Abstract: The conversion of lignocellulosic waste materials, such as sugar cane bagasse, to biofuels such as ethanol has attracted significant interest as a potential element for transforming transport fuel supplies to totally renewable sources. However, the refractory nature of the cellulosic structure of lignocellulosic materials has impeded progress on developing an economic process, whereby the cellulose component may be effectively broken down to glucose monosaccharides and then purified to allow downstream fermentation. Ionic liquid (IL) treatment of lignocellulosic biomass has been shown to disrupt the crystalline structure of cellulose thus potentially enabling the cellulose to be more readily hydrolysed to monosaccharides. Furthermore, conventional hydrolysis of lignocellulosic materials yields byproducts that are inhibitors for efficient fermentation of the monosaccharides. However, selective extraction of monosaccharides from an aqueous/IL phase into an organic phase utilizing a combination of boronic acids and quaternary amines has shown promise as a purification process. Hydrolysis of sugar cane bagasse immersed in an aqueous solution with IL (1-ethyl-3-methylimidazolium acetate) was conducted at different pH and temperature below 100 ºC. It was found that the use of a high concentration of hydrochloric acid to acidify the solution inhibited the hydrolysis of bagasse. At high pH (i.e. basic conditions), using sodium hydroxide, catalyst yields were reduced for total reducing sugars (TRS) due to the rapid degradation of the sugars formed. For purification trials, a supported liquid membrane (SLM) apparatus was constructed, whereby a synthetic solution containing xylose and glucose in an aqueous IL phase was transported across a membrane impregnated with phenyl boronic acid/Aliquat 336 to an aqueous phase. The transport rate of xylose was generally higher than that of glucose indicating that a SLM scheme may not only be useful for purifying sugars from undesirable toxic compounds, but also for fractionating sugars to improve fermentation efficiency.
Abstract: A comparative research on the impact of compost on uptake and allocation of nutrients and heavy metals and quality of Oriental tobacco Krumovgrad 90 has been carried out. The experiment was performed on an agricultural field contaminated by the lead zinc smelter near the town of Kardzali, Bulgaria, after closing the lead production. The compost treatments had significant effects on the uptake and allocation of plant nutrients and heavy metals. The incorporation of compost leads to decrease in the amount of heavy metals present in the tobacco leaves, with Cd, Pb and Zn having values of 36%, 12% and 6%, respectively. Application of the compost leads to increased content of potassium, calcium and magnesium in the leaves of tobacco, and therefore, may favorably affect the burning properties of tobacco. The incorporation of compost in the soil has a negative impact on the quality and typicality of the oriental tobacco variety of Krumovgrad 90. The incorporation of compost leads to an increase in the size of the tobacco plant leaves, the leaves become darker in colour, less fleshy and undergo a change in form, becoming (much) broader in the second, third and fourth stalk position. This is accompanied by a decrease in the quality of the tobacco. The incorporation of compost also results in an increase in the mineral substances (pure ash), total nicotine and nitrogen, and a reduction in the amount of reducing sugars, which causes the quality of the tobacco leaves to deteriorate (particularly in the third and fourth harvests).
Abstract: In this study, lipid-deprived residuals of microalgae
were hydrolyzed for the production of reducing sugars by using the
recombinant Bacillus cellulosome, carrying eight genes from the
Clostridium thermocellum ATCC27405. The obtained cellulosome
was found to exist mostly in the broth supernatant with a cellulosome
activity of 2.4 U/mL. Furthermore, the Michaelis-Menten constant
(Km) and Vmax of cellulosome were found to be 14.832 g/L and 3.522
U/mL. The activation energy of the cellulosome to hydrolyze
microalgae LDRs was calculated as 32.804 kJ/mol.
Abstract: The crude methanol extracts of five indigenous vegetables namely, Amarathus tricolor, Basella rubra L., Chochurus olitorius L., Ipomea batatas, and Momordica chuchinensis L., were examined for their phytochemical profile and antioxidant activity using 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical. The values for DPPH radical scavenging activity ranged from 7.6-89.53% with B. rubra and I. batatas having the lowest and highest values, respectively. The total flavonoid content of all five indigenous vegetables ranged from 74.65-277.3 mg quercetin equivalent per gram of dried vegetable material while the total phenolic content ranged from 1.93-6.15 mg gallic acid equivalent per gram dried material. Phytochemical screening revealed the presence of steroids, flavonoids, saponins, tannins, carbohydrates and reducing sugars, which may also be associated with the antioxidant activity shown by these indigenous vegetables.
Abstract: Papaya and banana bars were developed incorporating
inulin (IN) and fructooligosaccharides (FOS) (Liquid and Powder
form) in various proportions. The control bars were standardized
using 70% fruit pulp, 30% sugar, 0.3% citric acid while the treated
bars were standardized with 70% fruit pulp, 15% sugar, 15% of IN
and FOS and 0.3% citric acid. Among the various proportions tested,
papaya bars with 90% FOS (Powder) + 10% IN and banana bars with
90% FOS (liquid) + 10% IN were sensorially best accepted. The
study revealed that addition of IN and FOS improved the sensory
scores. The Physico-chemical and proximatecomposition analysis
revealed slight changes in brix°, total sugars, reducing sugars, nonreducing
sugars, moisture, protein, fat, vitamin C, ash, iron,
zinc, calcium and crude fibre between control and treated fruit bars.
Further the glycemic index of papaya bar was reduced from 65 to 54
when treated with FOS and IN.
Abstract: Agricultural waste is mainly composed of cellulose
and hemicelluloses which can be converted to sugars. The
inexpensive reducing sugar from durian peel was obtained by
hydrolysis with HCl concentration at 0.5-2.0% (v/v). The hydrolysis
range of time was for 15-60 min when the mixture was autoclaved at
121 °C. The result showed that acid hydrolysis efficiency (AHE)
highest to 80.99% at condition is 2.0%concentration for 15 min.
Reducing sugar highest to 56.07 g/litre at condition is 2.0%
concentration for 45min. Total sugar highest to 59.83 g/litre at
condition is 2.0%concentration for 45min, which was not significant
(p < 0.05) with condition 2.0% concentration for 30 min and 1.5 %
concentration for 45 and 60 min. The increase in concentration
increased AHE, reducing sugar and total sugar. The hydrolysis time
had no effect on AHE, reducing sugar and total sugar. The maximum
reducing sugars of each concentration were at hydrolysis time 45
min .The hydrolysated were analysis by HPLC, the results revealed
that the principle of sugar were glucose, fructose and xylose.
Abstract: The study was designed to evaluate the use of low
concentrations of separan flocculent (Less than 3 ppm) on
physicochemical properties of sugar cane juice. Colour, pH, purity,
turbidity, pol, brix, reducing sugars tannins and polyphenols of
crushed cane (green and burned) juice, mixed juice and clarified
juice were studied. The results showed that pol, brix, reducing sugar
and turbidity are higher in crushed cane juice. Clarified burned juice
had low turbidity, reducing sugars, pol and brix but had significantly
lower pH, purity and colour when compared to crushed juice.
Polyphenols of the crushed juice (1.19%) decreased significantly in
the clarified juice to 0.006%. Addition of separan at a concentration
of 0.015 ppm reduced significantly colour, polyphenols and tannins
and reducing sugar compared to the control.
Abstract: Sugarcane Shoots is an abundantly available
residual resources consisting of lignocelluloses which take it into
the benefit. The present study was focused on utilizing of
sugarcane shoot for reducing sugar production as a substrate in
ethanol production. Physical and chemical pretreatments of
sugarcane shoot were investigated. Results showed that the size of
sugarcane shoot influenced the cellulose content. The maximum
cellulose yield (60 %) can be obtained from alkaline pretreated
sugarcane shoot with 1.0 M NaOH at 30 oC for 90 min. The
cellulose yield reached up to 93.9% (w/w). Enzymatically
hydrolyzed of cellulosic residual in 0.04 citrate buffer (pH 5) with
celluclast 1.5L (0.7 FPU/ml) resulted in the highest amount of
reducing sugar at a rate of 32.1 g/l after 4 h incubation at 50°C,
and 100 oC for 5 min . Cellulose conversion was 55.5%.
Abstract: Pretreatment of lignocellulosic biomass materials from
poplar, acacia, oak, and fir with different ionic liquids (ILs)
containing 1-alkyl-3-methyl-imidazolium cations and various anions
has been carried out. The dissolved cellulose from biomass was
precipitated by adding anti-solvents into the solution and vigorous
stirring. Commercial cellulases Celluclast 1.5L and Accelerase 1000
have been used for hydrolysis of untreated and pretreated
lignocellulosic biomass. Among the tested ILs, [Emim]COOCH3
showed the best efficiency, resulting in highest amount of liberated
reducing sugars. Pretreatment of lignocellulosic biomass using
glycerol-ionic liquids combined pretreatment and dilute acid-ionic
liquids combined pretreatment were evaluated and compared with
glycerol pretreatment, ionic liquids pretreatment and dilute acid
pretreatment.