Review of ultrasound combinations with hybrid techniques for pectin extraction from agri-food by-products

Pectin is a plant cell wall structural polysaccharide. It exhibits a variety of properties, including stabilizing, emulsifying, and thickening effects. Consequently, it is widely utilized in the food industry. Pectin extraction is commonly done by conventional method, which includes the use of mineral acids with heating, and obtains varying pectin yield and quality. Ultrasound technique is one of the novel methods for pectin recovery, that has improved its properties. Therefore, this paper presents a brief review about the pectin sources, structure, widespread applications, extraction possibility based on using ultrasound technique within and without the combination with other non-conventional techniques (enzymes, microwaves), and evaluation of the yield and physicochemical characteristics of the extracted pectin. As indicated by the cited literature, the application of hybridized methodologies generally exhibits higher extraction efficiency, considering the need for the associated variables to be optimized.