Blueberries, with lots of antioxidants and a low sugar content, are one of the healthiest fruits of all. The difference in taste with fresh, in season blueberries bought close to where you live and out of season berries shipped from miles away is enormous. They're perfect just thrown in breakfast cereals or served with yogurt, but can also be a great addition to a tart or made into preserves or pies. The white "bloom" on the berries is a natural occurrence and should be intact.