Lactuca sativa L. losses and wastes as a source of biobased ingredients

BACKGROUND The growing global population and increasing consumer focus on healthy eating challenge the agricultural sector to ensure both sustainable food production and safety. Lettuce ( Lactuca sativa Mill.), the most cultivated leafy vegetable worldwide, can lose up to 40% of its weight during processing. This study investigates the biochemical composition of waste from six lettuce varieties, Curly‐leafed, Iceberg, Little Gems, Romaine, Frisée and Lollo Rossa, collected from losses during cultivation, transport, storage and processing. RESULTS Lollo Rossa showed the highest levels of beneficial compounds, including organic acids (189 g kg −1 dry weight (dw)), tocopherols (292 mg kg −1 dw), folates (2.7 mg kg −1 dw), carotenoids (1.1 mg g −1 dw) and essential minerals. Little Gems waste stood out for its content of nonessential amino acids, particularly glutamine (63 mg g −1 dw), asparagine (17.4 mg g −1 dw) and glutamic acid (6.5 mg g −1 dw). Lollo Rossa also exhibited high levels of phenolic compounds (29.77 mg g −1 extract), including anthocyanins such as cyanidin‐ O ‐hexoside and cyanidin‐3‐(6″‐malonyl)glucoside. Decoction extracts from Lollo Rossa showed the strongest antioxidant activity, while hydroethanolic extracts from four varieties displayed antimicrobial activity against Yersinia enterocolitica . CONCLUSION These findings highlight the potential of lettuce waste as a source of valuable bioactive compounds, supporting sustainable practices and value‐added applications in the food and pharmaceutical industries.