GRANULARITY AND ANTIBACTERIAL ACTIVITIES OF ULTRA-FINE CINNAMON AND CLOVE POWDERS

This article describes a novel and simple method that using ultra-fine powders of ball-milled cinnamon and clove directly to inhibit the growth of five spoilage organisms from meat. The effect of ball-milled time on powder granularity and the particle sizes on the antimicrobial effectiveness were evaluated. The results from the antibacterial tests demonstrated that the ultra-fine powders had strong antimicrobial activities, the minimum inhibitory concentrations (MICs) of the clove powder and the cinnamon powder were from 1.0 to 1.5% (w/v) against Escherichia coli, Staphylococcus aureus, Brochothrix thermosphacta and Lactobacillus rhamnosus, and the same against Pseudomonas fluorescens were 2.0 and 2.5%, respectively. The inhibitory effect increased with increasing powder concentrations from 0.5 to 2.5% (w/v). However, obvious reversing characteristic appeared when the particle sizes decreased to 7.085 µm for cinnamon and 8.915 µm for clove. This study suggested that traditional spice powders with proper particle sizes taking the place of essential oils as effective antibacterials had a wide application prospect for their low cost and safety. PRACTICAL APPLICATIONS Ball mills have been successfully used for grinding raw materials to ultra-fine powders because of their easier operation, higher grinding rate, lower energy consumption and considerably less plant space. However, before carrying out this study, it was unknown whether ultra-fine powders of ball-milled cinnamon and clove can directly inhibit the growth of five spoilage organisms from meat. In the present work, the effect of ball-milled time on the powder granularity and the particle sizes on the antimicrobial effectiveness were studied. This study showed that both traditional spice powders with proper particle sizes taking the place of essential oils as effective antibacterials had strong antimicrobial activities.