Caramel test

For this program, the caramel test as described in some scientific literature of the time was adopted. Events proved this to be a bad choice because the adsorption of caramel had very little relation to the utility of carbon for decolorizing the products being purified Two batches of carbon would be equal for adsorption of caramel, but be very unequal for decolorizing coconut oil or phosphoric acid. As the caramel test did not decrease the customers complaints, the next step was to pre-test each batch of carbon on the various products for which a market then existed. This eliminated complaints but created a burdensome testing program, particularly when the market later expanded to include an increasing number of products. 

The I-DND system was thus installed in SPX from the veiy beginning of the operation of this reactor, on an experimental basis to validate the detection principle and measure its performances in comparison with the sampling system (during the CARAMEL tests). 

Tests for Caramel.—Valuable indications of the nature of an extract are obtained in the process of determination of vanillin and coumarin. Pure extracts of vanilla beans give, with lead acetate, a bulky, more or less glutinous, brown-grey precipitate, and a yellow or straw-coloured filtrate, whereas purely artificial extracts coloured with caramel give a slight dark brown precipitate and a dark brown filtrate. If both vanilla bean extract and caramel are present the precipitate is more or less bulky and dark coloured, and the filtrate is more or less brown. The soluticm remaining after extraction of the vanillin and coumarin with ether, if dark coloured, should be tested for caramel. 

The most satisfactory test for caramel is to shake with Fuller s earth, as recommended - by Crampton and Simons. If the colour is due to caramel and a grade of I uller s earth is used, which experience has proved suitable, the solution, after filtering, is yellow or colourless. This test does not positively identify the colour, as some other brown substances may give similar reactions, but no such substance is liable to be present in vanilla extract. 

Sucrose caramels have been produced under anhydrous thermal conditions that are designed to maximize the content of fructose-rich oligosaccharides.100-102 These sucrose thermal oligosaccharide caramels (STOC) have been tested in animals as a nutritional supplement. Improved weight gains and feed conversion, and increased levels of bifidobacteria (see section VIII) were observed in broiler chickens that were fed this supplement.103... 

To provide data on the composition and heterogeneity of caramels Class I and IV and to provide test results on concentrated colour and flavour properties. 

The caramelized liquid is sent by railroad tank cars to the cola syrup formulators, who then test the solution for quality. If it is too light in color—penalty if it has too many carbon particles per unit volume, then the whole tank car is rejected. There is thus a delicate balance between underreacting and overreacting. 

Carotene 160 Carotene (others)— report of sulfite ammonia caramel used widely in soft drinks like cola causing problems in extra sulfite sensitive people, particularly asthma patients. 160e and 160f are too new to have been tested... 

The most elementary, nontechnical method of identifying a polysaccharide is to burn it, observe the yellow-to-brown color, and sniff the perfumelike aroma that should be reminiscent of the aroma of maple syrup, if the test is positive. If the caramelized residue is shaken with egg white and a visible reaction produces an insoluble, pigmented deposit (melanoidin), it is empirical proof that the sample was a polysaccharide. 

Four distinct classes of Caramel can be distinguished by the reactants used in their manufacture and by specific identification tests ... 

These tests are calculated on an equivalent color basis that permits the values to be expressed in terms of a Caramel having a color intensity standardized to 0.1 a.u. 

Absorbance Ratio (Note For the purposes of this test, Absorbance Ratio is defined as the absorbance of Caramel, at equal concentrations, at 280 nm divided by the absorbance at 560 nm.) Transfer 100 mg of sample into a 100-mL volumetric flask with the aid of water, dilute to volume, mix, and centrifuge if the solution is cloudy. Pipet 5.0 mL of the clear solution into a 100-mL volumetric flask, dilute to volume with water,... 

Properties of Sucrose (SECTIONS 366, 368).—(a) Preparation of caramel.—Place about 2 grams of sucrose in a test-tube and heat it for 15 minutes in an oil-bath at 210°. Taste the product and determine if it is soluble in water. 

In a report, Hellwig and coworkers attempted to standardize particular types of caramel by means of the following tests (a) with citric acid, (b) solubility in 65% (v ) ethanol, and (c) the Lassaigne test (see Table 11). They also presented gel-permeation (g. p.) chromatograms (size exclusion chromatography) of various types of caramel. Values of for zones on the chromatograms evidently characteristic for the caramels studied are attributable to color components of caramel. These studies were directed to caramels standardized by ITCA. They allow division of these caramels into ten types and into further subtypes (see Table III). 

Type of caramel Citric acid Test alcohol Lassaigne... 

The pH values of caramels are given in Table I they constitute an important property of caramels. A high pH may indicate an incomplete bum, or alkali present. In either case, the tinctorial strength [defined as the absorbance at 560 nm of a 0.1% (wt/vol) solution of caramel in a quartz cell (10 X 10 mm)] of the product increases as the product ages. Above pH 6.0, caramel is susceptible to attack by molds, and, below pH 2.5, it quite readily resinifies. For caramel solutions, the acid stability is commonly determined in practice, this is a test for cloudiness of solutions under the influence of an acidic medium. ... 

These chemical reactions and tests for caramel are complemented by a group of physical methods based on size-exclusion chromatography. These methods may be applied for the detection of caramel in beverages, beer, and wine. Caramel may be detected in bread and in various slightly colored products from the sugar industry (raw sugar, molasses, sugar syrups, and the like). Spectral methods are most useful for these purposes. 

Add 10 cc. of paraldehyde to 5 cc. of the sample in a test tube and shake. Add absolute alcohol, a few drops at a time, shaking after each addition until the mixture becomes clear. Allow to stand. Turbidity after 10 minutes is an indication of caramel. 

Hagiwara A, Shibata M, Kurata Y, et al. 1983. Long-term toxicity and carcinogenicity test of ammonia-process caramel colouring given to B6C3F1 mice in the drinking-water. Food Cosmet Toxicol 21 701-706. 

As in the case of molasses, the color of different samples of caramel varies in intensity. Usually 4 to 6 grams of caramel per liter of water will give a satisfactory solution. The method of buffering the solution and the procedure for conducting the test parallel those used for molasses. During the early development of carbons for the treatment of liquids, this test was extensively used. Since then, it has been found that the test has very little relation to the removal of impurities from most industrial solutions and is seldom used now. 

The worst substrate tested was milk powder. This probably occurred due to its thin granularity, which ends up allowing a gathering of the particles when moist, causing stickiness. Moreover, the heat treatment during sterilization may have promoted Maillard reactions, which maybe affected the availability of amino acids in the medium, and also caramelization reactions, both leading to a darkening and modification of the medium s texture. 

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