Studies on the application of thin layer isoelectric focusing to food analysis. III. Identification of mushroom by numerical value of isoelectric focusing pattern and application to food poisoning by Rhodophyllus rhodopolius.

Abstract

To identify the species of mushrooms mainly for the distinction of poisonous mushrooms from edible ones, thin layer isoelectric focusing analysis was applied on their water-soluble proteins. 1. The electrophoretic profiles were species-specific. The proteins extracted from the cap and stem in a species gave essentially identical profiles. 2. The profiles of cap proteins of 10 individuals of Akamomitake (Lactarius deliciosus) were indifferent, indicating that the intra-species variation of water-soluble proteins was little. 3. The heat treatment at higher than 60°C, for 10 min, of the water-soluble proteins of Dokutsurutake (Amanita virosa) caused temperature-dependent disappearance of protein bands, while not significant change up to 60°C. 4. The values of pI and relative peak height of isoelectro-focused water-soluble protein bands were numerically expressed. These numerical values were species-specific, indicating that mushroom species might be identified by analyzing the water-soluble proteins with a verification of the tables of these numerical values. 5. The present method was applied for the identification of poisonous Kusaurabenitake (Rhodophyllus rhodopolius) mixed in Urabenihoteishimeji (Rhodophyllus crassipes) which caused a food poisoning incident. The former mushroom was satisfactorily identified by this method.