Nutrient-Rich Varieties of Linseed ForThe Nutritional Security of The Country

Introduction

Flaxseed is one of the oldest crops having been cultivated since the beginning of civilization primarily for its oil content and fatty acid composition, leaving protein-rich meals as an underutilized by-product. The Latin name of the flaxseed, Linumusitatissimum L., means “very useful”. Linseed belongs to the family Lineaceae an important oilseed crop grown in almost every part of the country. It is of two types: brown and yellow or golden. It is usually in one of three ways: whole seed, ground powder, or oil. Traditionally, cultivated for edible as well as industrial purposes.

Flax (Linumusitatissimum L.) commonly known as linseed is an ancient crop belonging to the genus Linum family Linaceae. There is a small difference in using the terms ‘flaxseed & linseed’. Flaxseed is often used to describe flax when consumed by humans while linseed denotes when it is used especially for industry and feed purposes. Flaxseeds are extensively used world-over as a potential functional food ingredient as it provides various health benefits along with the nutritional value. It is the richest vegetarian source of omega-3 fatty acids. Flax is currently focused on enhancing the oil content and nutritional value to meet the demand of nutraceutical market supply, as an alternate source of fish oil, a rich source of eicosapentaenoic acid (EPA, C20:5) and docosahexaenoic acid (DHA, C22:6). Flax seed is also rich in soluble and insoluble fibres and lignans, makes it useful as a dietary supplement. Intake of flaxseed in daily diet may reduce the risk of cardiovascular diseases such as coronary heart disease and stroke. Omega 3 fatty acids are an object of considerable medical and nutritional research for a wide range of human health conditions and disorders, including inflammation, joint and bone health, menopause, ageing and obesity. With FDA-approved health claims that omega 3’s may lower the risk of cancer and coronary heart disease, adults are increasingly seeking to incorporate these essential fatty acids into their daily diets.

Every part of the flaxseed plant is utilized commercially, either directly or after processing. However, it is an underutilized crop, and because of consumer awareness demand for flaxseed has increased in the last few decades. It contains about 40-50 % oil, which is mostly made up of beneficial polyunsaturated fatty acids. It has a unique nutrient profile, particularly Omega 3 fatty acid, soluble and insoluble fibers, phytoestrogen lignans, protein antioxidants and fiber. In the diet of vegetarians, it is a potential source of Alpha-linolenic acid ranging from 45-60 %. Flaxseed contains 21 % protein. Majority of protein is concentrated in the cotyledons. The total protein content in flaxseed ranges between 20-30% compost of mainly 80% globulin and 20% glutelin. As compared to soya protein the nutritional value and amino acid profile are comparable. Flaxseed protein is rich in arginine, aspartic acid and glutamic acid, while lysine is limiting.

Nowadays, this crop is emerging as a good source of nutrition special reference to having an ample amount of Omega-3, which is a cheap and best source of essential nutrition for pregnant women, children, and all categories of human beings. Its cake is a source of cattle feed for production and nutrition. Due to value addition in cultivars, farmers will get more prices. For achieving more, an intensified research program is needed to generate new materials having the above-mentioned qualities which are neededfor the day. In the last two decades, flaxseed has been the focus of increased interest in the field of diet and disease research due to the potential health benefits associated with some of its biologically active components. Flaxseeds have nutritional characteristics and are a rich source of omega-3 fatty acids: alpha-linolenic acid (ALS), shot chain polyunsaturated fatty acid (PUFA) soluble and insoluble fibers, phytoestrogenic lignans (secoisolariciresinoldiglycoside-SDG), proteins and an array of antioxidants.

Flaxseed is establishing importance in the world’s food chain as a functional food. Functional food can be defined as food or food ingredients that may provide physiological benefits and helps in preventing and /or curing the disease. Flaxseed has new prospects as a functional food because of consumers’ growing interest in food with superb health benefits. Its growing popularity is due to health imparting benefits in reducing cardio-vascular diseases, decreased risk of cancer, particularly of the mammary and prostate gland anti-inflammatory activity, laxative effect and alleviation of menopausal symptoms and osteoporosis. Flax protein helps in the prevention and treatment of heart disease and in supporting the immune system. As a function food ingredient, flax or flaxseed oil has been incorporated into baked foods, juices, milk and dairy products, muffins, dry pasta products, macaroni and meat products. Looking into the versatility of linseed in human and animal nutrition, it has become a functional/healthy food and needs to be popularized and awareness has to be created regarding its multiple uses in maintaining overall health at low cost which is easily affordable to every segment of the Indian population. The state contributed 56 % both in area and production of the country which proved Madhya Pradesh is the major state as regard area and production of linseed crop. At present, several improved varieties developed under the ICAR-All India Coordinated Research Project at Regional Agricultural Research Station, Sagar, Madhya Pradesh by our research station namely JLS-9, JLS-27, JLS-66, JLS-67, JLS 73, JLS 79, JLS 95, LSL 93, JL 165 and JLS 122 having high seed & oil yield as well as high omega 3 fatty acid. These varieties havea wide range of omega 3 from 40-58.50 %. The highest omega 3 content was reported in variety JLS 73 (58.20) followed by JLS 66 (55.96%), JLS 27 (53.20), JLS 95 (53.56) and JLS 122 (53.51) and the lowest was reported in JLS 9.

Flaxseed for a New Millennium

An effort has been made under ICAR-AICRP linseed by creating a new framework for a food-based dietary recommendation, principally in the area of value addition, nutrients restoration and fortification of food and development of health-focused designer foods and utilization of flax seed as an important ingredient in the preparation of functional foods to achieve the optimal nutrition through the intake of healthy food. The initiative has been undertaken by the food industry to increase the level of omega-3 fatty acids, dietary fibers and antioxidants. Flaxseed has drawnthe attention of scientists, researchers and industry due to omega-3 fatty acids and lignans and various health benefits. In the arena of the 21^st century, flaxseed’s use is not just limited to its fibres but has been extended to its various nutraceuticals and medical attributes which make it a potent value-added food ingredient. Flax seed is rich in Alpha-linolenic acid, dietary fiber, high-quality protein, antioxidants, and lignans, some of which offer a model for whole grain or seeds and under crossed the recognition given to the nutritional value of “whole grain”, “whole seeds” and whole foods”.

Nutritional Composition

Among the oilseed crops, flaxseed emerged as a potential source of alpha-linolenic acid, lignans, high-quality proteins, soluble fiber and phenolic compounds. The chemicalcomposition of flaxseed depends upon growing environments, genetics and processing condition.

ALA and Omega-3 Fatty Acids 

Alpha-linolenic acid is an essential fatty acid and main functional component that cannot be synthesized in the human body. Fatty acid is termed essential because they are required by the body but the body cannot synthesize them, therefore need to be supplied in the diet. The human body lacks the enzymes required to synthesise these essential fatty acids. It constitutes the richest source of ALA, the parent compound of omega-3 fatty acids. One tablespoon of milled flax contains 1.8 g of ALA and one tablespoon of flax oil contains 8 g of ALA. From ALA, more physiologically potent forms viz., eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) can be synthesized in the human body. Essential α-linolenic acid (ω-3) fatty acid plays an important role in lowering cholesterol, reducing inflammatory disorders like rheumatoid arthritis and osteoporosis and providing immunity and cardiovascular benefits. It is naturally high in polyunsaturated fatty acids, more specifically in ω-3 fatty acids; and hence linseed as a component of poultry meal, cattle feed can provide ω-3 enriched eggs &milk. Livestock and poultry producers add flax to the feed for the production of omega -3 enriched meat and eggs. Fatty acid profile of various oilseeds is reported in Table 1[NB1] . It is evident from the data that flaxseed contains the highest amount of omega-3 followed by soybeans and mustard oil, while sunflower and safflower oils contain a large amount of omega-6 content. Over the decades the consumption of vegetable oils from sunflower, safflower, and soybean has greatly increased which resulted in a drastic imbalance of essential fatty acids. Today the ratio of omega 6 to omega 3 is shifted to 20-30: 1 in Western diet and the situation is even worse when this ratio attains a high value of 38 -50:1which reveals that more omega-6 fatty acids are incorporated in the cell membrane. The recommended ratio of omega-6 to omega-3fatty acids may be in the range of 4:1 to 10:1, and omega-6 and omega-3 fatty acid intakes should account for at least 3% and 0.5 % of total energy intake, respectively. These variations in the ratio of fatty acid may be considered a deciding factor for the development of therapeutic doses for the prevention of colorectal cancer, asthma, obesity and rheumatoid arthritis.

Table 1 Fatty acid profile of various oilseed crops grown in India