Key Findings
The aim of this study was to determine the structural factors which link temperature to flaxseed gum (FG). FG extracted at four different temperatures varied significantly in chemical composition with regard to type and content of monosaccharides and protein. Lower extraction
temperatures yielded FG samples with higher levels of neutral monosaccharides and lower levels of acidic monosaccharides. In addition, the protein contamination of FG samples increased with the rise in extraction temperature. The results indicate the importance of selecting the appropriate extraction temperature to match the FG properties of the specific application. FG extracted at lower temperatures is better for emulsifying applications, while FG extracted at higher temperatures is more suitable for food systems where high oil absorption capacity is required.
ABSTRACT
Flaxseed gum (FG) was extracted at four different temperatures (30, 50, 70 and 90°C). Chemical composition and structural features of FG extracted at different temperatures were investigated to determine the effect of temperature. Content of acidic monosaccharides and denatured protein increased with increasing FG extraction temperature. The ratio of neutral to acidic monosaccharides decreased from 6.7 to 5.7 as the extraction temperature was increased from 30 to 90°C. Physiochemical and functional properties, including zeta-potential, surface morphology, emulsifying activity index (EAI) and emulsion stability index (ESI), water absorption capacity (WAC) and fat absorption capacity (FAC) of FG samples, were also investigated as a function of extraction temperature. EAI and WAC of FG samples reduced significantly with rise in extraction temperature. Our study suggests that FG extracted at different temperatures may be specifically targeted for different applications, such as for emulsification or gel formation in food systems.
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