for true lipases go for long chain fatty acid triglycerides like olive oil

and for esterases , short chain fatty acid triglycerides like Tributyrin, or more specifically PNPB(para nitrophenol butyrate),PNPA(paranitrophenyl acetate ) can be used.

Comparative analysis using both the substrate is necessory as esterases and lipase shows overlaping activities.

Mind the mode of action of lipase which is very important for substrate preparation as lipase can work only on surface active molecules. so emultion preparation is necessory for assessing their activity.

Doing Lipase assay is like an art which involve lots of skills.

Hope this may help.

thanks for respons sir