Humans have long been intrigued by functional foods. The term is yet to be defined legally but the definition given by The European Commission’s Concerted Action on Functional Food Science in Europe (FuFoSE), coordinated by International Life Science Institute (ILSI) Europe defined functional food as follows: “a food product can only be considered functional if together with the basic nutritional impact it has beneficial effects on one or more functions of the human organism thus either improving the general and physical conditions or/and decreasing the risk of the evolution of diseases. The amount of intake and form of the functional food should be as it is normally expected for dietary purposes. Therefore, it could not be in the form of pill or capsule just as normal food form.”
The ‘nutritional impact’, as stated in the definition is exhibited mainly by the ingredients of a food followed by their processing changes. The conventional cereals like wheat, rice and maize which are dominating the food industry are now known to be inadequate for providing the essential nutrients such as the essential amino acids, micronutrients (vitamins and minerals), fibre, bioactive components and polyunsaturated fatty acids to the human body. These have paved way for the ancient grains like chia, flax and quinoa seeds. These crops are highly robust and can withstand extreme conditions and the seeds contain macronutrients (proteins, lipids, carbohydrates and fibre), micronutrients (vitamins and minerals) and other bioactive components in quantities and qualities which are highly sufficient for the human body to maintain a healthy lifestyle. Thus, these seeds are also important for providing food security for the world population.
Chia contains 16.54% protein (the highest can be 25%), 30.74% fat, 42.12% carbohydrates, 34.4% fibre and 4-5% ash, minerals and vitamins. It is a gluten-free grain and contains the highest amount of polyunsaturated fatty acids (PUFA>80.5%) compared to other seeds. It has a significant amount of ?-linolenic acid which improves the content of eicosapentanoic acid (EPA) and docosahexanoic acid (DHA) in the body. It also contains certain bioactive components (antioxidants) like tocopherols, chlorogenic and caffeic acid, myricetin, quercetin and kaempferol.
Quinoa is a pseudocereal with exceptional nutritional qualities, gluten-free properties and adaptability to varying ecological conditions. The protein content varies from 13 to 15% with a higher content of essential amino acids such as lysine (4.8%), threonine (3.7%), tryptophan and sulphur-containing amino acids. It also contains 4-9.7% fat, 57.18% carbohydrates, 7.8-14% dietary fibre and 2.72% minerals. It has a good calcium-phosphorus ratio (1:0.7) compared to other cereal (1:7) and contains a high level of B-vitamins especially folate. Major bioactive components include tocopherols, carotenoids, phytosterols, betalains and squalene. The UN General Assembly declared 2013 as the “International Year of Quinoa”.
Flaxseeds contain 20% protein, 41% fat, 29% carbohydrate and 28% dietary fibre. It contains the essential ?-linolenic acid upto 55% of the total lipid content. It is rich in arginine, aspartic acid, glutamic acid as well as sulphur containing amino acids (cysteine and methionine). Potassium (5600-9200mg/kg; highest amount compared to other foods), phosphorus, magnesium and calcium are present at higher levels. Flaxseeds are also rich sources of both fat soluble (Vitamin E) and water soluble vitamins. It has the highest content of phytoestrogens and phenolic compounds like ferulic acid, chlorogenic acid and flavonoids.
Since the grains are gluten-free, chia, flax and quinoa seeds can be consumed by celiac pateints. The high content of fibre in chia absorbs a very high amount of water thus improving the gastrointestinal movement and increasing the digestion time of carbohydrates thus providing a feeling of satiety for a long time. PUFAs in chia reduce the cholesterol, regulate the blood pressure and plasma triglyceride concentration. The chia protein is a potential source of bioactive peptides which are highly useful for specific vital purposes like reproduction, lactation, growth and replacement of metabolic losses and damaged tissues. Quinoa exhibits a low glycaemic index of 35-53 implying a low spike in glucose on consumption of foods containing quinoa seeds. Quinoa and flaxseeds also exhibit antioxidant, anti-allergic, anti-inflammatory, anti-carcinogenic and cardiovascular protective properties. This is due to the bioactive components for instance, betalains like betanins are good scavengers of reactive oxygen species thus prevent the oxidation of low-density lipoprotein, consequently preventing DNA damage. The high potassium intake with flaxseeds leads to lower blood platelet aggregation, incidence of stroke and free radicals in blood. Vitamin E, present as ?-tocopherol in flaxseeds acts as an antioxidant and limits the oxidation of cell proteins and fat, promotes excretion of sodium un urine and consequently helps in lowering the blood pressure and risks of heart diseases and Alzheimer disease.
Chia, flax and quinoa seeds can form a part of the staple diet and can be used as ingredients of conventional foods like bread, cookies, noodles, pasta, cereal bars, beverages and snacks. Any antinutritional components present in these seeds can be reduced or removed during food processing steps like soaking, fermentation, germination, milling, cooking, washing, microwave heating, extrusion, roasting etc. Chia and flaxseeds can be processed to produce oils rich in PUFAs and fat-soluble vitamins. Flaxseeds can be conveniently used in dough and batters of various bakery products. Moreover, mixture of flaxseed and water can act as a substitute for egg for vegetarian diet specifically in bakery products like cakes, muffins and pancakes. The mucilage of chia and flaxseeds can act as anti-staling agents in baked products. Quinoa flour has been used to replace wheat flour (upto specific levels) to result in good quality bread, pasta, cereal bars and biscuits thus reducing the glycaemic index of these products. Chia flour also exhibits water holding and emulsification capacities and thus can be used in beverages and bakery products.
It is high time that the consumer becomes aware of the conventional cereals and their lack of nutritive richness, and increase the intake of the functional foods especially those incorporating seeds like chia, quinoa and flax.
Ankita Kataria, New Delhi, India, firstname.lastname@example.org
PhD. Scholar, Food Technology, Punjab Agricultural University, Ludhiana
MSc. Food Technology, CSIR-Central Food Technological Research Institute, Mysore
B. Tech. Dairy Technology, National Dairy Research Institute, Karnal