Characteristics and Antioxidant Activity of Liquid Smoke Produced from Gelam Wood (Melaleuca cajuputi), Alaban Wood (Vitex pubescens Vahl), and Coconut Shells (Cocos nucifera L.)

Abstract

The antioxidant activity of liquid smoke is a major consideration in its use as a food preservative. Raw materials greatly determine the phenolic content in liquid smoke. The purpose of this study was to determine the physicochemical properties (phenolic & acid content, pH level, and chemical composition) and the antioxidant activity of liquid smokw made from gelam wood (Melaleuca cajuputi), alaban wood (Vitex pubescens Vahl), and coconut shells (Cocos nucifera L). The phenolic content was determined by the Follin-Ciocalteau method, whereas the acid content was determined using the titration method. The antioxidant activity was evaluated using a spectrophotometric method with DPPH radical compounds. The average phenolic contents of LSGW, LSAW, and LSCS were 0.855, 0.885, and 1.957 (% g GAE/mL), respectively, and the average acid contents were 4.256; 2.776 and 11.873 (%g/mL), respectively. Compounds detected in LS consist of organic acids, phenolic compounds, carbonyls, alcohols, furans, and esters. All three types of LS had high antioxidant activity, as indicated by their IC50 values of 0.53% for LSGW, 0.70% for LSAW, and 0.75% for LSCS, respectively. The findings of this study implied that the antioxidant activity of liquid smoke is not always directly proportional to its total phenolic content.