Effect of aqueous ethanol washing on functional properties of sunflower materials for meat analogue application

Abstract

Sunflower kernel is rich in protein and is considered an alternative plant protein source for meat analogue application. The effect of process conditions used to make ingredients from sunflower kernel needs to be investigated on the functional and structuring properties. Pre-pressing and de-oiling with 96% ethanol were applied to obtain de-oiled sunflower kernel (DSK). Pressed sunflower kernel (PSK) was obtained by more intensive pressing only. Their concentrates were obtained by aqueous ethanol washing to study the effect of oil and phenol removal. DSK and its concentrate formed a fibrous product at 40 wt% by shearing and heating at 140 ℃ in a shear cell. The washed DSK led to stronger products upon shearing and heating. However, PSK, before and after washing only formed a crumble gel under the same conditions. The differences for the water holding capacity, nitrogen solubility index, and rheological properties were remarkably small between DSK and PSK, and the washed concentrates. The remaining oil in the sunflower material is crucial for the structuring potential, while the phenol content does not seem to have a relevant influence. The primary de-oiling process turned out to be a determining factor for further oil removal with aqueous ethanol washing.