Yazar "Öksüz, Ömer" seçeneğine göre listele
Listeleniyor 1 - 11 / 11
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Artisan strawberry ice cream made with supplementation of lactococci or Lactobacillus acidophilus(Chiriotti Editori, 2007) Vardar, N. Belgeç; Öksüz, ÖmerThe main aim of this research was to determine whether strawberry, a highly acidic fruit, can mask the sour taste of ice cream made with the addition of lactic acid bacteria (LAB). The effect of different LAB on strawberry ice cream quality was assessed. Six strawberry ice creams containing single strains of commercial LAB were produced. Two lactic acid supplementing methods were used. In one of them, pasteurised ice cream mix was inoculated with a single starter of Lactobacillus acidophilus, Lactococcus lactis subsp. lactis and Lactococcus lactis subsp. cremoris and incubated until the pH dropped to 5.6. In the second method, the milk part of the ice cream mix was fermented with Lactobacillus acidophilus, Lactococcus lactis subsp. lactis and Lactococcus lactis subsp. cremoris separately. Sufficient live bacterial counts were obtained in both LAB supplementation methods. In addition, fermenting the mix to pH 5.6 resulted in better taste and flavour scores. The sour taste resulting from the addition of LAB can be masked by highly acidic fruit. The sensorial properties of strawberry ice cream made with LAB supplementation were preferred to the control. The addition of the LAB to the highly acidic fruity ice cream is beneficial for both sensorial and physico-chemical properties.Öğe Comparison of hardaliye produced by different starters: Back-slopping and kombucha(Burhan ÖZTÜRK, 2022) Pekcan, Ayşenur; Çoşkun, Fatma; Öksüz, ÖmerDuring traditional hardaliye production by fermentation from grape juice, mustard seeds are insufficient to inhibit yeast activities and alcohol formation. Chemical preservatives are used for the production of hardaliye of standard quality in traditional and industrial production. Today, consumers prefer natural products that do not contain chemical preservatives and additives. For this reason, in this study, considering that different production techniques should be tried in order to prevent alcohol formation, hardaliye production was carried out with two different methods as back-slopping (BH) and addition of kombucha mushrooms (KH). These methods were tried for the first time on hardaliye. Fermentation continued for 7 days (d) and storage for 14 d. During fermentation, pH and reducing sugar, L* and a* values of samples decreased, while phenolic compounds’ concentration, viscosity, and b* values increased. The pH continued to drop during storage. No significant changes were observed in reducing sugar contents. During storage, phenolic content of KH sample decreased and viscosity and L* values increased. The titratable acidity increase was greater in BH sample compared to the KH sample. While 5.5% alcohol formation was observed in the BH sample on the 7th day of fermentation, no alcohol formation was detected in the KH sample At the end of fermentation and storage, Total mesophilic aerobic bacteria (TMAB), yeast, Lactobacillus spp. and lactic streptococci numbers were found to be higher in BH sample than in KH sample. According to the results of the research, thanks to the metabolic activities of the kombucha mushroom microorganisms and their symbiotic association, natural fermentation takes place without any preservative chemicals in KH and more durable hardaliye production is provided compared to BH.Öğe Fortification of edible zein films with thyme, laurel and orange essential oils and determination of their antifungal and radical scavenging properties(Presse Dienstleistungsgesellschaft mbH und Co. KG, 2019) Gucbilmez, C.M.; Öksüz, Ömer; Arıcı, MuhammetThe purposes of this research were: (a) to produce zein films by adding certain essential oils (EOs), (b) to identify their antifungal activity on some yeasts and molds, and (c) to develop an edible zein film that can inhibit the growth of Aspergillus fumigatus which was identified in a previous study as the most heat resistant mold isolated from marga-rines. Zein films fortified with thyme (Thymus vulgaris), laurel (Laurus nobilis) and orange (Citrus sinensis) EO were tested for their antifungal activities against 3 molds and 5 yeasts by measuring inhibition zone diameters. Considering the single effect, thyme EO was determined as the most effective one. Furthermore, the antifungal activities of thyme EO combined with the other EOs were also studied. From the obtained data, films containing thyme EO in combination with laurel EO were found as the most effective against Aspergillus fumigatus. Then, minimally inhibitory concentration against Aspergillus fumigatus was determined for the zein film obtained from film solutions including only thyme EO as 1.7 % (v/w), combinations of thyme-laurel EO as 1.6 % (v/w). Also, thyme oil was found as EO having the highest radical scavenging activity and total phenolic compounds among the three EOs. © M. & H. Schaper GmbH & Co.Öğe Grape pomace as a promising source for gellan gum production(Elsevier B.V., 2021) Altan Kamer, D.D.; Gümüş, Tuncay; Palabıyık, İbrahim; Demirci, Ahmet Şükrü; Öksüz, ÖmerThe aim of the present study was to determine the potential use of grape pomace, local agricultural waste, as a sole carbon source in the production of gellan gum. For this purpose, optimization of fermentation conditions of Sphingomonas paucimobilis (ATCC 31461) to produce gellan gum with the maximum yield was studied. This study clearly confirmed that gellan yield depended on carbon source concentration, bacterial inoculum volume and mixing rate. Maximum yield was found as 12.08 g/L at 5% carbon ratio, 4% inoculum volume and mixing rate at 300 rpm. The conversion ratio of waste product into gellan gum was identified as 0.24 gellan gum/grape pomace (g/g). Commercial gellan gum samples had glucose:rhamnose:glucuronic acid ratio as around 2.6:1.15:1, while biosynthesized gellan gum had 2.6:0.5:1 which indicated the effect of carbon source on chemical composition of gelllan gum. The molecular weights of biosynthesized and commercial gellan were determined as 6.88 × 105, 1 × 106, respectively. FTIR and 1H NMR spectral analysis were applied for the purpose of clarifying structures of polymers. Regarding the rheological properties, Herschel–Bulkley model better described the flow behavior of the gum solutions. The commercial gellan gum showed higher viscosity than the biosynthesized gellan. Rheological properties of polymer were affected by changes in the acyl substitution. The biosynthesized gellan from grape pomace showed better stability against temperature changes than commercial gellan gum. © 2020Öğe Identification of Propionibacterium spp. Isolated from Mihaliç Cheeses by MALDI-TOF MS(2019) Sivri, Göksel Tırpancı; Öksüz, ÖmerPropionic acid bacteria (PAB) are responsible for characteristic properties of Mihaliç cheese, which is one of the most prevalent traditional cheese types produced in Turkey. Recently, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been reliable and rapid method for identifying bacterial isolates. The aim of this study was to evaluate the PAB profile of Mihaliç cheese by their identification by MALDI-TOF MS system. In this study, a total of 25 cheese samples were analyzed and 95 isolates were determined as probable PAB based on their morphological characteristics, gram staining, catalase activity and pigment production. All isolates were analyzed by MALDI-TOF MS and 21 of them were belong to PAB. Isolates were identified as Propionibacterium freudenreichii ssp. freudenreichii (57%), Propionibacterium freudenreichii ssp. shermanii (33%) and Propionibacterium thoenii (10%). This study indicates that the diversity of PAB found in Mihaliç cheese can be determined rapidly and economically by MALDI-TOF MS.Öğe Investigating the GMO Existence in Chips and Breakfast Cereals Marketed in Turkey(Univ Namik Kemal, 2021) Mutlu, Şebnem; Şimşek, Osman; Öksüz, ÖmerIn this research, processed or low processed samples containing corn or corn products (corn semolina, flour, etc.) and soybean were randomly collected from the market, and 25 products in total (chips, nuts, cereals, flour) were analyzed for genetic modification using DNA based detection method, the polymerase chain reaction. First, homogenization of the samples was performed. Then DNA isolation was done by using Cetyl Trimethyl Ammonium Bromide (CTAB) and Roche High Pure DNA Isolation Kit. Since the Roche High Pure DNA Isolation Kit gave better results, the analysis was completed with this method. After DNA isolation, the detection of the Lectin gene, Zein gene, CaMV 35S Promoter and NOS Terminator regions was performed by conventional PCR. Zein gene determination was done for searching and proving corn presence and similarly, Lectin gene determination was done for searching and proving soybean presence in the samples by conventional PCR. GMO3/GMO4 and Zein3/Zein4 primer pairs were used for Lectin and Zein gene determination, respectively. The amplification of DNA was observed in agarose gel electrophoresis. Lectin or Zein genes were detected in 17 samples while these genes were not detected in 8 samples. Samples, in which Lectin or Zein gene was detected were scanned for 35S promoter or NOS terminator. 35S-3/35S-6 and tNOS2F/tNOS2R primer pairs were used for scanning 35S Promoter and NOS Terminator, respectively. To observe possible contamination in the mix sterilized deionized water was used and 0% Bt-11 and 0% GTS 40-3-2 were used as a negative control, 5% Bt-11 and 10% GTS-40-3-2 were used as a positive control. All of the 25 samples did not provide enough DNA with the required quality. This result was considered to be sourced by the applications (frying, extruding, pressing etc.) that samples had been exposed to during processes. Neither 35S Promotor nor NOS Terminator was determined from any of the samples.Öğe Optimization of fat content and pH level of unsalted fresh cheese used in the manufacturing of cheese halva (Hosmerim)(Blackwell Publishing, 2008) Kurultay, Şefik; Öksüz, Ömer; Taş, MahireCheese halva (Hosmerim) is a popular Turkish dessert composed mainly of unsalted fresh cheese. In this research, the effects of critical process parameters such as different fat and pH levels on some compositional and structural characteristics of cheese halva were investigated. The fat levels of unsalted fresh cheese at four different pH values (4.8, 5.0, 5.2 and 5.4) were adjusted to 5%, 15%, 20% and 25% by the addition of pasteurised fresh cream. According to the results, some compositional and structural properties of experimental samples, determined for both parameters (fat, pH), are as follows, respectively: dry matter (%): 51.76-65.72, 58.24-61.21; total sugar (%): 21.16-25.64, 22.19-23.79; starch (%): 12.17-13.49, 12.21-14.18; protein (%): 6.70-7.46, 6.79-7.35; titratable acidity (%): 0.22-0.24, 0.20-0.28; ash (%): 0.87-0.93, 0.83-0.94; hardness (loadgram): 43.75-55.75, 34.50-78.75. Both of the investigated parameters were affected significantly by dry matter, total sugar and starch contents of the samples (P < 0.01). Decrease in the pH value from 5.4 to 5.2 caused approximately 1-2 units increase in dry matter and starch contents. In the manufacturing of Cheese Halva, 5% fat and pH 5.2 for fresh cheese were determined as the most suitable process parameters.Öğe Propiyonik Asit Bakterileri ile B12 Vitamini Üretimi ve Etkili Parametrelerin İncelenmesi(2022) Küçükaydın, Hayriye Göknur Ağca; Sivri, Göksel Tırpancı; Öksüz, ÖmerPropiyonik asit bakterileri (PAB) ürettikleri metabolitler nedeniyle (vitaminler, propiyonik asit, konjuge linoleik asit, biyoaktif peptidler) son derece önemlidir. Günümüzde sağlıklı beslenmeye yönelik olarak günden güne artan ilgi çalışmalarla birlikte probiyotikler, postbiyotikler ve fonksiyonellik kavramlarının oluşmasına neden olmuştur. B12 vitamini PAB’ın ürettiği postbiyotiklerden olup, insan sağlığına faydalı olduğu bilinmektedir. Koenzim özelliği taşımasından dolayı vücutta önemli olaylarda rol oynamasının yanında, antiinflamatuar özellik göstermektedir. Yetişkinler için önerilen diyette B12 vitamini alımı 4 ?g/gün’dür. B12 vitamininin hayvansal gıdalarda bulunduğu ve süt ürünlerinde bulunan B12 vitamininin biyoyararlığının daha fazla olduğu bilinmektedir. Fermente süt ürünleri özellikle PAB’ı doğal mikroflorasında bulunduran ürünler B12 vitaminin üretiminde ve alınmasında iyi birer araç olmaktadır. Bu çalışmada PAB’ın B12 vitamini üretim sürecini etkileyen pH, sıcaklık, havalandırma, inokulum tipi ve oranı gibi faktörler irdelenmiştir.Öğe Proving of the cheese Halva (Hosmerim) manufacturing process(Wiley, 2009) Kurultay, Şefik; Öksüz, Ömer; Kaptan, BinnurCheese Halva (CH) is a traditional Turkish dessert. The cooking stage is the most important process step in CH manufacturing, which needs a skilled person. Faults made in this step lead to structural defects in the final product. In this research, four commercial melting salt mixes and trisodium citrate were tested to establish whether the melting salts would eliminate the textural faults in the final product and provide a uniform texture. To determine the changes occurred in CH, some physicochemical, textural (hardness, firmness, springiness, gumminess) and sensorial properties were examined. Trisodium citrate was found to be the most suitable one among those tested.Öğe The Effect of Environmental Factors on Heavy Metal and Mineral Compositions of Raw Milk and Water Samples(Namık Kemal Üniversitesi, Ziraat Fakültesi, 2016) Bıgucu, Ertuğrul; Kaptan, Binnur; Palabıyık, İbrahim; Öksüz, ÖmerIn this research, the concentrations of essential metals (Mn, Zn, Cr, Cu, Co), toxic metals (Cd, Pb) and some minerals (Al, Ca, K, Na, Fe, Mg) were determined in raw cow's milk and water samples collected from 3 different regions at 3 different periods (November-December, February-March and April-May). The regions from those areas are close to heavy industry plants (Yeniçiftlik), food producing plants (Gümüşçay) and highways (Şakirbey) in Biga county of Çanakkale province, Turkey. Metals and mineral contents of the samples were determined by using inductively coupled plasma-atomic emission spectrometry (ICP-AES). This study showed that heavy metal concentrations in the two most important liquid food were found to differ from region to region due to environmental factors such as rainfall and industrialization. However, for mineral concentrations in the water and milk samples, no change was observed according to regional pollution parameters.Öğe The Influence of Different Total Solid, Stabilizer and Overrun Levels in Industrial Ice Cream Production Using Coconut Oil(Wiley, 2010) Kurultay, Şefik; Öksüz, Ömer; Gokcebag, OzkanThe purpose of this research was to explain the combined effects of different total solid (TS) contents (20, 30 and 40%), stabilizer types (guar gum [GG], locust bean gum [LBG], carboxymethyl cellulose [CMC]) and overrun rates (OR) (30, 60 and 90%) on mix viscosity, melting time and hardness properties, which are the most important quality characteristics on industrial ice cream production. According to the investigation parameters; GG gave significantly less viscosity to the mix than LBG and CMC. In other words, LBG and CMC may be preferred to increase the viscosity of the mix or to limit the growth rate of ice crystals during recrystallization. Softness of ice creams and melting rapidity were linearly proportional to the increase of TS and ORs.
