A review of the effects of ultrasound-assisted extraction factors on plant protein yield and functional properties

Proteins from plant sources are valuable components to explore. Protein can be extracted from various plant parts, viz., roots, stems, leaves, and seeds. These proteins are extracted for nutritional purposes and/or for application as functional additives in the food and cosmetic industries. Protein extraction can also be used to add value to by-products from plants, such as defatted oilseed meals. Conventionally protein is extracted by pH alteration. Alkaline circumstances cause the protein to solubilize, making extraction from the source possible. After the protein is solubilized, it is precipitated in acidic conditions to produce a protein isolate. Combining traditional protein extraction methods with ultrasound boosts yield and reduces extraction time. Ultrasound can be used as a pre-treatment or as part of the protein extraction process. This review has studied the effect of different extraction parameters viz., pH, particle size, ultrasound time, temperature, solid-liquid ratio on the yield and functional properties of plant proteins.