This study investigated the effects of the aging period on the black elephant garlic (Allium ampeloprasum L.) manufacturing process. Black elephant garlic is a processed elephant garlic product prepared by high-temperature and high-humidity treatment for 40 days. The proximate composition (moisture, crude lipid, crude protein, carbohydrate, and ash), minerals, color values, reducing sugars, pH, total polyphenol contents, total flavonoid contents and antioxidant activities of elephant garlic and black elephant garlic were evaluated. The browning intensity of elephant garlic increased with the aging period, but the browning reaction terminated after aging for 30 days, exhibiting the same browning level. Reducing sugars increased over the aging period until 20 days, and then decreased with the aging period, in contrast to the pH, which decreased from 6.47 to 3.68 over the aging period. Antioxidant components, including the total polyphenol and total flavonoid contents of black elephant garlic, increased significantly until day 30 of aging. From the metabolite profiles determined through GC/MS analysis, it was confirmed that primary metabolites related to antioxidant components, such as lactic acid and 5-hydroxymethyl-2-furoic acid, were generated during the aging process of elephant garlic.

Abeliophyllum distichum (Oleaceae), which is the only species in the monotypic genus and is grown only on the Korean peninsula, has a high scarcity value. Its five variants (white, pink, round, blue, and ivory) have different morphological characteristics in terms of the color of petals and sepals or shape of the fruits. Despite its high value, there has been no study on variant classification except in terms of their morphological characteristics. Thus, we performed a volatile component analysis of A. distichum flowers and multivariate data analyses to reveal the relationship between fragments emitted from five variants of A. distichum flowers with their morphological characteristics. As a result, 66 volatile components of this plant were identified by headspace solid-phase microextraction gas chromatography–mass spectrometry (HS-SPME-GC-MS), showing unique patterns for each set of morphological characteristics, especially the color of the petals. These results suggest that morphological characteristics of each variant are related to the volatile composition.

Chamaecyparis obtusa is a valuable conifer species, prized for its high-quality timber and bioactive essential oils. However, commercial micropropagation is challenging due to its resistance to vegetative propagation. This study aimed to develop an efficient in vitro plant regeneration system using leaf explants and to profile the metabolic changes during organogenesis. Leaf explants from one-year-old in vitro-grown plantlets were cultured on media with various plant growth regulators (PGRs) to optimize callus induction, shoot multiplication, and rooting. Secondary metabolites were systematically analyzed throughout the developmental stages: explant, callus, regenerated shoot, and rooted plantlet. The most effective shoot regeneration, leading to whole plantlets, was achieved on a medium supplemented with 1.0 mg/L 2,4-dichlorophenoxyacetic acid and 2.0 mg/L thidiazuron. Metabolic profiling revealed significant stage-specific biochemical transitions. High-Performance Liquid Chromatography (HPLC) precisely quantified individual phenolics, resolving cross-reactivity issues seen in total flavonoid colorimetric assays. Gas Chromatography-Mass Spectrometry (GC-MS) also identified substantial shifts in volatile terpenoid biosynthesis during shoot morphogenesis. This integrated protocol provides a reliable platform for mass propagation of C. obtusa and offers fundamental insights into the metabolic dynamics of in vitro development, with significant potential for future horticultural and biotechnological applications.