"Into a three neck flask equipped with stirrer, thermometer and reflux condenser is placed 10 grams of cassia oil and 100 ml of a 3% aqueous sodium carbonate solution. Boiling chips are added and a water-washed stream of nitrogen is passed over the reaction mass to help prevent oxidation of the formed benzaldehyde. The mixture is heated to reflux and refluxed for a period of 7 hours (100 DEG C.). The resulting material contains 70% benzaldehyde and 30% cinnamaldehyde"
Patent US4617419 (http://l2.espacenet.com/dips/viewer?PN=US4617419&CY=gb&LG=en&DB=EPD)
There are simular patents which describe adding an emulsifier.
Also others describe higher yield of benzaldehyde/acetaldehyde with only trace amounts of cinnamaldehyde.Same concept..
Ill look em up.