Pectin is a biocompatible polysaccharide with intrinsic biological activity, which may exhibit different structures depending on its source or extraction method. The extraction of pectin from various industrial by-products presents itself as a green option for the valorization of agro-industrial residues by producing a high commercial value product. Pectin is susceptible to physical, chemical, and/or enzymatic changes. The numerous functional groups present in its structure can stimulate different functionalities, and certain modifications can enable pectin for countless applications in food, agriculture, drugs, and biomedicine. It is currently a trend to use pectin to produce edible coating to protect foodstuff, antimicrobial bio-based films, nanoparticles, healing agents, and cancer treatment. Advances in methodology, use of different sources of extraction, and knowledge about structural modification have significantly expanded the properties, yields, and applications of this polysaccharide. Recently, structurally modified pectin has shown better functional properties and bioactivities than the native one. In addition, pectin can be used in conjunction with a wide variety of biopolymers with differentiated properties and specific functionalities. In this context, this review presents the structural characteristics and properties of pectin and information on the modification of this polysaccharide, its respective applications, perspectives, and future challenges.

A sustainable process for keratin recovery from chicken feathers using a bio-based ionic liquid was developed. The minimum selling price calculated for keratin is 22 $ per kg, suitable for biomedical and cosmetic applications.

The poultry-processing industry generates large quantities of waste rich in keratin, a fibrous protein representing around 90 wt% of chicken feathers, which is currently disposed of by landfilling or incineration.

This study investigates the utilization of squid pen waste through a biocompatible ionic liquid approach, focusing on choline acetate, [Ch][OAc]. This ionic liquid effectively extracts over 80 wt % of protein from squid pen waste. To optimize the extraction process, a factorial design of experiments was employed to achieve a protein recovery of 75% at an estimated purity of 86%, along with highly acetylated, crystalline β-chitin with a purity of up to 95%. The extracted protein was subsequently used to create biocomposite films from α- and β-chitosan, demonstrating impressive tensile strengths of 93.15 ± 7.9 and 83.5 ± 6.2 MPa, respectively, while maintaining hydrophilic properties (θ_water < 90°). Molecular dynamics simulations revealed that the anion [OAc]^- exhibits a stronger affinity for protein surfaces compared to other anions, while its combination with the cation [Ch]⁺ optimally facilitates protein recovery. A material mass balance indicated that from 1 kg of dry squid pen, 0.526 kg of protein and 0.34 kg of chitin were recovered. However, high solvent usage significantly impacts energy demands and CO₂ emissions, generating approximately 4.27 kg of CO₂ per kg of product, with 61% attributed to protein production. Technoeconomic analysis demonstrated that solvent costs account for nearly 65% of the minimum selling price of the protein, estimated at $9 kg^-1, which decreases to $0.6 for each kilogram of coproduced β-chitin. Technoeconomic analysis showed that solvent costs comprise nearly 65% of the minimum selling price of the protein, which can reach $9 kg^-1, but this price decreases to $0.6 for each kilogram of coproduced β-chitin. This research underscores the potential of squid pen waste as a valuable resource while highlighting the need for sustainable solvent management strategies.