Emulsifying Properties of Sericin Obtained from Hot Water Degumming Process

Abstract

AbstractSericin is a protein present in the silkworm cocoon of Bombyx mori. Although usually discarded during the silk degumming process, which causes environmental impact and high costs of wastewater treatment, this protein possesses properties that are particularly useful to the food industry. This work was carried out to determine the amino acid profile and evaluate the antioxidant and emulsifier capacity of sericin. The main amino acids present in sericin are glycine, serine and aspartic acid. The high‐molecular‐weight fractions of this protein have antioxidant activity. Furthermore, due to the predominant hydrophilic character of its amino acids, it acts as an emulsifier. The emulsions prepared with 1.0% of sericin were stable for 24 h. All emulsions showed pseudoplastic behavior and great internal strength, according to the rheological analysis. Thus, sericin can be used as an additive in emulsified products providing antioxidant properties in these products.Practical ApplicationsThe present work provides an application as emulsifier to sericin, which is normally discarded during the silk process. This protein prevents phase separation in emulsions and provides antioxidant activity to the formed emulsion, besides being a natural product. The resulting emulsions prepared with high concentration of sericin have high viscosity, and therefore sericin can be used in the production of mayonnaise and creams. It can also be used, in lower concentrations, in salad dressing for example, resulting in a lower viscosity product.