Hydrolyzes all ester bonds in triglyceride and displays a high affinity for triolein. For unsaturated substrates having long fatty acyl chains (C18:2 cis-9, cis-12 and C18:3 cis-9, cis-12, cis-15) GCL I shows higher specific activity than GCL II, whereas GCL II shows higher specific activity against saturated substrates having short fatty acid chains (C8, C10, C12 and C14)