Pressurized Water Extraction as a Tool for Rapid and Efficient Isolation of Proteins from Almonds

Pressurized water extraction (PWE) is a technique suitable for efficient extraction of almond proteins, some of which are known as potent allergens. In this work, we present a PWE protocol that allows fast and complete isolation of almond proteins achieved within one 5-min cycle at 40°C and 15 MPa. The extracted protein contents obtained using PWE or conventional extraction method with 22 selected solvents were compared based on sodium dodecyl sulphate-polyacrylamide gel electrophoresis. Individual proteins from separation gels were excised and identified using mass spectrometry with database searching. Our results showed that the PWE of almond proteins can offer similar efficiency as the conventional extraction method while being four times faster and providing water-based extracts without any additives with low environmental impact.