Multivariate Profiling of Metabolites and Volatile Organic Compounds in Citrus depressa Hayata Fruits from Kagoshima, Okinawa, and Taiwan

Abstract

Citrus depressa Hayata is a small-fruit citrus species; it is indigenous to Kagoshima, Okinawa, and Taiwan. The metabolites and volatile organic compounds (VOCs) that affect the flavor of its fruits have not been investigated based on geographical origin. In the present study, we investigated the metabolite and VOC profiles of 18 C. depressa cultivation lines from these regions. Multivariate analysis revealed differences in the metabolites of C. depressa based on its cultivation origins; variations in sugar, sugar alcohol, and amino acid contents were also observed. Fruits from Kagoshima and Okinawa had higher galactinol, trehalose, xylose, glucose, and sucrose intensities than fruits from Taiwan (log2-fold change; 2.65–3.44, 1.68–2.13, 1.37–2.01, 1.33–1.57, and 1.07–1.43, respectively), whereas the Taiwanese lines contained higher leucine, isoleucine, serine, and alanine. In contrast to the Taiwanese Nantou line, other cultivation lines had comparable total VOC contents, and the VOCs of all lines were dominated by limonene, γ-terpinene, and p-cymene. Accordingly, the highest VOC intensities were recorded in the Nantou line, which was followed by Shikunin sweet (Kagoshima) and Taoyuan (Taiwan) (log10 normalize concentration; 5.11, 3.08, and 3.01, respectively). Moreover, multivariate analysis plots elucidated the difference in the VOCs of Ishikunibu (Okinawa), Shikunin sweet, and Taoyuan and between those of most Kagoshima and Okinawa cultivation lines. These results suggest that both the cultivation line and origin influence the metabolites and VOCs of C. depressa, thus possibly affecting its flavor quality; the data provide a valuable insight for utilizing C. depressa of different cultivation lines and origins to produce foods and beverages.

Integrated HS-GC–IMS and UPLC-Q-Orbitrap HRMS-based metabolomics revealed the characteristics and differential volatile and nonvolatile metabolites of different citrus peels

“…By combining HS-GC–IMS and UPLC–Q-TOF-MS we can more comprehensively elucidate the differences in the chemical compositions of samples and the factors affecting them. The cultivation system and the origin of citrus cultivars affect their metabolites and volatile organic compounds, which may ultimately influence their flavor quality ( Asikin et al, 2023 ; Pieracci et al, 2022 ). Agricultural scientists have bred a wide variety of citrus hybrids in the pursuit of excellent properties, such as high sugar and low acidity, tenderness and low dregs, easy peeling, rich nutritional value, high yield, and easy management.…”

Citrus depressa peel extract act as a prebiotic to reduce lipid accumulation and modulate gut microbiota in obese mice

“…Chenpi extract contains flavonoids such as narirutin, hesperidin, nobiletin, tangeretin, and 5-demethylnobiletin, which show antioxidant, anti-inflammatory, and anti-obesity effects [ 12 , 13 ]. Citrus depressa Hayata is a small citrus known as hirami lemon, flat lemon, thin-skinned flat lemon, and is distributed in Japan and Taiwan [ 14 ]. Research has shown that the ethanol or methanol extract of the peel of C. depressa contains polymethoxylated flavonoids such as nobiletin, tangeretin, sinensetin, and 5-demethylnobiletin, which showed inhibitory effects on lipid accumulation in the liver and adipose tissue [ 15 , 16 ].…”