Caracterización de semillas de linaza (Linum usitatissimum L.) cultivadas en Venezuela

RESUMEN. En los ultimos anos se ha promovido el consumo de linaza (Linum usitatissimum L.) como alimento funcional por sus beneficios a la salud, atribuibles principalmente a su contenido de acidos grasos omega-3, lignanos, y fibra dietaria. En este estudio se evaluo la calidad microbiologica, composicion quimica y las propiedades antioxidantes de la semilla de linaza cultivada en Venezuela y se comparo con una variedad canadiense de amplia venta en el pais. Se determinaron coliformes totales, mohos y levaduras, S. aureus, y esporulados de los generos Bacillus (aerobios) y Clostridium (anaerobios), humedad, grasas, proteinas, fibra dietetica total, soluble e insoluble, mucilago, minerales, perfil de acidos grasos, contenido de HCN equivalente, aw, color, polifenoles y propiedades antioxidantes como Eficiencia Antirradical (EA), concentracion de antioxidante necesario para disminuir la concentracion inicial en 50 % (EC50) y el tiempo necesario para alcanzar la EC50 (TEC50). Se determinaron diferencias significativas en la composicion de las semillas, resaltando su elevado contenido de grasa, proteinas, acido alfa-linolenico y fibra dietaria. Se observaron diferencias en el contenido de mucilago, pero no en el de fibra soluble, insoluble y total. La concentracion de HCN equivalente en ambas semillas es del orden de 40 mg/100 g, lo cual no representa riesgos a la salud, si se consideran sus formas de consumo. La linaza venezolana contiene mayor contenido de polifenoles que la canadiense, pero la capacidad antioxidante de esta ultima es mayor; ambas tienen una EA calificada como media (TEC50>30 min). Palabras clave: Linaza, polifenoles, capacidad antioxidante. SUMMARY. Characterization of flaxseed (Linum usitatissimum L.) grown in Venezuela. In recent years, the consumption of flaxseed (Linum usitatissimum L.) has been promoted as a functional food for its health benefits, mainly attributable to its content of omega-3 fatty acids, lignans and dietary fiber. This study evaluated the microbiological quality, chemical composition and antioxidant properties of flaxseed grown in Venezuela and compared them to the values of a Canadian variety widely sold in the country. Total coliforms, molds and yeasts, S. aureus and sporulated of the genera Bacillus (aerobic) and Clostridium (anaerobic), moisture, fat, protein, total dietary fiber, soluble and insoluble, mucilage, minerals, fatty acid profile, equivalent HCN content, aw, color, polyphenols and antioxidant properties, like antiradical efficiency (AE), concentration of antioxidant needed to decrease the initial concentration by 50 % (EC50) and the time required to reach the EC50 (TEC50) were evaluated. Significant differences in seed composition were determined, where its high content of fat, protein, alfalinolenic acid and dietary fiber stand out. Differences were observed in the mucilage content, but not in soluble, insoluble and total fiber content. Equivalent HCN concentration in both seeds is in the order of 40 mg/100 g, which poses no health risks, considering their consumption patterns. Venezuelan flaxseed contains higher content of polyphenols than the Canadian does, but the antioxidant capacity of the latter is higher; both have an EA rated as average and a slow reaction time (TEC50> 30 min).