The phytic acid, phenolic compounds and total tannins contents of canola, sunflower and soybean meals subjected to different chemical treatments were evaluated in this study, aiming its inclusion in fish diets. The treatments were: a) A: acidified water (pH 1.0); b) EMA: ethanol (absolute) + methanol (absolute) + water, (45:45:10 ratio); c) ET: acidified ethanol (absolute) (pH 1.0); d) ETA: ethanol (absolute) + water (70:30 ratio) pH 1.0; e) AE: acidified water (pH 1.0) + ethanol (absolute) used separately. For canola meal, phytic acid content raised when treatments EMA, ET and ETA were used. Treatments AE and ETA were more efficient for reducing phenolic compounds. Total tannins showed reduction under all treatments, but ET, ETA, and AE were more effective. For sunflower meal, A and AE reduced phytic acid content, while the other treatments caused an increase in this antinutrient. Total phenols and tannins were most reduced under AE treatment. For soybean meal, treatment A was the only which reduced phytic acid content. Treatment AE was the best on reducing total phenols and tannins for soybean meal. Treatment AE represents the best alternative for reducing phytic acid, total phenols and total tannins of canola, sunflower and soybean meals.
phytic acid; tannins; phenolic compounds; antinutritional factors; protein sources