Flax

Flax (Linum usitatissimum) is a traditional oilseed crop in Saskatchewan that was grown in the area for a number of years prior to the establishment of the province in 1905, and continuously since then. It can be regarded as the first special, or non-cereal field crop, to be grown in the region. Flax is grown in Canada on an average of 638,000 ha annually. Today, 70% of the Canadian flax area is in Saskatchewan, with an average production of 500,000 tonnes and an average harvested yield of 1,230 kg/ha. Flax is an annual plant with a growing time similar to spring wheat. Flax flowers have five, usually blue, petals. They appear each morning during the flowering period, and the petals are shed in the early afternoon. The seed boll contains up to ten small, flattened and ovate seeds; seed colour is usually brown but may be yellow; mature seed contains 43% to 45% oil, and 21% to 25% protein.

The oil of flaxseed is rich in linolenic fatty acid (58%), which is known by a number of different names. The largest proportion of the crop is crushed to produce linseed oil. Linseed oil is an industrial drying oil used in the production of oil-based paints, stains and inks, as well as in the manufacture of linoleum flooring. When crushed for the small human health-food market, it is known as flaxseed oil and is used because of its high concentration of omega-3 fatty acid (linolenic acid). Another type of flax that is grown in Saskatchewan is solin. Solin was developed in the late 1980s and its oil has a linolenic fatty acid concentration of 2%, and a linoleic fatty acid concentration of 70%. This makes solin oil very similar to traditional sunflower oil, and it is marketed as an edible vegetable oil. The meal remaining from the crushing of both flax and solin is used as a livestock feed.

In recent years there has been great interest in the utilization of flax seed and its components in healthy food/feed or as a nutraceutical. The outer layer of the seed coat is made of mucilage, which is a polysaccaride. Mucilage makes up about 5% of the seed and is thought to impart the laxative properties to flax. Lignans are another type of fibre which is found in a deeper layer of the seed coat. The lignan concentration of flax is many times greater than in other plant foods, and lignans may have anticancer properties. The high level of alpha-linolenic fatty acid (omega-3) found in flaxseed is also believed to have therapeutic properties: this essential fatty acid has been implicated in reducing blood pressure and modifying the immune system.

Gordon. G. Rowland