According to Wikipedia "snacking" doesn't have a concrete definition. Ask anyone, young and old, and we all agree that what we eat in between meals is a snack but depending on where in the world you are defines what a snack is. As any good Persian would tell you, snacking is not just the small portions of sweets and deep friend goodies but there are a number of sour snacks. Persians have a sweet tooth and a sour tooth, and a Persian childhood is not complete without eating sour cherries, sour plums and sour fruit leather.
Fruit leather (Lavashak, literally meaning baby lavash) is a thin, flat large piece of fruit puree dried on large trays in the summer sun and eaten as a winter snack. Surprisingly, summer fruit turns very sour when cooked into a paste. No sugar and sweet fruit such as bananas are added to sweeten them. These are as pure as fruit.
If you have plenty of summer fruit and are willing to give this a go, simply reduce a pot full of fruit into a puree and pour a 1cm thickness of fruit puree on a baking tray. You can either dry them in your oven at 40C or in the sun (30C for two days). If you prefer to sun dry them, best to cover your trays with a cheese cloth. Apple and any stone fruit is a good combination. Best to use non-stick trays and no need to brush the trays with oil.