Distribution of Pyrrolothiazolate, a Pigment Formed through the Maillard Reaction between Cysteine and Glucose, in Foods and Beverages and Some of Its Properties

Abstract

Pyrrolothiazolate is a Maillard reaction product isolated from a model solution containing cysteine and glucose. This compound is a yellow pigment and it has a unique pyrrolothiazole ring, which has never been reported in the various heterocyclic compounds formed through the Maillard reaction. To clarify the distribution of this pigment in foods and some of its biological properties, we measured it in various foods and beverages and examined its antibacterial and mutagenic activities. As a result, this compound was found in soy sauce, miso, and beer. The contents of the pigment in these foods ranged from 1 to 106 µg/100 mL or 100 g. Thus, pyrrolothiazolate was formed during food processing and storage as well as in the model systems. Pyrrolothiazolate did not show antibacterial activity nor mutagenicity with the Ames test.