WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7150
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Article Citation - WoS: 1Citation - Scopus: 1Innovative Active and Intelligent Packaging Film Based on Pectin/Gelatin Biocomposites With Zein Nanoparticles and Anthocyanin: Quality Monitoring in Mandarin and Cucumber(Elsevier, 2025) Takma, Dilara Konuk; Bozkurt, Semra; Koc, Mehmet; Korel, Figen; Nadeem, Hilal SahinWith increasing demand for active and intelligent packaging to extend the shelf life of fresh produce and monitor its freshness, this study focused on developing a nanocomposite film. The film incorporates anthocyanin and bioactive chestnut shell extract-loaded zein nanoparticles, and its applications as coatings and packaging material for mandarin and cucumber fruits were investigated. Extracts derived from waste materials including chestnut shell, cedar tree bark and sweetgum (styrax liquidus) shell, chestnut shell extract-loaded active and intelligent nanocomposite films exhibited excellent properties, including low water vapor permeability (0.325 +/- 0.055 g.mm/m(2).h.kPa), high total phenolic content (77.20 +/- 5.64 mg GAE/g dry matter), and strong antioxidant capacity (220.04 +/- 2.70 mg Trolox equivalent /100 g dry weight). The film demonstrated sufficient tensile strength (29.35 +/- 3.40 MPa) and elongation at break (100.86 +/- 2.25 %) for its conversion into a practical packaging material. To evaluate its effectiveness, coating and packaging applications were carried out on mandarin and cucumber fruits, serving as non-climacteric model fresh produce. Coating and packaging significantly (p < 0.05) inhibited the growth of total aerobic mesophilic bacteria and yeast and mold in mandarins, though the effect on yeast and mold in cucumbers was limited. At the end of storage, packaged mandarin and cucumber fruits exhibited the highest total phenolic content, measuring 423.77 +/- 17.68 and 96.47 +/- 10.52 mg GAE/100 g dry matter, respectively. Coated fruits demonstrated significantly (p < 0.05) higher total phenolic content (382.57 +/- 18.32 mg GAE/100 g dry matter for mandarin and 91.52 +/- 7.63 mg GAE/100 g dry matter for cucumber) compared to control samples (281.22 +/- 10.49 mg GAE/100 g dry matter for mandarin and 69.56 +/- 8.99 mg GAE/100 g dry matter for cucumber). Color and textural properties of mandarin fruit were effectively maintained through coating and packaging. However, cucumber fruits, due to their high respiration rate and thin peel structure, did not show the same extent of improvements. The anthocyanin indicator in intelligent packaging exhibited more visible and effective color changes in cucumbers compared to mandarin fruits.Article Citation - WoS: 4Citation - Scopus: 3Enhancement of Post-Harvest Quality of Fresh Mandarins With Alginate-Based Edible Coating Containing Natamycin and Vanillin(Springer, 2024) Takma, Dilara Konuk; Korel, FigenEnvironmentally friendly technologies with regard to reducing the usage of commercial synthetic waxes are required for maintaining the quality of mandarin fruits during the post-harvest period. In this study, novel biocoatings that serve as a natural alternative to synthetic waxes were developed for obtaining sustained shelf life of freshly harvested mandarins. The effect of natamycin and vanillin as natural antimicrobial compounds on the post-harvest quality of mandarins were investigated by means of alginate-based edible coating. Alginate coating (1% w/v) formulations including 0.5% vanillin, 1.0% vanillin, 0.025% natamycin, 0.05% natamycin and without vanillin or natamycin were applied and compared with uncoated fruit as control. Weight loss, color change, fruit firmness, yeast and mold counts were examined over 21 days at 25 degrees C. Quality changes in mandarins such as losses of weight, color and softening changes were significantly delayed with alginate coatings. Brightness on the surfaces of fruits was improved by alginate coating layers. Fruit firmness decreased with storage time in control samples, while the firmness in coated samples remained relatively constant or increased. Moreover, yeast and mold counts considerably decreased (1.52 log cfu/g) for fruits coated with alginate coating incorporating 1% vanillin. Extension of the post-harvest storage of mandarin fruits could be performed by using alginate coating incorporating vanillin as an alternative to synthetic waxes.Review Citation - WoS: 25Citation - Scopus: 27Bacillus Cereus: a Review of “fried Rice Syndrome” Causative Agents(Academic Press, 2023) Leong, Sui Sien; King, Jie Hung; Korel, Figen“Fried rice syndrome” originated from the first exposure to a fried rice dish contaminated with Bacillus cereus. This review compiles available data on the prevalence of B. cereus outbreak cases that occurred between 1984 and 2019. The outcome of B. cereus illness varies dramatically depending on the pathogenic strain encounter and the host's immune system. B. cereus causes a self-limiting, diarrheal illness caused by heat-resistant enterotoxin proteins, and an emetic illness caused by the deadly toxin named cereulide. The toxins together with their extrinsic factors are discussed. The possibility of more contamination of B. cereus in protein-rich food has also been shown. Therefore, the aim of this review is to summarize the available data, focusing mainly on B. cereus physiology as the causative agent for “fried rice syndrome.” This review emphasizes the prevalence of B. cereus in starchy food contamination and outbreak cases reported, the virulence of both enterotoxins and emetic toxins produced, and the possibility of contaminated in protein-rich food. The impact of emetic or enterotoxin-producing B. cereus on public health cannot be neglected. Thus, it is essential to constantly monitor for B. cereus contamination during food handling and hygiene practices for food product preparation. © 2023 Elsevier LtdArticle Citation - WoS: 21Citation - Scopus: 22Characterization and Encapsulation Efficiency of Zein Nanoparticles Loaded With Chestnut Fruit Shell, Cedar and Sweetgum Bark Extracts(Elsevier, 2023) Konuk Takma, Dilara; Bozkurt, Semra; Koç, Mehmet; Korel, Figen; Şahin Nadeem, HilalZein nanoparticles (ZNPs) loaded with bioactive extracts of chestnut (Castanea sativa Mill.) shell, cedar (Cedrus libani) and sweetgum (Liquidambar orientalis) bark wastes were produced using different methods. Nanoprecipitation, high-speed homogenization and ultrasonic homogenization allowed the fabrication of ZNPs with particle sizes smaller than 202.40 nm, 430.25 nm and 325.50 nm, respectively. The smallest nanoparticle size was achieved at 132.81 nm for sweetgum bark extract-loaded ZNPs obtained by the nanoprecipitation method. Encapsulation efficiency (EE) was between 34.03 and 96.83% for all zein nanoparticles fabricated under different mixtures and process conditions. Zein concentration and extract ratio played an essential role in the EE of nanoparticles. The best conditions were determined to obtain the desired properties of ZNPs based on particle size, polydispersity index and EE by using a central composite rotatable design. The nanoprecipitation method was more appropriate for producing chestnut and cedar shell/bark extract-loaded nanoparticles. In contrast, the high-speed homogenization method was suitable for producing sweetgum bark extract-loaded nanoparticles. As a result of the encapsulation of various shell/bark extracts within zein nanoparticles, value-added products were generated from wastes having bioactive compounds. The developed zein nanoparticles for each extract type would offer eco-friendly, simple and safe food processing and packaging systems. © 2023Article Citation - WoS: 7Citation - Scopus: 9A Screen-Printed Electrode Modified With Gold Nanoparticles/ Cellulose Nanocrystals for Electrochemical Detection of 4,4'-methylene Diphenyl Diamine(Elsevier, 2023) Büyüktaş, Duygu; Ghaani, Masoud; Rovera, Cesare; Carullo, Daniele; Olsson, Richard T.; Korel, Figen; Farris, StefanoDeveloping simple, cost-effective, easy-to-use, and reliable analytical devices if of utmost importance for the food industry for rapid in-line checks of their products that must comply with the provisions set by the current legislation. The purpose of this study was to develop a new electrochemical sensor for the food packaging sector. More specifically, we propose a screen -printed electrode (SPE) modified with cellulose nanocrystals (CNCs) and gold nanoparticles (AuNPs) for the quantification of 4,4'-methylene diphenyl diamine (MDA), which is one of the most important PAAs that can transfer from food packaging materials into food stuffs. The electrochemical performance of the proposed sensor (AuNPs/CNCs/SPE) in the presence of 4,4'- MDA was evaluated using cyclic voltammetry (CV). The modified AuNPs/CNCs/SPE showed the highest sensitivity for 4,4'-MDA detection, with a peak current of 9.81 mu A compared with 7.08 mu A for the bare SPE. The highest sensitivity for 4,4'-MDA oxidation was observed at pH = 7, whereas the detection limit was found at 57 nM and the current response of 4,4'-MDA rose linearly as its concentration increased from 0.12 mu M to 100 mu M. Experiments using real packaging materials revealed that employing nanoparticles dramatically improved both the sensitivity and the selectivity of the sensor, which can be thus considered as a new analytical tool for quick, simple, and accurate measurement of 4,4 '-MDA during converting operations.Book Part Citation - WoS: 10Exopolysaccharides in Food Processing Industrials(Springer, 2021) Arserim-Uçar, Dilhun Keriman; Konuk Takma, Dilara; Korel, FigenMicrobial exopolysaccharides are a class of extracellular carbohydrates based on biopolymeric materials produced and secreted by bacteria, yeast, molds, and microalgae. Cellulose, pullulan, xanthan gum, dextran, kefiran, curdlan, emulsan, alginate, gellan, carrageenans, hyaluronic acid, levan, colanic acid, welan, glucuronides, succinoglycans, and mutan are the exopolysaccharides (EPSs) of different microbial origin. Most of the available EPSs are non-toxic, biocompatible, biodegradable, and obtain from renewable resources. Microbial EPSs display unique functional properties due to their nature and structural composition. The demand for natural microbial EPSs utilization in the food industry due to their unique properties, including emulsifier, gelling agent, and stabilizers. Microbial EPSs and their derivatives have found a wide range of applications in food systems, including fermented dairy products, bakery products, cereal-based products, beverages, delivery of active agents, coatings, and films. This chapter will present a comprehensive overview of the recent developments of EPSs and their potential utilization in the food industry.Article Citation - WoS: 7Citation - Scopus: 6Development of a Nano-Modified Glassy Carbon Electrode for the Determination of 2,6-Diaminotoluene (tda)(Elsevier, 2021) Büyüktaş, Duygu; Ghaani, Masoud; Rovera, Cesare; Olsson, Richard T.; Korel, Figen; Farris, StefanoThe objective of this study was to improve the overall performance of a glassy carbon electrode (GCE) for the detection of 2,6-diaminotoluene (TDA), a possibly carcinogenic primary aromatic amines (PAAs) that poses a serious risk for the consumer' health because they can transfer from multilayer food packages including adhesives based on aromatic polyurethane (PU) systems, to the food. The modification of the electrode surface was made by means of multi-walled carbon nanotubes (MWCNTs) and mesopomus carbon nanoparticles (MCNs). The MWCNTs-MCNs/GCE allowed achieving the best performance in terms of sensitivity, as revealed by cyclic voltammetry - CV, with an oxidation peak of 20.95 mu A over 0.079 mu A of the bare GCE. The pH of the medium influenced the oxidation of 2,6-TDA, with highest sensitivity at pH similar to 7. Amperometry experiments led to an estimated detection limit of 0.129 mu M, and three linear ranges were obtained for 2,6-TDA: 0.53-11.37 mu M, 11.37-229.36 mu M, and 229.36-2326.60 mu M. Chronoamperometry experiments combined with Cottrell's theory allowed estimating a diffusion coefficient of 2,6-TDA of 1.34 x 10(-4) cm(2) s(-1). The number of electrons (n similar to 1) involved in the catalytic oxidation of 2,6-TDA was determined according to the Lavimn's theory. Real sample tests demonstrated that the modification of the sensor using nanoparticls allowed to obtain a highly sensitive and selective sensor, which can possibly used as an alternative analytical device for the rapid, easy, and reliable determination of 2,6-TDA.Article Citation - WoS: 7Influence of Drying Temperature on Total Phenolic Content and Antioxidant Capacity of Grape Seeds(Pamukkale Üniversitesi, 2015) Konuk, Dilara; Korel, FigenGrape seed, which is an organic waste arise from production of wine, juice and molasses, is considered as a functional food ingredient in food formulations because of its rich content of bioactive compounds. This study was performed in order to evaluate the effect of air-drying temperature on the bioactive compounds of grape seeds. In the study, total phenolic content and antioxidant activity of grape seeds that are dehydrated at different drying temperatures (40, 50 and 60 degrees C) were determined. When comparing the fresh grape seeds with the corresponding dehydrated samples, it was shown that the drying operation led to reduction of total phenolic contents and the total phenolic contents decreased with an increase of the drying temperature. According to ABTS radical scavenging method, Trolox Equivalent Antioxidant Capacity (TEAC) was found to be highest for fresh grape seeds and presented lower values for grape seeds dried at three different temperatures. As a result of the study, it was demonstrated that grape seed is a powerful antioxidant source and it has still high antioxidant activity after drying process. However, drying at low temperatures was put forward to be advantageous in order to reduce the losses of phenolic components.Article Citation - WoS: 71Citation - Scopus: 76Characterization of Bacterial Cellulose Nanocrystals: Effect of Acid Treatments and Neutralization(Elsevier Ltd., 2021) Arserim-Uçar, Dilhun Keriman; Korel, Figen; Liu, LinShu; Yam, Kit LIn this study, bacterial cellulose nanocrystals (BCNCs) were obtained from bacterial cellulose nanofibers (BCNFs) by controlled hydrolysis of sulfuric and hydrochloric acids. The influence of hydrolysis temperature and acid type with the addition of the post-treatment step was studied. The obtained BCNCs were analyzed based on the structural characterization and the properties of the nanocrystals. The BCNCs crystallinity increased, and the size of nanocrystals decreased with increasing 10 °C hydrolysis temperature for both acid hydrolysis conditions. Hydrolysis conditions with neutralization post-treatment did not alter the thermal stability of nanocrystals, and BCNCs had high thermal stability like raw BCNFs. Elemental analysis results indicated that sulfur content (S %) was very low for sulfuric acid hydrolyzed samples, and X-ray results did not show any sulfate salt peaks. Thermal stable BCNCs with high crystallinity were successfully produced to meet the process requirements in various applications, especially in the food industry.Article Citation - WoS: 3Citation - Scopus: 3Effect of Different Raw Materials on Aroma Fingerprints of 'boza Using an E-Nose and Sensory Analysis(Wageningen Academic Publishers, 2019) Kemahlıoğlu, Kemal; Kendirci, Perihan; Kadiroğlu, Pınar; Yücel, Ufuk; Korel, FigenBoza is a Turkish traditional beverage produced by fermentation of maize, rice, wheat, millet, cracked wheat, and durum clear flour. The aim of this study was to determine the effect of different raw material combinations on the aroma fingerprints of boza samples using an electronic nose equipped with surface acoustic wave detector in combination with sensory analysis. According to flavour profile analysis of boza samples, significant differences were obtained among the samples. Hierarchical clustering analysis of e-nose and sensory analyses indicated that boza samples were clustered based on their aroma profiles, odour and taste properties revealing the effect of different cereals as raw materials. Rheological analysis showed that all boza samples exhibited pseudoplastic flow behaviour as the apparent viscosity decreased with increasing shear rate. This revealed that differences in raw materials did not change flow behaviour of boza samples. The results indicated that e-nose could be used as a fast and non-destructive method to assess the influence of raw material formulation on aroma profiles of boza samples in correlation with sensory analysis.