Glyceryl trioleate

Glyceryl trioleate, known widely as triolein, is an oily liquid that is a main constituent of some nondrying¹ oils and fats. Triolein occurs in many natural fats and oils, including sunflower oil, palm oil, cacao butter, and, most notably, olive oil.

In 1941, Thomas P. Hilditch* and L. Maddison at the University of Liverpool (UK) crystallized olive oils from Italy and Palestine at temperatures down to –30 °C to resolve them into several components. They found that olive oil from Palestine contained ≈30% triolein, whereas the Italian oil contained only ≈5%.

Eight years later, M. L. Meara, also at Liverpool, resolved cacao butter into 11 fractions “by exhaustive crystallization”. For his efforts, only 1.1% of the fat turned out to be glyceryl trioleate. From 1940 to 1961, several chemists devised syntheses of triolein by esterifying glycerol and oleic acid.

Why do we celebrate glyceryl trioleate, and therefore olive oil, during the holiday season? Sacramental uses of olive oil are strongly connected to Christian and Jewish traditions, especially Hanukkah.

During the period of the Hanukkah story (168 BCE), only pure olive oil blessed by the high priest could be used to light the Temple menorah, which had to be lit continuously. After their victorious battle over the Syrian Greeks, the Maccabees could find only enough holy oil to last for one day. The Hanukkah miracle is that the oil lasted eight days, enough time for more oil to be prepared and sanctified.

Olive oil was the major component of anointing oils and lamp fuel that date to biblical times. Kings were anointed with oil as a mark of their official status; and one title for Jesus is the Anointed One. References are found throughout the Hebrew and Christian scriptures about the use of oil as part of fasting and healing rituals.

In Imani (faith), the seventh principle of Kwanzaa, designated persons are instructed to pour libations of water and oil into a bowl “for our ancestors; for the dying; for the glorious cloud of witnesses; and for life, health, and strength”.

And if you associate olive oil just with cooking, there are lots and lots of recipes available for cookies and cakes and muffins for your holiday baking!

1. “Nondrying” is somewhat of a misnomer; it means that the substance does not harden when it is exposed to air.