Study on the application of two magnesium salts in low temperature adsorption refining of fragrant rapeseed oil

Magnesium silicate and basic magnesium carbonate were characterized and their application in the low temperature adsorption refining of fragrant rapeseed oil was investigated. The results showed that both materials had a loose porous structure, but their particle size distribution, active functional groups, crystallinity, specific surface area, pore volume, and pore size differed. Under the optimal adsorption refining conditions, magnesium silicate and basic magnesium carbonate reduced the phospholipid content from 4.18 to 0.83 and 1.57 mg/g, acid value from 1.67 to 0.88 and 0.90 mgKOH/g, yellow value from 38.2 to 32.1 and 36.2, and red value from 2.9 to 1.7 and 2.2, respectively. The use of these two magnesium salts did not significantly alter the composition of fatty acids and the content of tocopherol. The retention rates of total phytosterol by magnesium silicate and basic magnesium carbonate were 93.6% and 95.9%, respectively. The retention rates of total phenol were 88.9% and 93.9%, respectively. The adsorption refining process proved to be advantageous in purifying fragrant rapeseed oil while maintaining the dominant flavor components relatively unchanged (P < 0.05). As a result, these two magnesium salts have the potential to be used during the low temperature adsorption refining process of fragrant rapeseed oil.