Compositional characteristics and antibacterial activity of essential oils in citrus hybrid peels

Satsuma mandarin (Citrus unshiu Marc.), Hallabong [(C. unshiu Marc. x C. sinensis Osb.)x(C. reticulata Blanco)], Cheonhyehyang [((C. unshiuxC. sinensis)xC. reticulata)x(C. reticulatexC. sinensis)], and Redhyang (citrus hybrid `Kanpei), which are citrus hybrids, are mostly consumed in Korea. The flavor of citrus peel depends on the composition and content of volatile essential oils. Limonene, gamma-terpinene, beta-myrcene, linalool, ocimene, octanal, and sabinene were found to be the main components in Satsuma mandarin, Hallabong, Cheonhyehyang, Redhyang, and orange (C. sinensis Osb.) peel essential oils. Limonene was the main component (82.05-91.84%) of all citrus peel essential oils. gamma-Terpinene was present in a particularly high content (8.09%) in the essential oil of Satsuma mandarin peel. Linalool was found in the highest proportion (4.39%) in the essential oil of Cheonhyehyang peels. beta-Ocymene had the highest concentration (6.50%) in Redhyang peel essential oil. Citrus peel essential oils showed slight antibacterial activity against Salmonella choleraesuis (S. choleraesuis), Bacillus cereus (B. cereus), Listeria monocytogenes (L. monocytogenes), Staphylococcus aureus (S. aureus), and Pseudomonas aeruginosa (P. aeruginosa). Cheonhyehyang peel essential oil showed the highest antibacterial activity against all foodborne pathogens. Additionally, B. cereus was the most sensitive, and S. aureus was the most resistant to the Cheonhyehyang peel essential oil.