Inversion, saccharose

With products prepared with addition of sugar, determinations of the saccharose and other sugars, i.e. of the lactose and of the invert sugar which may be formed by the inversion of the saccharose, are carried out by the following methods. 

The method of procedure and calculation are as follows i. Determination of the Saccharose by Inversion, (a) 50 c.c. of the filtrate are made up to 100 c.c.1 and the liquid read directly in a 20 cm. tube in a saccharimeter with a Ventzke scale. Multiplication of the reading by 2 gives P, the polarisation of the filtrate. 

Inversion.—The principal sugars undergoing inversion are saccharose, lactose and raffinose. With saccharose, the procedure is as follows ... 

The above procedure is adopted for the inversion of saccharose solutions of about the concentration indicated with more dilute solutions, inversion may also be carried out by adding 5 c.c. of hydrochloric acid (sp. gr. 1 10) to about 0 c.c. of the solution to be inverted and heating for 15 minutes in a water-bath at 67-70° (see, for instance, determination of sugars in the chapters on milk and on wine). 

Determination of Saccharose, Raffinose and a Reducing Sugar together.—If the same notation as before is used and a represent the rotation due to 1 gram of the inversion products of raffinose, the following three equations hold ... 

In presence of invert sugar, 50 c.c. of the solution prepared as above are subjected to inversion in the usual way and polarised, the saccharose being calculated by Clerget s formula (see later Raw Sugar). 

Determination of the Sugars.—The principal sugar present is saccharose, but invert sugar is also found—mostly due to inversion of the saccharose during the preparation of the fruits—as well as glucose, which is added directly. The method of determination is as follows ... 

If such rotation is about equal to, or less laevo-rotatory than, that observed in the inverted liquid, only invert sugar is present. In such case, since the invert sugar originally present arises from the inversion of part of the saccharose used in the manufacture, the total quantity of saccharose added is equal to that actually found plus the amount of invert Sugar multiplied by 0-95. 

The difference between the reducing sugars found after inversion of the dextrin and those found in the determination of the sugars after inversion of the saccharose is multiplied by 0 9 to obtain the amount of dextrin. 

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 ... 

If saccharose (molasses) is present, another portion of the defecated and filtered solution is inverted by the usual procedure and the determination of the reducing sugars repeated. From the difference between the results before and after inversion, expressed as invert sugar, the saccharose is calculated by multiplication by 0-95. 

Daneben wird unter Inversion, weil sich dabei das Vorzeichen des Drehwertes andert, auch die Spaltung der rechtsdrehenden Saccharose in ein Gemisch von Glucose und Fructose (Invertzucker) durch ver-diinnte Sauren oder das Enzym Invertase verstanden. 

Invert Sugar. Inversion.—We have mentioned the fact that glucose may be obtained by the hydrolysis of cane-sugar. In this hydrolysis not only glucose but also fructose is obtained. Cane sugar is a di-saccharose of the composition C12H22O11. When it is hydrolyzed it splits and is converted into two molecules of mono-saccharoses. One of these molecules is glucose and the other is fructose. 

We see, in particular, that at the beginning of inversion we have Fo = KPS, which shows that the initial rate is proportional to the total quantity of sugar and to the weight of add. This law, which is well verified by the action of acids on saccharose, does not rigorously apply to the action of sucrasc, as O Sullivan and Tompson daimed. 

This law, which is indeed not perfect, however accounts fairly well for the facts observed. It has been verified by V. Henri as regards the inversion of saccharose, the hydrol3rsis of salidn by emulsin, that of starch by amylase, and also the action of maltase on maltose. Nidoux has verified it uring lipaseidin which he obtains from the seed of Ridnus. Finally, V. Henri and Larguier des Bancels have found that the action of trypsin on gelatin likewise follows the law indicated above. 

The third example corresponds to the case where sonochemistry is able to generate active species which catalyze the formation of the product(s). The catalyst may be an adventitious impurity sonochemically created as shown for the acid-catalyzed inversion of saccharose. Such an indirect, more or less hidden mechanism can be operative in the sonochemical addition of tin hydrides to olefins and alk5mes.i5 In this reaction, it was suggested that some radical species produced by solvent... 

Acid or enzymatic hydrolysis of sucrose, inversion, produces an equimolar mixture of n-glucose and n-fructose known as invert sugar. Invert sugar is used as a food additive substance, usually in the form of syrup (relative sweetness is 95-105% of saccharose sweetness). It also serves as a starting material for obtaining d-glucose and D-fructose, the sweeteners mannitol and glucitol and other substances. 

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