New technique may allow for improved production of low calorie cocoa butter

A team of Chinese researchers claim to have found a solution to the problem of creating reduced fat cocoa butter – by enhancing a process known as molecular distillation.

Writing in LWT - Food Science and Technology​​ the researchers noted that the production of a reduced calorie cocoa butter has been possible for several years using a chemical process that removes certain fatty acids from the fat molecules – called enzymatic transesterification.

However, they claim that process results in production of excessive free fatty acids, with undesirable effects on the colour, taste, and shelf life of oils and fats – thus reducing commercial viability to many industries.

The team – led by Professor JianXian Zheng from the South China University of Technology, China – said themolecular distillation process “could be suitable to refine crude low-calorie cocoa butter in industrial manufacture ... in respect that this procedure can remove a majority of free fatty acids from crude low-calorie cocoa butter.”​

Low calorie challenge​

Zheng and his colleagues said the removal of such free fatty acids from crude oils and fats “is a crucial step in the production of refined edible oils and fats.”​

The process, known as deacidification, “is regarded as the most significant and difficult refining process in commercial manufacture”,​ they explained.

Molecular distillation (MD), a novel deacidification method, has a separation and purification process to remove free fatty acids that is more efficient than other traditional methods. The process also preserves important components of the oils and butters due to lower pressures and processing times, said the researchers.

“Molecular distillation applications for removing the free fatty acids from high acidity crude oils and fats have attracted great interest including corn oil, vegetable oil, grape seed oil, and crude soybean oil ... However, research on MD for deacidification of low-calorie cocoa butter is still less explored,”​ claimed Zheng and his team.

Optimisation​

To enhance the processes for refining a reduced fat cocoa butter, the team examined how parameters of the MD process affect the deacidification rate and colour of the refined products. An optimum processing parameter for production of refined low-calorie cocoa butter was identified.

“The results suggested evaporator temperature, feed flow rate and their interaction significantly influenced both deacidification rate and colour, while pressure slightly affected these two responses,” ​explained the researchers.

“The optimised procedure highly improved the deacidification efficiency and ensured against darkening product colour that occurs during molecular distillation processing,”​ they said.

Zheng and his team said that by improving the molecular distillation MD process, they were able to produce a refined low calorie cocoa butter that may be suitable for industry.

Source: LWT - Food Science and Technology​
Published online ahead of print, doi: 10.1016/j.lwt.2011.10.028​
“Optimization of deacidification of low-calorie cocoa butter by molecular distillation”​
Authors: W. Wu, C. Wang, J. Zheng