Inulin, hydrolysis reaction with

There are several examples of one-pot reactions with bifunctional catalysts. Thus, using a bifunctional Ru/HY catalyst, water solutions of corn starch (25 wt.%) have been hydrolyzed on acidic sites of the Y-type zeolite, and glucose formed transiently was hydrogenated on ruthenium to a mixture of sorbitol (96%), mannitol (1%), and xylitol (2%) [68]. Similarly a one-pot process for the hydrolysis and hydrogenation of inulin to sorbitol and mannitol has been achieved with Ru/C catalysts where the carbon support was preoxidized to generate acidic sites [69]. Ribeiro and Schuchardt [70] have succeeded in converting fructose into furan-2,5-dicarboxylic acid with 99% selectivity at 72% conversion in a one-pot reaction... 

Hydrolysis of inulin was carried out through enzyme preparation PC-ENIN in 1 mg dosage per 1 g of inulin, isolated from Jerusalem artichoke. Samples of hydrolysates were taken in 30 min and 3 h after start of reaction and subjected to HPLC analysis. Results of experiment characterizing the sugar composition in samples are shown in Fig. 9. Based on these results it is evident that FOS with varying degrees of pol5mierization (DP) are obtained and maximum concentration of FOS is reached after 3 h of the hydrolysis reaction. 

In 1895 Dull,9 who was studying inulin and its products of hydrolysis, found that when either fructose or sorbose was treated with an aqueous solution of oxalic acid under pressure, a substance was obtained which had the formula CeHeOa and resembled furfural in its properties. This substance was further investigated by Kiermayer4 who found that fructose and sucrose were the best sources when they were heated with 0.3% aqueous oxalic acid at 120°. It was however only the fructose portion of the sucrose molecule which was transformed since the glucose moiety was recovered unchanged. Kiermayer prepared several derivatives of CeH Os and from its reactions concluded that its structure was probably /3-hydroxy-S-methylfurfural (III). Van Ekenstein and... 

The reaction of inulin with hydrogen gas in the presence of a catalyst results in cleavage, similar to the role of water in hydrolysis, and the formation of polyols such as glycerol, 1,2-propanediol, and ethylene glycol. Yields of up to 60% glycerol have been achieved (Fuchs, 1987). 

Inulin is measured colorimetrically, either by acid hydrolysis to generate a green product, or by a series of enzymatic reactions based on inulinase with subsequent reduction of NADH. HPLC methods are used for the remaining exogenous GFR tracers. PAH and TEA are measured colorimetrically (Newman and Price 1999). 

As a last example of an ultrasound application to catalytic reactions using solid catalysts, we refer to unpublished results. The hydrolysis of inuline (Eq. 12) is catalyzed by acid substances, i.e., inorganic or organic acids in aqueous solution, or acid solids or enzymes. The products of acid hydrolysis are fructose and glucose. Because of the use of the reaction in the food industry, an acid catalyst should not pollute the products at the end of the process. Therefore, solid acids, much more easily separable from the reaction products than liquid acids, must be preferred. In the present work, the employed catalyst was Amberlite IR-120-H (Carlo Erba), that is to say, a solid catalyst with a particle size from 15 to 45 mesh. The reaction was studied in a batch and in a continuous sonicated reactor. 

A kinetic study of the hydrolysis of woods and purified plant polysaccharides in 75 % sulphuric acid was monitored by electrical conductivity measurements. The coefficients of resistance of all polysaccharide substrates increased with increasing hydrolysis time. From these measurements, the degrees of polymerization of cellulose, xylan, and inulin were estimated to be 1900, 66, and 16 respectively. The polysaccharide components of various woods and pulps can be hydrolysed with trifluoracetic acid which, in contrast to sulphuric acid hydrolysis, does not require a neutralization step since trifluoracetic acid is volatile. The presence of lignin in the wood samples impeded the hydrolysis of the polysaccharides, requiring longer reaction times and correction factors to compensate for loss of monosaccharide by degradation reactions. 

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