Studies on the formation of 4-aminocarminic acid

Abstract

Dried bodies of the female insect Dactylopius coccus Costa were extracted using various extraction solvents. Whereas the amount of extracted carminic acid was between 4 and 24 % of insect material, 4-aminocarminic acid was detected in the extracts in only in low amounts of about 0.1 % of insect material. Compared to ratios of 4-aminocarminic acid to carminic acid, which had been reported to be present in some food additive and beverage samples, ratios in the insect extracts were very low (between 1:211 and 1:154, w/w). However, mixing carminic acid and ammonium hydroxide resulted in formation of significant amounts of 4-aminocarminic acid. Depending on the molar ratio of carminic acid to ammonia, the ratio of 4-aminocarminic acid to carminic acid was up to 1:1.2 (w/w). Spontaneous formation of 4-aminocarminic acid leading to a false positive result was also observed for the analysis of a ketchup sample when ammonia was used during sample preparation.