Cross-linkages with polysaccharides and lignin compromise hydroxycinnamic acid yields and purity in integrated biorefineries. A two-stage-alkaline-based process was sequentially optimised in a wheat straw (WS) and wheat bran (WB)-based biorefinery setup for selective co-production of hydroxycinnamic acids (p-Coumaric acid & ferulic acid) with hemicellulose at the mild-alkaline stage (MAS), and with lignin & cellulose-rich residues at severe-alkaline stage (SAS). The optimum MAS biorefining conditions gave hemicellulose, lignin, and hydroxycinnamic acid yields of 35, 60, and 85 % for WS, and 37, 72, and 66 % for WB, respectively.
View Article and Find Full Text PDFEndoinulinase gene was expressed in recombinant Aspergillus niger for selective and high-level expression using an exponential fed-batch fermentation. The effects of the growth rate (μ), glucose feed concentration, nitrogen concentration and fungal morphology on enzyme production were evaluated. A recombinant endoinulinase with a molecular weight of 66 kDa was secreted.
View Article and Find Full Text PDFTwo methods, HCl and enzymatic treatments, were evaluated for diversification of morphological and functional properties of cellulose nanofibers (CNF) from two- stage-alkaline pre-treated wheat straw (WS). The extraction conditions were optimized by a central composite designed experimental approach varying time (4-8 h) and temperature (80-120 °C) for the HCl-based treatment and time (4-8 h), and FiberCare dosage (50-100 endo-1,4-β-glucanase unit/g) and Viscozyme (10-20 fungal β-glucanase units/g) for the enzyme-based treatment. The CNF yields, morphological (polydispersity index (PdI), length and diameter), and functional (crystallinity and thermal degradation) properties were compared.
View Article and Find Full Text PDFLignin valorisation into materials such as resins is essential to increase the value obtained from biomass. However, biomass recalcitrance limits the selective isolation of lignin for economic gains. This study developed a new process for fractionating alkaline treated mango seed husk into high purity lignin and cellulose-rich pulp, using high shear homogenization-organosolv (HSHO) process.
View Article and Find Full Text PDFJ Food Sci Technol
February 2020
An increase in inulin and plant-protein based nutraceutical demand ultimately puts pressure on available resources. Therefore, there is a need to prospect for supplementary feedstocks and sustainable ways to exploit them. The aim of this study was to explore the technical feasibility of sequential extraction of inulin and protein from tubers and understand the interrelationships between processes and product functional properties.
View Article and Find Full Text PDFCassava waste is a potential bioresource for integrated biorefineries to co-produce bioproducts [succinic acid (SA), glucose syrup (GS), bioethanol] and combined heat and power (CHP). Techno-economic assessments of five biorefinery scenarios for integration in cassava starch plant (200 Mg/d), co-processing 377.83 Mg/h wastewater (CWW), 7.
View Article and Find Full Text PDFThis study evaluated the structural and performance differences between arabinoglucuronoxylan micro-hydrogels that were enzymatically produced from alkaline-extracted wheat bran arabinoglucuronoxylans using recombinant α-L-arabinofuranosidase (AbfB) that selectively removes arabinose side chains, and chemically through coacervation process, as delivery devices for bioactive substances. The encapsulations of model bioactive substance, gallic acid (GA), in the hydrogels, were done either in-situ or ex-situ to identify the most effective encapsulation and delivery method. The hydrogels particle size distribution, polydispersity index, GA encapsulation efficiency, retention and release of functional GA (based on antioxidant activity) were assessed.
View Article and Find Full Text PDFThe application of steam explosion pre-treatment to extract xylan-rich biopolymers from alkali-impregnated lignocelluloses, while simultaneously increasing the enzymatic digestibility of cellulose, was investigated. Steam-enhanced extraction of xylan from sugarcane trash (SCT) and aspen wood (AW) was performed at varying temperatures (176-204 °C) and retention times (3-17 min) after the impregnation of biomass samples with sodium hydroxide at 1:20 (w/w) solid loading ratio. Xylan extraction and cellulose digestibility results were statistically analysed to fix the condition/s for significantly enhanced values.
View Article and Find Full Text PDFThe aim of this study was to investigate the effect of low cost evaporative cooling system on the quality of two tomato cultivars, namely, 9065 jam and round tomatoes. Both the tomato cultivars were harvested from a smallholder farmer's field at Umsinga and stored for 20 days in one of the three storage conditions namely; cold room (CR), room temperature (RT) and evaporative cooling system (ECS) and sampling done every 5 days. The tomato samples were laid out as a factorial design with four replications.
View Article and Find Full Text PDFThe viability of single-step microwave-induced pressurized hot water conditions for co-production of xylan-based biopolymers and bioethanol from aspenwood sawdust and sugarcane trash was investigated. Extraction of hemicelluloses was conducted using microwave-assisted pressurized hot water system. The effects of temperature and time on extraction yield and enzymatic digestibility of resulting solids were determined.
View Article and Find Full Text PDFEffects on physical properties of white bread of adding crude (E1) and partially purified (E2) arabinoxylans (AX) from wheat bran to partially replace flour during baking, were investigated to identify optimal dosage. The E1 and E2 had molecular weights of 620,000 and 470,000Da with arabinose to xylose ratio of 0.7 and 0.
View Article and Find Full Text PDFThe functional properties of cellulose fibers can be modified by adsorption of xylan biopolymers. The adsorption is improved when the degree of biopolymers substitution with arabinose and 4-O-methyl-glucuronic acid (MeGlcA) side groups, is reduced. α-l-Arabinofuranosidase (AbfB) and α-d-glucuronidase (AguA) enzymes were applied for side group removal, to increase adsorption of xylan from sugarcane (Saccharum officinarum L) bagasse (BH), bamboo (Bambusa balcooa) (BM), Pinus patula (PP) and Eucalyptus grandis (EH) onto cotton lint.
View Article and Find Full Text PDFVery high gravity hydrolysis-fermentation of whole and decorticated sorghum grains were compared using conventional and cold hydrolysis methods to assess the extent by which decortication could minimize enzymes dosages and affect the quality of the distillers' dried grains with solubles (DDGS). All processing configurations achieved ethanol concentrations between 126 and 132 g/L (16.0-16.
View Article and Find Full Text PDFα-l-Arabinofuranosidase (AbfB) and novel α-d-glucuronidase (Agu1B) enzymes were applied for selective hydrolysis of beechwood (Fagus sylvatica) xylan (Sigma-Aldrich) as well as xylans extracted from Eucalyptus grandis and sugarcane (Saccharum officinarum L.) bagasse, leading to precipitation of these carbohydrate biopolymers. Hemicellulose extraction was performed with two mild-alkali methods, Höije and Pinto.
View Article and Find Full Text PDFAmong the world's continents, Africa has the highest incidence of food insecurity and poverty and the highest rates of population growth. Yet Africa also has the most arable land, the lowest crop yields, and by far the most plentiful land resources relative to energy demand. It is thus of interest to examine the potential of expanded modern bioenergy production in Africa.
View Article and Find Full Text PDFThe global sustainable bioenergy (GSB) project was formed in 2009 with the goal of providing guidance with respect to the feasibility and desirability of sustainable, bioenergy-intensive futures. Stage 1 of this project held conventions with a largely common format on each of the world's continents, was completed in 2010, and is described in this paper. Attended by over 400 persons, the five continental conventions featured presentations, breakout sessions, and drafting of resolutions that were unanimously passed by attendees.
View Article and Find Full Text PDF