Chia seeds: Omega-3 fatty acids and beyond, Leslie Kleiner Interview to Mabel Tom¨¢s

LESLIE KLEINER; MABEL C. TOMAS

Inform

AOCS Press

Lugar: Urbana, IL; Año: 2015 vol. 26 p. 162 - 163

1528-9303

With increasing consumer demand for healthier foods for better nutrition, there is a rising interest in exploring and developing functional foods with beneficial ingredients from around the world. Chia seeds arise from the Chia plant (Salvia hispanica L.). This plant was native to the diet of the Aztecs and Native Americans from the Southwest, and is currently grown in Latin America (Argentina, Bolivia, Colombia, Guatemala, Mexico, and Peru), as well as in Southeast Asia and Australia. Given its  fatty acid profile, which is  rich in the omega-3 fatty acid ¦Á-linolenic acid  (ALA , 18:3 ¦Ø-3), Chia seeds have been studied in animal feed to increase the omega-3 fatty acid content in chicken eggs (1), and the level of polyunsaturated fatty acids in hogs (2). Furthermore, Chia seeds are found in the US market in various products, such as beverages, granola bars, snacks, and candy. In an interview to Chia expert: Professor Mabel C. Tom¨¢s, from Universidad Nacional de la Plata, La Plata, Argentina, we explored key aspects of the Chia seed, ranging from the growth of the seed in different Latin-American regions, to oil extraction and fatty acid profile, as well as emerging applications of mucilage exudate in gelling. Q: What are the main differences between Chia seed grown in different regions of Latin America? A: In a study comparing seeds grown in the Argentinean province of Salta, with those grown in Quetzaltenango, Guatemala, it was seen that physically, the Argentinean seeds were larger and heavier than their counterparts in Guatemala. This is of importance because the morphology and gravimetrical properties of the seed dictate the type of equipment needed for processing , storing, and transporting. From a compositional perspective, the lipid content of the Chia seed oil is rich in triacylglycerols containing  ALA, with variations in content and speciation depending on region, climatological, and harvest-related factors.  Q: Chia seed oil is rich in omega-3 fatty acids, which have many health benefits but make the oil susceptible to lipid oxidation. Is there a particular antioxidant or system of antioxidants that can ameliorate lipid oxidation? A: We have studied the oxidative stability of Chia seed oil under various natural antioxidants (rosemary and  green tea extracts, tocopherol mixture, ascorbyl palmitate, and their respective blends),  as well as various storage conditions (3). In our work , depending on the type of antioxidant and its concentration, it was possible to increase the induction time . For example, ascorbyl palmitate (5000 ppm) was the most effective single antioxidant  tested, while the most effective blend was comprised of a combination of rosemary extract (2500 ppm) and green tea extract (5000 ppm). Q: Besides the oil, Chia seed is of interest for its mucilage exudate. Could you expand on mucilage exudation, and the applications of this mucilage? A: The chia plant fruit forms four fruitlets (nutlets), although the true seed is contained within each nutlets,  commercially the nutlets are called seeds. When the nutlets are soaked in water, exudation of a clear mucilaginous gel occurs. We have studied the mucilage exudation of chia nutlets from Argentina, and compared its proximal composition to that of Guar gum and Locust bean gum. We determined that in the temperatures studied (25-80 oC), the solubility of chia mucilage (10 g/ L, wt/v) was higher than that of guar and xanthic gums (4). This property along with others,  makes chia mucilage of interest as a food grade thickener for various food applications. Q: Would extraction of the exudate interfere with oilseed extraction? A: No, both oil and exudate can be extracted from the same source. Initially, the mucilage exudate would have to be extracted. Then, it would be possible to perform an oil extraction. Q: What are your perspectives  on the role of Chia seed in Latin America, and worldwide? A: Chia seed production is quickly growing, and there are many applications in the food industry that reflect the interest of consumers on incorporating this seed to their diet. As our understanding on the multiple functionalities of chia seed also grows, we will continue to see more applications in the food industry, as well as novel uses for specific functionalities.