HHP treatment of liquid egg products

Abstract

High Hydrostatic Pressure (HHP) is one of the most promising minimal processing technologies in food preservation. HHP decreases microbiological spoilage of products and extend shelf life, while freshly-like properties are retained. For controlling microbiological safety of liquid whole egg (LWE), liquid egg white (LEW), liquid egg yolk (LEY) several preservation methods are viable in industry, but most of these apply heat or preservatives. On the one hand high temperatures are effective, but techno-functional properties could be declined, on the other hand the use of preservatives is rejected by consumers. In our study liquid egg samples are treated between 150 and 600 MPa, for 5 min. After treatments rheological properties and protein structures of samples were investigated. In evaluation of rheological results, Herschel-Bulkley model was fitted. Relevant changes in values of Herschel-Bulky models were observed above 450 MPa. LWE after HHP treatment had a stronger pseudoplastic behaviour. Summarizing our data, using a higher pressure for preservation of LWE may have bad influence on techno-functional properties. But the border pressure for adequate techno-functional properties may differ depending on final use of LWE.