Acid hydrolysis of green pea, green bean pods and bean seeds in simulated gastric conditions was investigated. The following were analysed: polyphenols and reducing sugars content, antitrypsin, antipepsin and antipancreatine activity (in obtained hydrolysates); antioxidative properties of residue after hydrolysis. The obtained value depends on the vegetable variety and time of hydrolysis. The highest antioxidative potential was observed in green bean pods. The filtrate obtained after pea hydrolysis showed the highest antitrypsin activity, but the highest antipepsin activity was found in bean seeds.