Detection of Konjac glucomannan by immunoassay

Abstract

Konjac glucomannan is a hydrocolloid that has been used in food applications. The European ban on the use of Konjac glucomannan means that the detection and analysis has potential applications in the food industry, particularly detection of food adulteration. The aim of this work was to develop an assay capable of detecting Konjac glucomannan as an isolated sample and within food matrices. An indirect competitive ELISA was developed utilising a polyclonal antibody raised against Konjac glucomannan. The ELISA was found to be specific for Konjac glucomannan and sensitive, with a detection limit of 0.1 ng mL−1. Increasing salt concentration and freeze/thaw cycles did not affect the performance of the assay. The ELISA was able to detect Konjac glucomannan in admixtures with other gums and also in confectionery that had been spiked with Konjac glucomannan. The ELISA has potential as a kit for the differentiation of Konjac glucomannan from other hydrocolloids and detection in food.