The Quince is similar in appearance to a pear and is bright golden-yellow when mature. The Quince is a very nutritious fruit that also has a very low calorie  density. One 100-gram quince fruit contains just 57 calories, according  to the USDA Nutritional Nutrient database. It is also a great source of dietary fiber, antioxidants, vitamins and minerals. The fruit contains tannins and has a high  concentration of vitamin C. Quince is also a source of calcium, iron, magnesium and copper.