By: Prof. R K Yadav (Deptt of Genetics and Plant Breeding C.S. Azad Univ. of Agril. & Tech. Kanpur & Sr. Associate Editor-ICN Group) and Dr.Shweta (Asstt. Professor)
KANPUR: Linseed or flax seed was cultivated Babylon as early as 3000 BC. In the 8th century, King Charlemagne believed so strongly in the health benefits of flaxseed that the passed laws requiring his subjects to consume it. In general, there exist two common cultivars of flax; one is predominantly grown for its oil seeds and the other variety for fiber.
Seed flax generally features brown, and yellow or golden-yellow colour seeds, with most types having similar nutritional values and equal amounts of short-chain omega-3 fatty acids. As in other oil seeds, flax too is one of the very high-calorie foods. 100 g of seeds contain 534 calories or 27% of daily-required levels. Further, the seeds are an excellent source of numerous health-benefiting nutrients, dietary fiber (mucilage), minerals, antioxidants and vitamins that are essential for optimum health.
Flax seed is rich in monounsaturated fatty acids like oleic acid. It is also one of the top plant sources of omega-3 essential fatty acids such as linoleic acid, alpha-linolenic acid (ALA) and arachidonic acids. Regular intake of small portions of flax seeds in the diet helps to lower total as well as LDL or “bad cholesterol” and increases HDL or “good cholesterol” levels in the blood. Research studies suggest that Mediterranean diet that is rich in fiber, monounsaturated fatty acids and omega-3 fatty acids help to prevent coronary artery disease and strokes by favoring healthy blood lipid profile.
Flax seeds are perhaps one of the most widely available botanical sources of n−3 or ω (omega)-3 fatty acids. Flax seed oil consists of approximately 55% ALA (α-linolenic acid). One spoonful of flax seed oil provides about 8 g of omega-3 fatty acids. Research studies have suggested that n-3 fatty acids by their virtue of anti-inflammatory action help lower the risk of blood pressure, coronary artery disease, strokes and breast, colon and prostate cancers. Adequate quantities of n-3 oils are required for normal infant development and maturation of nervous system.
The seeds contain lignans, a class of phytoestrogens considered to have antioxidant and cancer preventing properties. Flax are an excellent source of vitamin E, especially rich in gamma-tocopherol; containing about 20 g (133% of daily-recommended values) per 100 g. vitamin E is a powerful lipid soluble antioxidant, required for maintaining the integrity of cell membrane of mucus membranes and skin by protecting it from harmful oxygen-free radicals.
The seeds are packed with many important B-complex groups of vitamins such as riboflavin, niacin, thiamin, pantothenic acid, vitamin B-6, and folates. Thiamin is an essential co-factor for carbohydrate metabolism and helps prevent beri-beri disease. Folates help prevent neural tube defects in the fetus when consumed during pre-conception period and pregnancy.
Furthermore, flax seed is rich source of minerals like manganese, potassium, calcium, iron, magnesium, zinc and selenium. Flax or linseed oil has flavorful nutty aroma and has been used in cooking, and as “carrier” or “base oil” in traditional medicines and in pharmaceutical uses.
Selection and storage: Flax seeds are available in the market year around. In the stores, one may come across different forms of flax such as whole dry seeds, roasted, ground, etc. Attempt to buy whole, golden-yellow flax seeds instead of ground (powder) as it ensures that the seeds are intact in nutrients, unadulterated and have a longer shelf life. There are two varieties of flax seeds; brown and yellow or golden, with most types having similar nutritional values and almost same amounts of short-chain omega-3 fatty acids. The seeds should feature bright, brown or golden-yellow (depending on the variety) colour, smooth, compact, and uniform in size and feel heavy in hand. They are generally available in the airtight packs as well as in bulk bins. Whole flax seeds may be placed in cool dry place for many months, while the ground form should be placed inside airtight container and kept in the refrigerator to avoid them turn rancid.
Culinary use: Flax seeds are rich in poly-unsaturated fatty acids. Exposing the ground seeds for longer time in the powder form oxidizes their fatty acids and deprives them of their nutritional value. Therefore, generally, the seeds are ground in a coffee or nut/seed grinder just before use in order to preserve their nutrition-profile. The seeds can also be enjoyed as snacks roasted, salted, or sweetened. Flax seeds are nutty yet pleasantly sweet in taste. Ground seeds are a great addition as toppings in yogurt, desserts, shakes, cereal based dishes, etc. Ground seeds often sprinkled over salads, desserts, particularly sundaes and other ice cream based preparations. Flax is widely used in the confectionery, as an addition to biscuits, sweets, muffins and cakes.
Safety profile: Flax-seeds have no harmful effects on health when used in small quantities. However, flax contains lots of mucilage fiber in their coat which when eaten in large amounts may cause stomach pain, bloating, and laxative diarrhea. Eating raw flax seed is not advised for its risk of cyanogen-glycosides toxicity. In addition, lignans in flax possess estrogen-like activity. It is therefore, excess consumption of flax, and its products may not be advised during pregnancy for its possible hormone interactions.
