WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7150

Browse

Filters

2023 - 20253

Settings

Author: search.filters.author.Sabanci, Kevser

Search Results

Now showing 1 - 3 of 3
  • Article
    Chain-Length Dependent and Synergistic Prebiotic Effects of Xylooligosaccharides and Xylan on the Fecal Microbiota of Mice in Vitro
    (Elsevier, 2025) Büyükkileci, Ali Oğuz; Güleç, Şükrü; Buyukkileci, Ali Oguz; 01. Izmir Institute of Technology; 03.08. Department of Food Engineering; 03. Faculty of Engineering
    Oligomeric and polymeric prebiotics differ in their structural complexity, which influences microbial accessibility and fermentation kinetics. This study investigated the microbial responses to xylooligosaccharides (XOS), xylan (XY), and their combinations in comparison with inulin (INU) using an in vitro model inoculated with BALB/c mice fecal microbiota. Temporal analyses over 48 h included substrate consumption, acid production, and changes in microbial diversity. XOS was rapidly fermented, yielding high acetate and lactate levels, whereas XY was utilized more slowly due to its polymeric structure. During XY fermentation, xylobiose (X2) and xylotriose (X3) accumulated transiently, suggesting a stepwise depolymerization and utilization mechanism. The XOS + XY mix showed enhanced prebiotic effect, producing the highest amount of acid (151.8 mmol/L) and notably promoted the simultaneous enrichment of Bifidobacterium (12.5-fold), Bacteroides (8.85-fold), and Lactobacillus (14.9-fold) species compared to individual treatments These findings demonstrate that coadministered XOS and XY highlights the potential for designing tailored prebiotic formulations to optimize microbiota modulation, with potential relevance for human health.
  • Article
    Citation - WoS: 3
    Citation - Scopus: 3
    An Ex Vivo Model for Evaluation of Prebiotic Activity of Xylan and Xylooligosaccharides
    (Elsevier, 2025) Güleç, Şükrü; Büyükkileci, Ali Oğuz; Buyukkileci, Ali Oguz; 03.08. Department of Food Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    Ex vivo techniques can provide more physiologically significant insights into prebiotic activity and overcome some limitations of in vitro tests. In this study, an ex vivo model, formed of a large intestine of mice, was tested to assess the effects of the hydrocolloidal natural polymer, xylan (XY), and its hydrolysis product, xylooligosaccharides (XOS). XY and XOS were loaded separately into the cecum, proximal colon, and distal colon. Their utilization and short-chain fatty acid (SCFA) formation by the colonized microflora and levels of dominant phyla and key genera such as Bifidobacterium, Bacteroides, and Lactobacillus were followed. XY and XOS were metabolized in all sections, and SCFAs were released. The results suggest that the slower utilization of XY compared to XOS in the cecum can enable this polysaccharide to move towards distal parts of the large intestine and extend the sites of prebiotic activity. Unlike widely used in vitro models, the ex vivo model allowed testing the utilization pattern and effects of the prebiotics in the natural environment of the microflora and examining the intestinal sections separately.
  • Article
    Citation - WoS: 5
    Citation - Scopus: 5
    The Potential of Walnut Shells for Production of Oligosaccharides by Liquid Hot Water Treatment
    (Springer Heidelberg, 2023) Surek, Ece; Büyükkileci, Ali Oğuz; Buyukkileci, Ali Oguz; 03.08. Department of Food Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    Walnut shell (WS), which is discarded in a large amount, is usually utilized for heating purposes; therefore, obtaining fuctional products can add value to this waste biomass. In this study, xylan was determined as the dominant carbohydrate (18.6% of dry weight) in WS. The potential applicability of liquid hot water (LHW) treatment to WS was investigated in order to solubilize hemicellulose and hydrolyze it into oligomers such as xylooligosaccharide (XOS) as a prebiotic oligosaccharide and recover solid and liquid fractions, which can be raw materials for other value-added products. LHW was applied at different temperatures (170-210 degrees C) for various times (15-120 min), and their effect was combined calculating severity factor (log R-o = 3.39-4.74). The solubilization of biomass was increased (up to 60.9%) with severity. Under optimum conditions (log R-o of 3.95, 190 degrees C-15 min), 81.5% of xylan was hydrolyzed and recovered as mainly XOS (69.8% of xylan), and also xylose and arabinose. The total oligosaccharide (XOS, arabino, gluco- and galacto-oligosaccharides) and monosaccharide (mainly xylose) concentration were 14.3 and 2 g/L, respectively, and by-products did not exceed 1.6 g/L. Moreover, 2.5 mg GAE/mL of total phenolics were obtained at those conditions, whereas that was raised to 3.4 mg GAE/mL at harsher conditions. This study presented that LHW treatment was an eco-friendly alternative method for valorization of WS through production of a liquid with high value-added compounds such as oligosaccharides and solid rich in cellulose and lignin.