Browsing by Author "Yilmaz, Mustafa Tahsin"

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Determination of Quality Parameters of Gilthead Sea Bream (Sparus Aurata) Fillets Coated With Electrospun Nanofibers
(Wiley, 2018) Ceylan, Zafer; Sengor, Gulgun F. Unal; Basahel, Abdulrahman; Yilmaz, Mustafa Tahsin
Practical applications The changes in texture, color, and odor parameters of the samples (C: uncoated samples, CN: the group coated with chitosan-based nanofibers, TLCN: the samples coated with thymol-loaded chitosan-based electrospun nanofibers) were tested. The changes in color of the groups were defined by using L* (lightness), a* (red/green), and b* (blue/yellow) parameters for pH values of C, CN, and TLCN. In terms of microbial spoilage, psychrophilic bacteria counts (TPBc) of the samples were revealed during storage period. The results of microbiological, sensory, and psychochemical analysis demonstrated that CN and TLCN were both effective against rapid deterioration, exhibiting up to 100% limitation of deterioration; furthermore, TLCN was more effective than that of CN samples. The study results suggested that coating of gilthead sea bream fillets with CN and TLCN would be a promising approach to delay the rapid deterioration in sensory properties (odor, texture, and color) and the delay bacteria growth. Also, the rapid changes in the physicochemical quality parameters (pH, L*, a*, and b*) of fish fillets were controlled by using electrospun nanofiber coating technique. Coating of the fish fillets with chitosan-based nanofibers delayed the deterioration. Thymol-loaded chitosan-based nanofibers were more effective to delay the deterioration. Applied tests revealed almost 100% difference between groups.
Determination of Textural Deterioration in Fish Meat Processed With Electrospun Nanofibers
(Wiley, 2020) Ceylan, Zafer; Meral, Raciye; Alav, Aslihan; Karakas, Canan Yagmur; Yilmaz, Mustafa Tahsin
Nano-applications are named as one of the novel methods, which provide many advantages like a larger contact area on the surface of fish fillets with less material. The goal of the study was to reveal the textural profile changes correlated with TPB growth of fish fillets coated with nanofibers having 2.47 +/- 0.68 mV zeta potential value and 172 nm diameter. The difference of TPB count between control (CS) and the fish fillets treated with nanofibers (NG) reached 3.45 log CFU/g (p < .05) on the sixth day. The hardness value of CS was decreased (p < .05) (the decline: 68%) while the hardness of NG was found to be much more stable (the change: 42%). The highest change in springiness for CS and NG samples was determined as similar to 24 and similar to 15%, respectively, for 12 days. Cohesiveness values of CS were slightly increased, but those of the fish fillets coated with nanofibers were remarkably decreased. The coefficient of correlation analysis between TPB count and cohesiveness values was determined as "r= -.026 andr= .796" for CS and NG, respectively. Chewiness values of CS were significantly decreased (p < .05). However, chewiness values of the fish fillets coated with nanofibers were found as much more stable (p > .05). The results revealed that nanofiber coating limited the increase of TPB in fish fillets; it also better kept the textural profile of fish fillets as compared to CS stored at 4 degrees C. The study could play a guiding role in further food nanotechnology applications in the industry and food science.
Effect of Coating With Thymol-Loaded Chitosan-Based Electrospun Nanofibers on Fatty Acid Composition of Gilthead Sea Bream Fillets (Sparus Aurata)
(Elsevier Science Bv, 2018) Ceylan, Zafer; Sengor, Gulgun F.; Meral, Raciye; Yilmaz, Mustafa Tahsin
Effect of Electrospun Thymol-Loaded Nanofiber Coating on Vitamin B Profile of Gilthead Sea Bream Fillets (Sparus Aurata)
(Elsevier Science Bv, 2018) Ceylan, Zafer; Yaman, Mustafa; Sagdic, Osman; Karabulut, Ercan; Yilmaz, Mustafa Tahsin
The effect of electrospun chitosan-based nanofibers (CH) and thymol-loaded electrospun chitosan-based nanofibers (TCH) were investigated in terms of stability of unstable B vitamin complex during cold storage period. Scanning Electron Microscopy revealed that the average fiber diameters were determined to range between 98.12 tan and 135.94 nm. CH and TCH were both effective against loss and rapid changes of unstable B vitamin complex. 7% average change in thiamin value was observed for samples coated with TCH, but it increased up to 39% in uncoated samples. In terms of thiamin content, the positive effect of nanofiber coating for the samples coated with TCH was observed on the 11th day of storage. Average change in riboflavin for CH and TCH was found to be lower. Particularly, sharply changes in nicotinamide acid, pyridoxal, pyridoxine and pyridoxamine contents were determined for uncoated samples, as compared to slightly changes in CH and TCH. The objective of this work was to obtain nanofibers. In this sense, potential effect of nanofibers on vitamin B profiles of fish fillets was to investigate. The results revealed that coating of the fish fillets with the nanofibers could be a promising technique to keep the stability of unstable B vitamin complex.
Electrospun Eugenol-Loaded Gelatin Nanofibers as Bioactive Packaging Materials To Preserve Quality Characteristics of Beef
(Elsevier, 2022) Yilmaz, Mustafa Tahsin; Hassanein, Wael S.; Alkabaa, Abdulaziz S.; Ceylan, Zafer
In this study, electrospinning technique was employed to fabricate eugenol loaded gelatin nanofibers (ELGNs) by using gelatin as an active material to encapsulate eugenol. The results indicated that eugenol could be suc-cessfully encapsulated within nanofibers, as verified by SEM, FTIR, and zeta potential analyses. The average zeta potential value of ELGNs was determined to be -15.08 mV. The average diameter of gelatin nanofibers was enlarged with eugenol encapsulation, increasing to diameter of 125 nm. ELGNs had a smooth and uniform fiber morphology observed by SEM. The ELGNs demonstrated a potent antibacterial activity by significant (P < 0.05) reduction in the number of total mesophilic aerobic bacteria counts by 1.62 log and psychrophilic aerobic bacteria counts by 1.33 log in fresh beef samples treated with ELGNs. Moreover, the bioactive ELGNs maintained textural properties (hardness-4.75 N, gumminess-1.75 N, and chewiness-3.87 N x mm at 9th day of storage) and sensory properties, exhibiting advantages as antimicrobial packaging materials that maintained the quality and freshness of the raw meat, along with the extension of its shelf life to 9 days. Significant (P < 0.05; 0.01) negative and positive correlations were found among the microbiological, textural, and sensory parameters, which explained and confirmed the reason for the effectiveness of the nanofiber treatment. In conclusion, our results suggested that the electrospinning approach in this study could be an effective technique to encapsulate eugenol within gelatin nanofibers and the electrospun ELGN mats could be a novel bio-degradable active packaging material with good antibacterial effects.
Fabrication and Characterization of Bioactive Nanoemulsion-Based Delivery Systems
(Ice Publishing, 2021) Yilmaz, Azime; Meral, Raciye; Kabli, Mohammad; Ermis, Ertan; Akman, Perihan Kubra; Dertli, Enes; Yilmaz, Mustafa Tahsin
In this work, a nanoemulsion-based delivery system was developed by encapsulation of different concentrations (0.50%, 0.75% and 1.00% v/v) of oregano essential oil (OEO) within poly(vinyl alcohol). The delivery systems (OEO-loaded nanoemulsion systems (NESs)) were characterized in terms of size distribution, zeta potential and thermal, molecular, microstructural and antifungal properties. The average droplet diameter values were determined to be within the range 70-75 nm, while zeta potential values within the range 3.13-19.90mV were recorded. An increase in the OEO concentration did not affect the size distribution of nanoemulsions. Change in the concentrations showed no visible differences in Fourier transform infrared spectra. However, for concentrations of 0.50, 0.75 and 1.00%, endothermic peak temperatures were recorded as 94, 105 and 117 degrees C, respectively. The antifungal activity of NESs against the mycelial growth of Aspergillus niger was evaluated, revealing a significant enhancement in the antifungal activity in comparison with that of free OEO. The zone diameter of mycelial growth could be reduced by around 20, 55 and 65% using NESs at levels of 0.50, 0.75 and 1.00% v/v, respectively, over 6 days of incubation. The results of this study revealed the stronger antifungal efficiency of OEO by its encapsulation into NESs as compared with that of free OEO.
Nanoemulsion-Based Delivery Systems To Improve Functionality of Oregano Essential Oil: Molecular Characterization and in Vitro Antifungal Activity
(Elsevier Science Bv, 2017) Ermis, Ertan; Cicek, Perihan Kubra; Meral, Raciye; Yilmaz, Azime; Dertli, Enes; Yilmaz, Mustafa Tahsin
Nanoencapsulation of Liquid Smoke/Thymol Combination in Chitosan Nanofibers To Delay Microbiological Spoilage of Sea Bass (Dicentrarchus Labrax) Fillets
(Elsevier Sci Ltd, 2018) Ceylan, Zafer; Sengor, Gulgun F. Unal; Yilmaz, Mustafa Tahsin
In this work, a combination of liquid smoke and thymol was encapsulated in chitosan nanofibers and the electrospun nanofibers were used to coat sea bass (Dicentrarchus labrax) fillets in order to delay growth of total mesophilic aerobic bacteria, psychrophilic bacteria and yeast and mold during storage period. The nanofibers were also characterized in terms of their zeta potential and fiber diameter values, microstructure and thermal decomposition. The dispersion stability (zeta potential) values were determined to range between 27.6 and 33.3 mV while fiber diameters were observed to differ from 72 to 132 nm. The electrospun nanofibers were in smooth, beadles, ultrafine, cylindrical and biopolymeric structure. The average weight loss in nanofibers were detected to be 85%. Microbiological stability tests demonstrated that the combination encapsulated in nanofibers was effective against growth of the tested microorganisms, exhibiting almost 60% limitation of growth in terms of total mesophilic bacteria. The coating of the fish fillets with the nanofibers encapsulated with the smoke/thymol combination would be a promising approach to delay microbial growth in fish fillets at cold storage conditions (6 +/- 1 degrees C). (C) 2017 Elsevier Ltd. All rights reserved.
A New Application on Fatty Acid Stability of Fish Fillets: Coating With Probiotic Bacteria-Loaded Polymer-Based Characterized Nanofibers
(Wiley, 2018) Ceylan, Zafer; Meral, Raciye; Cavidoglu, Isa; Karakas, Canan Yagmur; Yilmaz, Mustafa Tahsin
The effect of coating with Lactobacillus rhamnosus-loaded poly[vinyl] alcohol and sodium alginate-based nanofibers (LR) and also poly(vinyl) alcohol and sodium alginate-based nanofiber (PS) on fatty acid stability of fish fillets was tested. LR and PS dope solutions were successfully electrospun. Scanning Electron Microscopy images of nanofibers, with 60.09 nm < diameter of nanofibers <522.1 nm, were defined to be smooth, cylindrical, and ultrafine. Thermal decomposition of LR and PS were determined as higher than 200 and 300 degrees C, respectively by Differential Scanning Calorimeter. Nanofibers could be used to keep the stability of Polyunsaturated fatty acids (PUFA)s such as eicosapentaenoic acid and docosahexaenoic acid in fish fillets. Besides PUFAs, the rapid changes in predominant Monounsaturated fatty acids (MUFA) value like oleic acid in fish fillets coated with LR and PS were successfully limited as compared to the uncoated samples. Polyene index and predominant saturated fatty acids values (C16:0, C18:0, and C14:0) of the samples coated with LR and PS were found to be more stabile. Furthermore, the sharply decrease in omega-3/omega-6 ratio of fish fillets was limited. Loading LR to PS provided higher atherogenic and thrombogenic index. The use of probiotic bacteria-loaded polymer-based characterized nanofibers has been determined to be a new application for the fatty acid stability of fish. Practical applications Applied tests revealed differences between the fatty acid profile of uncoated and coated samples. Enrichment of PS and NaAlG-based nanofibers with Lactobacillus rhamnosus provided better stable in terms of PUFA and MUFA in fish fillets.
A Novel Perspective for Lactobacillus Reuteri: Nanoencapsulation To Obtain Functional Fish Fillets
(Elsevier, 2019) Ceylan, Zafer; Uslu, Emin; Ispirli, Humeyra; Meral, Raciye; Gavgali, Mehmet; Yilmaz, Mustafa Tahsin; Dertli, Enes
Enrichment of food products with beneficial Lactic Acid Bacteria (LAB) is an important methodology used to develop functional food products. Lactobacillus reuteri E81 was successfully nanoencapsulated into poly (vinyl alcohol)-based nanofibers for its application to the surface of fish fillets. The Scanning Electron Microscopy analysis confirmed the nanoencapsulation of L. reuteri E81 in electrospun nanofibers (LRNF) that had an average diameter of 381.83 +/- 130.69 nm. LAB growth in rainbow trout fillets and fatty fish (mackerel) and were found to be 2.92 and in the range of 3.27 and 2.66 log CFU/g, respectively. Importantly, the antioxidative characteristics of fish fillets significantly increased following their coating with LRNF. The results revealed a significant increase in the inhibition of free radicals in the samples treated with nanoencapsulated L. reuteri as compared to control group fish fillet samples. DPPH activity significantly increased to 40.24%, 44.96%, 44.97 in mackerel samples treated with nanoencapsulated L. reuteri (MLR) and increased to 19.76%, 20.87%, 21.46% in rainbow samples treated with nanoencapsulated L. reuteri (RLR). MLR samples exhibited the highest ABTS radical-scavenging activity (1631 mu mol TEAC/g). FRAP value of MLR samples was found to be 1.70 times higher than the control group samples.
A Novel Strategy for Probiotic Bacteria: Ensuring Microbial Stability of Fish Fillets Using Characterized Probiotic Bacteria-Loaded Nanofibers
(Elsevier Sci Ltd, 2018) Ceylan, Zafer; Meral, Raciye; Karakas, Canan Yagmur; Dertli, Enes; Yilmaz, Mustafa Tahsin
Nanoencapsulation of probiotic bacteria (L. rhamnosus) into poly(vinyl alcohol) & sodium alginate-based nanofibers (VSPBe) and also the production of poly(vinyl alcohol) & sodium alginate-based nanofibers (VS) were successfully obtained. VSPBe and VS nanofibers were used to limit the Total Mesophilic Aerobic Bacteria (TMABc), Psychrophilic Bacteria (TPBc) and also Yeast and Mold count (TYMc) growth in the fish fillet. Dispersion stability potential -6.29 mV and -7.74 mV, for VS and VSPBe, respectively), thermal decomposition (a reduction in mass of VS and VSPBe at temperatures 50 degrees C, corresponding to < 5% and > 5%, respectively) and morphological properties of nanofibers (diameters between 60 nm and 580 nm) were revealed by characterization analysis. Microbiological tests demonstrated that VS and VSPBe were effectively delayed the TMABc and TPBc growth in fish fillets up to 38%. However, the antimicrobial effects of nanofibers were not pronounced for TYM growth in the fish fillet. The viability of probiotic bacteria could be provided after electrospinning process and the use of L. rhamnosus-loaded nanofibers for delaying microbial growth in the fish fillets could be evaluated as a natural/novel technique.
Pasting, Textural and Sensory Characteristics of the Kofter, a Fruit-Based Dessert: Effect of Molasses and Water Concentration
(Walter de Gruyter Gmbh, 2015) Yildiz, Onder; Yurt, Bayram; Toker, Omer Said; Ceylan, Mehmet Murat; Yilmaz, Mustafa Tahsin; Basturk, Ayhan
Kofter is a traditional product which is composed of water, molasses and starch. The quality of Kofter depends on many factors involving concentration of the ingredients, starch concentration and type, composition and type of the molasses and drying temperature and time. In the present study, the effect of molasses concentration (75-25%) on the pasting and textural properties of the Kofter samples was investigated. All pasting properties (peak viscosity, trough viscosity, breakdown viscosity, final viscosity, setback viscosity, peak time, pasting temperature) were significantly affected by molasses concentration used in the formula. The increase in water concentration generally caused increase in hardness, adhesiveness, gumminess and chewiness value of the Kofter samples. Sensory analysis was also performed to determine mostly preferred sample regarding appearance, color, texture, taste, odor and overall preference. According to the sensory results, Kofter sample including 40% molasses and 60% water was found to be mostly preferred sample.
Recent and Advanced Techniques for Encapsulation of Probiotic Bacteria To Maintain Their Biofunctionality
(Elsevier Science Bv, 2016) Ermis, Ertan; Meral, Raciye; Yilmaz, Mustafa Tahsin; Sagdic, Osman; Arici, Muhammet
Response Surface Methodology Study on the Possibility of Nitrite Reduction by Glucono-Δ and Ascorbic Acid in Turkish-Type Fermented Sausage (Sucuk)
(Wiley, 2010) Yilmaz, Mustafa Tahsin; Zorba, Oemer
The primary goal of this study was to determine the residual nitrite-reducing effects of glucono-delta-lactone (GDL) and ascorbic acid (AA) in Turkish-type fermented sausage. Response surface methodology was used to investigate the simultaneous effects of processing variables, e.g., nitrite (0-200 mg/kg sausage), GDL (0-0.5% w/w) and AA (0-500 mg/kg sausage) on pH, moisture, residual nitrite, proteolysis, lipolysis, peroxide, yield and sensory score of the sausage. AA significantly (P < 0.01) decreased the residual nitrite level; however, quadratic effect of AA showed an inverse effect. GDL did not produce the same effect on the residual nitrite level. The processing variables had no prominent effect on the proteolysis, lipolysis and peroxide. GDL and AA addition showed a negative effect on the yield and sensory scores of the sausages. The regression model predicted the optimum residual nitrite content to be 0.75 mg/kg. The critical values for nitrite, GDL and AA to obtain this optimum level were 147.56 mg/kg, 0.17% and 565 mg/kg, respectively. PRACTICAL APPLICATIONS Residual nitrite level is a major problem in the Turkish-type fermented sausage product with respect to some health concerns, residual nitrite causes a possible formation of the carcinogenic N-nitrosamines. The results of this study can be applied to reduce the residual nitrite level in sausage and to find the optimum levels of nitrite, glucono-delta-lactone and ascorbic acid levels to maintain the characteristic sausage quality properties. Based on the results, ascorbic acid can be used to reduce the residual nitrite levels in the sausage.
A Tracer Microrheology for Determination of Viscoelasticity of Dilute Ovalbumin Colloids
(Ice Publishing, 2022) Bakhsh, Ahmed; Elobeid, Tahra; Avci, Esra; Demirci, Mehmet; Taylan, Osman; Ozmen, Duygu; Yilmaz, Mustafa Tahsin
This study seems to be the first effort to determine the viscoelastic properties of dilute ovalbumin colloids using dynamic-light-scattering-based optical microrheology using carboxylated melamine microparticles as the tracer probe. A generalized form of the Stokes-Einstein equation constructed based on Laplace transformation of the mean square displacement, Delta r(2)(t), was employed to compute the viscoelastic moduli (storage modulus, G ', and loss modulus, G ''). Delta r(2)(t) was determined to increase with time by reaching a maximum plateau at a time between 10(-3) and 10(-1)s with no further increase, revealing the elastic nature of dilute ovalbumin colloids within the given time. On the other hand, ovalbumin colloids exhibited different viscoelastic properties at two different frequency ranges. The measurements and interpretation of data revealed that the technique used seems to ensure a fast and effective method for measuring the viscoelastic properties of ovalbumin colloids at very low concentration levels.
Use of Encapsulated Pomegranate Seed Oil in Novel Coarse and Nanosized Materials for Improving the Storage Life of Strawberry
(Elsevier Sci Ltd, 2024) Hassanein, Wael S.; Meral, Raciye; Ceylan, Zafer; Ahmed, Marwa M.; Yilmaz, Mustafa Tahsin
Different-sized pomegranate seed oil-based emulsions (coarse (CsP) and nanoemulsions (NsP): 1246 and 325 nm) were successfully prepared. Strawberries treated with NsP and CsP showed a significant decrease (p < 0.05) in yeast-mold counts (TMY) by 1.80 log CFU g(-1), and mesophilic aerobic bacteria counts (TMAB) decreased (p < 0.05) by 0.91 log CFU g(-1), respectively. CsP- and NsP-treated strawberries had a TPC of 74.45 and 82.35 mg GAE kg(-1), respectively, while control samples had a TPC of 44.24 mg GAE kg(-1). The strawberries treated with NsP exhibited the highest antioxidant capacity with 179.44 mol TEAC g(-1). After treatment with a coarse emulsion, severity levels of A. niger and B. cinerea were 60 and 73 % while the nanoemulsion treatment significantly reduced severity levels to 55.3 and 56 %. The coarse and nanoemulsions may have potential use within the food industry owing to their antioxidant and antifungal properties as well as their ability to enhance strawberry quality and function.