Unlocking the potential of lemon by-products as functional ingredients: an opportunity for the food industry

Introduction: Citrus fruits are one of the most widely cultivated fruit crops and one of the most important products consumed in the Mediterranean region. The annual production of different types of citrus fruits was around 143 thousand tonnes in 2019, with lemons and limes accounting for around 20 thousand tonnes [1]. Industrial processes use only 45% of the total weight of the fruit, leaving a significant amount of waste, including peel (flavedo: 27%), pulp (albedo and endocarp: 26%) and seeds (2%) [2]. Lemon by-products are composed of significant amounts of bioactive compounds such as minerals, carotenoids, vitamins, essential oils (EOs), phenolic compounds (PCs) and fibers, which give them bioactivities related to food preservation, such as antimicrobial and antioxidant. These by-products can be explored to produce bioactive and functional ingredients to promote the zero-waste concept. Main conclusions: The valorization of lemon processing by-products, represent promising sustainable food preservation solutions with antioxidant and antimicrobial properties. This study also underlines the importance of turning waste into valuable resources in the global citrus industry, as a circular economy approach.