Promoting a circular economy by developing new gastronomic products from brassica non‐edible leaves

• Published in: International journal of food science & technology Vol. 59; no. 2; pp. 1071 - 1079
• Main Authors: Martin‐Gómez, Helena, Diez, Mikel, Abadias, Maribel, Rivera, Ana, Aguiló‐Aguayo, Ingrid
• Format: Journal Article
• Language: English
• Published: Oxford Wiley Subscription Services, Inc 01.02.2024
• Subjects: Acceptability; Aroma; Beverages; Black tea; Brassica; Circular economy; Fermentation; Fermented food; Flavors; Food waste; Leaves; Microorganisms; Odour; Physicochemical processes; Physicochemical properties; Plant parts; Polyphenols; Saccharides; Sensory evaluation; Shape; Starter cultures; sustainability; upcycling; Value chains; Volatile compounds
• ISSN: 0950-5423; 1365-2621
• DOI: 10.1111/ijfs.16877

Summary This study aims to apply circular economy principles by reintroducing discarded Brassica leaves into the value chain as innovative products. Non‐edible leaves of three Brassica varieties were used to develop kombucha, a fermented beverage with health benefits. The fermentation time (9 days), temperature (25 °C), starter culture, and container shape (2 L round‐shape glass jar) influenced the beverage's physicochemical properties, including pH, vitamin content, polyphenols, and sugar levels. Different Brassica varieties showed various effects on antioxidant capacity and polyphenol content during fermentation, with potential implications for microbial engagement. Sensory analysis revealed differences in appearance, colour, aroma, and taste between black tea and Brassica samples, which are due to glucosinolates and volatile compounds, thus providing opportunities for improving consumer acceptability through flavour masking. Overall, this work showcases the potential of using non‐edible Brassica by‐products and highlights the potential of fermented beverages like kombucha to address food waste and promote value addition from otherwise discarded plant parts. This study transforms non‐edible Brassica leaves, a significant waste stream, into fermented beverages. The findings support a circular food economy by upcycling vegetable by‐products and plant discards, offering valuable insights for sustainable agricultural resource utilisation.