Effects of germination on the bioactive and anti-nutritional properties of pseudocereals

Pseudocereals are regarded as nutritious grains that provide macro and micronutrients with high bioactive potential. However, the presence of some anti-nutrients such phytic acid and tannins reduces the bioavailability of these nutrients. Anti-nutrient contents can be decreased by germination to improve the nutritional value of pseudo cereals and increasing the bioavailability of nutrients. In this study, the two common pseudocereal grains, buckwheat (Aktaş, common) and quinoa (white and black) was germinated. Three germination methods (conventional, ultrasound and alkaline) were evaluated and compared during germination (0, 12, 24, 48, 72 h) in terms of changes in physical (colour values), chemical (moisture, ash, lipid, protein, starch), nutritional (total phenolic content, antioxidant activity) and anti-nutritional (tannin, phytic acid) compounds. The colour of pseudo grains was mostly affected by alkaline assisted germination with increasing germination period. The amount of macronutrients (protein, lipid, starch) decreased except the ash content in germinated buckwheat and quinoa grains. Germinated pseudo grains by ultrasound assisted methods have contained highest amount of total phenolic content as well as antioxidant activity. The phytic acid, an anti-nutritional compound, has been decreased by using germination, particularly ultrasonic assisted method. Alkaline germination was significantly more successful in lowering the amount of tannin which is another anti-nutrient. All in all, germination increases the nutritional value of pseudo cereals by reducing the amount of antinutrients and improving the bioavailability of nutrients. As an alternative to conventional grain consumption model, germinated pseudo grains and their flour or processed products can be used for the development of functional foods with high nutritional qualities. Also, these products may be valuable alternatives for people suffering from celiac disease due to their gluten free nature.