Browsing by Author "Boran, Gokhan"

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Collagen and Gelatin
(Annual Reviews, 2015) Liu, Dasong; Nikoo, Mehdi; Boran, Gokhan; Zhou, Peng; Regenstein, Joe M.
Collagen and gelatin have been widely used in the food, pharmaceutical, and cosmetic industries due to their excellent biocompatibility, easy biodegradability, and weak antigenicity. Fish collagen and gelatin are of renewed interest, owing to the safety and religious concerns of their mammalian counterparts. The structure of collagen has been studied using various modern technologies, and interpretation of the raw data should be done with caution. The structure of collagen may vary with sources and seasons, which may affect its applications and optimal extraction conditions. Numerous studies have investigated the bioactivities and biological effects of collagen, gelatin, and their hydrolysis peptides, using both in vitro and in vivo assay models. In addition to their established nutritional value as a protein source, collagen and collagen-derived products may exert various potential biological activities on cells in the extracellular matrix through the corresponding food-derived peptides after ingestion, and this might justify their applications in dietary supplements and pharmaceutical preparations. Moreover, an increasing number of novel applications have been found for collagen and gelatin. Therefore, this review covers the current understanding of the structure, bioactivities, and biological effects of collagen, gelatin, and gelatin hydrolysates as well as their most recent applications.
Comparative Effects of Fish and Cow Gelatins and Locust Bean Gum on Chemical, Textural, and Sensory Properties of Yogurt
(Taylor & Francis inc, 2016) Pancar, Eda D.; Andic, Seval; Boran, Gokhan
Yogurt is a traditional dairy product widely consumed all over the world. Syneresis, which is a result of lower water holding capacity, is a big concern and an important quality parameter. In this study, the efficiency of locust bean gum and different gelatins (fish skin, fish scale, and bovine skin) in preventing syneresis was investigated. Samples were stored at 4 degrees C for 2 weeks, a typical shelf life of yogurt, and analyzed periodically for quality parameters. Syneresis, viscosity, and water holding capacity of the control and gum added samples were almost identical, while gelatin added samples were generally significantly improved (p < 0.05).
Edible Films Based on Plant and Animal Origin Proteins: Comparison of Some Mechanical and Physicochemical Characteristics
(Wiley, 2025) Okutan, Gulistan; Koc, Gunes; Cansu, Umran; Boran, Gokhan
Edible films were manufactured from three different proteins to evaluate their mechanical strength and some physicochemical features. Wheat gluten (WG), cow hide gelatin (CHG), and cow milk casein (CMC) were used at three different concentrations (5%, 6%, and 7% w/v for WG or 2%, 3%, and 4% w/v for both CHG and CMC) for the film samples. Water activity of the film samples varied within a rather narrow gap, which was between 0.26 and 0.36, with the highest values for WG films and the lowest for CMC. WG and CMC gave basic films while CHG resulted in acidic films with a pH value between 5.6 and 5.7. CHG films showed the highest conductivity while pH and conductivity increased as CHG concentration increased. WG resulted in opaque and dark colored films while CHG and CMC led to almost transparent and light colored films. Water vapor permeability of CMC films was slightly higher compared to CHG and WG counterparts with values around 2.0 x 10-14 g m/s Pa m2. In addition, tensile strength of CHG films was significantly higher than CMC and WG counterparts with values over 25 N/mm2 and more flexible with higher values of Young's modulus and elongation at break. It is concluded that CHG may be utilized by the food industry to manufacture edible films with superior mechanical features along with ease of dissolving and transparent visual characteristics, while WG and CMC might be preferred for more rigid, opaque, and dark colored films as needed.
Effect of Gelatin Based Edible Coatings on Quality of Surimi From Pearl Mullet (Alburnus Tarichi,guldenstadt, 1814) During Cold Storage
(Soc Brasileira Ciencia Tecnologia Alimentos, 2022) Okutan, Gulistan; Boran, Gokhan
A two-phase study was designed to investigate the effects of pH and salt concentration of washing solution on quality and yield of surimi from pearl mullet fillets and edible coatings on quality of the resultant surimi during cold storage. In the first phase, higher salt concentration increased gel strength of surimi and improved some other textural attributes. Surimi obtained by conventional method was found to be superior as higher yield, dry matter and protein contents were achieved. In the second phase of the study, surimi samples coated by 4 different coating formulations were stored at 4 degrees C for 10 days along with fish mince and uncoated surimi as control. TVB-N values of coated samples were not significantly increased during storage while that of fish mince reached to 53.6 mg/100 g sample on the 7th day of storage. Acidity of all samples increased leading to lower ultimate pH values while ultimate pH of coated samples was not significantly different from that of control. In general, gelatin and chitosan based edible coatings were found not meaningfully effective in extending the shelf life of surimi under conditions studied and coating formulations used with while surimi itself showed prolonged shelf life compared to fish mince.
Effect of Gelatin-Based Active Coatings Formulated With Rosemary Extract on Quality of Cold Stored Meatballs
(Soc Brasileira Ciencia Tecnologia Alimentos, 2022) Torusdag, Gulsen Berat; Gumus, Sumeyra; Boran, Gokhan
Meatballs were coated by gelatin-based mixes incorporated with potassium sorbate and rosemary extract. Coated samples were evaluated by free fatty acids (FFAs), thiobarbituric acid reactive substances (TBARS), and total volatile basic nitrogen (TVB-N) content. In addition, texture profile analysis (TPA) was performed to evaluate the textural features of meatballs. Uncoated sample as control along with 3 other samples coated by different formulations were stored in zipped plastic bags at +4 degrees C for 10 days. No significant difference was observed between samples regarding FFA and TBARS although coating with potassium sorbate showed suppressive effect on TVB-N initially. The starting pH of meatball was 6.22 and the coatings generally limited the change in pH compared to the control. Although significant differences in color were observed due to the color of coating itself, the coatings limited the variations in color to some extent. Other quality parameters were not improved much with the studied formulations. It is concluded that active edible coatings might be utilized in muscle foods for preservation and shelf-life extension if appropriately formulated and applied. Comprehensive studies are needed to determine the performance of carrier polymers in release of active ingredients and suitable formulations for every single group of food.
Effects of Carboxyl Methyl Cellulose and Edible Cow Gelatin on Physico-Chemical, Textural and Sensory Properties of Yoghurt
(Friends Science Publ, 2013) Andic, Seval; Boran, Gokhan; Tuncturk, Yusuf
Effects of carboxyl methyl cellulose (CMC) and edible cow gelatin (ECG) on physico-chemical, textural, and sensory properties of yoghurt were investigated. Yoghurts were manufactured from full-fat cow milk with addition of CMC and ECG in combination or solely, at concentrations of 0.25 and 0.50% (w/w). Sole CMC addition at a concentration of 0.25% contributed to higher viscosity (7175 cP in comparison with the control being 4526 cP on day 1) and firmness (561 g compared to the control being 294 g on day 1), but caused lower water holding capacity and higher syneresis compared to the control. However, sole ECG addition at concentration of 0.50% resulted in higher water holding capacity (69.29% in comparison with the control being 48.41%) and lower syneresis (0.22 compared to the control being 2.64, in mL per 100 mL initial sample), while also contributing to viscosity (5551 cP on day 1) and firmness (369 g on day 1). The results suggest ECG is suitable for yoghurt compared to CMC, giving an improved gel network structure with lower syneresis and higher water holding capacity along with higher viscosity and firmness, while causing no significant harm on sensory perception. (c) 2013 Friends Science Publishers
The Effects of Hydrogen Incorporation in Modified Atmosphere Packaging on the Formation of Biogenic Amines in Cold Stored Rainbow Trout and Horse Mackerel
(Academic Press inc Elsevier Science, 2022) Sezer, Yasemin Celebi; Bulut, Menekse; Boran, Gokhan; Alwazeer, Duried
The formation of biogenic amines (BAs) in fish products during storage forms a serious challenge to producers and is generally related to the growth of decarboxylase-producing microorganisms. Controlling the formation of BAs is a serious challenge for the fishery industry. This study evaluates the impact of incorporating molecular hydrogen (H-2) in a modified atmosphere packaging on the formation of BAs in both freshwater and seawater fish, i.e., rainbow trout and horse mackerel, respectively, stored at + 4 degrees C for 15 days. Fish samples were packaged in modified atmosphere packaging [MAP1 (50% CO2/50% N-2) and MAP2 (60% CO2/40% N-2)], reducing atmosphere packaging [RAP1 (50% CO2/46% N-2/4% H-2) and RAP2 (60% CO2/36% N-2/4% H-2)], and under air (control). The amount of BAs, except spermidine and spermine, significantly increased during storage in all treated samples. Both MAPs and RAPs showed significant restrictive effects on the formation of heterocyclic, aromatic, and aliphatic di-amines (histamine, tyramine, putrescine, cadaverine) in both fish species, with a more potent effect seen in RAP rather than MAP. Reduction rates of BAs Pwere about two folds higher in RAPs than that of MAPs. This shows the advantage of hydrogen incorporation in the package atmosphere on the inhibition of biogenic amine formation, especially in the presence of a high level of CO2. Therefore, RAP may be proposed as a promising technology for limiting the BA formation in fishery products.
Effects of Some Herbal Extracts on Oxidative Stability of Corn Oil Under Accelerated Oxidation Conditions in Comparison With Some Commonly Used Antioxidants
(Elsevier, 2018) Basturk, Ayhan; Ceylan, Mehmet Murat; Cavus, Mustafa; Boran, Gokhan; Javidipour, Issa
A total of 10 corn oil samples, 6 with herbal extracts, 2 with butyl hydroxy toluene (BHT) and ascorbyl palmitate (AP), a refined corn oil and the control, the stripped corn oil, were evaluated for oxidative stability under accelerated oxidation at 60 degrees C for 6 wk. Oxidation was followed by determining peroxide value, thiobarbituric acid reactive substances (TBARS), conjugated dienes (CD) and trienes (CT). Antioxidant activity of each herbal extract was evaluated. According to the obtained results, sumac extract, alpha-tocopherol and AP had the highest antioxidant activity, whereas flaxseed and sage showed the lowest. Peroxide, TEARS, CD and CT values increased during storage in all samples. Samples with BHT, sumac and mint showed the highest inhibition of peroxide formation. Sumac and thyme extracts significantly inhibited TEARS formation compared to BHT and AP added samples. It is concluded that the antioxidant activities of sumac, thyme and mint were high and retarded the oxidation and can be utilized in the food industry for commercial purposes in retardation of oil oxidation.
Fish Gelatin
(Elsevier Academic Press inc, 2010) Boran, Gokhan; Regenstein, Joe M.
Gelatin is a multifunctional ingredient used in foods, pharmaceuticals, cosmetics, and photographic films as a gelling agent, stabilizer, thickener, emulsifier, and film former. As a thermoreversible hydrocolloid with a narrower gap between its melting and gelling temperatures, both of which are below human body temperature, gelatin provides unique advantages over carbohydrate-based gelling agents. Gelatin is mostly produced from pig skin, and cattle hides and bones. Some alternative raw materials have recently gained attention from both researchers and the industry not just because they overcome religious concerns shared by Jews and Muslims but also because they provide, in some cases, technological advantages over mammalian gelatins. Fish skins from a number of fish species are among the other sources that have been comprehensively studied as sources for gelatin production. Fish skins have a significant potential for the production of high-quality gelatin with different melting and gelling temperatures over a much wider range than mammalian gelatins, yet still have a sufficiently high gel strength and viscosity. Gelatin quality is industrially determined by gel strength, viscosity, melting or gelling temperatures, the water content, and microbiological safety. For gelatin manufacturers, yield from a particular raw material is also important. Recent experimental studies have shown that these quality parameters vary greatly depending on the biochemical characteristics of the raw materials, the manufacturing processes applied, and the experimental settings used for quality control tests. In this review, the gelatin quality achieved from different fish species is reviewed along with the experimental procedures used to determine gelatin quality. In addition, the chemical structure of collagen and gelatin, the collagen-gelatin conversion, the gelation process, and the gelatin market are discussed.
Hydrogen Inclusion in Modified Atmosphere Extends the Shelf Life of Chilled Rainbow Trout Fillets
(Central Fisheries Research inst, 2023) Bulut, Menekse; Okutan, Guelistan; Alwazeer, Duried; Boran, Gokhan
Different gas formulations with inclusion of hydrogen were evaluated for extension of shelf life of chilled rainbow trout. A control and four treatment samples were as follows: Control (air), MAP1 (50% CO2 / 50% N2), MAP2 (60% CO2 / 40% N2), RAP1 (50% CO2 / 46% N2 / 4% H2) and RAP2 (60% CO2 / 36% N2 / 4% H2). Samples were stored at +2 & PLUSMN;1 & DEG;C for 15 days and periodically analyzed for changes in their quality. TBARS exceeded consumable limits in control after 5 days while treatment samples were under the limit during storage. Consumable limits for TVB-N were exceeded after 7 days in control while treatment samples remained below the limit. The modified atmosphere was significantly effective in retarding protein degradation although a modest difference was observed due to hydrogen inclusion. Gradually increased microbial counts also confirmed quality loss in control while a rather limited change was observed under a modified atmosphere. Microbial loads of treated samples were under consumable limits until the 10th day, while control reached to limits by just the 3rd day. The incorporation of molecular hydrogen in a modified atmosphere may bring benefits to the seafood industry although further research is needed.
Kinetic Evaluation of Gelatin Extraction From Chicken Skin and the Effect of Some Extraction Parameters
(Wiley, 2022) Cansu, Umran; Boran, Gokhan
Kinetic models have been extensively studied for the prediction of yield and quality for plant-sourced ingredients although that is very rare for animal-sourced products. This study is designed to evaluate common kinetic models for the prediction of yield in gelatin extraction from chicken skin. Kinetic models used for comparison were the Peleg's, the first order, and the rate law models while extraction parameters studied were solvent pH, solid:liquid ratio, and sample size. Extraction is evaluated based on the protein and hydroxyproline (Hyp) concentrations of each extract. The success of the models is evaluated based on the root-mean-square error (RMSE) and the coefficient of determination (R-2) values calculated for fittings of the models to the experimental data. The protein content of the dried and degreased skin was over 50% before gelatin extraction. Neutral pH led to the highest yield for both protein and Hyp, which were close to 2,100 and 200 mg per 10 g of skin, respectively. Similarly, smaller sample size or lower solid:liquid ratio resulted in a higher yield. In general, the first 60 min of the extraction was by rapid washing and later on by slow diffusion. Peleg's model is found to be the best fit to the experimental data with the highest R-2 values between 0.97 and 0.99 and the lowest RMSE values compared to that of other kinetic models. This is the first report on the kinetics of gelatin extraction as well as one of the few studies on extraction kinetics of animal-sourced products. Practical Applications Extraction parameters including the size of the raw material and raw material:solvent ratio showed significant effects on extraction yield. The smaller the size and the ratio, the higher the yield. Kinetics of gelatin extraction is reported for the first time by this manuscript, dealing with the yield during the whole extraction process. Extraction parameters may create substantial variability in quality and yield; thus, the data presented here may be utilized in minimizing those potential variations, by minimizing the time, energy and solvent required. The gelatin industry may use this report in the design of the gelatin extraction process as the data presented concludes that a high-rate extraction was completed within the first hour of the extraction, leading over 80% of the expected yield. Gelatin manufacturers and researchers in this field may find this manuscript useful as it provides valuable insights on gelatin extraction and its kinetics.
Optimization of a Multi-Step Procedure for Isolation of Chicken Bone Collagen
(Korean Soc Food Science Animal Resources, 2015) Cansu, Umran; Boran, Gokhan
Chicken bone is not adequately utilized despite its high nutritional value and protein content. Although not a common raw material, chicken bone can be used in many different ways besides manufacturing of collagen products. In this study, a multi-step procedure was optimized to isolate chicken bone collagen for higher yield and quality for manufacture of collagen products. The chemical composition of chicken bone was 2.9% nitrogen corresponding to about 15.6% protein, 9.5% fat, 14.7% mineral and 57.5% moisture. The lowest amount of protein loss was aimed along with the separation of the highest amount of visible impurities, non-collagen proteins, minerals and fats. Treatments under optimum conditions removed 57.1% of fats and 87.5% of minerals with respect to their initial concentrations. Meanwhile, 18.6% of protein and 14.9% of hydroxyproline were lost, suggesting that a selective separation of non-collagen components and isolation of collagen were achieved. A significant part of impurities were selectively removed and over 80% of the original collagen was preserved during the treatments.
Physiochemical and Functional Properties of Gelatin Obtained From Tuna, Frog and Chicken Skins
(Elsevier Sci Ltd, 2019) Tumerkan, Elif Tugce Aksun; Cansu, Umran; Boran, Gokhan; Mac Regenstein, Joe; Ozogul, Fatih
Growing demand for gelatin has increased interest in using alternative raw materials. In this study, different animal skins; namely frog, tuna and chicken skins; were utilized in gelatin extraction by previously optimized extraction procedures. Quality characteristics and functional properties of the resultant gelatins were comparatively investigated. Frog skin gelatin had the highest protein content with 77.8% while the highest hydroxyproline content was found in chicken skin gelatin with 6.4%. Frog skin gelatin showed a significantly higher melting point (42.7 degrees C) compared to tuna and chicken gelatins. Bloom value was also significantly higher in frog skin gelatin compared to that of chicken and tuna skin gelatins. Results showed that processing waste like skins of different animals may present opportunities in gelatin production as high quality alternatives. This study may help the industry by providing one hand comparable data over potentially significant sources.
Seasonal Changes in Proximate Composition of Some Fish Species From the Black Sea
(Central Fisheries Research inst, 2011) Boran, Gokhan; Karacam, Hikmet
Nutritional composition of four marine fish species (horse mackerel, garfish, golden mullet, and shad), constitute to 25% of the total marine fish production in Turkey, was examined monthly during the catching season (October through March). Among fish species studied; horse mackerel, garfish, and golden mullet revealed increases in protein up to 35% until December and then a dramatic decrease in January up to 30%. Fat content was also found increasing until December in horse mackerel and garfish, and a sudden decrease was observed in January. Protein content varied between 13.0-19.8% among the species studied on fresh weight basis. The lowest protein content was found to be in horse mackerel, 14.8% and the highest in garfish, 16.9%. The results showed that shad gives the highest energy upon consumption due to high fat content, throughout four months from December to March. Fat content of garfish and golden mullet was found to below compared to other species studied Consequently, energy values of these two species were low, 479 and 460 kj/100 g, respectively.
Storage Properties of Refrigerated Whiting Mince After Mincing by Three Different Methods
(Elsevier Sci Ltd, 2006) Kose, Sevim; Boran, Muhammet; Boran, Gokhan
Minced fish is commonly used for production of surimi-based or traditional, ready-to-eat, precooked products such as fish balls or burger patties. In this study, three types of fish mince from whiting (Merlangius merlangus euxinus, N. 1840) were investigated for quality changes during refrigerated storage. The first type of mince was plain mince. It is commonly used in Turkey for producing fish balls. and requires no washing steps. The second one was surimi. It is not commonly used in this country, although it is popular in other countries for making ready-made products. The third type of mince was the type produced from the boiled fish, which is used in household preparation of fish balls. All mince types were stored under refrigerated conditions (at 4 +/- 1 degrees C) to analyze their shelf-life. Sensory and chemical analyses were used to test their quality changes during storage. The precooked samples showed the best quality and the longest shelf-life according to physical, sensory and chemical results. Plain mince showed the poorest quality in relation to sensory attributes. Surimi products had the best quality in terms of retaining their shape, but their whiteness was not as good as that of the pre-cooked ones. (c) 2005 Elsevier Ltd. All rights reserved.
Synthesis and Characterization of 2-hydroxyethylmethacrylate/2-(3-indol-yl)ethylmethacrylamide-based Novel Hydrogels as Drug Carrier With in Vitro Antibacterial Properties
(Wiley, 2017) Ilgin, Pinar; Zorer, Ozlem Selcuk; Ozay, Ozgur; Boran, Gokhan
In this study, a new cationic monomer 2-(3-indol-yl)ethylmethacrylamide (IEMA) derived from tryptamine was synthesized in a single step and characterized by Fourier transform infrared (FTIR), H-1-NMR, and C-13-NMR. Then, one-step preparation of novel poly[2-hydroxyethylmethacrylate-c-2-(3-indol-yl)ethylmethacrylamide], or p(HEMA-c-IEMA), copolymeric hydrogels has been performed successfully with IEMA and 2-hydroxyethylmethacrylate (HEMA) as monomers using free radical aqueous polymerization. The hydrogels were characterized with scanning electron microscopy, FTIR, elemental analysis, thermogravimetric analysis, and texture profile analysis instruments. p(HEMA-c-IEMA) hydrogels were used for swelling, diffusion, drug release, and antibacterial activity studies. The drug-release behavior of the hydrogels was determined as a function of time at 37 degrees C in pH1.2 and 7.2. The swelling and drug-release studies showed that an increased IEMA amount caused a higher increase in swelling and drug-release values. Additionally, zero-order, first-order, and Higuchi equation kinetic models were applied to the drug-release data, and the data fit well in the Higuchi model, and the Peppas power-law model was applied to the release mechanism. Finally, the antibacterial activities of the hydrogels were screened against Gram-positive bacteria (Bacillus cereus and Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli and Salmonella typhimurium). (c) 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45550.