Efficacy of Atmospheric Pin to Plate Cold Plasma Treatment for Functional Modification of Agar: Gel Strength, Rheological, and Thermal Behavior

ABSTRACT Study investigates the effects of cold plasma (CP) treatment on the physicochemical and functional properties of commercial agar exposed to different voltage‐time combinations (170–210 V, 5–15 min). Changes in moisture content, pH, sulfate content, 3,6‐anhydrogalactose (3,6‐AG), gel strength, and rheological behavior were analyzed. Structural modifications were evaluated using XRD, SEM, FTIR, DSC techniques. Results showed a significant reduction in moisture and sulfate content, while 3,6‐AG content increased, leading to enhanced gel strength and improved water‐holding capacity. CP treatment also modified agar microstructure, reduced crystallinity, and introduced surface roughness, which contributed to improved functional properties. Rheological analysis confirmed changes in viscosity and shear‐thinning behavior, indicating altered gelation characteristics. Findings demonstrate that CP treatment is an effective technique for enhancing the properties of agar.