There has been an increased interest in chia seeds in recent years, but chia is not a new crop. In fact, it has been around for quite a long time. It was one of the main crops of pre-Columbian societies, used by both the Aztecs and the Mayas as a basic component in their diet, and research has helped us understand why.(1) Today its seeds are used in many food products, while interesting health benefits and technological properties hold the key to even more novel food products and health-related discoveries. They have great potential, and this article outlines some of the reasons why.
Botanical characteristics of chia
Salvia hispanica, also known as chia, is an annual herb that blooms during the summer months and can grow up to 1m in height.(1) It has serrated leaves which contain essential oils that act as insect repellents, removing the need for the use of pesticides or other chemical compounds when growing the plant.(1) It has white and blue bisexual flowers and grows round fruit which contains many tiny, oval seeds of only 2mm in length and 1mm in width.(2) The seeds’ surface is smooth and varies in color, from white to grey and brown, with irregularly arranged black spots.(2) Nowadays it is grown worldwide, particularly in Argentina, Peru, Paraguay, Ecuador, Mexico, Nicaragua, Bolivia, Guatemala, Australia and Europe, the latter using greenhouses due to its climate.(2)
The nutrients in chia seeds
Chia seeds have high nutritional value because of their high contents of dietary fiber, fat, minerals, vitamins, protein and antioxidants.(2) Moreover, they are gluten free and can be consumed by celiac patients.(2)
Fiber
Chia seeds contain from 47.1 to 59.8% of total dietary fiber, of which 5.4% is soluble and 94.6% is insoluble.(3) When it comes to dietary fiber, chia seeds come out ahead of dried fruits, cereals or nuts,(2). When in contact with water, their soluble fiber is partially expelled from the seed as a mucilaginous gel and fermented in the colon, while the insoluble fiber can only be fermented to a certain extent.(3) Due to their mucilaginous gel, chia seeds can be used in cosmetics, pharmaceuticals and food companies as a protective agent against moisture, a foam stabilizer and emulsifier agent.(3)
Oil
Chia seeds contain up to 40% oil, though factors such as the extraction technique and geographical area can affect this number.(3) Oil has been extracted from chia seeds since ancient times and was used in traditional medicine against eye infections and stomach disorders.(3) The oil also has a high amount of unsaturated fatty acids, with α-linolenic acid representing over 50%.3 A consumption of 7.3g of chia per day provides 100% of the recommended intake of omega-3 fatty acids, which have a very important role in human health, due to their anti-inflammatory, antiarrhythmic and antithrombotic activity.(3)
Protein
They are a good source of protein, which accounts for approximately 19.0 – 26.5% of their mass.(3) Their protein content surpasses that of wheat, corn, rice, oats and barley, with the addition of other seeds, such as amaranth and quinoa.(1)
Vitamins and minerals
Chia is a good source of B vitamins, as it contains niacin (in higher doses than corn, soybeans and rice), thiamine and riboflavin (in doses similar to corn and rice), folate, vitamin C, vitamin A and vitamin E.(1) It is also an excellent source of minerals, containing magnesium, zinc, copper and 6 times more calcium, 11 times more phosphorous and 4 times more potassium than 100g of milk.(1) It even contains high amounts of iron – 6 times more than spinach, 1.8 times more than lentils and 2.4 times more than liver.(1)
Antioxidants
Chia seeds and oil contain many natural antioxidant compounds, which reduce the risk of chronic diseases, such as cancer and heart disease, and help protect against disorders including atherosclerosis, stroke, diabetes and neurodegenerative diseases such as Alzheimer’s and Parkinson’s.(3)
Chia seeds in the food industry
Chia seeds were not used for human consumption to a significant degree within the European Union before 15 May 1997 and are thus classified as novel food on the European food market, despite their natural origin.(2)
Today chia is used in the food industry in the form of whole seeds, ground seeds or mucilage.(2) Chia seeds are authorized for use in certain amounts in cereal bars, cookies, pasta, bread, ice cream, snacks, yogurt and sausages.(2) Chia is also used in the production of oil, where its main application is in the production of capsules that provide a nutritional supplement of omega-3.(1) Oil can also be extracted from chia leaves and consumed or used as a fragrance.(1) The seeds contain a lot of fiber, which is ideal for intestinal health, and important nutrients that help prevent cardiovascular diseases and possess anticancer, antioxidant, antibacterial and antifungal effects.(1)
Chia is also sometimes used as a fat or egg substitute, which does not significantly alter the product’s technological or physical properties.(2)
Chia seeds today and tomorrow
The interest in chia seeds is increasing and there are numerous proposals for adding them in dishes.(2) Many studies have been conducted to prove their health-related benefits, but, as with other plants with bioactive components, more human studies are required to determine their safety, mechanisms of action and efficacy.(2) They are a promising component of health-promoting food, with increased biological and technological potential.(2)
References:
(1) Muñoz, L. A., Cobos, A., Diaz, O., & Aguilera, J. M. Chia seed (Salvia hispanica): an ancient grain and a new functional food. Food reviews international. 2013;29(4): 394-408.
(2) Kulczyński, B., Kobus-Cisowska, J., Taczanowski, M., Kmiecik, D., & Gramza-Michałowska, A. The chemical composition and nutritional value of chia seeds—Current state of knowledge. Nutrients. 2019;11(6), 1242.
(3) de Falco, B., Amato, M. & Lanzotti, V. Chia seeds products: an overview. Phytochem Reviews. 2017;16, 745–760. Available from: https://doi.org/10.1007/s11101-017-9511-7 [Accessed 25.10.2021].
(4) U.S. Department of Agriculture. National Nutrient Database for Standard Reference. 2011;24.
(5) Ayerza, R; Coates, W. Ground chia seed and chia oil effects on plasma lipids and fatty acids in the rat. Nutr. 2005;25: 995–1003.
(6) Regulation (EU) 2015/2283 of the European Parliament and of the Council of 25 November 2015 on Novel Foods, Amending Regulation (EU) No 1169/2011 of the European Parliament and of the Council and Repealing Regulation (EC) No 258/97 of the European Parliament and of the Council and Commission Regulation (EC) No 1852/2001. Available from: https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX: 32015R2283&from=en [Accessed 27.10.2021].
(7) Commission Implementing Regulation (EU) 2017/2470 of 20 December 2017 Establishing the Union List of Novel Foods in Accordance with Regulation (EU) 2015/2283 of the European Parliament and of the Council on Novel Foods. Available from: https://eur-lex.europa.eu/ [Accessed 27.10.2021].
