Abstract Perilla frutescens seeds are a good source of polyunsaturated omega 3 6 9 fatty acids (PUFAs). The seeds of perilla are small end globular weight about 4 g/1000, contained approximately 35–45% oil. However the leaves are a very poor source of oil, since they contain only 0.2%. In addition, only the seed oil contains the omega 3 fatty acids alpha-linolenic acid (ALA). In comparing to other plant oils, perilla seed oil consistently contains the one of the highest proportion of omega 3 (ALA) fatty acids, at 54–64%. The omega 6 (linoleic acid) component is usually around 14% and omega 9 (Oleic acid) is also present in perilla oil. These polyunsaturated fatty acids are most beneficial to human health and in prevention of different diseases like cardiovascular disorders, cancer, inflammatory, rheumatoid arthritis etc.
Introduction
General description of Perilla frutescencs
Perilla frutescens, is a member of the Lamiaceae/Labiatae family and commonly called perilla. The crop is annual and is native to India and China. Major producing countries of perilla are China, India, Japan, Korea, Thailand, other East Asian countries. The herb is about 1 m high with small flowers, a gray-brown fruit, and glossy, downy-haired leaves. Cultivation of the crop is grown from seed and sown in May. Harvesting is usually between the end of September and beginning of October. The applicable parts of perilla plants are the leaves and seeds.
There are two main types: red and green perilla. Perilla seeds, also called EBARA seed. This oil is a kind of light yellow clear and transparent liquid, with aromatic odor and slight soluble in ethanol. Major fatty acids of the oil are unsaturated fatty acids like Oleic acid 14–23%, linoleic acid 11–16%, linolenic acid 54–64% (Graph 1). This oil also contains saturated fatty acids 6.7–7.6%. Perilla seeds contain different polyphenols or flavones (rosemarinic acid, luteolin, chrysoeriol, quercetin, catcehin, apegenin and shishonin). Perilla seed oil is used as cooking oil, fuel. It is dry oil used as in paint, varnish and ink manufacturing or as a substitute for linseed oil. The seed cakes are used as animals and birds feed (Gediminas et al. 2008; Talbott and Hughes 2006; Longvah et al. 2000; Borchers et al. 1997; Narisawa et al. 1994).
Source and uses of omega fatty acids
Perilla is used for oil production as a rich source of omega-3 polyunsaturated fatty acids (PUFAs), specifically alpha-linolenic acid (ALA). It also contains omega 6 and omega 9 fatty acids. Omega fatty acids are the essential for our health, so the omega-3s and 6s must be obtained through our diet or by supplementation. It is the best resources for additional human omega-3 polyunsaturated fatty acids (PUFAs). ALA (omega 3 fatty acid), is found in some other plant oils sources such as flaxseed (linseed), with lower amounts in walnut, canola, soy and animal sources like fish oil (cold water fish as salmon, cod and mackerel).
Perilla oil suppresses the production of chemical mediator in the allergy and inflammatory responses. These essential fatty acids have been associated with benefits in a wide range of inflammatory conditions, heart diseases, colitis/Crohn’s disease, asthma, allergies, antimicrobial, anticancer etc. Perilla is also used for nausea, sunstroke, to induce sweating and as an antispasmodic. In vivo metabolism of polyunsaturated omega-3 fatty acids, it mainly exists in the form of DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid). These two specific omega-3 fatty acids metabolites are inserted in cell membranes throughout the body, where cellular machinery converts them into substances which prevent abnormal clotting, reduce inflammation, and relax blood vessels and improved ventilatory parameters (Lewis 2008; Talbott and Hughes 2006; Calder 2004; James et al. 2000; Chin et al. 1992; Mattson and Grundy 1985).
Other dietary sources of omega-3 fatty acids
Botanical sources
Flax seeds produce linseed oil, which has a very high omega−3 fatty acid content Six times richer than most fish oils in n−3, flax (or linseed) (Linum usitatissimum) and its oil are perhaps the most widely available botanical source of n−3. Flaxseed oil consists of approximately 55% ALA (alpha-linolenic acid). Flax, like chia, contains approximately three times as much n−3 as n−6. 15 g of flaxseed oil provides 8 g of ALA, which is converted in the body to EPA and then DHA at efficiency of 5–10% and 2–5%, respectively (Azcona et al. 2008; Lewis 2008; Albert et al. 2002; Schacky and Dyerberg 2001; James et al. 2000; Mattson and Grundy 1985) (Tables 1 and 2).
Animal sources
Fish
The most widely available source of EPA and DHA is cold water oily fish such as salmon, herring, mackerel, anchovies and sardines. Oils from these fish have a profile of around seven times as much omega 3 fish oil as omega 6. Other oily fish such as tuna also contain omega 3 fish oil in somewhat lesser amounts. Consumers of oily fish should be aware of the potential presence of heavy metals and fat-soluble pollutants like PCBs and dioxin which may accumulate up the food chain. Although fish is a dietary source of n−3 fatty acids, fish do not synthesize them; they obtain them from the algae or plankton in their diet (James et al. 2000; Renaud 2002; Chin et al. 1992).
Eggs
Eggs produced by chickens fed a diet of greens and insects produce higher levels of n−3 fatty acids (mostly ALA) than chickens fed corn or soybeans. In addition to feeding chickens insects and greens, fish oils may be added to their diet to increase the amount of fatty acid concentrations in eggs. The addition of flax and canola seeds to the diet of chickens, both good sources of alpha-linolenic acid, increases the omega-3 content of the eggs (Azcona et al. 2008; Trebunová et al. 2007).
Meat
The n−6 to n−3 ratio of grass-fed beef is about 2:1, making it a more useful source of n−3 than grain-fed beef, which usually has a ratio of 4:1. In most countries, commercially available lamb is typically grass-fed, and thus higher in n−3 than other grain-fed or grain-finished meat sources. The omega 3 content of chicken meat may be enhanced by increasing the animals’ dietary intake of grains that are high in n−3, such as flax, chia, and canola (Azcona et al. 2008; Trebunová et al. 2007).
Seal oil
Seal oil is a source of EPA, DPH, and DPA. According to Health Canada, it helps to support the development of the brain, eyes and nerves in children up to 12 years of age (Azcona et al. 2008; Trebunová et al. 2007).
Other sources
Milk and cheese from grass-fed cows may also be good sources of n−3. The microalgae Crypthecodinium cohnii and Schizochytrium are rich sources of DHA (22:6 n−3) and can be produced commercially in bioreactors. This is the only source of DHA acceptable to vegans. Oil from brown algae (kelp) is a source of EPA. Walnuts are one of few nuts that contain appreciable n−3 fat, with approximately a 1:4 ratio of n−3 to n−6. Acai palm fruit also contains n−3 fatty acids. Omega-3 is also found in soft gels in pharmacies and nowadays it is also found in combination with omega 6, omega 9
