Heating and glycation of β-lactoglobulin and β-casein: Aggregation and in vitro digestion

• Published in: Food research international Vol. 55; pp. 70 - 76
• Main Authors: Pinto, Michele S., Léonil, Joëlle, Henry, Gwénaële, Cauty, Chantal, Carvalho, Antônio F., Bouhallab, Saïd
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.01.2014; Elsevier
• Subjects: Agglomeration; Aggregates; Aggregation; beta-casein; beta-lactoglobulin; Biological and medical sciences; dairy technology; digestible protein; Digestion; Electrophoresis; Food and Nutrition; Food engineering; Food industries; Fundamental and applied biological sciences. Psychology; gel chromatography; Glucose; Glycation; heat; Heat treatment; In vitro digestion; Life Sciences; light scattering; Milk; polyacrylamide gel electrophoresis; protein aggregates; Proteins; transmission electron microscopy; β-Casein; β-Lactoglobulin; Aggregation; β-Casein; Heat treatment; In vitro digestion; β-Lactoglobulin; Glycation; Milk protein; Casein; Heating; Digestion; Whey protein; In vitro; glycation; technologie laitière; agrégation; beta-lactoglobuline; traitement thermique; beta-caséine; digestion in vitro
• ISSN: 0963-9969; 1873-7145
• DOI: 10.1016/j.foodres.2013.10.030

Heat treatment is commonly used in dairy technology. Usually, milk is heated and cooled many times before to obtain the final product and milk components are then subject to cumulative heat treatments. In the present work, we investigated the heat induced aggregation (90°C until 24h) of two model proteins, β-lactoglobulin (β-Lg) and β-casein (β-CN), in the presence of glucose and subsequent consequences on simulated gastro-duodenal digestion. Protein aggregation and digestion were monitored using polyacrylamide gel electrophoresis, size exclusion chromatography, dynamic light scattering and transmission electron microscopy. Concomitant heating and protein glycation affect aggregation kinetics as well as protein sensitivity to enzymatic digestion. Spherical covalently linked aggregates were favored in the case of β-CN in the presence of glucose. Glucose limited the formation of twisted fibrils from β-Lg. We clearly showed that aggregates of both proteins formed in the presence of glucose were more resistant to enzymatic digestion. Those formed from β-Lg being highly resistant and still present at the end of simulated gastro-duodenal process. These findings underline the importance not only of the aggregation as such but also of the nature of formed aggregates on protein digestibility. •Glucose affects differently thermal aggregation of β-casein and β-lactoglobulin•Heating leads to spherical aggregates from β-CN against twisted fibrils from β-Lg•Aggregates formed in the presence of glucose are more resistant to enzymatic digestion