Preservation of meatballs with edible coating of chitosan dissolved in rice hull-based liquid smoke

The purpose of this study was to determine the effectiveness of edible coatings of chitosan dissolved with liquid smoke in preserving meatballs. The liquid smoke was derived from rice hulls pyrolyzed at 340 °C. The edible coating was made by dissolving 0.5%, 1%, and 1.5% chitosan in 100 ml of liquid smoke at concentrations of 3% and 5%. Preservation was carried out by soaking the meatballs in the edible coating solution for 15 min and storing them at room temperature with observations every 6 h. Food resistance was examined using the Antibacterial Activity Test, Total Plate Count (TPC), and Total Volatile Base Nitrogen (TVB-N). The results of the antibacterial activity test showed that chitosan-dissolved liquid smoke had inhibition zones ranging from 6.49–7.07 mm against E. coli and 6.52–7.26 mm against Salmonella bacteria. The use of 5% concentrated liquid smoke reduced the number of bacterial colonies, with TPC values not below the SNI threshold after 48-hour storage. This indicates that liquid smoke has potential as an antibacterial. The TVB-N value doubled after 24 h, but the meatballs still had good freshness. After 54 h of storage time, the TVB-N value in all treatments exceeded the SNI threshold of 0.254 mgN/100 g, and the meatballs were no longer suitable for consumption.