Cold atmospheric plasma-induced alterations in the multiscale structural and functional properties of guar gum

The use of guar gum in the food industry faces challenges owing to its large molecular weight and high viscosity. Cold atmospheric plasma (CAP) is a novel technique that utilizes the reactive species produced by high voltage discharge to modify food ingredients. In this study, guar gum was treated with CAP at different powers and duration, and its rheological properties, molecular structure, thermal stability, emulsifying activity, and stability were evaluated. CAP reduced the molecular weight of guar gum and altered its M/G ratio, leading to a decrease in the apparent viscosity of guar gum and an enhancement in its thermal stability and emulsifying function for soy protein isolate emulsions. Molecular structure analysis revealed the CAP treatment did not destroy the basic structure of guar gum, but caused alterations in the linkages between its glycosidic bonds and/or carbohydrate units. Scanning electron microscopy showed guar gum changed from a dense surface structure to a porous and loose structure after CAP treatment. Therefore, CAP effectively modifies guar gum, enhancing its potential in food and other industries.