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Öğe Benzoic acid formation and its relationship with microbial properties in traditional Turkish cheese varieties(Elsevier, 2021) Yerlikaya, Oktay; Gucer, Leyla; Akan, Ecem; Meric, Saban; Aydin, Emel; Kinik, OzerBenzoic acid, the simplest member of the aromatic carboxylic acid family, is a weak acid that is a precursor to the synthesis of many important organic compounds. In addition to being used to prevent microbial spoilage in foods, it can also form due to different factors in foods. Hippuric acid found in the natural content of milk can be converted into benzoic acid naturally and can be found in different levels in dairy products. The present study aimed to determine the naturally-forming benzoic acid values in fresh and ripened traditional type cheese varieties and to determine the effect of some physicochemical and microbiological changes of cheeses on the amount of benzoic acid. In this research, benzoic acid levels of six different cheese types (White pickled cheese (traditional-industrial), Tulum cheese (canned or goat skin-packed), and Kashar cheese (fresh and ripened)) were determined. As a result of the analysis performed by HPLC, the amount of benzoic acid in cheese samples varied between 5.95 and 55.72 mg/kg, and it was determined that the microbiota of cheese significantly affected the formation of benzoic acid (p < 0.05). Especially, a lower benzoic acid level was observed in fresh Kashar and industrial White pickled cheeses with short shelf life, whereas a higher shelf-life was observed in cheese types such as ripened traditional White pickled and skin-packed Tulum cheese (p < 0.05). Although there is a difference according to the cheese types, especially between hippuric acid content and changes in pH, and Lactococcus and Enterococcus, a correlation was found between benzoic acid content and yeast-molds changes.Öğe Changes in benzoic acid content of goat milk kefir produced using different kefir cultures(Croatian Dairy Union, 2021) Sendogan, Gizem; Akan, Ecem; Yerlikaya, Oktay; Meric, Saban; Kinik, OzerIn this study, the content of hippuric and benzoic acid of goat milk kefir produced with commercial lyophilized kefir cultures and kefir grain was investigated. 9 commercial kefir culture and 1 kefir grain were used in production of goat milk kefir. Based on the obtained results, hippuric acid was not found in kefir samples during the storage period, whereas goat milk samples contained hippuric acid (14.8 mg/kg). Benzoic acid levels of kefir samples ranged from 8.5 to 26.6 mg/kg during the 28-day storage period. The highest Lactobacillus and Lactococcus counts were observed in kefir sample produced with kefir grain while this sample was one of the sample containing the lowest (11.2 mg/kg) benzoic acid levels. in conclusion, the research results showed that starter kefir cultures and microbiota used in kefir production and storage period had a significant effect on the formation of benzoic acid levels (p<0.05).Öğe Comparative biological evaluation and identification of multifunctional endogenous and exogenous bioactive peptides in different matured Izmir Tulum cheeses(Elsevier Sci Ltd, 2024) Akan, Ecem; Tok, Kerem; Kocazorbaz, Ebru Kocadag; Zihnioglu, Figen; Yerlikaya, Oktay; Hayaloglu, Ali Adnan; Kinik, OzerBioactive peptides redefine health and disease by triggering unique biological functions in the body. The aim of this study was to evaluate and identify the endogenous and exogenous peptides (in vitro gastrointestinal digestion) of 360-day ripened Izmir Tulum cheese manufactured using cow, sheep, and goat milk. Peptide extracts from Izmir Tulum cheeses were found to have DPP-IV inhibitory, deglycation, antioxidant, metal chelating, and ACE-inhibitory activity. After the activity guided purification of peptide extracts were performed by HPLC, 8 peptide fractions were selected according to their biological activity, and the peptide sequence of each peptide were identified by mass spectrometry. It was observed that the use of different types of milk in the manufacture of Izmir Tulum cheese affects peptide diversity, that endogenous and exogenous peptides had a wide range of potential biological activities, and that new bioactive peptides were obtained from Izmir Tulum cheese. The potential peptide sequences obtained from the identified fractions ETFHPLKHQ, EVVPGPFPQ, and TLGLHTPK are the first peptide sequences that do not overlap with sequences published in the literature. In conclusion, these endogenous and exogenous peptides of Izmir Tulum cheeses have significant biological activities associated with type 2 diabetes, deglycation, antioxidants, and metal chelating agents to support the immune system, and ACEinhibitory effects to treat hypertension. These new peptides could open a new avenue for the noval peptide-based drug and contribute to therapeutic applications.Öğe The effect of aqueous extracts of some plants on in vitro antioxidant and antidiabetic activity of probiotic yogurt(Springer India, 2022) Akan, Ecem; Yerlikaya, Oktay; Bayram, Ozge Yildiz; Kinik, OzerIn this study, aqueous extracts of some medicinal and aromatic plants (garlic, Turkish Oregano, rosemary, basil, and peppermint) were used in probiotic yogurt production to increase functionality of probiotic yogurt. The in vitro antidiabetic, antioxidant activity, total phenolic compound content and phenolic compounds of yogurts were evaluated during the 28 day of storage period. Yogurt sample with Turkish Oregano had the highest alpha-amylase and alpha-glucosidase inhibitory activity. A strong correlation was found between total phenolic compound content and antioxidant activity (r = 0.84) and between total phenolic compounds content and alpha-amylase inhibitory activity (r = 0.82). In conclusion, it can be said that the total phenolic compound content and in vitro antioxidant and antidiabetic activities of probiotic yogurt could be increased by adding aqueous extracts of some plants.Öğe Effect of food matrix and fermentation on angiotensin-converting enzyme inhibitory activity and ?-glucan release after in vitro digestion in oat-based products(Elsevier, 2023) Akan, Ecem; Karakaya, Sibel; Ozkacar, Merve Eda Eker; Kinik, OzerThe aim of this study was to determine the effects of fermentation and food matrix on the ACE inhibitory ac-tivities of the peptides obtained after in vitro gastrointestinal digestion, protein profiles (SDS-PAGE) and beta-glucan amounts of oat products. Furthermore, the physicochemical and microbiological properties of fermented oat drinks and oat yogurt-like product obtained from oat fermentation were evaluated. Oat grains were mixed with a certain ratio of water 1:3 w/v (oat:water, yogurt consistency) and 1:5 w/v (oat:water, drink consistency), and this mixture was fermented with yogurt culture and probiotic Lactobacillus plantarum and fermented drinks and yogurt were produced. The results indicated that the fermented oat drink and the oat yogurt-like product had L. plantarum viability over 107 cfu/g. After the in vitro gastrointestinal digestion of the samples, the hydrolysis levels ranged from 57.70 % to 82.06 %. The hydrolysis level of the samples with fermented-drink consistency was significantly higher than the samples with yogurt consistency (p < 0.05). The SDS-PAGE profiles of the non -digested samples showed that the bands had molecular weights of 12-15 kDa and around 35 kDa. Bands whose molecular weights were around 35 kDA disappeared after gastric digestion. ACE inhibitory activities of the fractions composed of molecular weights of 2 kDa and 2-5 kDa obtained after in vitro gastrointestinal digestion of the oat samples were in the range of 46.93-65.91 %. The effect of fermentation on the ACE inhibitory activities of the peptide mixture with molecular weights between 2 and 5 kDa was not statistically significant, however, fermentation caused an increase in the ACE inhibitory activities of the peptide mixture with a molecular weight<2 kDa (p < 0.05). The beta-glucan amounts of fermented and non-fermented oat products were in the range of 0.57-1.28 %. The beta-glucan amounts detected after gastric digestion decreased considerably and beta-glucan could not be detected in the supernatant after gastrointestinal digestion. This indicated that beta-glucan did not solubilize in the supernatant (bioaccessible) and remained in the pellet. In conclusion, fermentation is a valuable process for releasing peptides with moderately high ACE inhibitory effects from the parent oat proteins.Öğe Effect of mineral salt replacement on properties of Turkish White cheese(Croatian Dairy Union, 2018) Akan, Ecem; Kinik, OzerIn this study, combinations of different mineral salt replacement for sodium chloride were used in Turkish White cheese production. The effect of sodium chloride substitutes on the physical, chemical and textural characteristics of cheese samples was examined. Five types of brine solution including NaCl only (K: control) (16 % w/w), only 50 % NaCl (L) (8 % w/w), 30 % CaCl2 and 70 % NaCl (M) (16 % w/w), 30% KCl and 70 % NaCl (N) (16% w/w), and PanSalt (P) (16 % w/w) were used in cheese production. PanSalt (57 % NaCl + 28 % KCl + 12 % MgSO4) is a commercial salt with low sodium content. The characteristics of cheeses determined within the study included the total dry matter, ash, protein, fat, salt, titratable acidity, pH values, percentage of water soluble nitrogen, percentage of trichloroacetic acid soluble nitrogen and proteose-pepton nitrogen; the sodium, calcium, potassium, phosphorus and magnesium content and the textural characteristics (via a texture profile analysis). In comparison to the control cheese, this substitution showed no significant effect on the comprehensive parameters evaluated. The Na, K, Ca and P content showed important differences among the cheese samples. The total sodium content of L, M, N and P samples decreased significantly. In regard to this research results it can be said that it is possible to produce low sodium cheese with using proper quantity of mineral salt replacers.Öğe The effect of packaging materials on physicochemical, microbiological, and sensorial properties of Turkish whey (Lor) cheese with some plants(Wiley, 2022) Akpinar, Asli; Yerlikaya, Oktay; Akan, Ecem; Karagozlu, Cem; Kinik, Ozer; Uysal, Harun RasitIn this study, 2% black cumin, 1% black cumin (Nigella damascena L-Damascus black cumin), 1% rosemary (Rosemarinus officinalis), and 1% black cumin and 1% thyme (Origanum onites L.-Izmir thyme) were added to whey cheese with a short shelf life and cheese samples stored in different packaging materials (goat-skin bags and artificial casing). pH levels and titratable acidity, degree of proteolysis, microbiological, and sensory attributes of the samples were examined. In 20 days of storage, the pH values of whey cheese with black cumin stored in goat-skin bags were statistically higher (ranged 6.34-5.30) than other samples (ranged 6.32-4.10). Proteolytic activity values were higher (0.34-0.58 mg/ml serine) in cheese samples containing black cumin and thyme in both packaging materials (p < .05). After 30 days of storage, black cumin and thyme-added cheese packaged in goat-skin bags have the highest Lactobacillus spp. count (8.64 log CFU/g), while cheese containing black cumin and thyme (6.32 log CFU/g) filled into an artificial casing has the least. Based on the results of sensory analysis, the samples containing black cumin were generally more preferred while cheese with rosemary had the lowest sensory scores. In conclusion, the difference in packaging materials has a significant effect on the physicochemical and microbiology properties and proteolytic activity of whey cheese produced by adding different plants. However, the sensory properties of whey cheese are influenced by the plants used rather than the differences in packaging materials. Novelty impact statement Turkish whey (Lor) cheese is food with limited storage time and rapid microbial spoilage. Black cumin, rosemary, and thyme were added to whey cheese. Black cumin, rosemary, and thyme have been added to whey cheese and this limited storage period has been tried to be extended. In addition, the effects of goat-skin and artificial casing packages on physicochemical and sensory properties were investigated.Öğe EFFECT OF SOME PRO AND PREBIOTICS ON FATTY ACID AND ORGANIC ACID COMPOSITION OF SYMBIOTIC GOAT CHEESE(North Univ Center Baia Mare, 2018) Kesenkas, Harun; Ergonul, Pelin Gunc; Akan, Ecem; Kinik, OzerThe effects of probiotic cultures including Enterococcus faecium, Bifidobacterium bifidum, Lactobacillus paracasei subsp. paracasei and prebiotics including inulin, oligofructose and their blends on fatty acid and organic acid compositions of goat-milk white cheese were examined throughout 90-day storage period. Goat-milk cheeses were produced in an industrial plant following the standard production procedure for white cheeses, with some modifications. The highest value of saturated and unsaturated fatty acids in experimental cheeses were found be palmitic acid (C16) and oleic acid (C18: 1) respectively. The most abundant organic acid among all experimental samples was lactic acid whereas the lowest one was acetic acid. The results indicated that the probiotic culture type and the percentage of prebiotic added to goat milk effected fatty and organic acid contents of goat-milk white cheeses at different levels.Öğe Effect of Supplementation with Green and Black Tea on Microbiological Characteristics, Antimicrobial and Antioxidant Activities of Drinking Yoghurt(Ankara Univ, Fac Agr, 2018) Unal, Gulfem; Karagozlu, Cem; Kinik, Ozer; Akan, Ecem; Akalin, Ayse SibelThe influence of supplementation with green and black tea on microbiological properties, antimicrobial and antioxidant activities of drinking yoghurt were investigated during 21 days of storage. The samples supplemented with 2% either green or black tea had higher viable counts of both yoghurt starter bacteria than those of infused by the ratio of 4%. Both green and black tea extracts showed antimicrobial activity on E. coil, B. cereus, S. aureus and C. albicans however this effect was detected higher in samples containing green tea. The samples added green tea extract had the highest DPPH scavenging activity when compared to those supplemented with black tea extract throughout the storage. Green tea had a superior effect than black tea in terms of total phenolic content of drinking yoghurt samples.Öğe The effect of using pro and prebiotics on the aromatic compounds, textural and sensorial properties of symbiotic goat cheese(Croatian Dairy Union, 2017) Kinik, Ozer; Kesenkas, Harun; Ergonul, Pelin Gunc; Akan, EcemThe aim of this study was to evaluate the effects of probiotics as an adjunct culture, and the use of inulin and oligofructose as a prebiotic product, on symbiotic goat cheeses during their ripening period. The control group had the lowest value in terms of aromatic compounds, and the probiotics used in the production of cheese increased the aromatic substances. The control group was found to have the highest hardness values and that the use of prebiotics and probiotic cultures in cheese production significantly changed the textural profile depending on the probiotic and prebiotic type. The most favoured cheeses were found to contain E. faecium and oligofructose.Öğe The effect of various herbs and packaging material on antioxidant activity and colour parameters of whey (Lor) cheese(Wiley, 2021) Akan, Ecem; Yerlikaya, Oktay; Akpinar, Asli; Karagozlu, Cem; Kinik, Ozer; Uysal, Harun RasitThis study aimed to research the effects of some herbs and the packaging material on total phenolic compound content and the antioxidant activity of Lor cheeses. The total phenolic content and antioxidant activity of Lor cheeses containing only black cumin were found to be significantly lower than cheeses containing black cumin and rosemary or black cumin and thyme (P < 0.05). 2,2-azino-di-(3-ethylbenzothialozine- sulfonic acid) (ABTS) and Cupric Ion Reducing Antioxidant Capacity (CUPRAC) methods were found to be more reliable than the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method in evaluating the antioxidant activity of herbs added to Lor cheeses. It has been observed that the packaging material effects the antioxidant activity of the samples differently during the storage.Öğe The effects of black and green tea on antioxidant activity and sensory characteristics of kefir(Teknoscienze Publ, 2017) Karagozlu, Cem; Unal, Gulfem; Akalin, A. Sibel; Akan, Ecem; Kinik, OzerThe effects of supplementation with green and black tea on chemical and sensory properties and antioxidant activities of kefir were investigated during 21 days of storage. pH and titrable acidity values were within acceptable levels during 21 days of storage. Total dry matter, fat and lactic acid contents of all samples were in accordance with Turkish Food Codex. The samples containing green tea extract had the highest DPPH center dot scavenging activity compared to those of supplemented with black tea extract throughout the storage. Green tea had a superior effect compared to black tea in terms of total phenolic content of kefir samples. Statistical differences change between parameters kefir samples. CK (control) group received higher scores compared to those in black and green tea groups and they were also appreciated by the panelists during storage. All kefir samples with added black or green tea showed acceptable sensory scores.Öğe Farklı starter kültür kullanımının yoğurtların tekstürel ve viskozite özelliklerine etkisi(2021) Saygılı, Derya; Yerlikaya, Oktay; Akan, Ecem; Kınık, ÖzerAmaç: Yoğurt üretiminde starter kültürler, depolama süresi boyunca üründe önemlidüzeyde tat ve aroma değişimine neden olmadan ürünün raf ömrünü uzatma,viskozite ve tekstürel özelliklerini iyileştirmek, tüketici beklentilerine uygun vestandart yapıda yoğurt üretmek amacıyla kullanılmaktadır. Çalışmanın amacı, farklıticari yoğurt kültürü kullanımının, yoğurtların tekstürel ve viskozite özelliklerine olanetkisini belirlemektedir.Materyal ve Yöntem: Yoğurt üretiminde sütlere herhangi bir koyulaştırma işlemiuygulanmamış, işletmeye alınan çiğ inek sütleri pastörize edilerek yoğurt starterkültürleri ile aşılanmıştır. Çalışmamızda farklı kültür firmalarından temin edilmiş olanon farklı starter kültür kullanılarak on adet farklı yoğurt üretimi gerçekleştirilmiş ve28 günlük depolama süresi boyunca yoğurtların sertlik, iç yapışkanlık, sakızımsılık,çiğnenebilirlik gibi tekstürel özellikleri ile viskozite değerleri incelenmiştir.Araştırma Bulguları: Yoğurt örneklerinin viskozite değerlerinin depolama süresiboyunca 597,33- 1902,33 mPa·s aralığında değişim gösterdiği; sertlik, içyapışkanlık, sakızımsılık ve çiğnenebilirlik minimum ve maksimum değerlerinin isedepolama süresi boyunca sırasıyla 71,83 - 179,67 (g), 0,39 - 0,58, 41,43 - 72,33 (g)ve 1,53 - 10,51 (mJ) şeklinde seyrettiği belirlenmiştir.Sonuç: Sonuç olarak çalışmamızda, yoğurt üretiminde farklı starter kültürkullanımının yoğurdun tekstürel ve viskozite özellikleri üzerine etkisi istatiksel olarakönemli bulunmuştur (p<0,05).Öğe Gıda Üretimi ve Depolanması Sırasında Probiyotiklerin Canlılıklarını Etkileyen Faktörler(2015) Akan, Ecem; Kınık, ÖzerProbiyotik gıdaların vücudun dengesinin ve intestinal floranın doğal yapısının sürdürülmesi, patojenlerin gelişimine karşı direnç gösterme gibi sağlığa pek çok yararı bulunmaktadır. Probiyotik bakterilerin kullanıldığı fonksiyonel gıdalara karşı eğilim tüketicilerin bu gıdaların sağlığa olumlu etkilerinin fark etmeleri sebebiyle giderek artmaktadır. Probiyotiklerin bağırsak mikroflorasını patojenlere karşı koruma, bağışıklık sistemini güçlendirme, serum kolesterol seviyesini ve kan basıncını düşürme, antikarsinojenik etki gösterme, besin maddelerinden faydalanımın ve gıdaların besin değerinin artması gibi çok sayıda sağlığa faydası vardır. Günümüzde probiyotik bakteriler kullanılarak pek çok ürün üretimi gerçekleştirilmektedir. Probiyotiklerin sağlık üzerine olumlu etki gösterebilmesi için ürün tüketimi sırasında yeterli miktarda probiyotik bakterinin gıda ile birlikte vücuda alınması gerekmektedir. Ancak bazen probiyotik bakterilerin kullanıldığı gıdaların tüketimi sırasında vücuda yeterli dozda probiyotik alınamayabilmektedir. Çünkü ürün üretimi ve depolaması sırasında çeşitli faktörler probiyotik bakterilerin hayatta kalmalarını etkilemektedir. Gıdalarda probiyotik varlığı bazen ürün kalitesini ve duyusal özelliklerini olumsuz yönde etkileyebilmektedir. Son yıllarda ürün üretiminden son tüketiciye ulaşana kadar probiyotiklerin canlılıklarının sürdürülmesi için farklı gıdalarda çeşitli uygulamalar yapılmaktadır. Bu uygulamalardan en önemlisi çeşitli koruyucular ilavesiyle üretim ve depolama koşullarının değişimi yoluyla enkapsülasyon tekniği yardımıyla mikroorganizmaların korunmasıdır. Bu makalede probiyotiklerin sağlığa yararlı etkileri, gıdaların üretimi ve depolanmaları sırasında gıdalarda yaşayabilirliklerini etkileyen faktörler, üretim ve depolama sırasında canlılıklarını sürdürmelerine yardımcı olabilecek teknolojik uygulamalar incelenecektirÖğe IMPORTANCE OF DECISION SUPPORT SYSTEMS ABOUT FOOD SAFETY IN RAW MILK PRODUCTION(Pamukkale Univ, 2015) Akan, Ecem; Kinik, OzerIn raw milk production decision support systems for control of food safety hazards has not been developed but main points of this system are available. The decision support systems' elements include data identification at critical points in the milk supply chain, an information management system and data exchange. Decision supports systems has been developed on the basis of these elements. In dairy sector decision support systems are significant for controlling of food safety hazards and preferred by producers. When these systems are implemented in the milk supply chain, it can be prevented unnecessary sampling and analysis. In this article it will be underlined effects of decision support system elements on food safety of raw milk.Öğe Importance of salt in dairy products and sodium reduction strategies in food and dairy products(Teknoscienze Publ, 2017) Akan, Ecem; Yerlikaya, Oktay; Kinik, OzerSalt (sodium chloride, NaCl) is the oldest food additive known used for the enhancement of the sensory properties of the food, extending their shelf-life and maintaining food safety. Although salt is one of the components that is needed for human body to maintain the normal physiological activity, high intake of sodium found in the composition of salt leads especially to heart disease and high blood pressure, and therefore sodium intake is limited. Usually foods contain more sodium than human requirement and table salt, baking powder and baking soda are the richest sources of sodium. The majority of the consumed sodium comes not from the salt added to the food in dining table but from the processed foods. New salt reduction strategies have been developed for many food products including dairy products. In this review, purposes of using salt in food products and salt reduction strategies including the use of salt substitutes were discussed.Öğe The influence of plant addition to some physicochemical, textural, microstructural, melting ability and sensory properties of Mozzarella cheese(Croatian Dairy Union, 2020) Yerlikaya, Oktay; Akan, Ecem; Bayram, Ozge Yildiz; Karaman, Ayse Demet; Kinik, OzerMozzarella cheese is produced by kneading the curd, which has a fibrous structure with melting and elongation properties, in hot water. the present study aimed to investigate the impact of the addition of some plants on certain properties of Mozzarella cheese. Rosemary (Rosmarinus qfficinalis L), basil (Ocimum basilicum L), mint (Mentha piperita L.) and Turkish Oregano (Origanum onites L) were added to Mozzarella cheese at the curd kneading stage, and physicochemical, textural, microstructural, meltability and sensory properties were investigated during the storage period. No plants were added to the control group cheese. Plant addition to Mozzarella cheese affected some physicochemical properties such as pH, acidity, free fatty acids, as well as textural and microstructural properties. Furthermore, it affected sensory properties, especially Turkish Oregano and mint addition provided high general acceptability and taste-aroma scores. While higher pH and lower titration acidity were determined in rosemary-added cheese samples, the lowest free fatty acid (ADV) levels were determined in the mint-added cheese sample. Rosemary-added cheeses had higher hardness and a more even microstructure, while the highest sensory scores were obstained for cheeses that included Turkish Oregano and mint. in conclusion, the present study findings demonstrated that the short shelf life of Mozzarella cheese could be extended with the addition of various plants due to their effects on pH, acidity and free fatty acids.Öğe Influence of Supplementation with Green and Black Tea on Viscosity and Sensory Characteristics of Drinking Yoghurt(2016) Ünal, Gülfem; Karagözlü, Cem; Kınık, Özer; Akan, Ecem; Akalın, Ayşe Sibel…Öğe İzmir Tulum Peyniri Üretiminde Peynir Altı Suyu Kültürü Kullanımı(2020) Tulukoğlu, Gizem Başak; Akan, Ecem; Kınık, ÖzerAmaç: Bu araştırmada farklı inkübasyon sıcaklığında elde edilen peynir altı suyukültürleri ile üretilen İzmir Tulum peynirlerinin fizikokimyasal, mikrobiyolojik, tekstürelve duyusal özellikleri incelenmiştir.Materyal ve Metot: İzmir Tulum peynirinden elde edilmiş olan peynir altı sularımezofilik (25?C) ve termofilik (35?C) inkübasyon sıcaklığına bırakılmıştır. Mezofilik (M),termofilik (T), mezofilik-termofilik (K) PAS kültürlü ve kontrol grubu (C) (klasik yöntemlepeynir altı suyu kültürü eklenmeyen) olmak üzere dört grup İzmir Tulum peynir üretimigerçekleştirilmiştir.Bulgular: Peynir altı suyu kültürü ilaveli peynir örnekleri kontrol grubuna göre dahadüşük kuru madde değerlerine sahip olmuştur. Örnekler arası yağ, protein ve toplamazot değerlerinde önemli düzeyde değişiklik görülmemiştir (p>0.05). Depolama süresiboyunca en yüksek suda çözünen azot oranı kontrol örneğinde en yüksek %12 likTCA’da çözünen azot oranı ise K örneğinde saptanmıştır. Duyusal açıdan kontrol örneğiön plana çıkmıştır. Depolama süresi boyunca en düşük Lactococcus ve en yüksek mayaküf sayısına kontrol örneği sahip olmuştur. Tekstürel açıdan depolamanın başlangıcındaen sert peynir mezofilik kültürle üretilen peynir iken depolama sonunda en yükseksertlik değerine kontrol örneği sahip olmuştur.Öğe İzmir tulum peynirinden ekstrakte edilen endojen ve eksojen peptitlerin olası biyolojik etkilerinin değerlendirilmesi(Ege üniversitesi, Fen Bilimleri Enstitüsü, 2020) Akan, Ecem; Kınık, ÖzerBu çalışmada geleneksel yolla inek sütünden İzmir Tulum peyniri üretilmiş ve peynirler 180 gün boyunca 4±1 °C ‘de depolanmıştır. Peynir örneklerinin genel bileşiminin belirlenmesinin yanında depolama süresince meydana gelen proteoliz, suda çözünen azot, %12‘lik TCA‘da çözünen azot ve OPA yöntemi ile değerlendirilmiştir. Bunun yanında peynir örneklerinin Laktobasil, Laktakok ve maya sayıları depolama süresi boyunca incelenmiştir. Bu çalışmada esas olarak İzmir Tulum peynir örneklerinden depolama süresi boyunca elde edilen endojen (%50 aseton ekstraktı) ve eksojen peptit (in vitro gastrointestinal sindirim) ekstraktlarının antioksidan, metal şelatasyon, DPP-IV inhibitör, deglikasyon, ACE inhibitör ve antimikrobiyal aktivitelerinin ve RP-HPLC profillerinin değerlendirilmesi amaçlanmıştır. Suda çözünen azot ve %12‘lik TCA‘da çözünen azot değerlerine bakıldığında özellikle depolamanın 60. gününde proteolizin hızla ilerlediği ve depolama süresi sonunda da maksimum değere ulaştığı belirlenmiştir. Laktobasiller peynirin olgunlaşma başlangıcından sonuna kadar peynir florasında baskın mikroorganizma grubunu oluşturmuştur. Depolama süresi boyunca Laktobasil sayıları 7,58-9,32 log kob/g aralığında değişmiştir. Depolama süresinin başlangıcında Laktakok sayısı 8,30 log kob/g iken depolama sonunda 7,09 log kob/g‘a düşmüştür. Laktobasil ve Laktakok sayılarının depolama süresi sonunda depolamanın başlangıcına göre istatiksel olarak önemli düzeyde değiştiği belirlenmiştir (p<0,05). Endojen ve eksojen peptit ekstraktlarının depolama süresi boyunca CUPRAC ve DPPH yöntemleriyle belirlenen antioksidan aktivitelerinin depolama süresi sonunda düştüğü, en yüksek antioksidan aktiviteye ilk gün örneklerinin sahip olduğu görülmüştür. Depolama süresi boyunca eksojen peptit ekstraktlarının metal şelatasyon aktvitelerinin endojen peptit ekstraktlarına kıyasla daha yüksek olduğu görülmüştür. Endojen peptit ekstraktlarının CUPRAC yöntemiyle elde edilen antioksidan aktivite sonuçları ile metal şelatasyon sonuçları arasında p<0,05 anlamlılık düzeyinde çok yüksek korelasyon (r=0,84) olduğu saptanmıştır. Eksojen peptit ekstraktlarının DPP-IV enzim inhibitör aktivitesinin endojen peptit ekstraktlarına göre daha düşük olduğu görülmektedir. Endojen ve eksojen peptit ekstraktlarının depolama süresi boyunca deglikasyon aktivitelerinin önemli düzeyde değişmediği görülmüştür. Depolama süresi boyunca eksojen peptit ekstraktlarının ACE inhibitör aktivitelerinin endojen peptit ekstraktlarından daha düşük olduğu görülmüştür. En yüksek ACE inhibitör aktiviteye her iki ekstraktta da depolamanın 60. günü rastlanılmıştır. Hem endojen hem de eksojen peptit ekstraktlarının gram negatif Escherichia coli ATCC 35210 üzerine antimikrobiyal etkisi olmadığı saptanmıştır. Endojen peptit ekstraktlarının Listeria monocytogenes, eksojen peptit ekstraktların ise Bacillus cereus üzerine yüksek antimikrobiyal aktivitesinin bulunduğu görülmüştür. Tüm biyolojik aktivitelere ait IC50 ve EC50 değerleri incelendiğinde endojen ve eksojen peptit ekstraktlarında en düşük IC50 değeri (15,22 μg/mL) deglikasyon aktivitesi için belirlenmiştir. RP-HPLC peptit profilleri değerlendirildiğinde depolama süresi boyunca eksojen peptit sayısının endojen peptitlere göre çok daha fazla olduğu görülmektedir. Bununla birlikte hem endojen hem de eksojen peptit profillerinin depolama süresine bağlı olarak çok değişmediği görülmüştür. Sonuç olarak, ülkemizde sıklıkla beğenilerek tüketilen İzmir Tulum peynirinin hem endojen hem de eksojen peptit ekstraktlarının vücut bağışıklığını arttırmada antioksidatif, metal şelatlayıcı ve antimikrobiyal etki, Tip 2 diyabet ile ilişkili DPP-IV inhibitör ve deglikasyon aktivitesi ve hipertansiyon için ACE inhibitör aktiviteye sahip olduğu ve bu sayede sağlık üzerine pozitif etki gösterebileceği ortaya konulmuştur.
