LIZ ASTORGA, MS Student

When May 6, 2021, 3:30 PM - 4:30 PM

Consumers are more interested in food/drinks featuring clean labels than those with minimal unhealthy ingredients or foods/drinks with added nutrients. Also, they aggressively seek to increase their intake of foods containing proteins from plant sources. As the food industry responds by moving away from the simple fortification of foods using protein-rich flours into protein isolates for specialized functionality, the thorough understanding of plant protein physicochemical phenomena in foods becomes critical. To match these demands, an alternative non-thermal processing technology as high-pressure jet (HPJ) processing has been proposed. High Pressure Jet (HPJ) is a novel non-thermal processing technology that uses a hydraulic pump to achieve hydrostatic pressure up to 600 MPa in a liquid. The pressurized liquid then flows through a restriction nozzle, which creates shear, resulting in an aerosol that is collected as liquid into a heat exchanger. In skim milk, HPJ processing has been shown to thoroughly disrupt casein micelles leading to enhanced functionality. However, the impact of HPJ on plant protein quaternary structure has yet to be investigated.

This research aims to study the effect of HPJ processing on the protein structure and subsequent changes in physicochemical properties (solubility and foaming capacity) of six commercial plant protein isolates: 3 soy protein isolate (SPI) and 3 pea protein isolate (PPI) dispersions subjected to 100, 200, 300, 400, and 500 MPa HPJ when compared to a non-HPJ-treated control.

Findings suggest that HPJ processing decreased particle size of SPIs and PPIs. Also, HPJ processing induced the release of significant number of monomers of β-conglycinin and glycinin for SPI, and legumin, vicilin and convicilin for PPI with each increase of pressure treatment as evidenced by SDS-PAGE analysis. Monomeric subunits formed big aggregates as evidenced by Native-PAGE analysis. Those changes in structure of HPJ-processed samples led to a significant increase of solubility and foaming capacity. This research demonstrates that HPJ processing leads to significant enhancing of functional properties of plant proteins such as solubility and foaming. With this, HPJ could potentially allow the creation of novel plant protein ingredients and reduce the need for additives, allowing to produce food with “clean label” claims.