Craft Brian D, Nagy Kornél, Seefelder Walburga, Dubois Mathieu, Destaillats Frédéric
Nestlé Research Center, Vers-chez-les-Blanc, Lausanne, Switzerland.
Nestlé Research Center, Vers-chez-les-Blanc, Lausanne, Switzerland.
Food Chem. 2012 May 1;132(1):73-9. doi: 10.1016/j.foodchem.2011.10.034. Epub 2011 Oct 21.
In a previous work, it was shown that at high temperatures (up to 280°C) glycidyl esters (GE) are formed from diacylglycerols (DAG) via elimination of free fatty acid (FFA). In the present study, the impact of DAG content and temperature on the formation of GE using a model vacuum system mimicking industrial edible oil deodorization is investigated. These deodorization experiments confirmed that the formation of GE from DAG is extensive at temperatures above 230-240°C, and therefore, this value should be considered as an upper limit for refining operations. Furthermore, experimental data suggest that the formation of GE accelerates in particular when the DAG levels in refined oils exceed 3-4% of total lipids. Analysis of the lipid composition of crude palm oil (CPO) samples allowed the estimation that this critical DAG content corresponds to about 1.9-2.5% of FFA, which is the conventional quality marker of CPO. Moreover, high levels (>100ppm) of GE were also found in palm fatty acid distillate samples, which may indicate that the level of GE in fully refined palm oils also depends on the elimination rate of GE into the fatty acid distillate.
在先前的一项研究中发现，在高温（高达280°C）下，甘油二酯（DAG）通过消除游离脂肪酸（FFA）形成缩水甘油酯（GE）。在本研究中，使用模拟工业食用油脱臭的模型真空系统，研究了DAG含量和温度对GE形成的影响。这些脱臭实验证实，在230-240°C以上的温度下，DAG大量形成GE，因此，该温度值应被视为精炼操作的上限。此外，实验数据表明，特别是当精炼油中的DAG水平超过总脂质的3-4%时，GE的形成会加速。对粗棕榈油（CPO）样品的脂质组成分析表明，这一关键的DAG含量约相当于CPO传统质量指标FFA的1.9-2.5%。此外，在棕榈脂肪酸蒸馏物样品中也发现了高含量（>100ppm）的GE，这可能表明全精炼棕榈油中GE的含量也取决于GE向脂肪酸蒸馏物中的消除率。
