Browsing by Author "Togay, Sine Özmen"

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Antimicrobial activity potential of enterococcus spp. isolated from some traditional Turkish cheeses
(Kafkas Üniversitesi, 2016-04-19) Ay, Mustafa; Altunatmaz, Sema Sandıkcı; Aksu, Filiz Yılmaz; Tınaztepe, Özlem Erol; Issa, Ghassan; Büyükünal, Serkan Kemal; Togay, Sine Özmen; Uludağ Üniversitesi/Ziraat Fakültesi/Gıda Mühendisliği Bölümü.; 36468917400
Enterococci can produce enterocins which have antimicrobial activity against Gram-positive and also Gram-negative pathogenic, toxigenic and food-spoilage bacteria. The aim of this study was to determine the antimicrobial activity of Enterococcus spp. isolated from traditional Turkish cheeses such as Kashar, Manyas, Sepet, Kelle, Mihalic, Tulum. The isolates were tested against Listeria monocytogenes, Listeria innocua, Listeria ivanovii, Staphylococcus aureus and Enterococcus faecalis and also detected the presence of entA and entB genes of these isolates. Total 66 of enterococcal isolates were obtained from 34 of cheese samples and 25 of these isolates showed antimicrobial activity against tested reference bacteria by using agar spotting method. Also it was determined most of Enterococcus spp. carried enterocin encoding entA and entB genes. We concluded that these isolates or their enterocins may have a potential for food preservation, however they should be evaluated in terms of food safety.
Evaluation of physicochemical, microbiological, sensory properties and aroma profiles of goat cheeses provided from Çanakkale
(Wiley, 2017-11) Güneşer, Onur; Yüceer, Yonca Karagül; Togay, Sine Özmen; Uludağ Üniversitesi/Ziraat Fakültesi/Gıda Mühendisliği Bölümü.; AAC-6337-2021; 36468917400
The 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.
Prevalence and identification by multiplex polymerase chain reaction patterns of Cronobacter spp. isolated from plant-based foods
(Soc Brasileira Ciencia Tecnologia Alimentos, 2016-08-08) Aksu, Filiz; Altunatmaz, Sema Sandıkcı; Issa, Ghassan; Aksu, Harun; Togay, Sine Özmen; Uludağ Üniversitesi/Ziraat Fakültesi/Gıda Mühendisliği Bölümü.; AAC-6337-2021; 36468917400
Cronobacter spp. involves a group of opportunistic pathogens that cause meningitis in newborns, immunosuppressed individuals with a mortality rate of 50-80%. Seven species like C. sakazakii, C. malonaticus, C. muytjensii, C. turicensis, C. dublinensis, C. universalis, C. condimenti are included in this genus which has been a subject of research especially in the bacteriologic analysis of baby foods. However, since these species were detected also in prepared foodstuffs. The objective of this study was to assert the presence of Cronobacter spp. in foodstuff offered for sale in Turkey. A total of 151 prepared foodstuffs including a variety of spice, flour, instant soup were purchased from different sales points. The presence of Cronobacter spp. were investigated in these samples. Cronobacter suspected isolates which were obtained by microbiological analyses were confirmed by PCR targeted to gyrB gene and were then identified by multiplex PCR. Prevalence of Cronobacter spp was estimated to be 17.88%. Out of 27 Cronobacter spp. isolates obtained, 13(48.1%), 6(22.2%), 5(18.5%), 3(11.1%) belonged to C. sakazakii, C. muytjensii, C. turicensis, C. malonaticus species, respectively. Consequently, the presence of the bacteria in widely consumed foodstuff revealed that Cronobacter spp. is subject to monitoring due to its opportunistic nature in terms of public health concern.
Production of flavor compounds from olive mill waste by Rhizopus oryzae and Candida tropicalis
(Springer, 2016-08-12) Güneser, Onur; Demirkol, Aslı; Yüceerl, Yonca Karagül; Hoşoğlu, Müge İşleten; Elibol, Murat; Togay, Sine Özmen; Uludağ Üniversitesi/Ziraat Fakültesi/Gıda Mühendisliği Bölümü.; AAC-6337-2021; 36468917400
The 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.
Stabilisation of lavender essential oil extracted by microwave-assisted hydrodistillation: Characteristics of starch and soy protein-based microemulsions
(Elsevier, 2021-09-17) Uzkuc, Nesrin Merve Çelebi; Uzkuc, Hasan; Berber, Mehmet Mert; Kuzu, Kübra Tarhan; Togay, Sine Özmen; Hosoğlu, Müge İşleten; Toklucu, Ayşegül Kırca; Kurt, Saliha B.; Şahiner, Nurettin; Yüceer, Yonca Karagül; ÖZMEN TOĞAY, SİNE; Bursa Uludağ Üniversitesi/Ziraat Fakültesi/Gıda Mühendisliği Bölümü.; AAC-6337-2021
In this work, microwave-assisted hydrodistillation (MAHD) technique was used to obtain lavender essential oil (LEO) with a yield of 5.5 %. Oil in water microemulsions of LEO were prepared with starch and soy protein by ultrasonic emulsification. Total phenolic content and antioxidant capacity of the samples were evaluated. Microemulsions exhibited antimicrobial effect against S. aureus and B. cereus. The major volatiles of LEO were linalool L (29.0 %), 1,8-cineole (13.9 %), camphor (12.3 %) and linalyl acetate (11.9 %). Camphene, 1,8-cineole, (Z)-ocimene, linalool, and 2,6-nonadienal were determined as aroma-active compounds by gas chromatographyolfactometry. The stability of emulsions at different pH (3, 6 and 9) and temperatures (4 and 25 degrees C) were evaluated by measuring their size distribution, zeta potential, viscosity and color during storage. The stable droplets of LEO microemulsion that ranged between 392 and 732 nm were obtained with starch at pH 6. The formulated starch-based emulsions of LEO at pH 6 revealed the highest stability at 25 degrees C.