The development of active food packaging has evolved rapidly in recent years, offering innovative solutions to enhance food preservation and safety while addressing sustainability challenges. This review compiles and analyzes recent advancements (2019–2024) in release-type active packaging, focusing on essential oils, natural extracts, and phenolic compounds as active agents. Primarily plant-derived, these compounds exhibit significant antioxidant and antimicrobial activities, extending shelf life and enhancing food quality. Technological strategies such as encapsulation and polymer blending have been increasingly adopted to overcome challenges related to volatility, solubility, and sensory impact. Integrating bio-based polymers, including chitosan, starch, and polylactic acid, further supports the development of environmentally friendly packaging systems. This review also highlights trends in compound-specific research, release mechanisms, and commercial applications, including a detailed analysis of patents and case studies across various food matrices. These developments have already been translated into practical applications, such as antimicrobial sachets for meat and essential oil-based pads for fresh produce. Moreover, by promoting the valorization of agro-industrial by-products and the use of biodegradable materials, emission-type active packaging contributes to the principles of the circular economy. This comprehensive overview underscores the potential of natural bioactive compounds in advancing sustainable and functional food packaging technologies.

Despite being usually discarded, agro-industrial by-products are rich in bioactive and nutritional compounds and can be redirected into new foods or food packaging. This study evaluated the nutritional composition of cardoon leaves (Cynara cardunculus L.), an agro-industrial by-product, and assessed the impact of the drying process on those characteristics. Furthermore, extracts of the dried leaves and dried leaves combined with lemon peel were incorporated into whey protein-based films at concentrations of 0.5%, 1.0%, and 2.0% (w/v). Their physical, barrier, mechanical, and thermal properties were also analysed. When compared on a dry weight (DW) basis, the dry leaves maintained a stable nutritional profile with no significant degradation of key components, presenting with high carbohydrates (15.4 ± 1.1 g/100 g), moderate protein (21.2 ± 0.4 g/100 g), and low fat (2.0 ± 0.1 g/100 g). The leaves were also a good source of dietary fibres (43.9 ± 1.8 g/100 g) and minerals (13.7 ± 0.2 g/100 g of ash). Incorporating the extracts altered the films’ physicochemical properties, reducing their water vapour permeability up to 4.05 ± 0.26 10⁻¹⁰ g/s.m.Pa, while their tensile strength decreased from 0.34 ± 0.06 to 0.23 ± 0.01 MPa depending on the formulation, and their elongation at break decreased by up to 6.58 ± 0.70%. In contrast, Young’s modulus increased by up to 0.11 ± 0.03 MPa, indicating higher rigidity. This behaviour may be attributed to the interactions between the phenolic compounds and the whey protein matrix, which restricted polymer chain mobility and increased film rigidity while reducing matrix cohesion and flexibility. The results demonstrate that while the extracts enhanced the barrier properties of the films, they reduced the mechanical properties. Overall, the results suggest that cardoon by-products have potential applications in active food packaging, contributing to the development of bio-based materials within a circular economy framework.