Yazar "Sagdic, Osman" seçeneğine göre listele

Listeleniyor 1 - 3 / 3
  • Küçük Resim Yok
    Öğe
    Development of a fermented ice-cream as influenced by in situ exopolysaccharide production: Rheological, molecular, microstructural and sensory characterization
    (Elsevier Sci Ltd, 2016) Dertli, Enes; Toker, Omer S.; Durak, M. Zeki; Yilmaz, Mustafa T.; Tatlisu, Nevruz Berna; Sagdic, Osman; Cankurt, Hasan
    This study aimed to investigate the role of in situ exopolysaccharide (EPS) production by EPS+ Streptococcus thermophilus strains on physicochemical, rheological, molecular, microstructural and sensory properties of ice cream in order to develop a fermented and consequently functional ice-cream in which no stabilizers would be required in ice-cream production. For this purpose, the effect of EPS producing strains (control, strain 1, strain 2 and mixture) and fermentation conditions (fermentation temperature; 32,37 and 42 degrees C and time; 2,3 and 4 h) on pH, S. thermophilus count, EPS amount, consistency coefficient (K), and apparent viscosity (eta(50)) were investigated and optimized using single and multiple response optimization tools of response surface methodology. Optimization analyses indicated that functional ice-cream should be fermented with strain 1 or strain mixture at 40-42 degrees C for 4 h in order to produce the most viscous ice-cream with maximum EPS content. Optimization analysis results also revealed that strain specific conditions appeared to be more effective factor on in situ EPS production amount, K and 1750 parameters than did fermentation temperature and time. The rheological analysis of the ice-cream produced by EPS+ strains revealed its high viscous and pseudoplastic non-Newtonian fluid behavior, which demonstrates potential of S. thermophilus EPS as thickening and gelling agent in dairy industry. FTIR analysis proved that the EPS in ice-cream corresponded to a typical EPS, as revealed by the presence of carboxyl, hydroxyl and amide groups with additional alpha-glycosidic linkages. SEM studies demonstrated that it had a web-like compact microstructure with pores in ice-cream, revealing its application possibility in dairy products to improve their rheological properties. (C) 2015 Published by Elsevier Ltd.
  • Küçük Resim Yok
    Öğe
    Effect of drying methods on free and bound phenolic compounds, antioxidant capacities, and bioaccessibility of Cornelian cherry
    (Springer, 2024) Bayram, Hatice Merve; Ozkan, Kubra; Ozturkcan, Arda; Sagdic, Osman; Gunes, Esra; Karadag, Ayse
    Cornus mas L. (Cornelian cherry, CM) fruits were dehydrated by solar-drying (SD) and freeze-drying (FD), and in addition to sugar and mineral contents, the free and insoluble-bound phenolics were determined in fresh and dried fruits. After subjecting the sample to simulated in vitro digestion, the change of free and bound phenolics at gastric and intestinal digestion steps was evaluated in fresh and dried CM fruits. In fresh CM fruits, the total phenolic content (TPC) was dominated by the bound fraction, whereas the contribution of free phenolics to the total content (free + bound) became more dominant (731-1439 mg GAE/100 g dw) in the dried fruits. The bioaccessibility (BI%) of TPC from fresh CM after digestion was 193%, whereas it was 18.60 and 48.02% for SD and FD fruits, respectively. The contribution free fraction to the total TPC value was around 28% in nondigested fresh samples and increased to 94% in digested samples; however, in dried samples, it was 64% prior to digestion and only increased to 70% in digested samples. A total of 17 phenolic compounds were identified in CM fruits: chlorogenic acid, caffeic acid, epicatechin, quercetin, cyanidin-3-O-glucoside, and pelargonidin 3-O-glucoside were only detected in the free fraction; gallic acid, vanillic acid, ferulic acid, and kaempferol were detected in higher amounts in the bound fraction. The quantity of detected phenolics in the nondigested sample generally decreased from the gastric to the intestinal stage of digestion. The release of phenolics from the fruit matrix and their degradation occurred simultaneously during digestion, and this could be affected by the state of the fruit, e.g., fresh or dried.
  • Küçük Resim Yok
    Öğe
    Effects of in situ exopolysaccharide production and fermentation conditions on physicochemical, microbiological, textural and microstructural properties of Turkish-type fermented sausage (sucuk)
    (Elsevier Sci Ltd, 2016) Dertli, Enes; Yilmaz, Mustafa Tahsin; Tatlisu, Nevruz Berna; Toker, Omer Said; Cankurt, Hasan; Sagdic, Osman
    In this work, the role of in situ exopolysaccharide (EPS) production under different fermentation conditions on physicochemical, microbiological, textural and microstructural properties of sucuk was determined. For this purpose, the effect of EPS producing strains (control, strain 1, strain 2 and mixture) and fermentation conditions (fermentation temperature; 14, 16 and 18 C and time; 8, 12 and 16 days) on physicochemical, microbiological, textural and microstructural properties were investigated using response surface methodology. In situ EPS production was observed to remarkably affect these properties while fermentation conditions were also seen to dominantly influence the physicochemical properties of sucuk, revealing that the ripening temperature appeared to be more determinant factor. EPS producing cultures enhanced the textural properties of sucuk which became harder, less adhesive and tougher. The microstructural analysis revealed the formation of web -like structure by in situ EPS production in sucuk mix during fermentation process. This study revealed the importance of in situ EPS production on final technological properties of sucuk. (C) 2016 Elsevier Ltd. All rights reserved.