Saccharose reactions

CARBOHYDRATES. These are compounds of carbon, hydrogen, and oxygen dm contain the saccharose grouping (below), or its first reaction product, and in which the ratio of hydrogen to oxygen is the same as in water. 

Saccharose hydrogenolysis was performed in a slurry type reactor in presence of a 5% Ru/carbon catalyst. Modification of pH during the reaction can increase the yield of 1,2-propane diol and glycerol noticeably. An adsorbed complex is proposed to account for the difference in selectivity for various Cg and Cg sugars. 

The study of the hydrogenolysis of saccharose to 1,2-propane diol has shown that a better yield can be obtained by the separation of hydrolysis and hydrogenation steps, from the bond cleavage. This can be achieved by adjusting the pH during the reaction. The hydrogenolysis of different oses has shown a difference in the selectivity of the reaction. An adsorbed form of the polyols can account for these differences. Indeed some oses like mannose and galactose have no hindrance to form the proposed complex. 

Colour Reactions.—These are used for the detection of commercial invert sugar and are based on the colorations given by certain substances with methylfurfural and hydroxymethylfurfural, which occur in commercial invert sugar as decomposition products formed from the levulose during the inversion of saccharose by acids. Invert sugar prepared with invertase or by other special methods does not contain these decomposition products and consequently does not give the colour reactions. The most reliable of the latter are as follows ... 

Since even a small excess of alkali may produce decomposition of the sugar, it is well, after exact neutralisation, to add a drop of dilute acetic acid the very faint acid reaction thus produced has no effect on any saccharose which maybe present. 

L. Amariutei, G. Descotes, C. Kugel, J. P. Maitre, and J. Mentech, Sucrochimie TV. Synthese regioselective de derives amines du saccharose via la reaction de Mitsunobu, J. Carbohydr. Chem., 7 (1998) 21-31. 

Powerful groups like American Corn Products and France s Roquette Freres produce starchy matters in this way. The former is also the leading producer of isoglucose (a blend of glucose and fructose) in the United States, while the latter is the largest producer of sorbitol. Starch can, therefore, compete directly with saccharose both for foodstuffs and for industrial uses as a fermentation or enzyme-reaction base. 

Di-saccharoses or Hexo-bioses.—(i) The first group is known as di-saccharoses. These are so called because they split, on hydrolysis, into two molecules of hexose mono-saccharoses. The general formula for these di-saccharoses is C H2 20n-i, and the known members all have the composition formula C12H22O11. They are represented by such common substances as cane sugar, milk sugar and malt sugar. The reaction of hydrolysis is,... 

Tri-saccharoses or Hexo-trioses.—(2) The other less important group of the poly-saccharoses that are true sugars is that of the tri-saccharosesy or hexo-trioses. These split, as their name indicates, into three molecules of hexose mono-saccharoses. The formula corresponds to the composition C18H32O16. The hydrolysis may be represented by the reaction,... 

Hydrolysis of Poly-saccharoses.— The most important relationship of the hexose sugars is that involved in the common method for their preparation. Poly-saccharoses, e.g.j cane sugar and starch, hydrolyze and split into two or more molecules of hexose sugars. On the hydrolysis of a di-saccharose two molecules of hexose sugars result. These two molecules may be the same hexose sugar or they may be different. When a true poly-saccharose, like starch, is hydrolyzed more than two molecules of hexose sugar result. These hydrolytic reactions will be considered in detail under the different poly-saccharoses. 

Solubility.— The poly-saccharoses differ from the sugars in the absence of a sweet taste, in their non-crystalline character and in their general insolubility. Inulin and dextrin are soluble in water, glycogen is soluble to an opalescent liquid, while starch and cellulose are insoluble. In hot water starch forms a colloidal solution or emulsion, known as starch paste. Starch reacts with a solution of iodine and gives a beutifiul blue color. This is a characteristic reaction for starch and is used as a qualitative test, especially in microscopic examination. Dextrin exists in several forms, one of which known as erythro-dextrin, gives a red color with iodine. 

Iodine Reaction.—The other forms of dextrin known as achroo-dextrins, give no color with iodine. The following enzymes act upon the different poly-saccharoses hydrolyzing them as indicated ... 

Amyloid.—When treated with concentrated sulphuric acid cellulose dissolves and undergoes hydrolysis. If the solution is diluted with water a gelatinous product is obtained which gives the blue color with iodine characteristic of starch. This product is known as amyloid. When boiled in the dilute acid the amyloid is hydrolyzed and dextrin and finally glucose are obtained. Concentrated hydrofluoric acid and phosphoric acid also dissolve cellulose. With glacial acetic acid in the presence of acetic anhydride and sulphuric acid cellulose yields acetyl derivatives indicating its alcoholic character. From the products of this reaction the acetate of a di-saccharose is obtained. 

By measuring activation parameters (Eq. (2) and Table 2), it has been shown that the cceleration arises from a favorable change of activation entropy, which is an indication of the implication of the hydrophobic effect [32], Concentrated aqueous carbohydrate solutions (glucose and saccharose for instance) have been shown to accelerate the Diels-Alder reaction. The acceleration is even greater than that observed with saturated fi-cyclodextrin solution (Eq. (3) and Table 3) [32],... 

A huge acceleration of the Michael reaction of nitroalkanes with methyl vinyl ketone was mentioned when going from non-polar organic solvents to water. The hydrophobic effect could be at least to some extent involved, since additives, such as glucose or saccharose, accelerate the reaction even more [72]. Cetyltrimethylam-monium chloride as an amphiphilic species which can influence the hydrophobic interactions was found to promote the Michael reaction of various nitroalkanes with conjugated enones in dilute aqueous solutions of sodium hydroxide [73],... 

Etherification of carbohydrate is an important reaction. The two-phase reaction of butadiene with saccharose by an aqueous palladium complex catalyst increases the reaction yield of the desired ether products (Eq. 5) [21]. 

Guyot et al. (1998) studied the inhibitory activity of 5-caffeoylquinic acid, the main component of the chlorogenic acids (see Section 2.1.4) on the formation of alkylpyrazines in Maillard reactions with model systems valine or leucine and saccharose. Applying their results to green robustas, they concluded that the aroma quality increased when the chlorogenic-acids content decreased and when the sucrose content increased. 

Enzymatic hydrolysis of polysaccharides (cellulose, starch) or oligosaccharides (maltose, saccharose, lactose) for the synthesis of food products is another class of processes MBR have been applied to. Paolucci-Jeanjean et al [4.56] have recently reported, for example, the production of low molecular weight hydrolysates from the reaction of cassava starch over a-amylase. In this case the UF membrane separates the enzyme and substrate from the reaction products for recycle. Good productivity without noticeable enzyme losses was obtained. Houng et al [4.57] had similar good success with maltose hydrolysis using the same type of MBR,... 

SACCHAROSE (57-50-1) Violent reaction with ammonium perchlorate, chlorine dioxide, iodine(V) oxide, sodium peroxide. Forms heat- or shock-sensitive explosive mixtures with ammonium nitrate. Reacts with potassium hydroxide, strong acids, strong oxidizers. 

In the early researches on 0. europaea, [35], Panizzi demonstrated that oleuropeic acid 31, the 4-( 1. hydroxyisopropyl> 1 -cycloexene-1 -carboxylic acid, occurs in the root bark of (). europaea, mainly as a sucrose ester, i.e. the 6-O-oleuropeil saccharose 32 (see Figure 14). The structure of 31 was determined by comparison with an authentic sample [36-38]. The demonstration of the position of ester linkage in oleuropeil saccharose 32 was achieved with a combination of enzymatic and chemical reactions [39]. 

In order to study the influence of the pH value on the sweetness enhancing effect of the novel Maillard reaction product, binary mixtures of the tasteless alapyridaine and the sweet tasting compounds glucose, saccharose, or L-alanine were sensorially evaluated in a triangle test using water with pH 5.0, 7.0 and 9.0, and the sweet detection thresholds determined were compared to the threshold concentrations of aqueous solutions containing the sweet tastants alone (Table I). 

To illustrate these points further, let us examine the results from a biochemical experiment in which the rate of hydrolysis of sucrose by the enzyme saccharose is investigated. This enzyme, or biological catalyst (of which we shall speak in more detail later), catalyzes the reaction ... 

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