Developing pH-sensitive materials for real-time freshness monitoring is critical for ensuring seafood safety. In this study, pH-responsive indicator films were prepared by incorporating purple cabbage anthocyanin (PCA) into a κ-carrageenan/carboxymethyl cellulose (CA/CMC) matrix via solution casting, with PCA concentrations of 2.5%, 5.0%, 7.5%, and 10% (w/w). The films exhibited remarkable pH sensitivity, with distinct color changes across pH 2.0–11.0. Incorporating PCA enhanced film crystallinity, antioxidant properties, and opacity while reducing water vapor transmission (WVP). High PCA content resulted in rougher morphology, lowering tensile strength (TS) but improving elongation at break (EB). The indicator film had good environmental stability, and the color difference was not visible after 10 days in the dark and 4 °C conditions. The CA/CMC/PCA-10% film showed the most pronounced pH-responsive color changes, transitioning from purple to green as hairtail freshness deteriorated. This innovative approach highlights the potential of CA/CMC/PCA films as reliable, eco-friendly indicators for real-time seafood freshness monitoring, offering significant advancements in smart packaging technology.

Drying is a crucial postharvest preservation step, particularly for fruits and vegetables, due to their high moisture content. Physical, sensory, and storage qualities after drying are of interest to food engineers; however, for medicinal purposes, such as nutraceuticals or functional foods, the retention of pharmacological or bioactive compounds is of great interest. This review discusses conventional novel/modern drying technologies and their impact on pharmacological compounds of MEFVs. Conventional drying techniques (sun drying and hot air drying) are cost-effective but slow and usually induce significant losses of thermolabile pharmacological compounds. In contrast, novel/modern drying techniques (solar drying, vacuum drying, freeze drying, microwave drying, infrared drying, heat pump, refractance window, and electrohydrodynamic drying) can accelerate faster moisture removal, but their impact on the pharmacological compounds varies. Current trends in drying research emphasize process optimization, technology hybridization, pretreatment methods, real-time monitoring, and green energy integration to enhance pharmacological compound retention while ensuring sustainability.

Deep eutectic solvents (DESs) with tunable hydrogen-bond network and solvation capacity and acid–base properties are a promising medium for selective fractionation of lignocellulose and valorization of lignin. However, efficient lignin removal and depolymerization, together with the cleavage of lignin–carbohydrate complexes (LCCs), remain critical challenges in DES-mediated lignin-first biorefining. Reactive lignin intermediates may become temporarily stabilized within the solvent environment and subsequently undergo recondensation. Recent developments in DES-assisted selective lignin fractionation, structural regulation, catalytic depolymerization and high-value utilization are critically summarized, and the relationship among molecular structures, the reaction microenvironment, conversion pathways and functional performance are emphasized. The impacts of DES composition, H-bond donors/acceptors, acidity/basicity and solvation parameters on lignin dissolution, LCC bond cleavage, and the stability of major linkages such as β-O-4 are highlighted, along with the intensifying effects of ultrasound and microwave fields. DESs are also regarded as multifunctional reaction platforms with capabilities for selective fractionation, in situ stabilization, and chemical functionalization. Bond cleavage, reactive-intermediate evolution, and radical regulation under thermal, photocatalytic, and electrocatalytic conditions are analyzed, along with strategies to suppress lignin recondensation and enhance aromatic monomer yields. High-value applications in nanomaterials, functional and stimuli-responsive materials, energy materials, and high-energy-density bio-oils are also reviewed. Finally, techno-economic analysis and life-cycle assessment are discussed to identify challenges in DES recovery, stability, mass transfer, energy consumption, and scale-up integration, providing guidance for rational DES design and sustainable lignin-first biorefining.