Improvement of functional properties of β-lactoglobulin glycated through the Maillard reaction is related to the nature of the sugar

The improvement of functional properties of proteins available in large quantity using non-toxic chemical modifications is of a great interest for the food industry. In this study, the Maillard reaction was used to improve the functional properties (solubility, heat stability, emulsifying and foaming properties) of beta -lactoglobulin (BLG) glycated with several sugars (arabinose, galactose, glucose, lactose, rhamnose or ribose). Protein samples were heated in the presence or absence (heated control) of different sugars for three days at 60 degreesC. Subsequent glycation induced a modification of the solubility profile shifting minimum solubility towards more acidic pl-L Glycated proteins exhibited a better thermal stability when heated at pH 5 as compared to native or heated control. Glycation of BLG with arabinose or ribose (the most reactive sugars) improved its emulsifying properties. Foaming properties were better when BLG was glycated with glucose or galactose (moderately reactive sugars). These results suggest that the nature of the sugar is an essential factor for improving the functional properties of glycated proteins by processes of Maillard reaction. (C) 2001 Elsevier Science Ltd. All rights reserved.