The delicious scent of citrus often found in essential oils can also inhibit liver cancer, according to a new study. 

A team of researchers analyzed the process of how citrus-smelling terpenes can inhibit the growth of different cancer cells - particularly in the liver.

This is the first time scientists have been able to fully understand the function of the essential oils in warding off cancer. 

A team of researchers from Ruhr-Universitaet-Bochum used a cellular model of hepatocellular carcinoma, a common live tumor, to expose the cells to a subset of terpenes with different concentrations, according to a news release. They found that two of the eleven terpenes tested resulted in a significant increase in calcium concentration in the cells: (-)-citronellal and citronellol.

In the follow-up analysis, the researchers found that the decisive olfactory receptor OR1A2 occurs in liver cells when they focused on (-)-citronellal. OR1A2 was also found to be responsible for detection of the citrus scent and cellular reaction, according to the release. 

"These results are yet another example for the significance of olfactory receptors outside the nose, and they give rise to hope that new drugs with no severe side effects may be developed for cancer therapy," the researchers said. 

The liver tumor used in the study, hepatocellular carcinoma, is the third most common tumour-induced cause of death, according to the release. 

The study was published in the journal Archives of Biochemistry and Biophysics.