Perilla: Same Roots, Different Origins—The Surprising Differences Between Perilla Seed Oil and Perilla Leaf Oil!

Perilla is a traditional Chinese medicinal herb with a long history of use in my country; it serves as both medicine and food, with its leaves, stems, and seeds all utilized for medicinal purposes. Although Perilla Seed Oil (extracted from the seeds) and perilla leaf oil (extracted from the leaves) originate from the same plant, they differ vastly in terms of the part used for extraction, chemical composition, and therapeutic applications.

Perilla seed oil is rich in fatty acids, with an alpha-linolenic acid content reaching as high as 62.73%, making it one of the plant oils with the highest known levels of this fatty acid. Additionally, it contains various active components such as phytosterols, tocopherols, minerals, polyphenols, and flavonoids.

The primary constituent of perilla leaf oil is volatile oil (essential oil); the oil yield is relatively high, and the oil is rich in active substances—predominantly monoterpenes, sesquiterpenes, and their oxygenated derivatives, such as perillaldehyde, perillaketone, perillyl alcohol, D-limonene, and β-caryophyllene. Notably, there are significant differences in the chemical profiles of volatile oils from different perilla varieties; some are dominated by perillaldehyde (PA type) and others by perillaketone (PK type), resulting in vast differences in composition.

**Extraction of perilla seed oil** primarily targets the fatty oil contained within the seeds. Common methods currently employed both domestically and internationally include pressing, ultrasound/microwave-assisted extraction, supercritical CO₂ extraction, subcritical fluid extraction, and aqueous enzymatic extraction; these techniques aim to efficiently recover the oil components from within the seed cells.

**Extraction of perilla leaf oil** focuses mainly on the volatile oil (essential oil) found in the leaves. Traditional methods include steam distillation and organic solvent extraction, while modern techniques encompass ultrasound-assisted organic solvent extraction, supercritical CO₂ extraction, and microwave-assisted extraction. Research indicates that the choice of extraction method influences the yield, chemical composition, and antioxidant capacity of the perilla leaf essential oil.