Mould Characterization and Mycotoxin Quantification of Chia Seeds (Salvia hispanica L.) Grown in Kenya

Abstract

Chia seeds are functional food that have been considered highly nutritious. They have high levels of polyunsaturated fatty acid content therefore counteract lifestyle disorder such as cardiovascular diseases. This study sought to determine the level of mould contamination in chia seeds; enumeration and characterization of the types of molds and quantification of mycotoxin level, for chia seeds grown and sold in Kenya. A complete randomized block design with triplicates was used in the study. Samples were collected at random from farmers and distributors in Nyeri, Nakuru, Busia and Trans Nzoia counties. Moulds species were isolated from PDA and MEA Medias and morphological characteristics was determined under X 40 magnification power. Mould counts were found to be between 1.33 X 103

cfu/ml to 2.67 X 103

cfu/ml. Mould characterization done by microscopic and macroscopic technique showed evidence of Rhizopus spp, Trichoderma spp and Fusarium spp. Amongst the three genera found, Rhizopus spp was the predominantly occurring mould. The percentage moisture content of chia seeds samples ranged from 6.49±1.26 and 9.16±0.43. Significant variations on moisture content (p< 0.05) were observed among chia samples from different farmers. Aflatoxin was not detected in all chia samples. It can therefore be concluded that the chia samples were not contaminated with aflatoxin although different species of mold were present. Farmers need to be trained on proper postharvest handling methods of chia seeds, as well as proper storage and an objective method of analyzing the moisture content of the chia seeds need to be developed.