Preparation of a Ammonia-Treated Lac Dye and Structure Elucidation of Its Main Component

• Published in: Food Hygiene and Safety Science (Shokuhin Eiseigaku Zasshi) Vol. 57; no. 6; pp. 193 - 200
• Main Authors: NISHIZAKI, Yuzo, ISHIZUKI, Kyoko, AKIYAMA, Hiroshi, TADA, Atsuko, SUGIMOTO, Naoki, SATO, Kyoko
• Format: Journal Article
• Language: Japanese; English
• Published: Japan Japanese Society for Food Hygiene and Safety 25.12.2016
• Subjects: 4-aminolaccaic acid; acid-stable carmine; Ammonia; Azo Compounds - analysis; Azo Compounds - chemistry; Azo Compounds - isolation & purification; Calcium Carbonate; Carmine - analysis; Carmine - isolation & purification; Chromatography, Liquid; Citrates; Drug Combinations; Drug Stability; Food Analysis; Food Coloring Agents - analysis; Food Coloring Agents - chemistry; Food Coloring Agents - isolation & purification; Food Contamination - analysis; lac dye; Magnesium Oxide; Magnetic Resonance Spectroscopy - methods; Mass Spectrometry
• ISSN: 0015-6426; 1882-1006
• DOI: 10.3358/shokueishi.57.193

Lac dye and cochineal extract contain laccaic acids and carminic acid as the main pigments, respectively. Both laccaic acids and carminic acid are anthraquinone derivatives. 4-Aminocarminic acid (acid-stable carmine), an illegal colorant, has been detected in several processed foods. 4-Aminocarminic acid is obtained by heating cochineal extract (carminic acid) in ammonia solution. We attempted to prepare ammonia-treated lac dye and to identify the structures of the main pigment components. Ammonia-treated lac dye showed acid stability similar to that of 4-aminocarminic acid. The structures of the main pigments in ammonia-treated lac dye were analyzed using LC/MS. One of the main pigments was isolated and identified as 4-aminolaccaic acid C using various NMR techniques, including 2D-INADEQUATE. These results indicated that ammonia-treatment of lac dye results in the generation of 4-aminolaccaic acids.