Their study published in the Journal of Food Process Engineering details a whipping method to prepare bubbles in cocoa butter using phospholipids, a surfactant.
“The foaming ability of phospholipids in the cocoa butter was found, which can replace the puffing method under vacuum and the inflating method under high pressure, which is commonly used in the production of aerated chocolate,” said the study.
“The results showed a new train of thought and basic data for the preparation of aerated chocolate.”
The researchers tested the foaming abilities of nine surfactants and found that only phospholipids were adequate. Concentrated phospholipids of soybean were considered the best and helped form molecular layers of phospholipids liquid crystalline in cocoa butter that helped maintained the stability of bubbles.
Bubbles can collapse with existing methods
Nestlé is currently working with the European Space Agency to create better chocolate air bubbles under zero-gravity and will eventually experiment in space.
A Nestle scientist previously told this site that exisiting methods to create aerated chocolate are challenging because bubbles often collapsed due to pressure differences.
The concentrated phospholipids of soybean
Authors of the present study used a whipping method to determine the foaming abilities of the surfactants in cocoa butter.
They added 3g of each surfactant to 97g of cocoa butter and mixed at 60°C for two hours before cooling.
The researchers tested the foaming ability by taking a 50ml sample putting it in a water bath and whipping it with an electric stirrer at 900 rpm.
They observed bubble morphology using a polarized light microscope.
Concentrated phospholipids of soybean were seen as the best surfactant to create bubbles in chocolate.
The researchers then tested different forms of concentrated phospholipids of soybean: PE50, PC-60 and PC80.
PC80, the highest concentration of the phospholipids, had the strongest foaming capacity, which was found to work best at 37°C.
Journal of Food Process Engineering
‘The Foaming Abilities of Surfactants in Cocoa Butter’
Authors: Shi Su-Jia, Cao Dong, Xie Shi-Chao