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15-15-15 gübresinin kitosan ile kaplanması ve elde edilen toz malzemelerin karakterizasyonu
(Aksaray Üniversitesi, 2021) Ayık, Bektaş; Çakmak, Yavuz Selim; Kaya, Murat
Gübrelerin polimerler ile kaplanarak daha yavaş ve uzun süre salınımı hem ekonomik hem de çevre kirliliğinin önüne geçilmesi açısından son derece önemlidir. Atık kerevit kabuklarından üretilen kitosanın biyolojik orijinli ve çevre dostu olması nedeniyle mevcut çalışmada tercih edilmiş ve 15-15-15 gübresinin kaplanması amaçlı kullanılmıştır. Kitosan ile 15-15-15 gübresinin kaplanması için çapraz bağlayıcı olarak glutaraldehit kullanılmıştır. Çalışmada farklı konsantrasyonlarda gübrelerin kaplanması denenmiş ve bu sayede kitosanın 15-15-15 gübresini taşıma kapasitesi belirlenmiştir. Kaplama sonrası üretilen toz örnekler fourier dönüşümlü kızıl ötesi spektrometresi (FT-IR), termogravimetrik analiz (TGA) ve taramalı elektron mikroskobu (SEM) teknikleri kullanılarak karakterize edilmiştir. Ardından kaplama yapılan gübrelerin toprakta günlere bağlı olarak bozunma yüzdeleri belirlenmiştir. Elde edilen tüm sonuçlar değerlendirildiğinde, glutaraldehit ile çapraz bağlananmış kitosan–15-15-15 gübre formülasyonunun tarım ve bahçecilik uygulamalarında pratik olarak kullanılabileceği ortaya konmuştur.
A study on antioxidant capacities and fatty acid compositions of two daphne species from Turkey: New sources of antioxidants and essential fatty acids
(Wiley-Blackwell, 2013) Zengin, Gökhan; Arkan, Tuba; Aktümsek, Abdurrahman; Guler, Gokalp Ozmen; Çakmak, Yavuz Selim
Daphne (Thymealaceae) species have been widely used in traditional Anatolian medicine. The antioxidant capacity and fatty acid composition of two Daphne taxa (D.oleoides subsp. oleoides and D.serica) were studied. The antioxidant properties of four solvent extracts of Daphne species were assessed using different chemical assays including phosphomolybdate assay, free radical-scavenging assay, -carotene/linoleic acid test system, ferric and cupric reducing power. The total phenolic and flavonoid content of the extracts also were determined. Ethyl acetate, methanol and ethanol extracts obtained from the Daphne species possess strong antioxidant potential. Polyunsaturated fatty acids in the studied oils were the highest level in the fatty acid components. Essential fatty acids accounted for 27.46-45.31% of total fatty acids. These results indicated that the extracts of studied Daphne taxa can be exploited as a source of natural antioxidants and essential fatty acids in pharmacological and food industry.
A UHPLC-QTOF-MS screening provides new insights into the phytochemical composition and biological properties of six Consolida species from Turkey
(Elsevier B.V., 2020) Rocchetti, Gabriele; Zengin, Gökhan; Çakmak, Yavuz Selim; Mahomoodally, Mohamad Fawzi; Kaya, Muhammed Fettah; Alsheikh, Sarah Mohammed; Glamocilja, Jasmina; Sokovi?, Marina D.; Lobine, Devina; Lucini, Luigi
The genus Consolida is one of the most important within the Ranunculaceae family and several members of this genus contain important biologically active compounds, such as phenolics and alkaloids. The present study attempts for the first time to assess the biological properties and phytochemical constituents of six Consolida species (C. glandulosa (Boiss. & A. Huet) Bornm, C. hellospontica (Boiss.) Chater, C. raveyi (Boiss.) Schrödinger, C. regalis (Boiss.) Schrödinger, C. staminosa P.H. Davis & Sorger and C. stenocarpa (P.H. Davis & M. Hossain) P.H. Davis) growing in Turkey. A comprehensive phytochemical profiling of the different species was achieved by using an ultra-high-performance liquid chromatography-quadrupole time-of-flight (UHPLC-QTOF) mass spectrometry, targeting polyphenols and diterpene alkaloids. Also, the in vitro antioxidant assays (2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2?-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS), ferric reducing antioxidant power (FRAP), cupric reducing antioxidant capacity (CUPRAC), metal chelating and phosphomolybdenum) and enzyme inhibition (cholinesterases, tyrosinase, ?-amylase, and ?-glucosidase) potentials of the different Consolida methanolic extracts were evaluated. The UHPLC-QTOF profiling revealed 492 compounds, being 236 flavonoids, 93 phenolic acids, 78 tyrosol derivatives, 49 diterpene alkaloids, 29 lignans, and 7 stilbenes. The cumulative phenolic content ranged from 17.65 mg Eq./g for C. staminosa up to 43.04 mg Eq./g for C. glandulosa, whilst the total diterpene alkaloids content was exclusively found in C. glandulosa extracts (3.53 mg Eq./g). Consolida regalis (58. 61 mg trolox equivalent (TE)/g for DPPH and 65.38 mg TE/g for ABTS) and C. stenocarpa (46.81 mg TE/g for DPPH and 78.12 mg TE/g for ABTS) exhibited the highest anti-radical abilities, while the best reducing power values were recorded for C. glandulosa (129.46 mg TE/g for CUPRAC and 77.01 mg TE/g for FRAP) and C. raveyi (124.56 mg TE/g for CUPRAC and 78.36 mg TE/g for FRAP). Also, following the cholinesterases inhibition assays, C. hellospontica and C. glandulosa exhibited the highest inhibitory effects. Regarding tyrosinase inhibitory effects, C. raveyi showed the highest value, being 126.60 mg kojic acid equivalent (KAE)/g, followed by C. glandulosa (125.82 mg KAE/g) and C. stenocarpa (123.09 mg KAE/g). Besides, Consolida staminosa showed potential inhibition against ?-amylase, but low glucosidase inhibitory properties. Therefore, the present findings could provide a starting point for further investigations to promote the industrial exploitation of these species with the aim of designing novel phyto-pharmaceuticals.
Anchusa Azurea var. Kurdica köklerinin farklı özütlerinin yaygın Kronik hastalıkların tedavisinde Kullanım potansiyellerinin belirlenmesi
(Aksaray Üniversitesi, 2024) Abdulqadir, Ako Hamasaeed; Şen, İsmail; Zengin, Gökhan; Çakmak, Yavuz Selim
Günümüzde yaygın olarak görülen bazı kronik hastalıkların hala bilinen bir tedavisi yoktur. Bu nedenle bu hastalıkların tedavisi için yöntem ve ilaç geliştirme çalışmaları devam etmektedir. Sentetik ilaçlar tedavide başarılı bir şekilde kullanılsa bile, bazı yan etkileri nedeniyle bu ilaç geliştirme çalışmalarında doğal ürünlerin tercih edilmesi giderek yaygınlaşmaktadır. Bu çalışma Anchusa azurea var. kurdica köklerinin antioksidan ve enzim inhibisyon aktivitelerinin belirlenerek bitkinin diyabet, Alzheimer ve kanser gibi hastalıkların tedavisinde kullanılabilme potansiyelinin ortaya konulmasına odaklanmıştır. Burada kök kısımlarından farklı çözücüler ile elde edilen özütlerinin antioksidan aktiviteleri serbest radikal giderme aktivitesi (DPPH, ABTS), FRAP, CUPRAC, fosfomolibdat ve metal şelatlama aktivite testleri ile belirlenmiştir. Enzim inhibisyon aktiviteleri kolinesteraz (asetil ve bütiril), ?-amilaz, ?-glukozidaz ve tirozinaz enzimleri için araştırılmıştır. Ayrıca özütlerin toplam fenolik ve flavonoid içerikleri yanında fenolik bileşimleri de belirlenmiştir. Antioksidan aktivite testlerinde genel olarak metanol özütü diğerlerine kıyasla yüksek aktivite gösterirken, enzim inhibisyonunda etil asetat özütü daha aktif bulunmuştur. Metanol ekstraktındaki toplam fenolik içerik 22,12 mg GAE/g ekstrakt olarak bulunurken, flavonoid içeriği tüm ekstraktlarda oldukça düşük seviyelerde bulunmuştur. Özütlerin fenolik bileşimlerinde kuersetin ve rosmarinik asit yüksek oranda bulunan fenolik bileşenler olmuştur. Elde edilen verilere göre A. azurea var. kurdica kök özütleri iyi düzeyde antioksidan ve enzim inhibisyon aktivitesi göstermiştir. Sonuçlar bitkinin kronik hastalıklarının tedavisine yönelik ilaç geliştirme çalışmalarında hammadde olarak kullanım potansiyelinin yüksek olduğunu göstermiştir
Antibacterial, antioxidant, and angiotensin-I converting enzyme inhibition effects of margotia gummifera extracts rich in phenolic compounds
(2022) Bouchekrit, Moufida; Laouer, Hocine; Çakmak, Yavuz Selim; Hajji, Mohamed; Boutellaa, Saber; Nasri, Moncef; Akkal, Salah
Aromatic and medicinal plants have been used to substitute synthetic drugs with natural bioactive products. Objective: The current investigation was conducted to evaluate phenol and flavonoid contents, antibacterial, antioxidant, and anti-hypertensive potentials of three extracts of Margotia gummifera aerial parts. Methods: The antibacterial effect was assessed using the wells agar diffusion method against 11 strains. The antioxidant effect was evaluated using different methods, 2, 2-diphenyl-1-picrylhy-drazyl, total antioxidant capacity, ferric reducing ability power, cupric reducing antioxidant capaci-ty, and ?-carotene/linoleic acid bleaching assay. The anti-hypertensive activity was performed using hippuryl-histidyl-leucine substrates. Results: The highest yield, i.e., 19.801%, was obtained by the hydro-methanolic extract. However, ethyl acetate extract seemed to be rich in phenolic and flavonoid compounds compared to other ex-tracts, i.e., 822.14±69.10 mg GAE g-1 ext. and 117.28±1.80 mg RE g-1 ext., respectively. The high free radical scavenging activity was mentioned in ethyl acetate extract with IC50 of 48.820±1.25 ?g/ml. The same extract showed better antioxidant activity in all tested procedures. In antibacterial activity, the hydro-methanolic extract exhibited moderate effect against all tested bacteria except Salmonella enterica and Enterococcus faecalis which gave 18±2.0 and 16±1.0 mm of inhibition, whereas it seemed to be inactive towards two Gram-negative bacteria. Concerning anti-hyperten-sive activity, all extracts can inhibit the Angiotensin-I Converting Enzyme, but the potential effect was given by hydro-methanolic and aqueous extracts, 97.75% and 96.65%, respectively. Conclusion: It can be stated that the bioactive compounds of Margotia gummifera extracts had different biological activities, which confirm their therapeutic uses in traditional medicine.
Antimicrobial and antioxidant properties of Ceriodaphnia quadrangula ephippia chitosan
(Editura Ars Docendi, 2016) Aşan Özüsağlam Meltem; Çakmak, Yavuz Selim; Kaya, Murat; Erdoğan, Sevil; Baran, Talat; Menteş, Ayfer; Saman, İhsan
The chitosan from ephippia of Ceriodaphnia quadrangula (Crustaceae) has been fully characterized in our previous study, and in this work it was tested for antibacterial and antifungal activities against human and fish pathogens, while also determining its antioxidant activities. Using the disc diffusion method showed that the antimicrobial activity was observed against all tested microorganisms in the range of 12.84 - 16.28 mm.The minimal bactericidal concentration (MBC) value was found to be 0.63 - 2.50 mg/ml. Chitosan obtained from C. quadrangula ephippia showed higher antimicrobial activity against some pathogenic bacteria than commercial antibiotics. While chitosan inhibited 35.83% of the 1,1-diphenyl-2-picrylhydrazyl radicals (at 5 mg/ml), it showed an activity of 14.48 µg/ml for ferrous ion reducing. Consequently, it is suggested that chitosan obtained from the ephippia of C. quadrangula (Crustacea) can be used as food/feed additives, preservatives or in the pharmaceutical industry instead of using synthetic antimicrobials and antioxidants. © 2016 University of Bucharest.
Antioxidant activity and biochemical screening of two glycyrrhiza l. Species
(Sciencedomain Int, 2016) Çakmak, Yavuz Selim; Aktümsek, Abdurrahman; Duran, Ahmet; Çetin, Özlem
faunistic survey carried out in Turkey.
Antioxidant potentials and anticholinesterase activities of methanolic and aqueous extracts of three endemic Centaurea L. species
(Pergamon-Elsevier Science Ltd, 2013) Aktümsek, Abdurrahman; Zengin, Gökhan; Güler, Gokalp Özmen; Çakmak, Yavuz Selim; Duran, Ahmet
The methanol and aqueous extracts of three endemic Centaurea species (C. polypodiifolia var. pseudobehen, C pyrrhoblephara and C antalyense) were investigated for their antioxidant and cholinesterase inhibitory activities. The antioxidant activities of these extracts were evaluated by in vitro models including, phosphomolybdenum assay, free radical scavenging assays (DPPH and ABTS), beta-carotene/linoleic acid test system, metal chelating assay, FRAP assay, ferric and cupric reducing power. Cholinesterase inhibitory activities were examined using Ellman's calorimetric method. Total phenol, flavonoid, and saponin contents were also measured. Among the six Centaurea extracts evaluated, the highest antioxidant abilities were obtained from C polypodiifolia var. pseudobehen. Methanolic extracts from C polypodiifolia var. pseudobehen and C antalyense had a noticeable inhibition towards AChE and BChE. These findings suggest that Centaurea species could be an anticholinesterase agent and antioxidant resource in some industries, such as food, pharmacology, and cosmetics. (C) 2013 Elsevier Ltd. All rights reserved.
Antioxidative and antimicrobial edible chitosan films blended with stem, leaf and seed extracts of Pistacia terebinthus for active food packaging
(Royal Soc Chemistry, 2018) Kaya, Murat; Khadem, Sanaz; Çakmak, Yavuz Selim; Mujtaba, Muhammad; İlk, Sedef; Akyüz, Lalehan; Salaberria, Asier M.; Labidi, Jalel; Abdulqadir, Ako Hamasaeed; Deligöz, Engin
Methanol extracts of stem, leaf, and seed obtained from Pistacia terebinthus which are rich in phenolic compounds were used for the first time to produce chitosan-based antioxidative and antimicrobial films. All the produced films were characterized by FT-IR, TGA, DSC, SEM, contact angle measurements, and UV-Vis spectroscopy and mechanically. As was expected, incorporation of the plant extracts into chitosan films enhanced the antioxidant and antimicrobial activities effectively. Also, the elasticity of chitosan-seed and chitosan-stem films was improved. The eco-friendly nature of the produced blend films was determined through soil and water degradation analyses. All these findings lead to the conclusion that the produced blend films with Pistacia terebinthus extracts can be applied as alternative food packaging material.
Antioxidative, antimicrobial and cytotoxic properties of Isatis floribunda Boiss. ex Bornm. extracts
(2013) Karakoca, Kübra; Aşan Özüsağlam, Meltem; Çakmak, Yavuz Selim; Erkul, Seher Karaman
The Isatis species has antibacterial, anticancer and antiviral properties and these important endemic plants grow widely in various parts of Anatolian-Turkey. In the present study, the antioxidant activities of Isatis floribunda Boiss. ex Bornm. flower and root extracts were determined with total antioxidant activity, free radical scavenging activity, ferric ion reducing power, and cupric ion reducing antioxidant capacity assay. The total phenolic compounds and flavonoids were also examined for the extracts. The antimicrobial activities of the extracts were investigated by using the disc diffusion and microdilution-broth methods against human and fish pathogen microorganisms. The phenolic composition of I. floribunda root methanolic extract was analyzed by high performance liquid chromatography (HPLC). The major component in the extract was cholorogenic acid (1980.20 µg/g). The cytotoxic effect of the methanolic root extract was also tested on human breast cell (MCF12A). The results showed that I. floribunda could be used as a natural source in the food and feed industry and clinical and food chemistry, and that the antimicrobial agents could be used against human and fish pathogens.
Assessing Algerian Ilex aquifolium L.’s phenolic compounds, antioxidant and enzyme inhibitory properties to find a new natural remedy for Alzheimer’s, diabetes and skin diseases
(Taylor & Francis, 2024) Hadroug, Aldjia; Zengin, Gökhan; Belhattab, Rachid; Çakmak, Yavuz Selim
This research explored the impact of methanolic extracts from the fruits and leaves of Ilex aquifolium L., a rare Algerian species, on several enzymes, focusing on tyrosinase, ?-amylase, ?-glucosidase, and cholinesterases, as well as their antioxidant potential in vitro assays, including phosphomolybdenum, DPPH, ABTS, CUPRAC, FRAP, and MCA. HPLC-DAD analysis identified chlorogenic acid, rosmarinic acid, hesperidin, and quercetin as predominant phenolic components. Both extracts exhibited notable antioxidant properties, up to 250.08?mg TE/g for fruits and 237.08?mg TE/g for leaf extracts. Enzyme inhibitory assays demonstrated significant inhibition against AChE and BChE with maximum activities of 2.34?mg GALAE/g in leaves and 4.32?mg GALAE/g in fruits. Additionally, considerable tyrosinase inhibition was observed in leaves at 39.69?mg KAE/g. These findings highlight I. aquifolium L. as a valuable source for investigating natural antioxidants and enzyme inhibitors, particularly for possible cosmetics and food additives applications.
Characterization of chitosan-Based films with different aniseed oil content
(Sivas Cumhuriyet Üniversites, 2018) Akyüz Yılmaz, Bahar; Akyüz, Lalehan; Çakmak, Yavuz Selim; Karaman Erkul, Seher; Sargın, İdris; Koç, Behlül
This paper reports the findings of a study describing the production of chitosan-based edible films incorporated with different amount of Pimpinella anisum seed oil. The chitosan-aniseed oil (CAO) composite films (CS, CAO-0.5, CAO-1, and CAO-2) were characterized with FT-IR and DSC and their mechanical, optical transmittance, hydrophobicity and anti-oxidative properties were also investigated. With the increasing concentration of aniseed oil in the films, a continuous decrease was observed in tensile strength and Young’s modulus. Optical transmittance of chitosan-aniseed oil composite films in the UV-Visible region was lower than that of chitosan control film (without aniseed oil). Incorporation of aniseed oil into chitosan films enhanced antioxidant activity of films. The results suggested that chitosan-aniseed oil composite films can be used as a food packaging material.
Comparison of fatty acid compositions and ?3/?6 ratios of wild brown trout and cultured rainbow trout
(Central Fisheries Research Institute of Turkey and Japan International Cooperation Agency (JICA), 2017) Güler, Gökalp Özmen; Zengin, Gökhan; Çakmak, Yavuz Selim; Aktümsek, Abdurrahman
Fish are a unique dietary source beneficial to human health. These valuable effects originate from omega 3 polyunsaturated fatty acids, particularly the eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in the fish oil. In this study, fatty acid composition of the muscle lipids of Salmo trutta macrostigma (wild brown trout) and Oncorhynchus mykiss (cultured rainbow trout) in Gezende Dam Lake were determined by gas chromatographic technique. In both species, palmitic acid (16.26-18.94%), oleic acid (17.88-20.49%) and DHA (14.08-18.49%) were identified as major saturated fatty acid (SFA), monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA), respectively. Wild fish contained significantly more linolenic acid, arachidonic acid, eicosapentaenoic acid, docosapentaenoic acid, total omega 3 fatty acids and has higher omega 3/omega 6 ratio than cultured fish. In conclusion, wild brown trout may have a higher nutritional value considering total omega 3 fatty acids (35.52-27.43%) and omega 3/omega 6 ratio (3.84-1.56) compared to cultured rainbow trout.
Contribution to pharmacological valorisation of Algerian arctium minus (Hill) bernh. subsp. atlanticum (Pomel) maire; antioxidant and acetylcholinesterase inhibitory activities
(Bentham Science Publishers, 2022) Guettaf, Sofiane; Benmerzoug, Abdelmoumen; Chawki, Bensouici; Çakmak, Yavuz Selim; Dahamna, Saliha; Baghiani, Abderrahmane; Harzallah, Daoud
The traditional pharmacopoeia is full of potential resources for molecules with therapeutic effects involving the inhibition of enzymes linked to some diseases. Objective: This work aimed to test in vitro neuroprotective activity against Alzheimer's disease (AD) combined with the antioxidant effect of root extracts obtained by water, water/methanol, and ethyl acetate of the endemic Arctium minus. subsp. Atlanticum, a native of Algeria. Methods: The different extracts of the root of the studied plant were obtained by decoction or maceration. The inhibitory effect of acetyl/butyrylcholinesterase (AChE/BChE) was achieved by a colorimetric method. Similarly, the antioxidant activity was measured based on several mechanisms: 1, 1diphenyl-2-picryl-hydrazyl (DPPH) and galvinoxyl (GOR) radicals free scavenging assays, ?-carotene bleaching inhibition activity, and cupric ion reducing antioxidant capacity (CUPRAC). Results: In the various tests carried out, the ethyl acetate extract (EAE) possessed the most powerful antioxidant and anticholinesterase activities compared to the other samples. The IC50 and A0.5 values of DPPH, GOR, ?-carotene, CUPRAC, anti-AChE, and anti-BChE assays were 69.45±5.49, 28.87±0.18, 121.58±16.76, 37.41±1.59, 265±21, and 240±6.3 µg / mL, respectively. Likewise, a correlation could be deduced between the type of extract and the potent antioxidant/anticholinesterase potential. Conclusion: This work examines for the first time the anticholinesterase potential combined with the antioxidant effect of Algerian Arctium minus. subsp. atlanticum. This association between the two effects could be effective in the fight against AD, and therefore, the use of this natural resource may be possible in combating this aspect of neurodegeneration.
Conversion of waste parasitic insect (Hylobius abietis L.) into antioxidative, antimicrobial and biodegradable films
(Tech Science Press, 2019) Kaya, Murat; Sargın, İdris; Mulercikas, Povilas; Labidi, Jalel; Salaberria, Asier Martinez; Çakmak, Yavuz Selim; Kazlauskaite, Sonata; Erdönmez, Demet; Baublys, Vykintas
Hylobius abietis is a plant parasitic insect belonging to the order Coleoptera and which causes severe damages to coniferous forests in Northern and Eastern Europe. This current study is aimed to provide a new viewpoint into the waste of this insect by producing chitosan. Dry insect corpses consisted of 27.9% chitin and 86.2% of the chitin was converted into the chitosan. FT-IR spectra analyses confirmed the purity and the deacetylation degree of the produced chitosan (molecular weight of chitosan; 7.3 kDa). This chitosan exhibited antimicrobial activity against 18 bacterial strains. Further, biodegradable chitosan composite films with beta-carotene were produced. Antioxidant activity of chitosan films were found to be higher than chitosan gels; and beta-carotene incorporation further increased the antioxidative properties of the chitosan films. This study demonstrated that the waste of parasitic insect like H. abietis can be evaluated as a source for production of biodegradable and edible chitosan-based films for applications in food coating.
Diatomite as a novel composite ingredient for chitosan film with enhanced physicochemical properties
(Elsevıer Scıence Bv, 2017) Akyüz, Lalehan; Kaya, Murat; Koç, Behlül; Mujtaba, Muhammad; İlk, Sedef; Labidi, Jalel; Salaberria, Asier M.; Çakmak, Yavuz Selim
Practical applications of biopolymers in different industries are gaining considerable increase day by day. But still, these biopolymers lack important properties in order to meet the industrial demands. In the same regard, in the current study, chitosan composite films are produced by incorporating diatomite soil at two different concentrations. In order to obtain a homogeneous film, glutaraldehyde was supplemented to chitosan solution as a cross-linker. Compositing diatomaceous earth to chitosan film resulted in improvement of various important physicochemical properties compared to control such as; enhanced film wettability, increase elongation at break and improved thermal stability (264-277 degrees C). The microstructure of the film was observed to haveconsisted of homogeneously distributed blister-shaped structures arised due to the incorporation of diatomite. The incorporation of diatomite did not influence the overall antioxidant activity of the composite films, which can be ascribe to the difficulty radicals formation. Chitosan film incorporated with increasing fraction of diatomite revealed a notable enhancement in the antimicrobial activity. Additionally with the present study, for the first time possible interactions between chitosan/diatomite were determined via quantum chemical calculations. Current study will be helpful in giving a new biotechnological perspective to diatom in terms of its successful application in hydrophobic composite film production. (C) 2017 Elsevier B.V. All rights reserved.
Effect of different animal fat and plant oil additives on physicochemical, mechanical, antimicrobial and antioxidant properties of chitosan films
(Elsevier, 2018) Akyüz, Lalehan; Kaya, Murat; İlk, Sedef; Çakmak, Yavuz Selim; Salaberria, Asier M.; Labidi, Jalel; Akyüz Yılmaz, Bahar; Sargın, İdris
Practical application of chitosan-essential oil blend films is limited due to the uneconomical extraction procedure of essential oils from plants. This study aimed to produce chitosan films blended with low cost and commercially available oils and fats consumed in daily human diet (olive, corn and sunflower oils, butter and animal fats). The study also focused on how physicochemical, biological and mechanical properties of chitosan blend films were influenced by the incorporation of oils and fats with varying unsaturation degrees. Possible interactions of chitosan film matrix with incorporated oils or fats were investigated. Chitosan-olive oil film showed better surface morphology and higher thermal stability than the films with other unsaturated oils. Tensile strength, Young's modulus and elongation at break were improved by 57.2%, 25.1% and 31.7% for chitosan-olive oil film, respectively. Chitosan-olive oil blend film had the highest antibacterial activity (almost equal to that of commercial antibiotic gentamicin). Edible films obtained from by incorporation of natural oils and fats into chitosan can help produce an environmentally friendly packaging material that is low cost and easily manufactured. (C) 2018 Elsevier B.V. All rights reserved.
Evaluation of antioxidant potential of two Daphne species (D. gnidioides and D. pontica) from Turkey
(United Arab Emirates University, 2015) Sanda, Murat Aydın; Zengin, Gökhan; Aktümsek, Abdurrahman; Çakmak, Yavuz Selim
Daphne species have been used traditionally for treatment of several ailments including rheumatism, abscess and diarrhoea. Purpose of present study was to evaluate antioxidant activities of methanol and water extracts of Daphne parts (roots, stems and leaves). Different experimental models including phosphomolydenum, DPPH, ?-carotene/linoleic acid, ferric and cupric reducing power assays were performed to characterize the antioxidant potentials of the extracts. Folin-Ciocalteu and AlCl3 methods were also used to quantify total phenolic and ? avonoid content, respectively. D. pontica leaf extract showed high phenolic contents (123.09 mgGAEg-1 in methanol and 146.94 mgGAEg-1 in water extract) therefore has the strongest antioxidant potential. Present study showed that Daphne extracts (D. gnidioides and D. pontica) can be considered as good sources of natural antioxidants for medicinal and food applications.
Evaluation of fatty acid compositions of yogurts in Turkey
(Chemical Publishing Company, 2014) Çağlayan, Okan; Çakmak, Yavuz Selim; Güler, Gökalp Özmen; Zengin, Gökhan; Aktümsek, Abdurrahman
In this study, fatty acid composition and conjugated linoleic acid content of some yogurts in Turkey were determined. Total 50 yogurt samples belonging to 16 different national yogurt brands were analyzed by using GC. These samples categorized as whole yogurts, light yogurts, probiotic yogurts and fruity yogurts. Generally, palmitic acid (28.840-30.160 %), oleic acid (26.003-27.533 %) and stearic acid (11.413-12.077 %) were major fatty acids. Total conjugated linoleic acid percentages varied between 0.790 and 0.862 %. The results have shown that fatty acids compositions of yogurts have a desirable characteristic for healthy diet when their levels of conjugated linoleic acid contents are considered.
Extraction and characterization of chitin and chitosan with antimicrobial and antioxidant activities from cosmopolitan Orthoptera species (Insecta)
(Korean Soc Biotechnology & Bioengineering, 2015) Kaya, Murat; Baran, Talat; Aşan Özüsağlam, Meltem; Çakmak, Yavuz Selim; Tozak, Kabil Özcan; Mol, Abbas; Menteş, Ayfer; Sezen, Göksal
This study examined two gregarious Orthoptera species (Calliptamus barbarus and Oedaleus decorus) as potential sources of chitin. The chitin content of the dry weight of C. barbarus was 20.5 +/- 0.7%, and it was 16.5 +/- 0.7% for O. decorus. Furthermore, the yield of chitosan (70 - 75% deacetylation degree) from the grasshopper species was found to be 74 - 76%, which is close to the yield of commercial preparations obtained from the unused parts of crabs and shrimp. The chitin and chitosan obtained in this way were analyzed using FTIR, TGA, XRD and SEM techniques, and the antimicrobial properties of chitosans obtained from C. barbarus and O. decorus against pathogenic microorganisms of humans and fish were investigated using the disc diffusion and microdilution broth methods. The antimicrobial screening procedures indicated that the chitosan showed significant antimicrobial activity against all of the tested pathogenic microorganisms. The MBC or MFC values were determined to be 0.16 - 2.50 mg/mL. The IC50 values for the chitins obtained from C. barbarus and O. decorus were 10.68 +/- 0.27 and 10.91 +/- 0.96 mg/mL, respectively, which were greater than the value for butylated hydroxytoluene (BHT): 0.04 +/- 0.01 mg/mL. These results suggest that these two species, which are currently considered to be pests because of over-breeding, are potentially alternative sources of chitin and chitosan, which are used in the food/feed industry for their antimicrobial and antioxidant properties.

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