Heat treatment affects gastric digestion kinetics but not amino acid bioavailability of milk proteins: a pig study

Xiyu Qin; Caiziyu Yu; Xiaolu Geng; Yi Chai; Xiaoxue Liu; Xiaoxu Zhang; Menghui Wang; Xiaomin Ren; Yanling Hao; Ran Wang; Yixuan Li; Pengjie Wang; Bing Fang; Wentao Qian; Hongliang Li; Xiaoyu Wang

doi:10.1016/j.foodchem.2025.145198

Heat treatment affects gastric digestion kinetics but not amino acid bioavailability of milk proteins: a pig study

Food Chem. 2025 Jun 17:491:145198. doi: 10.1016/j.foodchem.2025.145198. Online ahead of print.

Authors

Xiyu Qin¹, Caiziyu Yu¹, Xiaolu Geng², Yi Chai³, Xiaoxue Liu⁴, Xiaoxu Zhang⁴, Menghui Wang⁵, Xiaomin Ren⁵, Yanling Hao⁴, Ran Wang⁴, Yixuan Li⁴, Pengjie Wang⁴, Bing Fang⁶, Wentao Qian⁷, Hongliang Li⁸, Xiaoyu Wang⁹

Affiliations

¹ College of Food Science & Nutritional Engineering, China Agricultural University, Beijing 100083, China.
² Mengniu Hi-Tech Dairy Products (Beijing) Co., Ltd., Beijing 101100, China; Inner Mongolia Mengniu Dairy (Group) Co., Ltd., Hohhot 011500, China.
³ College of Food Science and Engineering, Tianjin University of science and technology school, Tianjin 300457, China.
⁴ Key Laboratory of Food Precision Nutrition and Quality Control, Department of Nutrition and Health, China Agricultural University, Beijing 100083, China.
⁵ Mengniu Hi-Tech Dairy Products (Beijing) Co., Ltd., Beijing 101100, China.
⁶ College of Food Science & Nutritional Engineering, China Agricultural University, Beijing 100083, China; Key Laboratory of Food Precision Nutrition and Quality Control, Department of Nutrition and Health, China Agricultural University, Beijing 100083, China. Electronic address: bingfang@cau.edu.cn.
⁷ Inner Mongolia Mengniu Dairy (Group) Co., Ltd., Hohhot 011500, China; Key Laboratory of Dairy Quality Digital Intelligence Monitoring Technology, State Administration for Market Regulation, Hohhot 011500, China. Electronic address: qianwentao@mengniu.cn.
⁸ Inner Mongolia Mengniu Dairy (Group) Co., Ltd., Hohhot 011500, China; Key Laboratory of Dairy Quality Digital Intelligence Monitoring Technology, State Administration for Market Regulation, Hohhot 011500, China. Electronic address: lihongliang@mengniu.cn.
⁹ College of Food Science & Nutritional Engineering, China Agricultural University, Beijing 100083, China; Key Laboratory of Food Precision Nutrition and Quality Control, Department of Nutrition and Health, China Agricultural University, Beijing 100083, China. Electronic address: xy.wang@cau.edu.cn.

PMID: 40544601
DOI: 10.1016/j.foodchem.2025.145198

Abstract

Impact of heat treatment on digestion and absorption of milk proteins in vivo remains unclear. This study used Bama minipigs with duodenum-ileum double cannulas to investigate milk protein digestion and absorption under four heat treatments. During early gastric digestion (20 min), high-temperature treated milk (HTM) and ultra-high-temperature treated milk (UHTM) formed more fragmented protein curds. Additionally, β-lactoglobulin bands disappeared earlier than pasteurized milk (PM), indicating faster gastric digestion. Casein bands appeared sooner in HTM and UHTM than PM, indicating faster gastric emptying. Postprandial changes in plasma ghrelin and cholecystokinin kinetics confirmed faster gastric emptying for HTM and UHTM. However, no notable differences were observed in late gastric digestion (105 min) and plasma amino acid accumulation among different heat-treated milk. Collectively, this study illustrates that heat treatment can accelerate early gastric digestion of milk proteins without affecting overall digestion outcomes or amino acid bioavailability, providing guidance for advancing milk processing technologies.

Keywords: Amino acid; Bioavailability; Gastric digestion; Heat treatment; Milk; Pig.