OBJECTIVE: This experiment tested the protein quality of flaxseed when used for the growth and maintenance of rats. METHODS: In the first phase, 18 just-weaned female Wistar rats (Rattus norvegicus), receiving water and chow ad libitum, were divided into three groups (n=6): the flaxseed group received a flaxseed-based diet; the control group received a casein-based diet; and the modified control group received a casein-based, high-fiber, high-oil diet. In the second phase (28 days later), 5.4% of casein was added to the flaxseed-based diet. The diets of the other groups remained unchanged. All animals received isocaloric diets with 10% protein content until they were 180 days old. Protein efficiency ratio and albumin concentration was determined in the 2 phases of the experiment. RESULTS: In the first phase, the protein efficiency ratio of the flaxseed group (0.8, SD=0.05) was significantly lower than those of the control group (2.3, SD=0.1) and modified control group (2.3, SD=0.2). The albumin concentration of the flaxseed group (3.0, SD=0.04g/dL) was smaller (p<0.01) than those of the control group (3.9, SD=0.06g/dL) and modified control group (3.9, SD=0.01g/dL). In the second phase, protein efficiency ratio of the modified flaxseed group (1.2, SD=0.1) was higher (p<0.01) than those of the control group (0.9, SD=0.02) and modified control group (0.9, SD=0.05). Albumin concentration was similar in all groups, characterizing recovery from malnutrition. CONCLUSION: In conclusion, flaxseed should not be used as an exclusive source of protein, especially during growth.
Growth; Flaxseed; Rats; Nutritive value
