selling foods in Australia requires food safety certificates (just another barrier)

preserving food generally - yes. People preserve food in many way, and sell it in many ways. Fruit gets dried with ease too. That might be a more viable option.

Do you have an angle on the marketplace that others do not. i.e. strawberry growers, existing jam making companies? I suspect you have no chance to compete... (this is a rational check generally - "are other people poised to have seen this idea first and acted on it". While not always possible to predict; and not always accurate - for simple ideas it can help temper the excitement of shiny new ideas)