The question of what perilla is made of has a complex answer, as different parts of the Perilla frutescens plant contain unique and valuable compounds. Native to East Asia, this herb from the mint family (Lamiaceae) is prized for its seeds, which are an outstanding source of omega-3s, and its leaves, which are packed with potent phytochemicals.
The Composition of Perilla Seeds and Oil
Perilla seeds are the primary source of the plant's valuable oil and a rich source of protein. On average, perilla seeds are composed of approximately 40% lipids (oils) and 20–30% protein. The seeds also contain significant amounts of dietary fiber and minerals. The composition is broken down further into:
- Lipids (Oils): The most notable component is alpha-linolenic acid (ALA), a polyunsaturated omega-3 fatty acid, which makes up 54–64% of the total fatty acids in the oil. Perilla oil also contains other fatty acids, including linoleic acid (omega-6) and oleic acid (omega-9), typically with a very favorable omega-6 to omega-3 ratio.
- Proteins: The protein content in perilla seeds is comparable to or higher than many other oilseeds. When oil is extracted, the remaining seed meal, or press cake, becomes an even more concentrated source of protein, containing a balanced ratio of essential amino acids.
- Vitamins and Minerals: The seeds are a good source of minerals like calcium, iron, and phosphorus, which are necessary for many bodily functions. They also contain vitamin E, an antioxidant that helps protect the oil from oxidation.
- Other Bioactives: Beyond the major nutrients, perilla seeds also contain various flavonoids, phenolic acids, tocopherols, and phytosterols, which contribute to their potent antioxidant, anti-inflammatory, and antimicrobial activities.
The Chemical Makeup of Perilla Leaves
Perilla leaves, known as kkae-nip in Korea and shiso in Japan, are the other major component used in culinary and medicinal applications. Unlike the seeds, the leaves are not a source of oil but are rich in aromatic compounds and hydrophilic phytochemicals. Their composition varies significantly between different cultivars, such as the green (var. frutescens) and purple/red (var. crispa) varieties.
- Essential Oils (Volatile Compounds): The distinctive flavor and aroma of perilla leaves come from volatile compounds in their essential oils. Key aromatic compounds identified in the leaves include:
- Perillaldehyde
- Perilla ketone
- Limonene
- Beta-caryophyllene
- Linalool
- Phenolic Acids: The leaves are abundant in phenolic acids, especially rosmarinic acid and caffeic acid, which are known for their strong antioxidant properties. Purple varieties often have higher concentrations of these compounds.
- Flavonoids and Anthocyanins: Perilla leaves contain various flavonoids, including apigenin and luteolin. The vibrant purple or red color seen in some varieties is due to high concentrations of anthocyanins, a type of flavonoid. These anthocyanins, such as cyanidin and delphinidin glucosides, are responsible for the color and contribute to the plant's health benefits.
- Vitamins: Perilla leaves are a good source of vitamins, particularly vitamins A, C, and riboflavin.
Comparing the Composition of Perilla Seeds and Leaves
While both seeds and leaves come from the same plant, they offer different nutritional and phytochemical benefits due to their unique compositions. This table highlights the primary differences:
| Component | Perilla Seeds | Perilla Leaves |
|---|---|---|
| Primary Nutrient | Lipids (oil) rich in omega-3s | Bioactive compounds (phenolic acids, flavonoids) |
| Oil Content | ~40%, consisting mainly of alpha-linolenic acid (ALA) | Low oil content, with volatile essential oils for aroma |
| Protein | High protein content (15–24%) | Moderate protein content (~4.5% raw) |
| Vitamins | High in vitamin E | Rich in vitamins A, C, and riboflavin |
| Flavonoids/Phenolics | Present, but often different types and concentrations than in leaves | Rich source, particularly of rosmarinic acid and luteolin |
| Aromatic Compounds | Nutty, earthy flavor from seed compounds | Distinctive, often minty aroma from essential oils |
| Omega-3s (ALA) | Exceptionally high concentration (up to 64% of oil) | Present, but not a significant source |
Perilla's Role in Modern Applications
Because of its diverse composition, perilla has a wide range of uses beyond traditional Asian cuisine. The seeds are increasingly popular for pressing into oil, used as a cooking oil, a health supplement, and an ingredient in cosmetic products. The seeds also serve as a protein source and can be ground into a meal for use in food or animal feed. The leaves are used as a seasoning, garnish, and vegetable, and extracts containing their rich phenolic and flavonoid content are being explored for potential health applications.
Conclusion
In summary, perilla is not a single substance but a plant with different parts yielding distinct chemical and nutritional profiles. Its seeds offer a potent concentration of omega-3 fatty acids, protein, and minerals, making them a valuable oilseed crop. Meanwhile, the leaves are a treasure trove of antioxidant and anti-inflammatory phytochemicals, including essential oils, phenolic acids, and flavonoids. The unique and complementary composition of its seeds and leaves solidifies perilla's place as a versatile and functional ingredient in both food and wellness industries globally.
For more detailed information on the chemical composition and pharmacological properties of Perilla frutescens, you can consult authoritative research, such as the review published in Molecules.
