Selection of common edible herbs which inhibit aflatoxin production or fungal growth

Abstract

Aflatoxin is a toxic secondary metabolite produced by certain strains of Aspergillus flavus. The contamination of aflatoxin occurred in a wide variety of food and feed and has been implicated in a range of human and animal diseases. Because it is mainly concerning with human consumption, hence the method used for controlling aflatoxin should be safe to human. The aim of this study was to select the varieties of edible herbs which commonly grow in Thailand and can inhibit aflatoxin production or fungal growth in order to use as aflatoxin control agent in food and feed. Generally, most herbs were known to inhibit fungal growth. In this study we tried to select herbs which directly do inhibit aflatoxin production aside from growth inhibition. Sixteen varieties of edible herbs which commonly grow in Thailand were selected for the tests. Tip culture method was employed to characterize the efficiency of herb extracts to inhibit aflatoxin production or mycerial growth. Amount of aflatoxin production and mycerial weight of each treatment were determined as percent inhibition from control. Six varieties of herbs were found to cause high percentage of aflatoxin production inhibition (64-99 %) whereas percent inhibition of mycerials weight was low or no inhibition. They were Pluyllanthus amarus, Zingiber afcinale, Thuybergia taurifolia, Occimum basilicum, Boesenbergia pandurata and Tumaric sp. The other 5 varieties Syzyglum aromaticum, Occimum tenuif forum, Cymbopogon citrates, Alpinia nigra and Allium sativum gave high percentage of mycerial weight inhibition(50-70 %) which enhanced to have high percentage of aflatoxin inhibition(80-99 %). The effectiveness of these common herbs can be utilized as biological control of aflatoxin production or fungal growth in food and feed.