Cold plasma-assisted valorization of food industry byproducts: a review of mechanisms, applications and research gaps

Cold plasma (CP) effectively valorizes food byproducts through cell wall disruption, surface oxidation, and enhanced permeability. Our review reveals that fruit and vegetable wastes exhibit the highest plasma responsiveness, yielding 20–40% increases in phenolic content and antioxidant capacity under mild conditions (5–15 min, 1–60 kV). In contrast, lignocellulosic wastes require intensive treatment (1–7 h, ozone-rich plasma) to achieve up to 95% lignin degradation and improved enzymatic hydrolysis. Protein-rich byproducts demand careful optimization to prevent denaturation and allergenicity changes. Synergies with ultrasound and enzymes further amplify extraction efficiency. However, major barriers including parameter standardization, limited techno-economic assessments, and safety concerns (nitrosamines, acrylamide) hinder industrial translation, while marine and animal wastes remain underexplored. We conclude that CP is a promising sustainable technology, but successful adoption requires standardized protocols, comprehensive toxicity evaluation, and integrated biorefinery approaches to fully realize circular economy objectives.