Effect of Cold Atmospheric Pressure Argon Plasma Jet Treatment on the Freeze-Dried Mucilage of Chia Seeds (Salvia hispanica L.).

In the present study, the effects of the treatment of chia seeds with a cold atmospheric pressure plasma jet (CP) using argon as a working gas for different times (30, 60, and 120 s) on the rheological, structural, and microstructural properties of the freeze-dried mucilages at -54 °C were investigated. All mucilage gels showed pseudoplastic flow behavior, and CP treatment of chia seeds increased the viscosity of mucilages, probably due to the cross-linking between polymer molecules. The dynamic rheological analysis revealed that all mucilages were elastic gels and that CP treatment improved the elastic properties in a treatment time-dependent manner. Large amplitude oscillatory shear (LAOS) results showed that freeze-dried mucilages showed Type I strain-thinning behavior. Similar to small amplitude oscillatory shear (SAOS) results, CP treatment has affected and improved the large deformation behavior of mucilages depending on treatment time. Meanwhile, Fourier transform infrared spectroscopy (FTIR) revealed the incorporation of hydroxyl groups onto the surface and the formation of C-O-C glycosidic bonds during plasma treatment. Scanning electron microscope (SEM) micrographs showed the formation of denser structures with CP treatment time. Regarding color properties, CP treatment decreased the lightness values of mucilages. Overall, this study showed that CP is an effective way to modify both the SAOS and LAOS properties of freeze-dried chia mucilage and improve viscosity.

Cold plasma modification of food macromolecules and effects on related products.

The food industry is in search of innovative processing technologies that are capable of providing food safety and improving quality with low processing costs and fast operations. As a new technique, cold plasma (CP) fulfills these requirements and thus gained significant attraction from researchers. Apart from general microbial inactivation purposes, CP can effectively modify the food macromolecules through reactions with reactive plasma species. In this context, this review focuses on the interactions between reactive plasma species and proteins, lipids, and polysaccharides. It also covers the changes in interfacial and mechanical properties of proteins and polysaccharides, effects on oleogels and xerogels, modifications in the allergenicity of proteins, and trans-free hydrogenation of oils. On the other hand, the concepts underlying the interactions between reactive plasma species and these macromolecules and the effects of processing parameters should be better understood, thus further studies should focus on these aspects.