Food Engineering / Gıda Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/12
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Article Citation - WoS: 9Citation - Scopus: 8Development of a New Electrochemical Sensor Based on Molecularly Imprinted Biopolymer for Determination of 4,4'-methylene Diphenyl Diamine(MDPI, 2023) Ghaani, Masoud; Büyüktaş, Duygu; Carullo, Daniele; Farris, StefanoA new molecularly imprinted electrochemical sensor was proposed to determine 4,4' methylene diphenyl diamine (MDA) using molecularly imprinted polymer-multiwalled carbon nanotubes modified glassy carbon electrode (MIP/MWCNTs/GCE). GCE was coated by MWCNTs (MWCNTs/GCE) because of their antifouling qualities and in order to improve the sensor sensitivity. To make the whole sensor, a polymeric film made up of chitosan nanoparticles was electrodeposited by the cyclic voltammetry method on the surface of MWCNTs/GCE in the presence of MDA as a template. Different parameters such as scan cycles, elution time, incubation time, molar ratio of template molecules to functional monomers, and pH were optimized to increase the performance of the MIP sensor. With a detection limit of 15 nM, a linear response to MDA was seen in the concentration range of 0.5-100 mu M. The imprinting factor (IF) of the proposed sensor was also calculated at around 3.66, demonstrating the extremely high recognition performance of a MIP/MWCNT-modified electrode. Moreover, the sensor exhibited good reproducibility and selectivity. Finally, the proposed sensor was efficiently used to determine MDA in real samples with satisfactory recoveries ranging from 94.10% to 106.76%.Editorial Citation - WoS: 5Citation - Scopus: 7Natural Hydrocolloids in the Food Sector - Recent Applications Beyond Conventional Uses(Wiley, 2020) Yemenicioğlu, Ahmet; Farris, Stefano; Türkyılmaz, Meltem; Güleç, ŞükrüIn food industry, natural hydrocolloids have been extensively used to increase the functionality of different food products such as beverages, bakery and confectionery, sauces and dressings, and meat and poultry. Conventional applications of hydrocolloids in the food industry are still based on their rheological and surface‐active properties (Dickinson, 2018; Nishinari et al., 2018; Yousefi & Jafari, 2019). However, recent developments in the hydrocolloids sector fuelled by sophisticated market demands and emerging new technologies expanded the applications of hydrocolloids beyond their conventional uses.Article Citation - WoS: 15Citation - Scopus: 21Development of Pectin-Eugenol Emulsion Coatings for Inhibition of Listeria on Webbed-Rind Melons: a Comparative Study With Fig and Citrus Pectins(John Wiley and Sons Inc., 2020) Çavdaroğlu, Elif; Farris, Stefano; Yemenicioğlu, AhmetThe objective of this study was to employ pectin-based antimicrobial coatings for inhibition of Listeria on surfaces of whole webbed-rind melons that cause frequent outbreaks of listeriosis. For this purpose, emulsion-based coatings were developed using citrus pectin (CPEC) or pectin extracted from processing wastes of sun-dried figs (FPEC) and eugenol (EUG). The emulsions of FPEC and CPEC with EUG (droplet size range: 1.99-11.22 mu m) were highly stable for minimum 10 days at 10 degrees C. The FPEC-EUG films showed higher flexibility and degree of wettability than CPEC-EUG films. In contrast, CPEC-EUG films had a higher gas barrier performance against oxygen at 50% relative humidity than FPEC-EUG films. The zone inhibition tests showed that FPEC-EUG films are more effective against Listeria innocua than CPEC-EUG films. However, FPEC and CPEC coatings with 2% EUG caused 2.2 and 2.7 decimal inactivation of Listeria on Galia melons within 1 week, respectively. The pectin coatings with EUG could reduce the risk of listeriosis from webbed-rind melons.Article Citation - WoS: 19Citation - Scopus: 20Transparent Pullulan/Mica Nanocomposite Coatings With Outstanding Oxygen Barrier Properties(MDPI Multidisciplinary Digital Publishing Institute, 2017) Uysal Ünalan, İlke; Boyacı, Derya; Trabattoni, Silvia; Tavazzi, Silvia; Farris, StefanoThis study presents a new bionanocomposite coating on poly(ethylene terephthalate) (PET) made of pullulan and synthetic mica. Mica nanolayers have a very high aspect ratio (α), at levels much greater than that of conventional exfoliated clay layers (e.g., montmorillonite). A very small amount of mica (0.02 wt %, which is φ ≈ 0.00008) in pullulan coatings dramatically improved the oxygen barrier performance of the nanocomposite films under dry conditions, however, this performance was partly lost as the environmental relative humidity (RH) increased. This outcome was explained in terms of the perturbation of the spatial ordering of mica sheets within the main pullulan phase, because of RH fluctuations. This was confirmed by modelling of the experimental oxygen transmission rate (OTR) data according to Cussler’s model. The presence of the synthetic nanobuilding block (NBB) led to a decrease in both static and kinetic coefficients of friction, compared with neat PET (≈12% and 23%, respectively) and PET coated with unloaded pullulan (≈26% reduction in both coefficients). In spite of the presence of the filler, all of the coating formulations did not significantly impair the overall optical properties of the final material, which exhibited haze values below 3% and transmittance above 85%. The only exception to this was represented by the formulation with the highest loading of mica (1.5 wt %, which is φ ≈ 0.01). These findings revealed, for the first time, the potential of the NBB mica to produce nanocomposite coatings in combination with biopolymers for the generation of new functional features, such as transparent high oxygen barrier materials.Article Citation - WoS: 24Citation - Scopus: 23Graphene Oxide Bionanocomposite Coatings With High Oxygen Barrier Properties(MDPI Multidisciplinary Digital Publishing Institute, 2016) Uysal Ünalan, İlke; Boyacı, Derya; Ghaani, Masoud; Trabattoni, Silvia; Farris, StefanoIn this work, we present the development of bionanocomposite coatings on poly(ethylene terephthalate) (PET) with outstanding oxygen barrier properties. Pullulan and graphene oxide (GO) were used as main polymer phase and nanobuilding block (NBB), respectively. The oxygen barrier performance was investigated at different filler volume fractions (φ) and as a function of different relative humidity (RH) values. Noticeably, the impermeable nature of GO was reflected under dry conditions, in which an oxygen transmission rate (OTR, mL m-2 24 h-1) value below the detection limit of the instrument (0.01 mL m-2 24 h-1) was recorded, even for ' as low as 0.0004. A dramatic increase of the OTR values occurred in humid conditions, such that the barrier performance was totally lost at 90% RH (the OTR of coated PET films was equal to the OTR of bare PET films). Modelling of the experimental OTR data by Cussler’s model suggested that the spatial ordering of GO sheets within the main pullulan phase was perturbed because of RH fluctuations. In spite of the presence of the filler, all the formulations allowed the obtainment of final materials with haze values below 3%, the only exception being the formulation with the highest loading of GO (φ 0.03). The mechanisms underlying the experimental observations are discussed.