Use applesauce
Apples are high in pectin which is a soluble dietary fiber found in cell walls. Heat breaks down the cell walls and releases pectin into the liquid where it forms a gel network to give jam its texture.
Adding in lemon juice lowers the pH of the jam to an optimal range for pectin to gel up. Vitamin C from lemon also helps stabilize the antioxidants in strawberries and keeps the color bright!
