Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

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Access Right: Closed AccessSubject: search.filters.subject.Xylooligosaccharides

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  • 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: 8
    Citation - Scopus: 7
    Delignification of Corncob by Choline Chloride-Urea Deep Eutectic Solvent for Enzymatic Production of Xylooligosaccharides
    (Elsevier B.V., 2024) Büyükkileci, Ali Oğuz; Buyukkileci,A.O.; 01. Izmir Institute of Technology; 03.08. Department of Food Engineering; 03. Faculty of Engineering
    Deep eutectic solvent (DES) pretreatment was applied to corncob to obtain xylooligosaccharides (XOS) by enzymatic hydrolysis using xylanase. Based on the XOS titers in the hydrolysate, urea was the most effective among the hydrogen bond donors tested to couple choline chloride (ChCl). DES pretreatment at 130 °C for two hours with ChCl-Urea (molar ratio of 1:2) containing 40 % water, decreased lignin fraction from 12.8 % to 6.9 %, while 79 % of the xylan was retained in the pretreated corncob. The highest XOS production was obtained using 400 U/g xylanase at 60 °C, which yielded 12.0 g/L XOS with a low degree of polymerization (LDP-XOS). The total XOS yield based on the raw corncob was calculated as 14.4 %, 90 % of which was LDP-XOS. The cellulose-rich residual biomass could be hydrolyzed enzymatically to glucose with 65 % cellulose digestibility. The discarded biomass after hydrolyzes was 21.7 % of the raw material. The results showed that DES was a promising pretreatment for enhancing enzymatic XOS production. © 2024 Elsevier B.V.
  • Article
    Citation - WoS: 6
    Citation - Scopus: 6
    Organosolv Pretreatment of Corncob for Enzymatic Hydrolysis of Xylan
    (Springer, 2023) Büyükkileci, Ali Oğuz; Büyükkileci, Ali Oğuz; Temelli, Nuran; 03.08. Department of Food Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    Xylan is a renewable polysaccharide, readily available in agricultural and forestry residues. It can be hydrolyzed to produce xylooligosaccharides (XOS) with prebiotic activity and xylose, a precursor for several industrial chemicals. Enzymatic hydrolysis of xylan in the lignocellulosic biomass to obtain xylose and XOS requires a pretreatment to facilitate xylanase activity. In this study, organosolv was evaluated for the delignification of corncob while retaining xylan in the pretreated biomass. The treatment at 170 °C for 1 h with 70% ethanol provided 50% lignin removal and 81% xylan recovery. Increasing temperatures and decreasing ethanol fractions decreased the pH and the xylan recovery. Loss of xylan in the organosolv at 190 °C and in the liquid hot water treatment could be prevented by the addition of 100 mM MgO, without compromising lignin removal. Pretreated corncob was suspended in citrate buffer and hydrolyzed by commercial xylanases. Accellerase XY (250 U/ml) at pH 5.5 and 55 °C and Econase XT (0.6 U/ml) at pH 6.0 and 70 °C provided around 65% xylan digestibility and generated xylose (9.8 g/l) and XOS (10.9 g/l), respectively. This approach could decrease xylan loss and degradation in the pretreatment step and yield clear hydrolysates composed of essentially xylose or XOS. Lignocellulosic biorefineries can benefit from the efficient utilization of xylan, increasing sustainability. © 2023, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.