不同种类硅酸镁对油茶籽油处理效果的研究

通过测定油茶籽油的酸值、过氧化值和色值，探讨了不同种类硅酸镁、不同处理时间对不同酸值油茶籽油处理效果的影响。结果表明，随着处理时间的增加，油茶籽油的酸值、过氧化值均呈现明显的下降趋势，色值L*均有所上升，色值b*均有所下降。不同种类硅酸镁对油茶籽油的酸值降低程度由高到低依次为高碱硅酸镁、高钠硅酸镁和国外硅酸镁，对油茶籽油的过氧化值降低程度由高到低依次为高钠硅酸镁、国外硅酸镁和高碱硅酸镁。这是因为高碱硅酸镁碱度较高，而高钠硅酸镁中二氧化硅含量较高，氧化镁含量低。此外，高钠硅酸镁具有较佳的脱色效果，这是可能与高钠硅酸镁中二氧化硅含量较高，而水分含量较低有关。当油茶籽油的酸值越低，不同种类硅酸镁对油茶籽油酸值、过氧化值的降低程度越大，对提高油茶籽油的亮度、去除黄色色素和降低绿色色素能力越强。综上，采用硅酸镁进行油茶籽油的精炼适用于酸值小于3.0 mg/g的油茶籽毛油，且处理时间20~40 min较佳，三种硅酸镁中高钠硅酸镁具有较佳的脱色脱酸效果。

Effects of Oil-tea Camellia Seed Oil Refining by Different Kinds of Magnesium Silicate

The effects of different kinds of magnesium silicate and different treatment time on oil-tea camellia seed oil were studied by measuring the acid value, peroxide value and color value of the oils. The results showed that with the time increasing, the acid value and peroxide value of oil-tea camellia seed oil decreased obviously, and the color value L* increased and b* decreased. The acid value of different types of magnesium silicate on oil-tea camellia seed oil decreased from high to low followed by high alkali magnesium silicate, high sodium magnesium silicate and foreign magnesium silicate. The peroxide value of different types of magnesium silicate on oil-tea camellia seed oil decreased from high to low followed by high sodium magnesium silicate, foreign magnesium silicate and high alkali magnesium silicate. This was because the alkalinity of high alkali magnesium silicate was higher, and high sodium magnesium silicate had higher silica and lower magnesium oxide. In addition, high sodium magnesium silicate had better decolorization effect, this might be related to the higher silica and lower moisture. When the acid value of oil-tea camellia seed oil was lower, different types of magnesium silicate would reduce the acid value and peroxide value of oil-tea camellia seed oil more, and the ability to improve the brightness of oil-tea camellia seed oil, remove yellow pigment and reduce green pigment was stronger. In short, the use of magnesium silicate for the refining of oil-tea camellia seed oil is suitable for the crude oil of oil-tea camellia seed oil with acid value less than 3.0 mg/g, and the treatment time should be 20~40 min. In addition, high sodium magnesium silicate has better decolorization and deacidification effects.