Production and purification of xylooligosaccharides from oil palm empty fruit bunch fibre by a non-isothermal process

Oil palm empty fruit bunches (OPEFB) fibre, a by-product generated from non-woody, tropical perennial oil palm crop was evaluated for xylooligosaccharides (XOS) production. Samples of OPEFB fibre were subjected to non-isothermal autohydrolysis treatment using a temperature range from 150 to 220 ºC. The highest XOS concentration, 17.6 g/L which relayed from solubilisation of 63 g/100 g xylan was achieved at 210 ºC and there was a minimum amount of xylose and furfural being produced. The chromatographic purification which was undertaken to purify the oligosaccharide-rich liquor resulted in a product with 74–78% purity, of which 83–85% was XOS with degree of polymerisation (DP) between 5 and 40

Validation et assurance qualité appliquée à la composition chimique du lait de chèvre : mesures des minéraux et éléments traces.

In the present study, quality assurance programmes were implemented to validate and control the analytical methodologies used for the characterization of minerals and trace elements in goat milk from Portuguese breeds. With the exception of chloride that was determined by potentiometric titration, all the other elements were determined by spectroscopic techniques after different sample decomposition: P was measured by ultraviolet-visible molecular absorption spectrometry, Ca, Fe, K, Mg, Mn, Na and Zn by flame atomic absorption spectrometry and Cd, Co, Cr, Cu, Mo, Ni and Pb by electrothermal atomic absorption spectrometry. The methods performance characteristics, namely specificity, limit of detection, limit of quantification, working range, precision and trueness were evaluated. Measurement uncertainty was expressed in terms of precision and trueness. Precision under intralaboratory reproducibility conditions was estimated from triplicate analysis, and the trueness component was estimated in terms of overall recovery using either skim milk powder certified reference materials or spiked samples. The results obtained are discussed on the basis of the performance criteria required by EC regulations to verify when a method is suitable for food control. The methods used for the characterization of minerals and trace elements in goat milk complied with EC requirements since there was no matrix influence, the Horrat values were $<$ 2.0, recoveries were within the interval 1.00 $\pm$ 0.10 for minerals and 1.00 $\pm$ 0.20 for trace elements and the combined uncertainty of the results were lower than the maximum standard uncertainty calculated using the uncertainty function approach. In relation to the limits of detection and quantification, the limits obtained for Pb were lower than those specified by EC regulation.Dans ce travail, des programmes d'assurance de la qualité ont été mis en œuvre afin de valider et de contrôler les méthodes d'analyse utilisées pour caractériser les minéraux et les éléments traces du lait de chèvres de race portugaise. À l'exception du chlorure, qui a été déterminé par titrage potentiométrique, tous les autres éléments ont été déterminés par différentes techniques spectroscopiques après décomposition de l'échantillon : P a été mesuré par spectrométrie d'absorption moléculaire ultraviolet-visible (UV-VIS-MAS), Ca, Fe, K, Mg, Mn, Na, et Zn par spectrométrie d'absorption atomique de flamme (FAAS) et Cd, Co, Cr, Cu, Mo, Ni et Pb par spectrométrie d'absorption atomique électrothermique (ETAAS). Les caractéristiques de performance des méthodes, à savoir la spécificité, limite de détection, limite de quantification, la plage de travail, la précision et la justesse ont été évaluées. Les incertitudes de mesure ont été exprimées en termes de précision et de justesse. La précision sous des conditions de reproductibilité intralaboratoire a été estimée à partir des analyses en triple. La justesse a été estimée en termes de récupération globale, soit en utilisant des poudres de lait matériaux de référence certifiés ou des échantillons dopés. Les résultats obtenus sont discutés sur la base des critères de performance requis par les règlements CE pour vérifier qu'une méthode est adaptée au contrôle des aliments. Les méthodes utilisées pour la caractérisation des minéraux et des éléments traces dans le lait de chèvre se conformaient aux exigences de la CE car il n'y avait pas d'influence de la matrice, les valeurs de Horrat étaient inférieures à 2,0 ; les récupérations étaient dans l'intervalle $1,00 \pm 0,10$ pour les minéraux et dans l'intervalle $1,00 \pm 0,20$ pour les éléments traces et l'incertitude combinée des résultats était inférieure à l'incertitude normalisée maximale, calculée en utilisant la fonction de l'incertitude. En ce qui concerne les limites de détection et de quantification, nos limites calculées pour le plomb étaient inférieures à celles spécifiées par le règlement CE

Fractionation of Hemicelluloses and Lignin from Rice Straw by Combining Autohydrolysis and Optimised Mild Organosolv Delignification

An integrated strategy was followed to valorise rice straw, one of the most relevant biomass feedstocks available worldwide, to selectively recover solubilised hemicelluloses and lignin. The pathway encompassed the use of autohydrolysis to hydrolyse the hemicelluloses and an ethanol-based organosolv process to solubilise lignin. Several autohydrolysis conditions were assayed with the best results obtained at 210 ºC (log R0 4.15), which enabled high removal of hemicelluloses, yielding an oligosaccharide-rich hydrolysate and a treated biomass with low content of hemicelluloses and enriched in cellulose and lignin. The effects of ethanol concentration (5 to 75%), and reaction time (0 to 24 h) on lignin removal under mild temperature (30 ºC) were studied. In optimal conditions (60.5% ethanol, 24h) the delignification yield reached 42%, whereas glucan solubilisation was below 17%. Lignin solubilisation yield was not influenced by the organosolv treatment duration while ethanol concentration favored the delignification up to 60.5% ethanol. The organosolv liquors contained economic interesting lignin-derived compounds such as vanillin, ferulic, and coumaric acids. The chemical composition and enzymatic digestibility of the treated biomass from autohydrolysis and organosolv delignification were compared, with the latter presenting an almost 10% higher enzymatic digestibility than the former

The use of flow cytometry to assess Rhodosporidium toruloides NCYC 921 performance for lipid production using Miscanthus sp. hydrolysates

The yeast Rhodosporidium toruloides NCYC 921 was used for lipid production, using Miscanthus biomass hydrolysate as carbon source. The hydrolysate was obtained by enzymatic hydrolysis of Miscanthus biomass (at high solids loading) previously subjected to a hydrothermal pre-treatment. Afterwards R. toruloides was grown on Miscanthus sp. hydrolysate (MH), undiluted and diluted, at the ratios of 1:4 (20 % v/v), 1:2 (33.3 % v/v) and 3:1 (75 % v/v). The best yeast performance was observed for MH 1:2 medium dilution, reaching the maximal biomass concentration of 6.3 g/L, the lipid content of 30.67 % w/w dry cell weight and the lipid concentration of 1.64 g/L. Flow cytometry demonstrated that R. toruloides cell membrane was massively damaged when the yeast was grown on undiluted MH, due to the presence of phenolic compounds; however, when the yeast was grown on diluted MH 1:2 and 1:4, the proportion of intact cells has increased during the yeast cultivation

Bioproducts from forest biomass: Essential oils and hydrolates from wastes of Cupressus lusitanica Mill. and Cistus ladanifer L.

Unattended forest wastes are, among others, a potential source of wildfires, as well as a growth media for forest pests. As a way of lowering the detrimental effect of these wastes, it is important to convert these under-valued resources into a value-generating market forest wastes use. Essential oils (EOs) and hydrolates (Hs) from Cupressus lusitanica and Cistus ladanifer waste products, resulting from forest landscaping in Portugal, were evaluated for chemical composition and biological activity. Essential oils and Hs were obtained by steam-distillation (SD) and hydrodistillation (HD). Essential oils and Hs volatiles were analysed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC–MS). The antimicrobial activity of EOs was studied by disk agar diffusion method against Escherichia coli, Staphylococcus aureus and Candida albicans. Antioxidant activity of EOs and Hs was evaluated by 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) free radical, superoxide anion radical formation, xanthine oxidase and chelating metal ions assays. Antiinflammatory activity of Hs was assessed by albumin denaturation assay. Monoterpene hydrocarbons and oxygen-containing monoterpenes dominated C. lusitanica EO (SD, 82–86 %, HD, 80–85 %) and Hs volatiles (SD, 93–94 %; HD 64–81 %), respectively. α-Pinene (14–36 %), limonene (8–21 %), δ-3-carene (8–19 %) and sabinene (6–18 %) were the main EO constituents. Hydrolates volatiles were dominated by cis-3-hexen-1-ol (0.1–13 %), camphor (1–11 %), umbellulone (t-48 %), p-cymene-8-ol (11–16 %) and terpinen-4-ol (21–31 %). C. ladanifer EOs were dominated by monoterpene hydrocarbons (SD, 48–80 % and HD, 29 %) and Hs by oxygencontaining monoterpenes (SD, 38–43 %, HD, 39 %). The EO major constituents were α-pinene (13–28 %) and camphene (5–25 %), whereas 2,6,6-trimethyl cyclohexanone (2–12 %) and trans-pinocarveol (5–13 %) dominated the Hs volatiles. This study reports for the first time the chemical composition of the hydrolate volatiles of these two species and their anti-inflammatory properties. Among the studied biological activities, the EOs showed the best antioxidant properties while Hs demonstrated higher anti-inflammatory activity.info:eu-repo/semantics/publishedVersio