Gas chromatography (GC) was used to determine biological components in commercial essential oils from leaves of Melaleuca cajuputi collected in the Thua Thien Hue province of Vietnam. The results show that the major components of cajuput oil were α-pinene, β-pinene, limonene, 1,8-cineole and terpineol, with 1,8‑cineol being present in the largest amounts, from 15 to 59 %. High-performance liquid chromatography (HPLC) was used to determine benzoic acid and sorbic acid preservative concentrations in different foodstuffs. The results demonstrate that the concentrations were below the maximum levels allowed by European Commission regulations in all samples.