Inorganic salts effect on wheat straw during steam explosion treatment

Wheat straw is an abundant low cost byproduct. Its use is usually limited in litter and cattle feed. In order to better valorize this lignocellulosic biomass in high added value products, a material preliminary fraction should be done. In this study, a steam explosion pretreatment was applied at different pressure 15 and 20 bar with a residence time of 2 min using different solvents (distilled water and salt water 35g/l NaCl). The objective is to investigate the effect of the operating parameters and salts on the extraction yield of different molecules and their degradation products. The results shows that sodium chloride enhanced the hemicellulose and cellulose removal compared to distilled water

Inorganic salts effect on wheat straw during steam explosion treatment

Wheat straw is an abundant low cost byproduct. Its use is usually limited in litter and cattle feed. In order to better valorize this lignocellulosic biomass in high added value products, a material preliminary fraction should be done. In this study, a steam explosion pretreatment was applied at different pressure 15 and 20 bar with a residence time of 2 min using different solvents (distilled water and salt water 35g/l NaCl). The objective is to investigate the effect of the operating parameters and salts on the extraction yield of different molecules and their degradation products. The results shows that sodium chloride enhanced the hemicellulose and cellulose removal compared to distilled water

Hydrothermal dehydration of D-glucose and D-xylose in deionized water

The industrial trend is moving toward biobased plateform molecule preparation using biobased-processes integrating into green chemistry discipline. These “building blocks” molecules are intermediate for the synthesis of value-added chemicals. 5-hydroxymethylfurfural (5-HMF) and 2-furfural are two plateform molecules derived from monosaccharides. In order to produce these furanic compounds, xylose and glucose conversion were conducted in hot deionized water, which represent the greenest solvent, at 211°C, 20 bars by means of batch-type reactor. A selected rang of times T1= 1min, T2=15 min , T3=30 min ,T4=45 min and T5 =60 min were investigated. Results shows that at 15 min, the best 5-hydroxymethyl furfural ( 5- HMF) yield is 18,52%, produced by glucose dehydration, then it recorded a stable rate . At the same time 2-furfural was produced from xylose with a yield of 26,71% and didn’t vary significantly over time. A 11, 09 % and 9,67 % yield of Lactic acid (LA) and Fromic Acid (FA) were obtained as a co-product from glucose dehydration and 5.53 % of LA was generated from xylose decomposition

Oil analysis of wheat germ

A better use of agricultural by-products is an interest for sustainable development in view of green chemistry. Wheat (Triticum) is one of the main cereals grown worldwide, its human use is primarily limited to the albumen and the by-products of milling including the germ are destined for animal feed. Moreover the germ is the part of grain which lipid concentration is higher and its oil is rich in polyunsaturated fatty acids, bioactive compounds and E vitamin. Therefore, the oil is an alternative to more value the wheat germ and for the development of this cereal grain resource.   A Soxhlet extraction was performed based on hexane solvent. In order to compare the performance and composition of this vegetable oil extracted from the whole grain and extracted only from the germ. Analysis by Gas Chromatography (GC) was subsequently performed to identify and quantify the fatty acids of the oil. The amount of oil in the germ is about 8%, it is four times larger than in the whole grain (2%). wheat germ oil, comprises polyunsaturated fatty acids: linoleic acid C18:2 (Omega 6) and gamma linoleic acid C18:3 respectively 58.31% and 4.2% and the mono acid -unsaturated: oleic acid C18:1 (24.52%) but also some saturated acids: palmitic acid C16:0 with (19.50%) and stearic acid C18:0 (1.34% ) . For this variety of durum wheat, the wheat germ oil contains, in addition, 80.27 mg / 100g of α- tocopherols ( E vitamin)

Caractérisation biochimique de l'huile de germe de blé dur (tunisien) variété)

The wheat germ oil may constitute an alternative to the misuse of this cereal grain resource. His Tunisian exploitation is limited, at present, in the human and animal feed in the grain form, straw or some transformed products. For the purpose of characterization, the wheat germ oil has been extracted by Soxhlet apparatus from a Tunisian variety of durum wheat (Maali) based on the hexane as a solvent. An analysis by gas chromatography (GC) was then performed to identify and quantify the fatty acids of the oil. Then, the oil has submitted to a second chromatography analysis in liquid phase (HPLC) to quantify the tocopherols. The most important fatty acids constituting have been the two polyunsaturated acids linoleic acid C18:2 (OMEGA 6) and the gamma acid- linoleic C18:3 : 58.24 % and 4.19 % respectively; and the acid mono-unsaturated oleic acid C18:1 ( 24.49 %) but also some saturated acid: palmitic acid C16:0 with ( 19.50 % ), and the stearic acid C18:0 (1.29%). For this variety of Tunisian durum wheat, the wheat germ oil contains, in addition, 80.27 mg / 100g of α- tocopherols (vitamin E). The wheat germ oil extracted from the Tunisian variety 'Maali' has proved rich in vitamin E and omega-6 ; a better valorisation on the nutritional or pharmaceutical plan is to this title recommended

Déshydratation hydrothermale de monosaccharides promus par l'eau de mer: principes fondamentaux du rôle catalytique des sels inorganiques

In biorefining, the conversion of carbohydrates under subcritical water conditions is a field of extensive studies. In particular, the hydrothermal decomposition of benchmark C6- and C5-monosaccharides, i.e. D-glucose and D-xylose, into furanics and/or organic acids is fully considered. Herein, we propose to establish the fundamentals of the decomposition of D-glucose and D-xylose under subcritical water conditions in the presence of specific salts (i.e. NaCl and KI) and in seawater. Our results demonstrated that the introduction of inorganic salts was found to modify sugars dehydration yields. Different NaCl concentrations from 0.21 to 1.63 mol L-1 promoted the conversion of D-xylose to 2-furfural (2-F) from 28 to 44% (molar yield). NaCl also improved 5-hydroxymethylfurfural (5-HMF) generation from D-glucose as well as rehydration of 5-HMF to levulinic and formic acid. KI favored other pathways towards formic acid production from D-glucose, reaching 20% in the upper concentration. Compared to a solution of equivalent NaCl concentration, seawater enhanced selectivity towards lactic acid which was raised by 10% for both monosaccharides, and sugars conversion, especially for D-glucose whose conversion was increased by 20%. 5-HMF molar yield around 30% were achieved from D-glucose in seawater at 211°C and 20 bars after 15 min