Industrial Production of Citrus By-products and Its Processing Techniques

Citrus industry generates a large quantity of citrus by-products such as peels, seeds, and pulp which are very valuable resource. Essential oils, flavonoids, and pectin are some of the major compounds obtained from citrus by-products. Several techniques are employed for processing of citrus wastes such as physical extraction techniques (solvent free microwave extraction, pressurized liquid extraction, and solid phase extraction), chemical extraction techniques (solvent extraction), and novel extraction techniques (solid-state fermentation and enzyme-assisted solvent extraction). Citrus by-products have wide applications in various industries, including food, pharmaceuticals, and cosmetics. For example, essential oils obtained from citrus wastes are commonly used as flavoring and fragrances in the food and cosmetics industries. Pectin, a carbohydrate extracted from citrus by-products, is used as a gelling agent in the food industry, while flavonoids are used as antioxidants and natural colorants. The industrial production of citrus by-products not only generates value from waste but also contributes to sustainability by reducing the amount of waste generated by the citrus industry. Additionally, the use of citrus by-products can provide economic benefits for citrus producers and processors. Hence, this chapter aims to provide information about utilization of citrus fruit wastes as well as the various processing techniques available in the industries. Applications of the citrus by-products in various fields have also been discussed here.