Food Wastes and By-Products as Valuable Ingredients for Processed Foods

Food industries generate a significant amount of waste and by-products with the potential for valorization as ingredients for processed foods. The addition of pre-treated fruit and vegetable pomace powder into foods can enhance dietary fiber, vitamin C, phenolics, pigments, and many other antioxidants. Cereal and legume by-products like bran, pod, husk, and skin increase the protein, fiber, and mineral content. While whey can be used for its protein functionality, fish bone and eggshell can be used as calcium fortificants. However, the addition of food waste can also have negative effects on the structural properties, namely, specific volume of leavened bakery products, expansion index of hot extruded snacks, and physical stability of dairy foods and beverages. In general, use of no more than 10%–20% has been found acceptable by the consumers on a sensory basis. This review critically examine the composition of source-specific food wastes and by-products and also elaborate their impact on processed foods like bread, biscuits, cookies, cakes, muffins, dairy foods, beverages, and extruded products. Also, the review addresses the physical, chemical, and biological hazards that could enter the food stream through valorization of food waste were discussed.