Color reaction

About: Color reaction is a research topic. Over the lifetime, 1194 publications have been published within this topic receiving 19579 citations.

Compound 460b, its production, food additive, processing of sporozoa-parasitizing fish meat, and production of minced fish and boiled marine paste products

Abstract: PROBLEM TO BE SOLVED: To produce a new compound, 460B, which is obtained from a culture of microorganisms of Aspergillus sp., has inhibitory activity on proteolytic enzymes which decompose thiol-based proteins, a good preventive effect on jelly meat formation, and is useful as an additive for processing fish having jelly meat to minced fish meat. SOLUTION: This new compound, 460B, is produced by culturing microorganisms of Aspergirus sp. which has ability to produce the compound of the formula, 460B (for example, Aspergirus oryzae ATCC 20386), and extracting the compound 460B out of the culture. This compound is preferably added to protein to be processed in a quantity of 0.001-0.01 pts.-wt. to 100 pts.wt. of the protein. This compound has the following properties: appearance: white powder; molecular formula: C20 H30 N4 O5 ; molecular weight: 406.48; solubility: easily soluble in water, methanol, etc., insoluble in ethyl acetate and chloroform; color reaction: positive to ReydonSmith reaction and ninhydrin reaction, negative to Sakaguchi reaction and Anthron reaction; amino acid analysis: phenylalanine is detected as a result of hydrolysis with 6N hydrochloric acid.

Spectrometric Determination of Trace Copper in Foods by BCA (2,2'-Biquinoline-4,4'-dicarboxylic acid disodium salt) Method

Abstract: The colour reaction between BCA(2,2'-biquinoline-4,4'-dicarboxylic acid disodium salt) and copper was developed for determining trace copper in foods.In the presence of pH 11.0 buffer solution and hydroxylamine hydrochloride,BCA could react with copper(II) to form a purple complex with a ratio of 2:1.The molar absorbance constant was 7.72 × 103 L/(mol.cm) at 562 nm.The absorbance obeyed Beer s law in the range of 0-4.8μg/mL Cu(Ⅱ).The established method was used for the determination of trace copper in tea and kelp.The determination results are consistent with the results from atomic absorption spectrometry(AAS) method.In conclusion,this method has the advantages of good accuracy,stability and can therefore be applied to the determination of trace copper in foods.

Color Reaction of Cholesterol with Benzoyl Peroxide in Concentrated Trichloroacetic Acid

Abstract: Cholest-2, 4, 6-triene (I), 3, 3'-bicholesta-2, 4, 6, 5'-tetraene (II) and benzoic acid were isolated in the reaction of cholesterol with BPO in carbon tetrachloride, and the substances I and II were observed to color blue on shaking with conc. TCA. It was assumed that I formed initially was further subject to the radical reaction to yield II. It was also presumed that a series of reactions forming the substances I and II should proceed via the addition reaction of benzoxy radical caused by the thermolysis of BPO to cholesterol, resulting the radical dehydration and the radical dehydrogenation. The products I and II should be colored blue by the formation of corresponding cation or carbonium ion. It was found that this color reaction was specific for the steroids with the structure of 5-ene-3-ol or its ester, so that it may be useful for the detection and the determination of them.

Color Reaction of Aromatic Aldehydes with Acenaphthene in Concentrated Sulfuric Acid

Abstract: The color reaction of aromatic aldehyde with acenaphthene was investigated to clarify the mechanism of the coloration. When the colored solution of aldehyde with acenaphthene in concentrated sulfuric acid was treated with ice water, bis [1-(5-acenaphthenyl) benzyl] ether derivative was obtained, as a reaction product. It was assumed that the coloration might be ascribed to 1-(5-acenaphthenyl) benzyl cation derivative.