Preliminary study on antimicrobial activity of liquid smoke from cacao pod shells (Theobroma cacao L)
Hera Desvita(a), M Faisal (*b), Mahidin (b) and Suhendrayatna (b)

a)Doctoral Program, School of Engineering, Universitas Syiah Kuala
b)Chemical Engineering Department,Faculty of Engineering, Universitas Syiah Kuala
Jalan Tengku Syech Abdur Rauf No. 7, Darussalam, Banda Aceh 23111, Indonesia
*mfaisal[at]unsyiah.ac.id

Abstract

Cacao pod shells (Theobroma cacao L) is one of the biomass wastes that can be made as raw materials for liquid smoke because this biomass contains lignin, cellulose, and hemicellulose. This research studied the antimicrobial activity of liquid smoke from cacao pod shells on several common food-borne pathogens such as salmonella choleraesuis, Escherichia Coli, Staphylococcus aureus, Bacillus subtilis. The liquid smoke used was obtained from Cacao pod shells which were pyrolyzed at a temperature of 300 °C (T1), 340 °C (T2), and 380 °C (T3). Liquid smoke concentration was varied from 1-5%. The antimicrobial activity test was conducted by using the Kirby Bauer method. The results showed that liquid smoke produced from T1 and T2 (and at a liquid smoke concentration of 4% and 5% ) could inhibit the growth of all the tested bacteria. At T3 and 1%-5% of liquid smoke, only E.Coli could be inhibited (inhibition zone= 6-7.05 mm), while the growth of Salmonella choleraesuis and S.Aureus were inhibited at 3-5% liquid smoke with inhibition zone ranging from 6 -7.2 mm. However, B. Subtilis can be inhibited by 2-5% liquid smoke concentration. All the tested bacteria have shown the sensitivity to liquid smoke, but E.Coli was the stronger resistant compared to others. The results of this study show the possibility of the use of liquid smoke from Cacao pod shells as a preservative agent to inhibit microorganisms in food.

Keywords: Liquid smoke; pyrolysis; cacao pod shells; antibacterial activity

Topic: Chemical Engineering