the oxygen barrier performance of pectin films. Films of stalk waste pectins showed some properties beyond the limits of those obtained from commercial pectins.Article Citation - WoS: 17Citation - Scopus: 18Incorporation of Organic Acids Turns Classically Brittle Zein Films Into Flexible Antimicrobial Packaging Materials(Wiley, 2021) Sözbilen, Gözde Seval; Çavdaroğlu, Elif; Yemenicioğlu, AhmetThis study aimed to turn classically brittle zein films into flexible antimicrobial ones by the use of lactic (LA), malic (MA) and tartaric acids (TA). The most effective plasticizer was LA (400% elongation at break [EB] at 4%), while MA (189% EB at 4.5%) and TA (68% EB at 5%) showed moderate and limited plasticizing effects, respectively. The LA- and MA-loaded films maintained their flexibility during 30-day storage at 4 degrees C or 25 degrees C. Fourier transform infrared (FTIR) analysis suggested that the plasticization of LA and MA could be related to secondary structural changes in zein such as increased alpha-helix and random coils (mainly by MA) and spaced/modified intermolecular (only by LA) and intramolecular (mainly by MA) beta-sheets. Atomic force and scanning electron microscopy showed that LA and MA gave more homogenous and smoother films than TA. Films with LA showed the highest water vapour permeability followed by those of control, MA- and TA-loaded films. Films with 3%-4% LA or MA formed clear zones on Listeria innocua and Klebsiella pneumonia, but only films with LA formed clear zones on Escherichia coli. All OA-loaded films gave unclear zones on Staphylococcus aureus in disc-diffusion tests, but this bacterium was inactivated rapidly in antimicrobial tests based on surface inoculation tests. LA is the best OA to develop flexible antimicrobial films from zein, an industrial by-product that films could not have been utilized as a widespread packaging material due to their brittleness.Article Citation - WoS: 36Citation - Scopus: 50Development 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, AhmetThe 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.Article Citation - WoS: 76Citation - Scopus: 85Development of Flexible Antimicrobial Packaging Materials Against Campylobacter Jejuni by Incorporation of Gallic Acid Into Zein-Based Films(American Chemical Society, 2011) Alkan, Derya; Aydemir, Levent Yurdaer; Arcan, İskender; Yavuzdurmaz, Hatice; Atabay, Halil İbrahim; Ceylan, Çağatay; Yemencioğlu, AhmetIn this study, antimicrobial films were developed against Campylobacter jejuni by incorporation of gallic acid (GA) into zein-based films. The zein and zein-wax composite films containing GA between 2.5 and 10 mg/cm 2 were effective on different C. jejuni strains in a concentration-dependent manner. Zein and zein-wax composite films showed different release profiles in distilled water but quite similar release profiles at solid agar medium. Depending on incorporated GA concentration, 60-80% of GA released from the films, while the remaining GA was bound or trapped by film matrix. The GA at 2.5 and 5 mg/cm 2 caused a considerable increase in elongation (57-280%) of all zein films and eliminated their classical flexibility problems. The zein-wax composite films were less flexible than zein films, but the films showed similar tensile strengths and Young's modulus. Scanning electron microscopy indicated different morphologies of zein and zein-wax composite films. This study clearly showed the good potential of zein and GA to develop flexible antimicrobial films against C. jejuni.Article Citation - WoS: 36Citation - Scopus: 38Antimicrobial Activity of Lactoperoxidase System Incorporated Into Cross-Linked Alginate Films(John Wiley and Sons Inc., 2009) Yener, Fatih Yalçın Güneş; Korel, Figen; Yemenicioğlu, AhmetIn this study, the antimicrobial effect of lactoperoxidase (LPS) incorporated alginate films was investigated on Escherichia coli (NRRL B-3008), Listeria innocua (NRRL B-33314), and Pseudomonas fluorescens (NRRL B-253) in presence of different concentrations of H2O2 (0.2, 0.4, and 0.8 mM) and KSCN (1, 2, and 4 mM). The incorporation of 70 nmol ABTS/min/cm2 LPS into alginate films gave 0.66 to 0.85 nmol ABTS/min/cm2 enzyme activity at 0.2 to 0.8 mM H2O 2 concentration range. The antimicrobial activity of LPS system on target bacteria changed according to the concentrations of KSCN and H 2O2. The growth of all tested bacteria was prevented for a 6-h period by applying LPS system in presence of 0.4 or 0.8 mM H 2O2 and 4 mM KSCN. At 0.8 mM H2O2 and 4 mM KSCN, the LPS system also inhibited growth of L. innocua and P. fluorescens for a 24-h incubation period, whereas E. coli growth could not be inhibited for 24 h under these conditions. At 0.2 mM H2O2 and 1 to 4 mM KSCN, a considerable inhibitory effect was obtained only on P. fluorescens. The decreasing order of the resistance of studied bacteria to LPS system is as follows: E. coli, L. innocua, and P. fluorescens. The developed antimicrobial system has a good potential for use in meat, poultry, and seafood since alginate coatings are already used in these products. Further studies are needed to test the LPS incorporated edible films in real food systems.Article Citation - WoS: 125Citation - Scopus: 156Antimicrobial and Antioxidant Activity of Edible Zein Films Incorporated With Lysozyme, Albumin Proteins and Disodium Edta(Elsevier Ltd., 2007) Mecitoğlu Güçbilmez, Çiğdem; Yemenicioğlu, Ahmet; Arslanoğlu, AlperIn this study, partially purified lysozyme was incorporated into zein films in combination with chickpea albumin extract (CPAE), bovine serum albumin (BSA) and disodium EDTA. The zein films showed an inherent free radical scavenging activity. Incorporation of lysozyme did not contribute to soluble free radical scavenging activity of zein films. However, the incorporation of lysozyme in combination with CPAE increased the soluble and immobilized free radical scavenging activity of zein films 17% to 25% and almost 84%, respectively. The incorporation of CPAE also improved the distribution of partially purified lysozyme preparation in zein films and enabled the controlled release of lysozyme by reducing its release rate from zein films between 1.5- and 3.5-fold, depending on the concentration of incorporated CPAE. In contrast, the BSA incorporation made distribution of lysozyme more heterogeneous and it did not contribute to the free radical scavenging activity of films significantly. The combinational incorporation of partially purified lysozyme with disodium EDTA · 2H2O or CPAE and disodium EDTA · 2H2O gave zein films effective on Escherichia coli and Bacillus subtilis. This study clearly showed the benefits of using functional protein extracts to control lysozyme distribution and release rate and to improve antioxidant activity in zein films.Article Citation - WoS: 125Citation - Scopus: 147Incorporation of Partially Purified Hen Egg White Lysozyme Into Zein Films for Antimicrobial Food Packaging(Elsevier Ltd., 2006) Mecitoğlu, Çiğdem; Yemenicioğlu, Ahmet; Arslanoğlu, Alper; Elmacı, Zehra Seda; Korel, Figen; Çetin, Ali EmrahLysozyme, partially purified from hen egg white by precipitation of non-enzyme protein with ethanol and lyophilized after dialysis, was incorporated into zein films. The recovery and specific activity of the enzyme after partial purification varied between 45% and 72% and 2173 and 3448 U/mg, whereas the activity of the lyophilized enzyme varied between 2900 and 3351 U/mg. The partially purified enzyme was very stable and lost almost no activity in lyophilized form or in zein films stored at -18 and 4°C for up to 8 and 4 months, respectively. During partial purification and in zein film preparation, ethanol treatment caused 123-137% and 132-315% activation of the enzyme, respectively. In zein films incorporated with 187-1318 U/cm2 (63-455 μg/cm2) lysozyme, the release rates at 4°C, changed between 7 and 29 U/cm2/min, increased at high lysozyme concentrations. Zein films incorporated with partially purified lysozyme showed antimicrobial effect on Bacillus subtilis and Lactobacillus plantarum. By the addition of disodium EDTA, the films also became effective on Escherichia coli. The results of this study showed that the partially purified lysozyme may be used in antimicrobial packaging to increase food safety.