Effect of protein aggregates on foaming properties of β-lactoglobulin

• Published in: Colloids and surfaces. A, Physicochemical and engineering aspects Physicochemical and engineering aspects, 2008-12, Vol.330 (2), p.96-102
• Main Authors: Rullier, Bénédicte, Novales, Bruno, Axelos, Monique A.V.
• Format: Article
• Language: English
• Subjects: Chemical and Process Engineering; Chemistry; Colloidal state and disperse state; Emulsions. Microemulsions. Foams; Engineering Sciences; Exact sciences and technology; Foam; Food engineering; General and physical chemistry; Interfacial properties; Life Sciences; Protein aggregates; Surface physical chemistry
• ISSN: 0927-7757; 1873-4359
• DOI: 10.1016/j.colsurfa.2008.07.040

Our paper aims at determining the respective part of protein aggregates and non-aggregated proteins in the foam formation and stability of β-lactoglobulin. We report results on fractal aggregates formed at neutral pH and strong ionic strength (aggregates size from 30 to 190 nm). Pure aggregates and mixtures of non-aggregated/aggregated proteins at varying ratios were used. The capacity of aggregates to form and stabilize foams has been studied in relation with their ability to absorb at air/water interfaces. Our results show that protein aggregates are not able by themselves to improve the foaming properties but participate to a better foam stabilization in the presence of non-aggregated proteins. Non-aggregated proteins appear to be necessary to produce stable foams. We have shown that the amount and the size of aggregates had an influence on the drainage rate.