Characterization of Essential Oil Composition, Polymethoxyflavones, Total Carotenoids, and Sensory Properties of Japanese and Taiwanese Hirami Lemon (Citrus depressa Hayata)

  • J Oleo Sci. 2026;75(4):465-476. doi: 10.5650/jos.ess25234.
Momoko Shimomura  1 ,  Yoshio Tamura  2 ,  Yonathan Asikin  1  3  4 ,  Moena Oe  1 ,  Masashi Yamamoto  3  5 ,  Fumimasa Mitsube  6  7 ,  Shu-Yen Lin  8 ,  Mika Arakaki  9 ,  Fitriyono Ayustaningwarno  4  10 ,  Kensaku Takara  1  3 ,  Koji Wada  1  3  11
Affiliations
  • 1. Department of Bioscience and Biotechnology, Faculty of Agriculture, University of the Ryukyus, Nishihara, Okinawa 903-0213, JAPAN.
  • 2. Zennoh Central Research Institute for Feed and Livestock, Tsukuba, Ibaraki 300-4204, JAPAN.
  • 3. The United Graduate School of Agricultural Sciences, Kagoshima University, Kagoshima 890-0065, JAPAN.
  • 4. Department of Nutrition Science, Universitas Diponegoro, Semarang, Central Java, 50275, INDONESIA.
  • 5. Department of Agricultural Sciences and Natural Resources, Faculty of Agriculture, Kagoshima University, Kagoshima 890-0065, JAPAN.
  • 6. Okinawa Prefectural Agricultural Research Center Nago Branch, Nago, Okinawa 905-0012, JAPAN.
  • 7. Hokubu Agriculture, Forestry and Fisheries Promotion Center, Okinawa Prefectural Government, Nago, Okinawa 905-0015, JAPAN.
  • 8. Department of Horticulture and Landscape Architecture, National Taiwan University, Taipei 10617, TAIWAN.
  • 9. Subtropical Field Science Center, Faculty of Agriculture, University of the Ryukyus, Nishihara, Okinawa 903-0213, JAPAN.
  • 10. Center of Nutrition Research (CENURE), Universitas Diponegoro, Semarang, Central Java, 50275, INDONESIA.
  • 11. Okinawa Study Center, The Open University of Japan, Nishihara, Okinawa 903-0213, JAPAN.
PMID: 41922207 DOI: 10.5650/jos.ess25234
Abstract

Hirami lemon (Citrus depressa Hayata) is a small citrus plant native to southern Japan and Taiwan. This study distinguishes the essential oil composition, polymethoxyflavones (PMFs), total carotenoids, and sensory characteristics of Hirami lemons from Japan (Kagoshima and Okinawa) and Taiwan. The mature fruit essential oils of 23 evaluated strains (5 from Kagoshima, 16 from Okinawa, and 2 from Taiwan) primarily contained volatile organic compounds (VOCs), with limonene and γ-terpinene being predominant (40.4-76.2 % and 9.7-29.3 %, respectively). Distinct geographical signatures were also observed-piperitone and octanal in Kagoshima strains, ethyl dodecanoate and ethyl decanoate in Okinawan strains, and 2-hexenal and phenylacetaldehyde in Taiwanese strains-implying a potent aroma distinctiveness of each cultivation region. Nantou (Taiwan), Shikunin spicy (Kagoshima), and Izumi kugani (Okinawa) had higher PMF concentrations, including nobiletin and tangeretin, whereas Shikunin sweet from Kagoshima exhibited notably higher total carotenoid content than the Other strains. Furthermore, variations in total soluble solids and titratable acidity were correlated with perceived differences in sweetness and sourness, while VOCs influenced aroma traits, including citrus, fruity, herbal, and green notes, refining overall flavor perception. These findings offer important implications for breeding strategies and product diversification of Japanese and Taiwanese Hirami lemons.

Keywords
Hirami lemon; aroma compounds; carotenoids; nobiletin; sensory characteristics.
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