ANTIBACTERIAL ACTIVITY OF LIQUID SMOKE POWDER FROM RICE HUSK
Keywords:Rice huks, Liquid smoke powder, Kirby–Bauer method, Antimicrobial activity, Inhibition zone
The technological trend toward waste reduction has attracted the attention of researchers using rice husk as a value-added material. Rice husk, which mostly consists of lignocellulose, is a potential feedstock for generating liquid smoke powder, which can be used to preserve food. The present work investigates the antimicrobial activity of liquid smoke powder from rice husk on Gram-negative (Salmonella choleraesuis and Escherichia coli) and Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis). Liquid smoke was prepared through the pyrolysis of rice husk at 300°C, 350°C, and 400°C. After purification by distillation, the liquid smoke was prepared into liquid smoke powder using the spray-drying method. The Kirby–Bauer method was used to test antibiotic activity. Gas chromatography-mass spectrometry (GC–MS) analysis shows that rice husk liquid smoke contains various chemicals, such as acetic acid, 2-propanone, butanal, propanoic acid, 2-cyclopentene, and phenolic compounds. The liquid smoke powder inhibited the growth of all the tested bacteria, with various inhibition zones (6–9 mm). The findings of this study suggest that rice husk liquid smoke powder can be used as a natural alternative to synthetic food preservatives.