Preparation of emulsion gels utilizing modified guar germ protein isolates: microstructure, rheological attributes, and oral behaviour of hybrid frozen dessert.

Native guar germ protein isolates (GGPI) were modified with atmospheric cold plasma (ACP at 20 kV) and superheated steam (SHS at 130 °C) for 5 or 10 min to produce a highly concentrated emulsion for a hybrid frozen dessert. SEM showed that 5 min of ACP increased surface roughness, while 10 min created larger cavities with uneven surfaces in GGPI powder. The BET analysis confirmed that extended SHS treatment caused agglomeration and reduced porosity and surface area. However, the ACP-10 min treated GGPI emulsion had the highest packing density and nearly uniform droplet sizes. All GGPI emulsions demonstrated pseudoplastic and weak frequency-dependent behaviour. The structural recovery rate of all GGPI emulsions was greater than 89%, indicating superior thixotropic behaviour. Oral tribology analysis revealed that the hybrid frozen dessert containing ACP-5 min treated GGPI exhibited friction factors comparable to those of the milk cream-based frozen dessert at varying sliding speeds.