Valorization of fruit and vegetable waste for bioactive pigments: extraction and utilization

Fruit and vegetable processing industries produce millions of tons of waste annually worldwide. Most fruit and vegetable wastes such as peels, pomace, seeds, stalks, leaves, and pods end up in landfills or dumped in rivers, causing environmental hazards. Only a small fraction is valorized as livestock feed, sources of bioactive compounds/pigments, biofuel production, and soil improvement material. Bioactive pigments are colored compounds that have potential health benefits for humans and can be obtained from animals, plants, or microorganisms, such as chlorophylls, carotenoids, anthocyanins, and betalains. Bioactive pigments can be used as food additives, antioxidants, color intensifiers, natural colorants, or as substrates for the generation of value-added products. In this chapter, the extraction and utilization of bioactive pigments such as anthocyanins, betalains, and carotenoids from selected fruit and vegetable (i.e., grape, red beet, and tomato) wastes are discussed.