Review: Upcycling Potential for Romaine Lettuce Outer Leaves

Worldwide, food losses and waste exert a substantial negative environmental impact. The harvesting of Romaine lettuce, for instance, generates significant waste as outer leaves are typically removed from the cores during harvest and left to decompose in the field. Upcycling technologies offer innovative methods to convert these leaves into valuable products, enhancing sustainability in food systems. This approach not only mitigates waste during the Romaine lettuce harvest but also reduces contaminants. Furthermore, Romaine lettuce is rich in nutritional value and its phenolic compounds are known for their antioxidant, antiinflammatory, antilipemic, antidiabetic, and antihypertensive properties. In this review, we explore opportunities for upcycling Romaine lettuce outer leaves and the environmental benefits with consideration of potential contaminants. Understanding the nutritional value and health benefits of Romaine lettuce underscores the importance of sustainable practices in agriculture and food management.