Most brewers will say that with frozen store bought fruits you can just throw it in the fermenter.
If you are worried, then a quick pasteurization is all that is needed. Raise the temp to 145f for 5 minutes no higher. You do not want to set the pectin. If you have ever made jam you will know what set pectin looks like. Warm it looks like fruit snot, cold it setup like jelly. If you add set pectin to beer it will have a permanent haze. That haze will get worse the colder you get the beer.