Argentinian researchers find that, even after extrusion cooking, flax maintains much of its nutrition.
Argentinian researchers have found that, despite the high heat involved in extrusion cooking, extruded flax meal can enhance the nutritional quality of cereal bars.
Flax is a popular crop in Argentina, but little is known of its nutritional quality once flax is extruded to make it suitable for textured food products. To get a better understanding, a team of researchers conducted nutritional analysis on brown flax seed (Linum usitatissimum var. panambi) as the raw seed, extruded flax meal, and as flour mixes and cereal bars formulated with extruded flax meal.
Extrusion did not significantly influence flax’s amino acid score-be it for essential or non-essential amino acids-and a complementary animal feeding study found “acceptable” protein digestibility for extruded flax meal. The product also enhanced fiber content and omega-3 content in flour mixes and cereal bars, and the researchers noted that omega-3 alpha-linolenic acid (ALA) was mostly retained after extrusion. Still, because flax has a high risk of oxidation, manufacturers should consider formulating related products with added antioxidants.
Of all the nutrients tested, only thiamin and riboflavin decreased significantly in extruded flax versus the raw flax, at 49% and 32% respectively.
“The cereal bars enriched with extruded flaxseed meal provide an acceptable nutritional quality, with enhanced quality and quantity of proteins, dietary fiber, and [omega-6 to omega-3] ratio,” wrote the researchers. “Particularly, it is of great interest to formulate this type of products aimed at short-age children, due to the international concern on the poor nutritional quality of snacks and related products highly consumed by this population group.”