Extraction and characterization of protein-polysaccharide complex in cashew apple bagasse: A new insight for cashew apple bagasse extract valorization in the food industry

Anacardium occidentale L., an important tropical tree produces a fruit with two edible parts including the cashew nut and the cashew apple (CA). CA is one of the largest sources of residues produced by the cashew agronomic industry. Cashew apple bagasse (CAB), a by-product underutilized of this fruit after juice extraction contains nutrient compounds such as ascorbic acid, antioxidant and proteins (9-16%) that could be valorized.

In this study, response surface methodology (RSM) design and ultrasound-assisted extraction (UAE) were used to obtained a CAB extract (CABe) with a high concentration of protein. Indeed, from a raw material with 10.02% protein, after extraction we obtain a extract with a protein purity of 22.10%. This value seems low but HPSEC analysis coupled with RI and UV detectors, focused on the structure determination of the CABe highlight that mains component of the CABe were in fact a complex of protein and polysaccharides that cannot be dissociated.
Further, physicochemical analysis shown that CABe acts like gum arabic, cashew gum, and soy soluble polysaccharide. Thus, CABe could be used in food for various functions, including gelling, thickening, stabilizing, dispersing, water holding, foaming, and emulsifying, among others.