Green Tea Polyphenols Decrease Strecker Aldehydes and Bind to Proteins in Lactose-Hydrolyzed UHT Milk

• DOI: 10.1021/acs.jafc.7b04137
• Publication Date: 2017-11-09T10:18:26Z
• Authors: Therese Jansson; Valentin Rauh; Bente P. Danielsen; Mahesha M. Poojary; Sandra S. Waehrens; Wender L. P. Bredie; John Sørensen; Mikael A. Petersen; Colin A. Ray; Marianne N. Lund
• Keywords: epigallocatechin gallate; Food Handling; Lactose; Camellia sinensis; Catechin; 0404 agricultural biotechnology; Animals; green tea extract; UHT; Aldehydes; flavor; Tea; Hydrolysis; storage stability; Temperature; Polyphenols; 04 agricultural and veterinary sciences; alpha-dicarbonyls; Milk Proteins; lactose-hydrolyzed milk; Maillard Reaction; Maillard reaction; Milk; Strecker aldehydes; shelf life; Cattle; Food Additives; Plant Preparations; protein-polyphenol binding; Protein Binding

The effect of epigallocatechin gallate enriched green tea extract (GTE) on flavor, Maillard reactions and protein modifications in lactose-hydrolyzed (LH) ultrahigh temperature (UHT) processed milk was examined during storage at 40 °C for up to 42 days. Addition of GTE inhibited the formation of Strecker aldehydes by up to 95% compared to control milk, and the effect was similar when GTE was added either before or after UHT treatment. Release of free amino acids, caused by proteolysis, during storage was also decreased in GTE-added milk either before or after UHT treatment compared to control milk. Binding of polyphenols to milk proteins was observed in both fresh and stored milk samples. The inhibition of Strecker aldehyde formation by GTE may be explained by two different mechanisms; inhibition of proteolysis during storage by GTE or binding of amino acids and proteins to the GTE polyphenols.