Contents of total and damaged starch were observed, together with lipid and protein contents, during the evaluation of abiotic stresses influence (dry conditions, high temperature, low pH value) on the yield and seed of wheat. Contents of total and damaged starch were not changed. Seed growing in filial generation (2nd year) from stressed seeds becomes evident decrease of lipids (0.71 times) and increase of damaged starch 1.31 times. Changes of the total starch and proteins contents were minor. The starch assay procedures were used for the evaluation of the influence of microwave treatment on chemical and physicochemical characteristics of rice. Microwave treatment did not affect the total content of starch in rice, the but the content of damaged starch increased with absorbed microwave energy and temperature of treatment, chiefly for the moisture of 30% and a temperature of 100°C. Changes of damaged starch were in accordance with amylographic characteristics of rice flour. Changes in the contents of total starch, proteins and α-galactooligosaccharides and trypsin inhibitors activity were also monitored during microwave treatment of germinated pea seeds. The contents of total starch, lipids and proteins were without significant changes, whereas the content of α-galactooligosaccharides decreased up to 42% of the value before treatment and trypsin inhibitor activity decreased up to 56-60%. These changes are favourable from the nutritional point of view.