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The cell walls of cereals are rich sources of polysaccharide β-glucan. In this study, the β-glucan was extracted from oat bran using the hot-water extraction method and dried in a pure powder form. The concentration of the β-glucan in the extract was determined using the l-cysteine sulfuric acid method. The results showed that the yield of β-glucan using the hot-water extraction method is the highest compared to its yield achieved by enzymatic, acid, and alkaline methods. In this paper, the usage of the β-glucan as a coating material for a water-insoluble carotenoid is considered. This study demonstrates for the first time the encapsulation of β-carotene with modified octanoic acid β-glucan. It implements to obtain a stable encapsulated polysaccharide-carotenoid system, which has been studied by a set of physicochemical methods and a cytotoxic analysis was performed on the HCT-116 cell line. The SEM image of the resulting encapsulated system is perfectly correlated with the DLS data, which has determined the size of MG capsules at 200 nm. The cytotoxic analysis demonstrates that the cell viability was more than 70%, which indicates its potential using in the food industry. [ABSTRACT FROM AUTHOR]

Wheat straw and okra stalk were studied to evaluate their potential use for integrated lignocellulosic biorefining. Besides chemical pulp, a wide spectrum of value-added by-products were prepared by hot-water extraction of the feedstocks under varying conditions (140 °C for 60 and 240 min and 150 °C for 25 and 100 min) prior to sulfur-free soda-anthraquinone (AQ) pulping (NaOH charge 15 and 20% by weight on o.d. feedstock for wheat straw and okra stalk, respectively, with an AQ charge of 0.05% by weight on o.d. for both feedstocks). During the hot-water pre-treatment, the most significant mass removal, respectively, 12% (w/w) and 23% (w/w) of the initial wheat straw and okra stalk was obtained at 150 °C with a treatment time of 100 min. The hydrolysates were characterized in terms of pH and the content of carbohydrates (6-20% (w/w) of the initial amount), volatile acids (acetic and formic acids), and furans. The pre-treatment stage also facilitated the delignification stage, and, for example, the pulp yields (w/w), 57% (145 °C, 15 min, and kappa number 18) and 41% (165 °C, 180 min, and kappa number 32) were obtained for the pre-treated (150 °C, P200) wheat straw and okra stalk, respectively. Results clearly indicated that both non-wood materials were suitable for this kind of biorefining approach. [ABSTRACT FROM AUTHOR]

The effect of hot-water extraction and two types of fungal decay, brown rot and white rot, on wood crystalline cellulose structure was examined using a combination of X-ray diffraction (XRD) and C solid-state nuclear magnetic resonance (NMR) spectroscopy. Although having opposite effects on the overall crystallinity of the wood, the XRD results revealed that both extraction and brown-rot decay caused a significant decrease in the 200 crystal plane spacing ( d-spacing) not seen for the white-rotted samples. This effect was found to be additive, as samples that were first extracted, then decayed showed a double decrease in d-spacing compared to that caused by extraction alone. This suggested that, despite having a similarly directed effect on the spacing of the crystalline planes, the two treatment methods facilitate a decrease in d-spacing in different ways. NMR results support the conclusion of differing structural effects, suggesting that the hot-water extraction procedure was causing a co-crystallization of existing crystalline domains, while the brown rot decay was depolymerizing the cellulose chains of the crystals, possibly allowing the remaining crystalline material the freedom to relax into a more energetically favorable, tightly packed state. These findings could have important implications for those seeking to understand the effects of modification treatments or biodegradation of crystalline cellulose nanostructures in their native states. [ABSTRACT FROM AUTHOR]

Hot-water pretreatment was performed on wood strands to investigate effects of the extraction of hemicellulose under different temperature (140, 155, and 170 °C) and time durations (30 and 60 min) conditions. Hydrolysate was analyzed by means of high-performance liquid chromatography. Chemical changes in the surface of wood strands were studied by infrared spectroscopy. The effects of hemicellulose extraction on the wettability of wood strands were studied by measuring the contact angle and surface free energy. The mechanical properties of wood cell walls before and after treatment were studied by nanoindentation. Among the extracted monosaccharides, mannose was found in the highest concentration. The mechanical properties of cell walls showed little decrease after extraction. The chemical changes in the surface of the wood strands reduced wettability of wood surface by water and produced hydrophobic characteristics after extraction. [ABSTRACT FROM AUTHOR]

The relationship between total extractive content and durability of Nauclea diderrichii (de Wild.) Merr. and Corynanthe pachyceras Welw. from the Rubiaceae and Nesogodornia papaverifera (A. Chev.) R. Capuron. from the Tiliaceae has been investigated. The extractive content of each wood was measured and blocks were exposed to Coriolus versicolor (Linnaeus) Quelet for 8 weeks. An inverse relationship was found between extractive content and weight loss. From the results, it was found that N. diderrichii (extractive content = 13.29-13.96%; weight loss = 1.02-1.91%) is the most durable species, followed by C. pachyceras heartwood (extractive content = 12.56-14.19%; weight loss = 5.80-8.21%) and N. papaverifera (extractive content = 10.18-10.65%; weight loss = 8.22-9.01%). For these species, total extractive content is consistently related to the durability of the hardwoods. [ABSTRACT FROM AUTHOR]