Ultrasound-assisted extraction of mucilaginous seed hydrocolloids: Physicochemical properties and food applications

Background: Mucilaginous seeds are novel sources of hydrocolloids with great functionalities. However, conventionally extracted mucilage is not of high quality due to the physical damage of seeds and the presence of seed particles in mucilage. Ultrasound-assisted extraction (UAE) of mucilage is a cost-effective and promising application of power ultrasound. Scope and approach: In this review, the recent findings about extraction yield, chemical composition, color, apparent and intrinsic viscosity, emulsifying properties and antioxidant activity of mucilage obtained from seeds by conventional extraction (CE) and UAE were investigated and compared with each other. Key findings and Conclusions: The results revealed that the UAE system had many positive effects such as increase in the extraction yield, lightness, emulsifying properties, antioxidant activity, and decrease in the impurities. However, the efficiency of UAE in improving the functional properties and bioactivity of mucilage seed gums was influenced by process conditions such as power, amplitude intensity, frequency, sonication time, temperature, and the intrinsic attributes of mucilage such as molecular structure. Therefore, in order to accomplish optimum bioactivity and functioning of seed gums, we should determine and apply optimized processing parameters.