Agri-food wastes (such as brewer’s spent grain, olive pomace, residual pulp from fruit juice production, etc.) are produced annually in very high quantities posing a serious problem, both environmentally and economically. These wastes can be used as secondary starting materials to produce value-added goods within the principles of the circular economy. In this context, this review focuses on the use of agri-food wastes either to produce building blocks for bioplastics manufacturing or biofillers to be mixed with other bioplastics. The pros and cons of the literature analysis have been highlighted, together with the main aspects related to the production of bioplastics, their use and recycling. The high number of European Union (EU)-funded projects for the valorisation of agri-food waste with the best European practices for this industrial sector confirm a growing interest in safeguarding our planet from environmental pollution. However, problems such as the correct labelling and separation of bioplastics from fossil ones remain open and to be optimised, with the possibility of reuse before final composting and selective recovery of biomass.

Bio-polybutylene succinate (PBS) is a biodegradable polymer obtained from renewable feedstock having physical–mechanical properties like traditional low-density polyethylene (LDPE). PBS is employed by many manufacturing sectors, from biomedical to agri-food and cosmetics. Although some studies have already evaluated the resistance of PBS to photodegradation caused by natural outdoor solar exposure (UVA-UVB), a systematic study on the resistance to degradation caused by exposure to UVC rays, which is the subject of this study, has not yet been carried out. PBS was exposed to UVC either neat or filled with 2% carbon black (CB). Mechanical and physical characterization (tensile, hardness, calorimetry, contact angle, morphology, and surface roughness analyses) indicates that the bulk and surface properties of the polymer matrix changes after exposure to UVC radiations, due to a severe degradation. However, the presence of carbon black compensates for the degradation phenomenon. Because UVC rays are used for the sterilization process, necessary in applications such as biomedical, cosmetic, pharmaceutical, food, and other products, a comparison of the protocol used in this paper with the literature’s data has been reported and discussed.

The recyclability of pots made entirely from brewer’s grains (BSGs) and poly(butylene succinate) (PBS) at a PBS/BSG weight ratio of 70:30, hereafter referred to as MIXr, was evaluated. The resulting pots exhibited tensile strength at break comparable to that of conventional fossil-based polymeric materials. The study aimed to determine the maximum content of recycled materials that could be incorporated into virgin (PBSv) while maintaining acceptable properties, thereby extending the material’s life cycle through mechanical recycling before disposal via biodegradation or composting. For comparison, blends of virgin PBS with recycled PBS (PBSv–PBSr) and recycled BSG/PBS material (PBSv–MIXr) were prepared at the same recycled-material contents. The materials were characterized in terms of processability, tensile properties, thermal stability (TGA), chemical group analysis (FTIR), and surface properties. The results showed that the presence of BSG significantly influences the recyclability of the biocomposite. While virgin PBS could incorporate up to 10 wt.% recycled PBS without a significant loss in ductility or thermal stability, PBSv–MIXr blends exhibit a ~20–30% reduction in deformability at MIXr contents ranging from 2 wt.% to 20 wt.% and a reduction in thermal stability ranging from 16–22% at levels of incorporation ranging between 10 wt.% and 40 wt.%.

The close-to-market Life Restart project, co-financed by the European Union (LIFE Program for the Environment and Climate Action), focuses on recycling agri-food waste to produce biodegradable bio composites within a “green” and circular economy framework