Conventional plastic materials accumulation has led to a constant search to develop friendly packaging, edible coatings from biopolymers are an example. Since different proteins have different behavior and plastizicer compatibility, in this work, the effect of different polyalcohols (glycerol, sorbitol, maltitol, mannitol, and xylitol) as plasticizers on squid protein films behavior was studied. The results show that except for mannitol, transparent, and flexible films can be obtained. None of them showed transmission to light on the ultraviolet (UV) spectrum. However, only glycerol and sorbitol were sufficiently flexible to evaluate their mechanical properties, in which glycerol had a more elastic behavior with an elongation at a break of 920% and tensile strength (TS) of 0.94 MPa, while sorbitol exhibited a more plastic behavior with an elongation at break of 511% and a TS of 4.41 MPa. Water-vapor transmission rate was higher in glycerol, with 194.41 g·m⁻²d⁻¹, while sorbitol had 44.27 g·m⁻²d⁻¹ but presented blooming. This could be due to low interaction between sorbitol and the protein matrix, correlating with the film-solubility results. Amide I band of the Fourier transform infrared (FT-IR) spectra demonstrated higher denaturation and loss of alpha helical structure in glycerol film, followed by maltitol/sorbitol, xylitol, mannitol, and the control film. This in accordance with thermogravimetric analysis (TGA) results. The results of this study prove that only glycerol and sorbitol are suitable to obtain a see-through flexible film.

Proteins have the ability to form foam, which is a system consisting of a gas phase dispersed within a continuous phase, either liquid or solid. In certain types of food, the incorporation of gas is important for maintaining quality and sensory attributes. However, foam is a thermodynamically unstable system, and its stabilization is a highly researched area. In recent years, there has been growing interest in the application of ultrasound not only to improve foaming properties, but also to alter physicochemical and structural characteristics of proteins, making it an environmentally friendly and versatile technology. Ultrasound can enhance formation and stability by inducing conformational changes through the cavitation phenomenon. However, the benefits of this technology depend on the inherent characteristics of the proteins and the conditions applied during its use, such as frequency, time, amplitude, energy, protein concentration, volume, and medium conditions. This review aims to explore how ultrasound influences the physicochemical properties, induces structural modifications, and consequently enhances functional characteristics such as foaming capacity.

In marine organisms primarily intended for human consumption, the quality of the muscle and the extracted oils may be affected by lipid oxidation during storage, even at low temperatures. This has led to a search for alternatives to maintain quality. In this sense, antioxidant compounds have been used to prevent such lipid deterioration. Among the most used compounds are tocopherols, which, due to their natural origin, have become an excellent alternative to prevent or retard lipid oxidation and maintain the quality of marine products. Tocopherols as antioxidants have been studied both exogenously and endogenously. Exogenous tocopherols are often used by incorporating them into plastic packaging films or adding them directly to fish oil. It has been observed that exogenous tocopherols incorporated in low concentrations maintain the quality of both muscle and the extracted oils during food storage. However, it has been reported that tocopherols applied at higher concentrations act as a prooxidant molecule, probably because their reactions with singlet oxygen may generate free radicals and cause the oxidation of polyunsaturated fatty acids in fish oils. However, when tocopherols are included in a fish diet (endogenous tocopherols), the antioxidant effect on the muscle lipids is more effective due to their incorporation into the membrane lipids, which can help extend the shelf life of seafood by reducing the lipid deterioration that occurs due to antioxidant synergy with other phenolic compounds used supplements in fish muscle. This review focuses on the most important studies in this field and highlights the potential of using tocopherols as antioxidants in marine oils.