Effect of pulsed electric field on functional and structural properties of canola protein by pretreating seeds to elevate oil yield

- Pulsed electric field (PEF) was applied to pretreat canola seed to elevate oil yield.
- Effect of PEF on functional and structural properties of canola protein isolate were investigated.
- Secondary and tertiary structures of protein were investigated and linked to the functional properties.
- PEF might cause aggregation of small molecules.

Pulsed electric field (PEF) was applied to moisture-preconditioned canola seeds to evaluate the effect on oil yield. The effect of PEF on functional and structural properties of canola protein left over after oil extraction were also examined in albumin and globulin fractions obtained at optimal conditions for oil yield. Generally, PEF pretreatment significantly improved (P < 0.01) the following functional properties of canola protein and its fractions: solubility, water-holding capacity, emulsibility, emulsion stability, oil-holding capacity, foamability, and foam stability. Infrared spectrometry revealed that the secondary structure of the protein changed upon PEF, as shown by changes in the proportions of α-helices, β-sheets, and β-turns in the amide I region. An increased amount of free sulfhydryl groups and surface hydrophobicity suggested alterations in tertiary structure as well. PEF caused the formation of new protein aggregates with low molecular mass, demonstrated by sodium dodecyl sulfate polyacrylamide gel electrophoresis and changes in the number of total sulfhydryl groups.