The present invention describes a method of enhancing clarity and/or stability properties of a protein-containing liquid or gel, comprising subjecting said liquid or gel to a pressure treatment of 100 Mpa or greater. Preferred proteins useful in the invention are whey protein isolates and whey protein concentrates. The methods of the invention may be used to improve the clarity and/or stability properties of fruit juices, vegetable juices, protein concentrates and protein syrups.