(LB02-21-25) Effects of Heating Combined With High-Intensity Ultrasonic Treatment on the Physiochemical, Structure, and Proteolysis of Goat Milk β-Lactoglobulin

Objectives: The objective of this study was to study the physiochemical, structure, digestive properties of goat milk β-lactoglobulin after heating and ultrasound treatments.

Methods: Goat milk β-lactoglobulin was prepared in phosphate buffer. It underwent various treatments: no treatment, high-intensity ultrasound , high-temperature, or combinations thereof, with sodium azide added to all samples. Simulated gastrointestinal digestion involved pH adjustments for gastric and intestinal phases using simulated fluids, followed by peptide isolation through ultrafiltration and solid-phase extraction before LC-MS/MS analysis to monitor changes in peptide composition.

Results: Results shown that elavated temperature treatment combined with high-intensity ultrasonic treatment has a greater influence on the structure of goat milk β-lactoglobulin than just ultrasonic treatment or heating treatment. High-heat and high-intensity ultrasonic treatment resulted β-lactoglobulin to form polymers. Peptides obtained from goat milk β-lactoglobulin after in-vitro digestion were analyzed by peptidomics platform. Compared with just high-intensity ultrasonic treatment, high temperature treatment could significantly affect the digestive characteristics of goat milk β-lactoglobulin. Cluster analysis indicated that a highly peptides similarity has been found for the samples treated by high-heat (before or after treatment) combined with high-intensity ultrasound treatment. Relative abundance of bioactive peptides which was obtained from in-vitro digestion was decreased for the goat milk β-lactoglobulin sample when it was treated by high temperature treatment.

Conclusions: This study explored the impact of combined high-temperature (85°C, 30 min) and ultrasound (20 kHz, 40% amplitude, 30 min, 12 ± 3°C) treatments on goat milk β-lactoglobulin (β-LG), showing that these treatments alter β-LG structure, enhancing digestibility but potentially reducing nutritional quality and increasing health risks through cytotoxic components.

Funding Sources: This project was supported by a special grant from the Northeast Agriculture University of China.