Coating formulas protect shelled nutmeg seeds from Aspergillus colonization

Abstract

Coating of nutmeg seeds may prevent the colonization of Aspergillus contamination. The study aimed to evaluate the effect of coating formulas to A. flavus on shelled nutmeg. Shelled nutmeg seeds were coated with aqueous (TT) and gel (GM+) formulas containing propylparaben (0.1%), potassium sorbate (0.8%), and clove oil (1.25%), and the aqueous GM- (0.65% clove oil and 0.4% potassium sorbate). The coated seeds were then sun-dried and sprayed with A. flavus conidia. The untreated control was only inoculated with A. flavus. The colonization of A. flavus on the seeds was visually observed. The aflatoxins, propylparaben, and potassium sorbate in the treated seeds were analyzed with HPLC. The results showed that seeds treated with GM+, GM-, and TT formulas were visually free from A. flavus. The total aflatoxins were not detected in the seeds treated with the GM+, but in the coated with GM- and TT was 0.95 µg/kg and 12.6 µg/kg, respectively. In the uncoated seeds, the total aflatoxins were 695.9 µg/kg. Propylparaben and potassium sorbate residues in the coated seeds were 66-11 mg/kg and 213-415 mg/kg, respectively. The coating formula effectively minimized A. flavus colonization and aflatoxin. Therefore, the coating formula could be used for reducing Aspergillus contamination.