One approach to prevent turbidity at pH > 3.5 has been the addition of compounds that prevent protein denaturation and aggregation of proteins. For example, addition of food-grade laurel resulted in completely clear whey protein beverages at pH 4.6 and 5.0 . Other compounds that are known to affect protein aggregation have not yet been investigated. Amino acids such as proline have been widely used to enhance protein refolding and suppress aggregation of denatured proteins. Denaturants that interact with exposed reactive groups can also prevent protein aggregation. Urea enhance the unfolding and exposure of interior protein residues and forms a complex with denatured proteins. Alcohols interact favorably with hydrophobic region of protein molecules, such as lactoglobulin, that become exposed during heating. Aggregation can be inhibited either by stabilizing proteins against denaturation, or by preventing aggregation of already denatured proteins.