Comparative study on volatile compounds and taste components of various citrus cultivars using electronic sensors, GC-MS, and GC-olfactometry.

Various citrus fruits' flavor compounds were analyzed using an electronic sensor (E-sensor), and odor-active compounds were identified using gas chromatography-mass spectrometry-olfactometry (GC-MS-O). In the E-tongue analysis, the intensity of sweetness, saltiness, and bitterness was highest in Citrus unshiu , while sourness and umami were highest in C. setomi . A total of 43 volatile compounds were detected in the E-nose analysis, and the compound with the highest peak area was limonene, a type of terpenoid, which exhibited a prominent peak area in C. unshiu . Principal component analysis between flavor compounds and each sample explained a total variance of 83.15% and led to the classification of three clusters. By GC-MS-O, 32 volatile compounds were detected, with limonene being the most abundant, ranging from 20.28 to 56.21 mg/kg. The odor-active compounds were identified as (E)-2-hexenal, hexanal, α -pinene, β -myrcene, limonene, γ -terpinene, nonanal, and D-carvone, respectively.