Effect of seed treatments on the chemical composition of two amaranth species: oil, sugars, fibres, minerals and vitamins

The effects of seed treatments, including cooking, popping, germination and flour air classification on several components of Amaranthus caudatus and A. cruentus seeds, including oil, sugars, fibre, minerals and vitamins were studied. The lipid, crude and dietary fibre, ash, and sugar contents were 71, 43, 140, 30 and 18 g kg-1 in raw A. caudatus and 85, 39, 134, 40 and 22 g kg-1 in raw A. cruentus seeds, respectively. Sucrose was the dominant sugar in the raw and thermal treated seeds of both species, while glucose and galactose were the dominant ones in the high protein and the germinated seed flours. Phosphorus, potassium, magnesium and calcium were the dominant minerals in the raw seeds of both species. Air classification increased the content of minerals by more than 35% while thermal treatments did not affect their content and germination increased the calcium and zinc contents. The ascorbic acid contents were 0.030 and 0.023 g kg-1 sample in raw A. caudatus and A. cruentus seeds, respectively. All the treatments reduced the ascorbic acid content, with a high effect for the air classification and the germinated seeds dried at 90 °C. The levels of vitamin B complex, including niacin, niacinamide, pyridoxine and riboflavin were increased in the high protein flour fraction (protein contents of these fractions of A. caudatus and A. cruentus were 263.9 g kg-1 and 246.6 g kg-1, respectively) and decreased in the thermal treated flours. Germination mostly increased the amounts of those vitamins while drying reduced their amounts