Natural antimicrobial properties of liquid smoke derived from cocoa pod shells in meatball preservation

Abstract

The liquid smoke, which is produced by pyrolyzing wood materials containing cellulose, hemicellulose, and lignin, can be used to preserve food. Phenolic, acetic, and carbonyl compounds found in liquid smoke can serve as a natural preservative. This study aimed to determine meatball preservation ability of liquid smoke from cocoa pod shells. Specifically, cocoa pod shells were converted to liquid smoke using slow pyrolysis at three different temperatures, 300 °C, 340 °C and 380 °C. Prior to its use, liquid smoke was purified using distillation at 190 °C. Liquid smoke at concentrations of 0.5%–3.0% was then used to preserve meatballs using an immersion method. Total volatile base-nitrogen (TVB-N), total plate count (TPC), and most probable number (MPN) analyses were used to evaluate preservation performance of liquid smoke. The statistical methods for MPN using one-way ANOVA followed by Tukey's tests. The SNI (Standar Nasional Indonesia) threshold to test whether meatballs remained fresh (TVB-N <20 mg N/g). TPC test results indicated that beef meatballs stay fresh at room temperature for 42 h or 48 h of storage using 0.5% or 1%–3% liquid smoke concentrations, respectively. Based on MPN tests showed meatballs could last for 48 h for all samples. Liquid smoke produced from cocoa pod shells can be used as a natural preservative for beef meatballs; however, liquid smoke concentrations influence the maximum preservation period for meatballs.

Keywords

• Cocoa pod shells
• Pyrolysis
• Liquid smoke
• Total volatile base-nitrogen
• Total plate count
• MPN