4 / 2016-08-23 22:36:33

High Pressure Induced Structural Changes in Pea Protein Concentrates

The demand for high protein foods has been increasing in recent years. Pulse proteins, such as pea protein, offer a reduced-allergenic protein source that is increasingly explored for the development of new food products. In this context, modification of these proteins by high pressure processing (HPP) has potential applications in a wide array of protein based and protein enriched food products.

This work utilizes HPP to induce controlled structural modifications in pea protein concentrates (PPC), with the aim of developing novel textures. PPC powders (AGT Foods), containing 55.0% (dry weight) protein and 4.0% (dry weight) starch, were dispersed in water to form solutions of 8.0, 12.0, 16.0, 20.0 and 24.0% protein (w/w) concentration. The protein solutions were then subjected to 15 min HPP treatments at 250, 350, 450 and 550 MPa at 20-33 °C, in a 10 L high pressure unit (Elmhurst Research Inc.). Dynamic rheological measurements (strain sweeps and frequency sweeps) of the pressure treated samples and untreated controls were conducted using a strain controlled ARES rheometer (TA Instruments, New Castle, DE). HPP induced significant changes in PPC, which were both concentration and pressure dependent. Gel formation occurred after pressure treatments above 250 MPa and 8.0% protein (w/w) concentration, with gel strength increasing with concentration. Compared to the untreated controls, HPP treated samples had 10 to 1000-fold increase in storage modulus (G’) and loss modulus (G’’). The high pressure conditions used also induced starch gelatinization. These findings suggest that HPP treatment of pea protein concentrates at ambient temperatures can result in unique structures and textures, without the utilization of heat or chemical ingredients.