Catalyzes the hydrolysis of triacylglycerols to yield free fatty acids, diacylglycerol, monoacylglycerol, and glycerol (By similarity). Shows a preferential hydrolysis at the sn-3 position of triacylglycerol (By similarity). a triacylglycerol + H2O = a diacylglycerol + a fatty acid + H(+) 1,2,3-tri-(9Z-octadecenoyl)-glycerol + H2O = (9Z)-octadecenoate + 1,2-di-(9Z-octadecenoyl)-sn-glycerol + H(+) 1,2,3-trioctanoylglycerol + H2O = 1,2-dioctanoyl-sn-glycerol + H(+) + octanoate Belongs to the AB hydrolase superfamily. Lipase family.