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Öğe Antioxidant and antimicrobial properties of thyme essential oil encapsulated in zein particles(Wiley-Blackwell, 2015) Bilenler, Tugca; Gokbulut, Incilay; Sislioglu, Kubra; Karabulut, IhsanZein has been used successfully for encapsulation of functional foods. Thyme essential oil was encapsulated in zein particles by liquid-liquid dispersion method. Functional properties of thyme essential oil can be enhanced by encapsulation technology. Based on the SEM images, size of the particles was in micron scale. A centrifugation step was applied to separate encapsulated particles during production. This treatment caused some differences in structural and functional properties. The highest encapsulation efficiency value of 97.02 % was achieved at 503xg for 10min centrifugation. Interaction time between samples and DPPH radicals was extended by encapsulation. Advantage of encapsulation in terms of antioxidant actions was highlighted by Rancimat test. A fast release rate of thyme essential oil encapsulated in zein was observed in triacylglycerols media. Antimicrobial activity of encapsulated thyme essential oil was lower than that of free form in 24h incubation. A better encapsulation efficiency rate was obtained compared to reported values. Rancimat test can be effectively used to measure antioxidant activity when essential oils are used as antioxidants in encapsulated form. A fast release rate of thyme essential oil encapsulated in zein was observed in TAGs media. Copyright (c) 2015 John Wiley & Sons, Ltd.Öğe Antioxidant efficacy of thymol and carvacrol in microencapsulated walnut oil triacylglycerols(Elsevier Sci Ltd, 2019) Gursul, Sevilay; Karabulut, Ihsan; Durmaz, GokhanAntioxidant efficiency of thymol and carvacrol in walnut oil triacylglycerols (WO-TAGs) was investigated. WO-TAGs alone or fortified with thymol/carvacrol were emulsified with sodium caseinate-lactose mixture. Oxidative stability of freeze dried emulsions was assessed via Rancimat and accelerated oven tests. Bulk WO-TAGs with and without thymol/carvacrol were also tested for comparison. Higher induction periods (IPs) were recorded for encapsulated and antioxidant fortified WO-TAGs compared to non-encapsulated and non-fortified counterparts. IP of thymol included and encapsulated WO-TAGs were found to be 1.5-2 fold higher than that of carvacrol at all concentrations (0.05-0.20%). IP of WO-TAGs was increased dose-dependent manner in the case of thymol and the highest protection was obtained with 0.20% thymol concentration (p < 0.05). Peroxide formation in bulk WO-TAGs fortified with carvacrol showed a slightly higher oxidative stability compared to thymol after 24 d of storage whereas thymol was a bit more effective in encapsulated WO-TAGs.Öğe C18 Unsaturated Fatty Acid Selectivity of Lipases During the Acidolysis Reaction Between Tripalmitin and Oleic, Linoleic, and Linolenic Acids(Springer, 2010) Karabulut, Ihsan; Durmaz, Gokhan; Hayaloglu, Ali AdnanThe C18 unsaturated fatty acid (UFA) selectivity of three immobilized lipases, namely, Lipozyme TL IM from Thermomyces lanuginosa, Lipozyme RM IM from Rhizomucor miehei, and Novozym 435 from Candida antarctica, was determined in acidolysis conducted in hexane. Tripalmitin with a mixture of equimolar quantities of C18 UFAs was used as the substrate. Significantly different incorporation rates were observed for C18 UFAs used (p < 0.05). The highest incorporation was obtained for all three C18 UFAs with Novozym 435 followed by Lipozyme RM IM and Lipozyme TL IM catalyzed acidolysis under default conditions (substrate mole ratio 1:1; temperature 50 A degrees C; reaction time 6 h; enzyme dosage 10%). Incorporation of the equimolar quantities of C18 UFAs was in the order C18:3 > C18:2 > C18:1 which also reflects C18 UFAs preferences of the lipases. The effects of operating variables on incorporation or UFA selectivity of lipases were also investigated. Among the experimental parameters including the mole ratio of fatty acid to triolein, temperature, enzyme dosage, and time on incorporation, the effect of the substrate mole ratio on UFA selectivity was greater than those of the others.Öğe ?-carotene rejection mechanism from organic medium by using activated carbon produced from waste biomass apricot(Taylor & Francis Inc, 2017) Akmil-Basar, Canan; Durmaz, Gokhan; Karabulut, Ihsan; Onal, YunusThe present paper deals with the study of adsorption of beta-carotene in tetrahydrofuran solution on activated carbon. Activated carbon was prepared from apricot waste, which is a by-product of apricot processing by means of chemical activation with ZnCl2. BET surface area of activated carbon was measured to be 1060m(2) g(-1). The effect of adsorption time, percentage of activated carbon in beta-carotene solution, and beta-carotene concentration on adsorption efficiency was also determined. Results were analyzed by the Langmiur, Freundlich, Dubinin-Redushkevich (D-R), Temkin, Frumkin, Harkins-Jura, Halse, Henderson, and Henry isotherms with linearized correlation coefficient. The characteristic parameters for each isotherm have also been determined. The kinetics of beta-carotene adsorption has been discussed by the pseudo-first-order model, the pseudo-second-order model, the Elovich equation, the intraparticle diffusion model, the Bangham equation, and the modified Freundlich equation. Three error analysis methods of residual mean square error (RMSE), chi-square statistic ((2)), and the average percentage error (% APE) have been used.Öğe Changes in Compositional Properties during Fruit Development and On-Tree Ripening of Two Common Apricot (Prunus armeniaca L.) Cultivars(Wiley-V C H Verlag Gmbh, 2021) Karabulut, Ihsan; Ozdemir, Ibrahim S.; Koc, Tugca B.; Sislioglu, Kubra; Gokbulut, Incilay; Saritepe, YukselThe objective of the present study was to investigate the variations in some major primary (sugars and organic acids) and secondary (phenolics, beta-carotene) metabolite contents during fruit development and ripening in two important apricot cultivars (Hacihaliloglu and Kabaasi). The changes in the compositional properties of two apricot cultivars were monitored during fruit development with one-week intervals from 56 to 119 days after blossom. During fruit development, the contents of organic acids and phenolics decreased whereas that of sucrose and sorbitol increased. p-Coumaric acid was the only phenolic compound which increased in concentration during fruit development regardless of the cultivar. The content of the other phenolic compounds decreased in a cultivar-dependent manner. The beta-carotene content of the cultivars showed distinct patterns of change such that 3 fold increase in beta-carotene content of Kabaasi cultivar was observed whereas the beta-carotene content of the Hacihaliloglu cultivar did not show any significant change during fruit development.Öğe Changes in oxidative stability and phytochemical contents of microencapsulated wheat germ oil during accelerated storage(Elsevier, 2021) Aslan, Kubra Sengul; Karabulut, Ihsan; Koc, Tugca BilenlerWheat germ oil (WGO) contains high amounts of tocopherols, phytostemls, and carotenoids. The high amount of unsaturated fatty acid content of WGO increases sensitivity to oxidative degradation. This study aimed to assess the efficacy of WGO micmencapsulation in buttermilk (BM) to prevent oxidative degradation. A mixture consisting of WGO:BM (1:2) and water (60%) was emulsified by a high-pressure homogenizer, and then freeze-dried. Both bulk and micmencapsulated WGO samples were kept at 60 degrees C for 24 days to evaluate oxidative stability, changes in contents of tocopherol, phytosterol, and carotenoid. Peroxide and p-anisidine values of micro-encapsulated WGO were significantly lower than the bulk WGO throughout the storage days (p < 0.05). Similarly, tocophemls, phytosterols, and carotenoid contents degraded less in microencapsulated WGO than those in bulk WGO (p < 0.05). Improved stability of the sensitive compounds in WGO through microencapsulation can extend the potential use of WGO's as a functional ingredient in food formulations.Öğe Characterization and Comparison of Free Fatty Acid Profiles of Eleven Varieties of Turkish Cheeses(Taylor & Francis Inc, 2013) Hayaloglu, Ali Adnan; Karabulut, IhsanFree fatty acids profiles of 11 different cheese varieties sold in Turkey were determined to assess the development of lipolysis. Results obtained showed that the concentrations of short chain fatty acids (C-4 and C-6 free fatty acids) were close in all cheeses (P > 0.05), except for Canak cheese. However, significant differences were noted among the samples for other free fatty acids including C-8 to C-18:2 (P < 0.05). Palmitic (C-16) and oleic (C-18:1) acids were the most abundant free fatty acids in all cheese samples. Principal component analysis was applied to simplify interpretation of the data and distinguish the variety of the cheeses on the plot. Canak cheese gave a dramatically different free fatty acid profile from the other cheeses, probably because of the fact that ripening of this variety is achieved in the earthenware pots for about 1 year. Van Otlu (ripened with special herbs) and Civil (ripened by spontaneously molding on its surface) cheeses differed from the others by ANOVA and principal component analysis techniques. In conclusion, the degree of lipolysis in the cheeses could be classified into extreme (Canak), high (Civil, Divle Tulum, Mihalic, and Van Otlu), mild (Ezine, Orgu, and Urfa), and low (Dil, Hellim, and Malatya) based on their FFA profiles.Öğe Chemical composition of apricots affected by fruit size and drying methods(Taylor & Francis Inc, 2018) Karabulut, Ihsan; Bilenler, Tugca; Sislioglu, Kubra; Gokbulut, Incilay; Ozdemir, Ibrahim Sani; Seyhan, Ferda; Ozturk, KadirCombined practice of sulfuration and drying is widely applied for extending shelf life of fruits. The differences in fruit size are not taken into consideration during these applications and during fresh fruit consumption. In this study, effect of fruit size and drying methods (hot air-drying and sun drying) on the chemical composition of fresh and sulfurated apricot was investigated. Total drying times for sun drying and hot air-drying were 11 d and 51 h, respectively. A temperature gradient was applied during hot air-drying. The fruit size substantially affects the composition of both fresh and dried apricots. The results were subjected to principal component analysis. The small-sized fresh apricots discriminate themselves from large ones with higher amounts of phenolic compounds, whereas the large-sized fresh apricots contain more sugar and organic acids. Size classification and hot air-drying are advisable for high-quality dried apricot production.Öğe Determination of Antioxidant Properties and beta-Carotene in Orange Fruits and Vegetables by an Oxidation Voltammetric Assay(Taylor & Francis Inc, 2022) Koc, Tugca Bilenler; Savan, Ebru Kuyumcu; Karabulut, IhsanRecently, the evaluation of antioxidant properties using voltammetric techniques based on electrooxidation has attracted considerable attention. In this study, the antioxidant capacity, total phenolic compounds, and beta-carotene content of orange-fleshed fruits and vegetables, including carrots, persimmons, and pumpkins, were evaluated by standard and electrochemical methods. The antioxidant capacity, evaluated by the ABTS and DPPH measurements, and the total phenolic compounds were determined spectrophotometrically. The results were expressed as Trolox equivalent antioxidant capacity (TEAC) and gallic acid, respectively. The beta-carotene contents of the samples were determined by high-performance liquid chromatography (HPLC). Electrochemical measurements were performed with differential pulse voltammetry at a sensor formed by attaching single-walled carbon nanotubes onto the glassy carbon electrode surface. Trolox, gallic acid, and beta-carotene were determined electrochemically with high sensitivity, repeatability, and low detection limits. Regression analysis was performed to correlate the results of the spectrophotometric assays and HPLC with those obtained electrochemically and satisfactory results were obtained.Öğe Determination of Chemical Composition, Total Phenolic, Antimicrobial, and Antioxidant Activities of Echinophora tenuifolia Essential Oil(Taylor & Francis Inc, 2013) Gokbulut, Incilay; Bilenler, Tugca; Karabulut, IhsanIn this study, the antioxidant and antimicrobial activities, total phenolic content, and essential oil composition of Echinophora tenuifolia L. subsp. sibthorpiana were investigated. The antioxidant activity of investigated essential oil was assessed by ABTS and DPPH assays. DPPH radical scavenging activity expressed by IC50 was 2.84 g/L, whereas the TEAC value determined by ABTS assay was 0.032 g TEAC/kg plant. Total phenol content of essential oil determined by Folin-Ciocalteu method was calculated as 1.32 g GAE/kg plant. The essential oil extracted by hydrodistillation (Clevenger apparatus) was investigated by GC-MS technique and 78 compounds were identified. The main components of essential oils were found to be -3-carene (17.93%), p-cymene (8.99%), methyleugenol (16.41%), and -phellandrene (9.33%). The antimicrobial activity of investigated essential oil was tested using a broth dilution method against 13 bacterial and 2 fungal microorganisms. The lowest minimum inhibitory concentration of essential oil against Bacillus cereus was 62.5 g/mL while the antifungal activity was greater than 1000 g/mL for both Candida albicans and Saccharomyces cereviciae. Investigated essential oil has a certain level of antioxidant and antimicrobial effects, which may be attributed to their chemical compounds. The antimicrobial efficiency of essential oil, especially against Bacillus cereus and Staphylocoocus spp., offers its effectiveness to treatment of wound or disease caused by Gram positive bacteria.Öğe Effect of Altitude and Location on Compositions and Antioxidant Activity of Laurel Cherry (Prunus Laurocerasus L.)(2023) Bilenler, Tuğça; Karabulut, IhsanThe compositional and antioxidant properties of cherry laurel (Prunus laurocerasus L.) fruit, which grow in two different locations (Trabzon and Rize) and altitudes, were investigated. The results indicated that antioxidant activity, total phenolic content, citric acid, sugars and phenolic compounds were affected by location and altitude. While fruits of Trabzon province have higher composition content than those of Rize province, fruits collected at low altitudes in both regions were found to have superior properties. Total phenolic content in fruits from Trabzon and Rize provinces increased from 21.90 to 23.32 and from 16.84 to 18.91 mg gallic acid equivalent / 100 g dry weight (DW), ?-carotene increased from 5.19 to 6.75 and from 4.16 to 5.61 mg / kg DW, and total sugar increased from 81.68 to 131.99 and from 86.44 to 99.58 mg / g DW when altitude decrease from 351 to 49 m and 316 to 14 m, respectively. Chlorogenic acid (1404.46-7358.63 mg / kg DW) and rutin hydrate (1491.05-2712.91 mg / kg DW) were major phenolic compounds in all samples.Öğe EFFECT OF ENCAPSULATED STARTER CULTURE INCLUSION AND HEAT TREATMENT ON BIOGENIC AMINES CONTENT OF SUCUK(2019) Bilenler, Tuğça; Karabulut, IhsanAbstract: In this study, the effect of encapsulated starter culture (Lactobacillus plantarum plus Staphylococcus xylosus) inclusion on biogenic amines (BAs) content of sucuk was investigated comparatively in heat treated (at ~70 °C for 20 min) and fermented sucuks. The highest contents of histamine, which is known as the most toxic BA, were observed in the fermented samples including nonencapsulated (103.6 mg/kg) and encapsulated (102.3 mg/kg) starter cultures, while the lowest values were detected in the heat treated sucuks (p < .05), including non-encapsulated (24.2 mg/kg) and encapsulated (21.4 mg/kg) starter cultures, at the end of 45 days of storage. Based on the principal component analysis of the microbiological count and BAs content of the samples, the heat treated and encapsulated starter culture included sucuks discriminated themselves from control groups and non-encapsulated encapsulated starter culture included samples with lower histamine and tyramine contents as well as their microbiological loads.Öğe Effect of fruit canopy positions on the properties of apricot (Prunus armeniaca L.) varieties(Wiley, 2018) Karabulut, Ihsan; Bilenler, Tugca; Sislioglu, Kubra; Gokbulut, Incilay; Seyhan, Ferda; Ozdemir, Ibrahim Sani; Ozturk, BulentEffect of fruit position in the tree on properties of two commercially important apricot varieties (Hachalilolu and Kabaa) was investigated. Principal component analysis separated apricots based on their variety and canopy position. Hachalilolu variety was distinguished from Kabaa variety by its higher pH, weight, dry matter (DM), soluble solid, citric acid, and catechin content. Major features which contribute to variation of the canopy position were -carotene, malic acid, catechin, ascorbic acid, soluble solid content, DM, malic acid, and neochlorogenic acid. Fruits located on the top of the tree were richer in phenolic compounds and exhibited higher degree of antioxidant activity measured by 2.2-azinobis[3-ethylbenzthiazoline-6-sulphonic acid] (ABTS) method than those located on the bottom of the tree. Except for chlorogenic and neochlorogenic acids, all other forms of phenolic compounds were higher in concentration in the fruits located on the top of the canopy especially for the Hachalilolu variety. Practical applicationsThe results of this study may be of interest for apricot breeders as it provides important information about cultivar specific canopy effect on fruit quality. Furthermore, the results can be used by apricot producers for canopy management and pruning strategies to create of homogenous microclimate in the fruit canopy which would limit quality variation.Öğe Effect of fruit maturity level on quality, sensory properties and volatile composition of two common apricot (Prunus armeniaca L.) varieties(Springer India, 2018) Karabulut, Ihsan; Gokbulut, Incilay; Bilenler, Tugca; Sislioglu, Kubra; Ozdemir, Ibrahim Sani; Bahar, Banu; Celik, BelginThe effect of maturity level on fruit quality properties, volatile composition and sensory attributes was investigated in two important apricot varieties (HacA +/- haliloglu and KabaaAYA +/-). The soluble solid content was used as the maturity index for the classification of apricots according to their maturity levels as immature (14-20 A degrees Brix), mature (20-24 A degrees Brix) and over-mature (> 24A degrees Brix). Changes in the volatile composition of samples at different maturity levels were characterized using headspace solid phase micro-extraction gas chromatography-mass spectrometry. The results showed that the quality attributes of the KabaaAYA +/- were affected to a lesser extent by the maturity level than HacA +/- haliloglu. From the immature to over-mature, fruit weight, dry matter and pH increased while firmness and titratable acidity decreased (p < 0.05) in both varieties. Volatile composition was affected by both apricot variety and maturation levels. The main volatiles were aldehydes, alcohols, ketones, esters, terpenes and hydrocarbons. Compared to KabaaAYA +/-, the concentrations of the volatile compounds were higher in HacA +/- haliloglu regardless of the maturity levels. Among the samples, HacA +/- haliloglu at over-mature level received the highest overall liking score. The principal component analysis made on the measured quality attributes allowed the discrimination of apricot varieties and their maturity levels.Öğe Effect of hot air drying and sun drying on color values and ?-carotene content of apricot (Prunus armenica L.)(Elsevier Science Bv, 2007) Karabulut, Ihsan; Topcu, Ali; Duran, Ayhan; Turan, Sernra; Ozturk, BulentIn this study, sulphurated and nonsulphurated Hacihaliloglu apricots (Prunus armenica L.) which is the most widely produced cultivar in Turkey were used to study the effects of different hot air drying temperatures (50, 60, 70, and 80 degrees C) and sun drying on color and beta-carotene content of apricot. The time required to obtain the desired final dry matter in hot air drying was lower than sun drying. Sulphuration also decreased drying time at all drying conditions. Color values and beta-carotene content of hot air dried samples were favorable in comparison to air drying. beta-carotene content in dried apricots at 70 and 80 degrees C was 7.14, 7.17 mg 100 g(-1) dry matter and 6.12, 6.48 mg 100 g(-1) dry matter for sulphurated and nonsulphurated apricots, respectively. A good relationship was found between treatments (drying temperatures and drying times) and beta-carotene content for sulphurated and nonsulphurated apricots (R-2 = 0.9422 and 0.9129, respectively). (c) 2006 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.Öğe Effects of ?-tocopherol, ?-carotene and ascorbyl palmitate on oxidative stability of butter oil triacylglycerols(Elsevier Sci Ltd, 2010) Karabulut, IhsanButter oil triacylglycerols (BO-TAGs), free of antioxidants, including beta-carotene, were obtained via sequential treatments with activated carbon (AC) adsorption and alumina column chromatography. cc-Tocopherol, beta-carotene and ascorbyl palmitate (AP) were added to BO-TAGs, individually, or in different combinations. An accelerated oven-oxidation test was carried out at 60 degrees C to determine the most effective dosages of the antioxidants. Among the antioxidants evaluated, alpha-tocopherol was found to be the most effective, at the concentration of 50 mu g/g. To determine the possible synergism between the antioxidants, binary or ternary combinations of alpha-tocopherol, beta-carotene and AP were added to BO-TAGs at concentrations of 50, 5, and 50 mu g/g, respectively. Ternary combinations of these antioxidants were significantly better in retarding oxidation than were binary blends of alpha-tocopherol with beta-carotene or AP. However, a prooxidant effect was observed, especially when beta-carotene and AP were used individually or in binary combination. (C) 2010 Elsevier Ltd. All rights reserved.Öğe Effects of encapsulated starter cultures on microbial and physicochemical properties of traditionally produced and heat treated sausages (sucuks)(Elsevier, 2017) Bilenler, Tugca; Karabulut, Ihsan; Candogan, KezbanStarter cultures (Lactobacillus plantarum and Staphylococcus xylosus) were encapsulated by emulsion method using alginate-starch mixture to increase the live cell number when they used in the heat treated (at similar to 70 degrees C for 20 min) and in fermented sucuks. Effects of encapsulated bacteria on microbial and physicochemical properties of heat treated sucuk were investigated. Freeze dried micro particles were characterized in terms of survival rate surface morphology and release profile. The highest survival rate was observed for L. plantarum and S. xylosus at 2% and 0.5% concentrations, respectively. Release test was completed for 14 days with the release rates of 70.21% and 70.34% for S. xylosus and L. plantarum, respectively. The starter cultures were protected by encapsulation against the harsh conditions during fermentation and heat treatment with lower reduction rates suggesting that the microencapsulation of starter cultures is a robust option for the use in the production of heat treated meat products. (C) 2016 Elsevier Ltd. All rights reserved.Öğe Efficacy of Microencapsulated Carvacrol in Oxidative Stability of Sunflower Oil(Wiley, 2020) Bagis, Ulkuhan; Karabulut, IhsanThe objective of this study is to improve the oxidative stability of sunflower oil using encapsulated carvacrol during 25 times repeated frying experiments. Microencapsulated carvacrol powders are produced by spray drying using binary and ternary blends of gum arabic (GA), maltodextrin (MD), and corn starch as encapsulating agents. In most cases, the encapsulation efficiency decreases as the amount of GA decreases in the wall mixture. Microencapsulated carvacrol powders prepared with GA (100%), GA + MD (75:25), and GA + MD + starch (67.5: 22.5: 10), which are found to have higher encapsulation efficiency values, are used as antioxidants in dough frying experiments. Frying experiments are performed with the addition of encapsulated and/or unencapsulated forms of carvacrol into the sunflower oil or dough. Encapsulated carvacrol is found to be more effective than unencapsulated carvacrol and butylated hydroxyanisole (BHA) in repeated frying experiments. The addition of carvacrol into oil provides better protection compared to addition into dough. Protective effects of encapsulated and unencapsulated forms of carvacrol in frying trials are successfully discriminated by applying principal component analysis. Practical Application: Carvacrol and thymol are the major constituents of thyme (Thymus vulgarisL.) essential oil. These compounds are responsible for the main bioactive properties of thyme oil. Therefore, in this study, pure commercial carvacrol was encapsulated and tested for its protective effect in sunflower oil during repeated dough frying. The effectiveness of the carvacrol in encapsulated form may be a consequence of the prevention of volatilization. The results of this study are remarkable for food applications requiring high temperatures.Öğe Electrochemical Determination of the Antioxidant Capacity, Total Phenolics, and Ascorbic Acid in Fruit and Vegetables by Differential Pulse Voltammetry (DPV) with a p-Toluene Sulfonic Acid Modified Glassy Carbon Electrode (TSA/GCE)(Taylor & Francis Inc, 2023) Koc, Tugca Bilenler; Savan, Ebru Kuyumcu; Karabulut, IhsanThe determination of antioxidant capacity, total phenolics, and ascorbic acid using accurate, efficient, low cost, and rapid methods has great analytical importance. The antioxidant capacity, total phenolics, and ascorbic acid content of apricots, arugula, banana, cranberries, spinach, and strawberries were investigated with an electrochemical approach and examined for compatibility with conventional methods. The antioxidant activity was determined by ABTS and DPPH assays. The total phenolic content was determined by the Folin Ciocalteu method and ascorbic acid was quantified by high-performance liquid chromatography (HPLC). In order to perform sensitive and simultaneous electrochemical measurements, the surface of a glassy carbon electrode (GCE) was modified by electropolymerization with p-toluene sulfonic acid (TSA). The TSA/GCE modified sensor was used for the first time for the determination of antioxidant capacity and total phenolic content. The surface of the modified sensor was characterized by cyclic voltammetry and scanning electron microscopy. The TSA/GCE was linearly correlated with the differential pulse voltammetry (DPV) for Trolox and gallic acid in 0.1M NaNO3 and ascorbic acid in pH 7.4 phosphate buffer. Electrochemical methods offer a promising alternative for the determination of antioxidant capacity and total phenolic content due to their simplicity, rapid response, low cost, sensitivity, and reproducibility.Öğe Fatty acid composition of frequently consumed foods in Turkey with special emphasis on trans fatty acids(Taylor & Francis Ltd, 2007) Karabulut, IhsanFatty acid compositions of frequently consumed foods in Turkey were analyzed by capillary gas chromatography with particular emphasis on trans fatty acids. The survey was carried out on 134 samples that were categorized as meat products, chocolates, bakery products and others. The meat products except chicken-based foods have trans fatty acids, arising as a result of ruminant activity, with an average content of 1.45 g/100 g fatty acids. The conjugated linoleic acid content of meat and chicken doner kebabs were found higher than other meat products. Chocolate samples contained trans fatty acids less than 0.17 g/100 g fatty acids, with the exceptional national product of chocolate bars and hazelnut cocoa cream (2.03 and 3.68 g/100 g fatty acids, respectively). Bakery products have the highest trans fatty acid contents and ranged from 0.99 to 17.77 g/100 g fatty acids. The average trans fatty acid contents of infant formula and ice-cream, which are milk-based products, were 0.79 and 1.50 g/100 g fatty acids, respectively. Among the analyzed foods, it was found that coffee whitener and powdered whipped topping had the highest saturated fatty acid contents, with an average content of 98.71 g/100 g fatty acids.
