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Öğe Bioflavour production from tomato and pepper pomaces by Kluyveromyces marxianus and Debaryomyces hansenii(Springer, 2015) Guneser, Onur; Demirkol, Asli; Yuceer, Yonca Karagul; Togay, Sine Ozmen; Hosoglu, Muge Isleten; Elibol, MuratBioflavours are called natural flavour and/or fragrance compounds which are produced using metabolic pathway of the microorganism and/or plant cells or their enzyme systems with bioengineering approaches. The aim of this study was to investigate bioflavour production from tomato and red pepper pomaces by Kluyveromyces marxianus and Debaryomyces hansenii. Obtained specific growth rates of K. marxianus and D. hansenii in tomato pomace were 0.081/h and 0.177/h, respectively. The bioflavour profile differed between the yeasts. Both yeasts can produce esters and alcohols such as phenyl ethyl alcohol, isoamyl alcohol, isoamyl acetate, phenyl ethyl acetate and isovaleric acid. Tarhana and rose were descriptive flavour terms for tomato and pepper pomaces fermented by K. marxianus, respectively. Tomato pomace fermented by D. hansenii had the most intense green bean flavour while fermented vegetable and storage/yeast were defined as characteristic flavour terms for pepper pomaces fermented by D. hansenii.Öğe Biosynthesis of eight-carbon volatiles from tomato and pepper pomaces by fungi: Trichoderma atroviride and Aspergillus sojae(Soc Bioscience Bioengineering Japan, 2017) Guneser, Onur; Yuceer, Yonca KaragulThe aim of this study was to investigate the possibility of using tomato and red pepper pomaces for the production eight-carbon volatiles by Trichoderma atroviride and Aspergillus sojae. The fermentation of tomato and pepper pomace based media by both moulds was conducted in shake flasks and bioreactors. Microbial growth behaviours and fermentation abilities of T. atroviride and A. sojae under both fermentation conditions were followed by microbial counting. The production of flavours from tomato and pepper pomaces by fungal metabolism was determined by gas chromatography olfactometry, gas chromatography-mass spectrometry and sensory analysis. The results showed that T. atroviride grew faster than A. sojae, and the survival of T. atroviride in the tomato pomace was longer than that of A. sojae. However, T. atroviride grew slower than A. sojae in the pepper pomace. Eight-carbon flavour compounds, including (Z)-1,5-octadien-3-ol, 1-octen-3-ol, (E)-2-octenal and (E)-2-octenol, were produced by T. atroviride and A. sojae from the tomato and pepper pomaces. The highest production levels (265.55 +/- 2.79 and 187.47 +/- 0.92 mu g kg(-1)) were observed for 1-octen-3-ol in the tomato fermentation by T. atroviride and A. sojae, respectively. The relationships between volatile compounds and their flavour characteristics in tomato and pepper pomaces were analysed using principal component analysis. (C) 2017, The Society for Biotechnology, Japan. All rights reserved.Öğe Characterisation of aroma-active compounds, chemical and sensory properties of acid-coagulated cheese: Circassian cheese(Wiley, 2011) Guneser, Onur; Yuceer, Yonca KaragulThe objectives of this study were to determine basic composition, aroma and sensory characteristics of Circassian cheese. Seven Circassian cheeses were provided by local producers. Aroma compounds were extracted by using solid-phase microextraction procedure and determined by gas chromatography-olfactometry system. Water-soluble, trichloroacetic acid-soluble and phosphotungstic acid-soluble nitrogen fractions ranged between 2.30-29.35%, 2.48-9.96% and 3.33-6.26%, respectively. Diacetyl, butyric acid, 2-acetyl-1-pyrroline, 1-octen-3-one and methional were identified at high intensities in cheeses. In addition, 'cooked', 'whey', 'creamy' and 'fermented' were defined as characteristic flavour terms for Circassian cheeses.Öğe CHEMICAL COMPOSITION AND ANTIOXIDANT CAPACITIES OF MOSSES GATHERED FROM MOUNT IDA (CANAKKALE, TURKEY)(Parlar Scientific Publications (P S P), 2019) Yayintas, Ozlem Tongue; Ozyurt, Dilek; Demirata, Birsen; Yuceer, Yonca Karagul; Yilmaz, SelehattinFour species of bryophytes were used as material and were gathered from various areas in Mount Ida (Kazdag), Canakkale, Turkey. Volatile compounds were isolated from the moss species with solid phase microextraction (SPME). GC-MS was applied to determine volatiles. The antioxidant capacity of bryophytes was established using CERAC and CUPRAC techniques. Trolox equivalent (TEAC) of aqueous extract of bryophytes was determined at concentrations of 0.0109 (+/- 0.0008)-0.0212 (+/- 0.0009) mmol trolox/g bryophyte and 70% methyl alcohol extract 0.0259 (+/- 0.0013)-0.0058 (+/- 0.0012) mmol trolox/g bryophyte using the CERAC technique and for water extract as 0.0027 (+/- 0.0006)-0.0083 (+/- 0.0012) mmol trolox/g bryophyte and methanol extract 0.0035-0.0095 (+/- 0.0005) mmol trolox/g bryophyte using the CUPRAC technique. The total flavonoid content was analyzed as equivalent mmol catechin/g bryophyte with the AlCl3/NaNO2 colorimetry technique. The total phenolic content of the species was analyzed with a Folin-Ciocalteu spectrophotometric technique.Öğe Chemical composition, antimicrobial, antioxidant and anthocyanin activities of mosses (Cinclidotus fontinaloides (Hedw.) P.Beauv. and Palustriella commutata (Hedw.) Ochyra) gathered from Turkey(Taylor & Francis Ltd, 2017) Yayintas, Ozlem Tonguc; Alpaslan, Duygu; Yuceer, Yonca Karagul; Yilmaz, Selehattin; Şahiner, NurettinCinclidotus fontinaloides (Hedw.) P. Beauv. and Palustriella commutata (Hedw.) Ochyra were used in this study. The chemical composition of mosses in the ethanol and water extract was determined using GC-MS and FT-IR. Antioxidant activities of moss extracts were tested by total phenol and ABTS methods. Trolox equivalent value (TEAC) of mosses was calculated as 26 +/- 0.32 and 10 +/- 0.22 mg/g. The amounts of the flavonoid compounds were calculated as mg gallic acid. Gallic acid equivalent value of mosses was calculated as 587 +/- 0.55 and 496 +/- 0.22 mg/g. The extracts antimicrobial activity was tested against Escherichia coli (ATCC 8739), Bacillus subtilis (ATCC 6633), Staphylococcus aureus (ATCC 6538), Pseudomonas aeruginosa (ATCC 10145) and Candida albicans (ATCC 10231). Significant antibacterial effect was observed for C. fontinaloides and P. commutata in ethanol extract. Total anthocyanin activities of C. fontinaloides and P. commutata were determined as 50 +/- 0.17 and 144 +/- 0.33 mg/L. [GRAPHICS] .Öğe Comparative analysis of essential oil oleogels containing beeswax and sunflower wax with petrolatum gels(Wiley, 2024) Cokay, Hatice; Uzkuc, N. Merve Celebi; Yuceer, Yonca Karagul; Ogutcu, MustafaIn this study, three different oil (black seed, St. John's Wort, and grape seed oils [GSO]) oleogels, which are especially used in complementary medicine, were produced with natural waxes (sunflower and beeswax [BW]). The physicochemical, textural, thermal, and structural features and volatile composition of the oleogels were determined and compared with commercial petrolatum gels (control sample). The sunflower and BW gels had a higher melting point than the petrolatum gels. Particularly, the firmness values of the fresh sunflower and BW oleogels were close to the petrolatum gels, except for the BW-based St John's Wort and GSO gels. The firmness and stickiness values of the oleogels and the control samples increased in relation to the storage period. The increase in firmness value was less in the sunflower wax than in the BW and control samples. All sunflower, BW and petrolatum gels exhibited the beta ' form. Volatile component data showed that different waxes have different volatile adsorption capacities. As a result, natural wax oleogels produced with various essential oils could be an alternative to similar products used in the cosmetics, pharmacology, and food supplement industries, which are already commercially available.Practical applications: (Oleogels have become a popular technique for structuring oils in recent years. In this way, oleogels are considered an alternative to solid fat such as margarine, butter, and shortening and an oil-restricting agent against oil leakage in oil-based foods. Consumers establish a close relationship between their own health and the foods they consume and the cosmetics they use. This situation has led to an increasing interest in natural products. Essential oils (EOs) are used in many fields, ranging from cosmetics to complementary medicine. In this context, essential oleogels produced with natural waxes were compared with the commercial products, revealing their potential for use in both cosmetic and food supplements. EO-oleogels represent a new approach to the oleogel product range with high commercialization potential for related industries.) Graphical Abstract: The textural and structural properties of the essential oil oleogels prepared with beeswax and sunflower wax were almost similar to their commercial counterparts such as petrolatum. imageÖğe Effects of spontaneous fermentation on Karalahna and Cabernet Sauvignon young red wines: volatile compounds, sensory profiles and identification of autochthonous yeasts(Springer, 2020) Uzkuc, Nesrin Merve Celebi; Sisli, Burcu; Ay, Mustafa; Togay, Sine Ozmen; Yuceer, Yonca Karagul; Bayhan, Asli; Toklucu, Aysegul Kircat The purposes of the present study were to evaluate the volatile compounds and sensory characteristics of young red wines produced by spontaneous and inoculated fermentations of Karalahna (KL) and Cabernet Sauvignon (CS) grapes and to identify the yeasts responsible for spontaneous fermentation by molecular methods. A total of 28 volatile compounds in KL wines and 35 compounds in CS wines were identified and quantified by GC-MS. The concentration of higher alcohols and esters differed significantly among spontaneously fermented and inoculated wines. Spontaneous fermentation resulted in greater amount of higher alcohols in KL wines, while inoculated wines had greater amount of higher alcohols in CS wines. Spontaneously fermented KL and CS wines showed greater amounts of esters than inoculated wines. KL wines obtained by spontaneous fermentation had significantly higher scores than inoculated wines based on fruity and green aromas, body and overall impression. Spontaneously fermented CS wines were found significantly higher in fruity and floral aromas than inoculated wines.Öğe ENGINEERING OF MILK-BASED BEVERAGES: CURRENT STATUS, DEVELOPMENTS, AND CONSUMER TRENDS(Woodhead Publ Ltd, 2019) Guneser, Onur; Hosoglu, Muge Isleten; Guneser, Buket Aydeniz; Yuceer, Yonca Karagul[Anstract Not Available]Öğe Evaluation of physicochemical, microbiological, sensory properties and aroma profiles of goat cheeses provided from Canakkale(Wiley, 2017) Togay, Sine Ozmen; Guneser, Onur; Yuceer, Yonca KaragulThe purpose of this study was to determine physicochemical and sensory properties, aroma-active compounds and number of lactic acid bacteria in goat cheeses. High variation was observed among the cheeses in terms of fat %(w/w) and salt %(w/w) contents and titratable acidities %(w/w). Average counts of lactococci lactobacilli and enterococci were 6.90, 6.43 and 5.26log cfu (colony-forming unit)/g, respectively. The following compounds had high aroma intensity in the cheeses: acetic acid, butanoic acid, hexanoic acid, p-cresol and phenyl acetic acid. Cooked, whey, creamy, animal-like, waxy, salty and sour were the characteristic sensory descriptors.Öğe Growth and by-product profiles of Kluyveromyces marxianus cells immobilized in foamed alginate(Wiley, 2015) Wilkowska, Agnieszka; Kregiel, Dorota; Guneser, Onur; Yuceer, Yonca KaragulThe aim of this research was to study how the yeast cell immobilization technique influences the growth and fermentation profiles of Kluyveromyces marxianus cultivated on apple/chokeberry and apple/cranberry pomaces. Encapsulation of the cells was performed by droplet formation from a foamed alginate solution. The growth and metabolic profiles were evaluated for both free and immobilized cells. Culture media with fruit waste produced good growth of free as well as immobilized yeast cells. The fermentation profiles of K. marxianus were different with each waste material. The most varied aroma profiles were noted for immobilized yeast cultivated on apple/chokeberry pomace. Copyright (c) 2014 John Wiley & Sons, Ltd.Öğe Investigation of antimicrobial activity and entA and entB genes in Enterococcus faecium and Enterococcus faecalis strains isolated from naturally fermented Turkish white cheeses(Korean Society Food Science & Technology-Kosfost, 2016) Togay, Sine Ozmen; Ay, Mustafa; Guneser, Onur; Yuceer, Yonca KaragulIn this research, the antagonistic effects of Enterococcus faecalis and E. faecium bacteria isolated from naturally fermented Turkish white cheeses, produced without starter culture, against Listeria monocytogenes, L. innocua, L. ivanovii, Staphylococcus aureus, and E. faecalis were evaluated. The presence of entA and entB genes was also detected in the isolates, which had antimicrobial activity. Total 71 strains of E. faecalis and 7 strains of E. faecium were tested; 20 of E. faecalis and none of E. faecium strains showed antimicrobial activity against the tested bacteria using agar spot method. Among E. faecalis strains, which had antimicrobial activity, three strains contained both entA and entB genes, two strains carried only entA gene, and five strains had only entB gene. These cheese-sourced enterococcal strains or their enterocins should be considered to be used for food preservation especially in the dairy industry.Öğe Physical Properties, Volatiles Compositions and Sensory Descriptions of the Aromatized Hazelnut Oil-Wax Organogels(Wiley-Blackwell, 2015) Yılmaz, Emin; Ogutcu, Mustafa; Yuceer, Yonca KaragulThe purpose of this study was to determine the physicochemical, thermal and sensorial features of vitamin enriched and aromatized hazelnut oil-beeswax and sunflower wax organogels. Another objective was to monitor the influence of storage on textural and oxidative stability and volatile composition of the organogels. The results show that organogels with beeswax had lower levels of solid fat content, melting point and firmness than sunflower wax counterparts. The microphotographs revealed that beeswax organogels had spherical crystals while sunflower wax organogels continued need-like crystals, but both organogels continued crystallized a' polymorph. All organogels maintained their oxidative stability during storage. Quantitative descriptive analysis results were consistent with these findings that the organogel structure and properties were similar to breakfast margarine. The main volatile components of the organogels with added strawberry aroma were ethyl acetate, ethyl butanoate, ethyl-2-methyl butanoate, D-limonene, ethyl caproate; banana-aroma were isoamyl acetate, isoamyl valerianate, ethyl acetate; and butter-aroma were 2,3-butanedione, 3-hydroxy-2-butanone. These volatile components were not only detected in the fresh samples but also at the end of the storage period. Sensory definition terms were matched with the sensory descriptors of the detected volatiles. In conclusion, the new organogels were shown to be suitable for food product applications.Öğe PHYSICOCHEMICAL AND SENSORY PROPERTIES OF MIHALIC CHEESE(Taylor & Francis Inc, 2014) Aday, Serpil; Yuceer, Yonca KaragulMihalic is a hard, brined and quite salty cheese. In this study, selected physical, chemical, and sensory properties of 15 Mihalic cheese samples (matured more than six months) in vacuum packaging were investigated using representative samples collected from its major production area in northwestern Turkey. Aroma-active compounds were analyzed by solid phase microextraction and determined by gas chromatography-olfactometry. Average dry matter and fat contents of the cheese were 60.4 and 27.4 g/100 g cheese, respectively. Significant differences were observed among the cheese samples for hardness, adhesiveness, chewiness, and gumminess. Sulfurous, free fatty acids, and barny/animal were major sensory descriptors for the cheese. Methional (boiled potato), (E, E)-2,4-nonadienal (fatty, stale), diacetyl (buttery), 1-octen-3-one (mushroom), ethyl butyrate (sweet, bubble gum), and butyric acid (rancid) were common aroma-active compounds found in Mihalic cheese.Öğe Process engineering for bioflavour production with metabolically active yeasts - a mini-review(Wiley, 2015) Carlquist, Magnus; Gibson, Brian; Yuceer, Yonca Karagul; Paraskevopoulou, Adamantini; Sandell, Mari; Angelov, Angel I.; Gotcheva, VelitchkaFlavours are biologically active molecules of large commercial interest in the food, cosmetics, detergent and pharmaceutical industries. The production of flavours can take place by either extraction from plant materials, chemical synthesis, biological conversion of precursor molecules or de novo biosynthesis. The latter alternatives are gaining importance through the rapidly growing fields of systems biology and metabolic engineering, giving efficient production hosts for the so-called 'bioflavours', which are natural flavour and/or fragrance compounds obtained with cell factories or enzymatic systems. Yeasts are potential production hosts for bioflavours. In this mini-review, we give an overview of bioflavour production in yeasts from the process-engineering perspective. Two specific examples, production of 2-phenylethanol and vanillin, are used to illustrate the process challenges and strategies used. Copyright (c) 2014 John Wiley & Sons, Ltd.Öğe Production of flavor compounds from olive mill waste by Rhizopus oryzae and Candida tropicalis(Soc Brasileira Microbiologia, 2017) Guneser, Onur; Demirkol, Asli; Yuceer, Yonca Karagul; Togay, Sine Ozmen; Hosoglu, Muge Isleten; Elibol, MuratThe purpose of this study was to investigate the production of flavor compounds from olive mill waste by microbial fermentation of Rhizopus oryzae and Candida tropicalis. Olive mill waste fermentations were performed in shake and bioreactor cultures. Production of flavor compounds from olive mill waste was followed by Gas Chromatography Mass spectrometry, Gas chromatography- olfactometry and Spectrum Sensory Analysis. As a result, 1.73-log and 3.23-log cfu/mL increases were observed in the microbial populations of R. oryzae and C. tropicalis during shake cultures, respectively. C. tropicalis can produce a higher concentration of n-limonene from olive mill waste than R. oryzae in shake cultures. The concentration of n-limonene was determined as 185.56 and 249.54 mu g/kg in the fermented olive mill waste by R. oryzae and C. tropicalis in shake cultures respectively. In contrast, R. oryzae can produce a higher concentration of n-limonene (87.73 mu g/kg) n-limonene than C. tropicalis (11.95 mu g/kg) in bioreactor cultures. Based on sensory analysis, unripe olive, wet towel, sweet aromatic, fermented aromas were determined at high intensity in olive mill waste fermented with R. oryzae meanwhile olive mill waste fermented with C. tropicalis had only a high intensity of unripe olive and oily aroma. (C) 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda.Öğe Production of flavor compounds from rice bran by yeasts metabolisms of Kluyveromyces marxianus and Debaryomyces hansenii(Springer, 2022) Guneser, Onur; Yuceer, Yonca Karagul; Hosoglu, Muge Isleten; Togay, Sine Ozmen; Elibol, MuratThe aim of this study was to evaluate the biosynthesis of flavor compounds from rice bran by fermentation facilitated by Kluyveromyces marxianus and Debaryomyces hansenii. The growth of both yeasts was assessed by specific growth rates and doubling time. The biosynthesis of flavor compounds was evaluated by gas chromatography-olfactometry (GC-O), gas chromatography-mass spectrometry (GC-MS), and Spectrum (TM) sensory analysis. The specific growth rate (mu) and doubling time (t(d)) of K. marxianus was calculated as 0.16/h and 4.21h, respectively, whereas that of D. hansenii was determined as 0.13/h and 5.33h, respectively. K. marxianus and D. hansenii produced significant levels of higher alcohols and acetate esters from rice bran. Results showed that K. marxianus can produce 827.27 mu g/kg of isoamyl alcohol, 169.77 mu g/kg of phenyl ethyl alcohol, and 216.08 mu g/kg of phenyl ethyl acetate after 24-h batch fermentation. A significant amount of isovaleric acid was also synthesized by K. marxianus (4013 mu g/kg) after the batch fermentation of 96 h. 415.64 mu g/kg of isoamyl alcohol and 135.77 mu g/kg of phenyl ethyl acetate was determined in rice bran fermented by D. hansenii after 24-h fermentation. Fermented cereals and rose were the characteristic flavor descriptors of the fermented rice bran samples. Rose flavor in fermented rice bran samples was found to be associated with phenyl ethyl alcohol, phenyl ethyl acetate, isoamyl acetate, and guaiacol. Thus, the findings of this study demonstrate that the valorization of rice bran can be achieved with the production of natural flavor compounds by yeast metabolism.Öğe The effect of fenugreek seed (Trigonella foenum-graecum) supplementation on the performance and milk yield characteristics of dairy goats(Copernicus Gesellschaft Mbh, 2022) Akbag, Hande Isul; Savaş, Türker; Yuceer, Yonca KaragulThe use of fenugreek seed as a galactagogue has been investigated in ruminants. However, only a few studies have analyzed the effects of fenugreek seed on the milk fatty acid composition. To the authors' best knowledge, none of these studies have investigated the effects of fenugreek seed on milk volatile compounds. The objective of this study, which lasted 8 weeks, was to determine the effects of fenugreek seed supplementation on the performance, milk fatty acid profile, and milk volatile profile of goats. A total of 20 Turkish Saanen dairy goats that were mid-lactation were used in the study. This study was carried out with two homogeneous groups: the control group (CON) and fenugreek group (FG). Both groups were fed a total mixed ration (TMR), but the FG treatment had their diet supplemented with 0.1 kg d(-1) of fenugreek seed per animal. The feed intake, live weight, milk yield, milk chemical composition, serum cholesterol and triglyceride concentration, milk fatty acid profile, and milk volatile compound profile were determined. The feed intake, live weight gain, and milk yield of the goats did not significantly differ between the CON and FG treatments (P >0.05), whereas the milk fat concentration increased (P = 0.05) and the serum cholesterol and triglyceride concentrations decreased (P <0.05) in the FG treatment. The unsaturated fatty acid concentration in milk (P <0.05) was also enhanced in the FG treatment. In addition, the FG treatment increased 2-propanone, 2-butanone, benzene, 1-methyl-3-(1-methylethyl), and eucalyptol concentrations in milk (P <0.05). In conclusion, the supplementation of goats' diets with fenugreek seed during the mid-lactation period did not affect their performance and improved the unsaturated fatty acid profile of their milk Of particular importance, we have also detected an increase in the 2-propanone concentration in milk following fenugreek supplementation.Öğe The Effects of Infrared Roasting on HCN Content, Chemical Composition and Storage Stability of Flaxseed and Flaxseed Oil(Springer, 2017) Tuncel, Necati Baris; Uygur, Aysen; Yuceer, Yonca KaragulFlaxseeds were roasted at 1150 W/m(2) radiation intensity with short and medium wave infrared (IR) emitters for specific durations, which provided good visual and sensory quality. The effects of IR roasting on color properties, hydrogen cyanide (HCN) content, tocopherols and fatty acid composition of the flaxseed and flaxseed oil were investigated. Further, flaxseeds were stored for 6 months and free fatty acid content and peroxide values were followed at 1-month intervals to understand the effect of IR treatment on hydrolytic and oxidative stability. HCN content of the flaxseeds was reduced up to 59% with IR roasting. Tocopherol content of the IR roasted flaxseed oil was higher than that of the control. No notable variation was observed in fatty acid composition with regard to IR treatment. Free fatty acid content of IR roasted flaxseeds did not increase during storage, while peroxide value of the seeds significantly increased up to 95 mEq O-2/kg oil.Öğe Torulaspora delbrueckii ve Trichoderma atroviride Kullanılarak Pirinadan (Zeytin Katı Atığı) Biyoaroma Üretimi(2014) Güneşer, Onur; Yuceer, Yonca Karagul; Toğay, Sine Özmen; Hoşoğlu, Müge İşleten; Elibol, MuratBu çalışmada, Torulaspora delbrueckii ve Trichoderma atroviride kullanılarak, pirinadan mikrobiyal fermentasyon yoluyla doğal aroma maddelerinin üretilme olanaklarının araştırılması amaçlanmıştır. Bu amaçla, Torulaspora delbrueckii ve Trichoderma atroviride ile %10'luk pirina solüsyonunun hem erlen hem de biyoreaktör düzeyinde 30oC'de 120 saat fermentasyonu gerçekleştirilmiştir. Her iki fermentasyon boyunca mikroorganizmaların pirinadaki gelişimleri incelenmiştir. T. delbrueckii ve T. atroviride tarafından üretilen aroma maddelerinin tanımlanması ve miktarlarının belirlenmesi gaz kromatografisi kütle spektrometresi ve gaz kromatografisi-olfaktometre ile yapılmıştır. T. delbruecki ve T. atroviride'nin erlen düzeyinde maksimum hücre sayısı artışının sırasıyla 1.49 ve 1.07 log kob/mL olduğu belirlenirken, biyorekatör düzeyindeki hücre artışları ise 2.23 ve 0.92 log kob/mL düzeyinde olduğu tespit edilmiştir. 0-120 saat fermentasyon süresinde T. delbrueckii ve T. atroviride için spesifik üreme hızları sırasıyla 0.079/saat ve 0.0299/saat olarak hesaplanmıştır. T.delbrueckii'nin pirinadan fenil etil alkol (gül) ve mentol (nane), T. atroviride'nin ise 1 okten-3-ol (mantar) ve 2-oktenol (yanık, kirli) ürettiği belirlenmiştir. Mikrobiyal fermentasyon sonucunda üretilen fenil etil alkol, mentol, 1-okten-3-ol ve 2 oktenol'un maksimum üretim miktarları sırasıyla 6.69±0.01 µg/kg, 3.50±0.69 µg/kg, 330.75 µg/kg ve 25.65 µg/kg olarak belirlenmiştir. En yüksek verimlilik değerinin 88.81 µg/ kg.saat ile 1-okten-3-ol'e ait olduğu tespit edilmiştir. Yapılan duyusal analizler sonucunda, fermente pirina örneklerinde ıslak bulgur, toprak, ıslak kirli havlu, fermente ve mantar aromalarının yüksek yoğunlukta olduğu belirlenmiştir. Yüksek yoğunlukta algılan söz konusu bu aromalar, miktarı artan mentol, fenil etil alkol, 1-okten-3-ol ve 2-oktenol ile ilişkilendirilebilirÖğe Volatile Compounds, Chemical and Sensory Properties of Butters Sold in Çanakkale(2016) Demirkol, Aslı; Güneşer, Onur; Yuceer, Yonca KaragulBu çalışmanın amacı Çanakkale'de satılan tereyağı örneklerinin fiziksel, kimyasal ve duyusal özelliklerinin belirlenmesidir. Bu amaçla onbir tereyağı örneğinin, renk, viskozite, refraktif indeks, erime noktası, nem (%), toplam asitlik (%), asit değeri ve yağ içeriği belirlenmiştir. Uçucu bileşenler gaz kromatografisi-kütle spektrometresi kullanılarak belirlenmiştir. Örneklerin duyusal özellikleri SpectrumTM metodu ile ortaya konmuştur. Fiziksel, kimyasal ve duyusal özellikler bakımından örnekler arasında önemli farklar olduğu bulunmuştur. Örneklerin viskozite, refraktif indeks, erime noktası, nem, toplam asitlik ve yağ içeriği sırasıyla 45.40-62.0 cP, 1.3331-1.4672, 32.50-37.50 ?C, % 15.03-19.06,% 0.24-0.42, % 82-89 arasında değişmektedir. Diasetil, asetoin, asetik asit, hekzanoik asit, butirik asit ve ?-dekalakton tereyağı örneklerinin önemli uçucu bileşenleridir. Ayrıca, pişmiş, kremamsı, ransit ve margarin benzeri panelistler tarafından geliştirilmiş karakteristik terimlerdir.
