Improvement of Functional Properties of Rapeseed (<i>Brassica campestris</i>Var. Toria) Preparations by Chemical Modification

Abstract

Rapeseed freeze-dried meal and water-soluble fraction were acylated with succinic and acetic anhydride and methylated with formaldehyde at different concentrations of these reagents, and changes in phytic acid, phenols, glucosinolate content, and functional properties were determined. In general, the greater was the extent of acetylation, the lesser was the extractability of phytic acid, phenols, and glucosinolates in both preparations. Water absorption and fat absorption capacities were enhanced by acetylation, but succinylated meal absorbed a maximum amount of oil at a minimum level of modification. Nitrogen solubility, foaming capacity, and viscosity were markedly improved by succinylation. Emulsifying properties were adversely affected by acylation, while methylation proved to be stimulatory. Modified water-soluble fractions had low content of antinutritional constituents, and acylated extracts showed better emulsifying and foaming properties. Keywords: Antinutritional factors; chemical modification; functional properties; rapeseed meal; water-soluble fraction