102 research outputs found
Lime pretreatment of sugar beet pulp and evaluation of synergy between ArfA, ManA and XynA from Clostridium cellulovorans on the pretreated substrate
Sugar beet pulp (SBP) is a waste product from the sugar beet industry and could be used as a potential biomass feedstock for second generation biofuel technology. Pretreatment of SBP with âslake limeâ (calcium hydroxide) was investigated using a 23 factorial design and the factors examined included lime loading, temperature and time. The pretreatment was evaluated for its ability to enhance enzymatic degradation using a combination of three hemicellulases, namely ArfA (an arabinofuranosidase), ManA (an endo-mannanase) and XynA (an endo-xylanase) from C. cellulovorans to determine the conditions under which optimal activity was facilitated. Optimal pretreatment conditions were found to be 0.4 g lime/g SBP, with 36 h digestion at 40 °C. The synergistic interactions between ArfA, ManA and XynA from C. cellulovorans were subsequently investigated on the pretreated SBP. The highest degree of synergy was observed at a protein ratio of 75% ArfA to 25% ManA, with a specific activity of 2.9 U/g protein. However, the highest activity was observed at 4.2 U/g protein at 100% ArfA. This study demonstrated that lime treatment enhanced enzymatic hydrolysis of SBP. The ArfA was the most effective hemicellulase for release of sugars from pretreated SBP, but the synergy with the ManA indicated that low levels of mannan in SBP were probably masking the access of the ArfA to its substrate. XynA displayed no synergy with the other two hemicellulases, indicating that the xylan in the SBP was not hampering the access of ArfA or ManA to their substrates and was not closely associated with the mannan and arabinan in the SBP
The use of electric fields for edible coatings and films development and production: A review
Edible films and coatings can provide additional
protection for food, while being a fully biodegradable,
environmentally friendly packaging system. A diversity of
raw materials used to produce edible coatings and films are
extracted from marine and agricultural sources, including
animals and plants. Electric fields processing holds advantage
in producing safe, wholesome and nutritious food.
Recently, the presence of a moderate electric field during
the preparation of edible coatings and films was shown to
influence their main properties, demonstrating its usefulness
to tailor edible films and coatings for specific applications.
This manuscript reviews the main aspects of the use of
electric fields in the production of edible films and coatings,
including the effect in their transport and mechanical
properties, solubility and microstructure.Fundação para a CiĂȘncia e a Tecnologia (FCT), Portugal.Coordenação de Aperfeiçoamento de Pessoal de NĂvel Superior (CAPES), Brasil
An Integrated Biorefinery Concept for Conversion of Sugar Beet Pulp into Value-added Chemicals and Pharmaceutical Intermediates
Over 8 million tonnes of sugar beet are grown annually in the UK. Sugar beet pulp (SBP) is the main
by-product of sugar beet processing which is currently dried and sold as a low value animal feed. SBP
is a rich source of carbohydrates, mainly in the form of cellulose and pectin, including D-glucose
(Glu), L-arabinose (Ara) and D-galacturonic acid (GalAc). This work describes the technical feasibility
of an integrated biorefinery concept for fractionation of SBP and conversion of these
monosaccharides into value-added products.
SBP fractionation is initially carried out by steam explosion under mild conditions to yield soluble
pectin and insoluble cellulose fractions. The cellulose is readily hydrolysed by cellulases to release
Glu that can then be fermented by a commercial Yeast strain to produce bioethanol with a high
yield. The pectin fraction can be either fully hydrolysed, using physico-chemical methods, or
selectively hydrolysed, using cloned arabinases and galacturonases, to yield Ara-rich and GalAc-rich
streams. These monomers can be separated using either Centrifugal Partition Chromatography (CPC)
or ultrafiltration into streams suitable for subsequent enzymatic upgrading.
Building on our previous experience with transketolase (TK) and transaminase (TAm) enzymes, the
conversion of Ara and GalAc into higher value products was explored. In particular the conversion of
Ara into L-gluco-heptulose (GluHep), that has potential therapeutic applications in hypoglycaemia
and cancer, using a mutant TK is described. Preliminary studies with TAm also suggest GluHep can be
selectively aminated to the corresponding chiral aminopolyol. Current work is addressing upgrading
of the remaining SBP monomer, GalAc, and modelling of the biorefinery concept to enable economic
and Life Cycle Analysis (LCA)
Overexpression of the Aspergillus niger GatA transporter leads to preferential use of D-galacturonic acid over D-xylose
Cardiac remodeling following reperfused acute myocardial infarction is linked to the concomitant evolution of vascular function as assessed by cardiovascular magnetic resonance
Thermal behavior of native and hydrophobized wheat gluten, gliadin and glutenin-rich fractions by modulated DSC
International audienc
Wheat gluten film: improvment of mechanical properties by chemical and physical treatments
International audienc
In vitro polymerisation of sulfite-treated gluten proteins in relation with thiol oxidation
International audienc
Feruloylated arabinoxylan and arabinoxylan-protein solutions do not gel upon gamma-irradiation
42 ref.International audienc
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