Gas makes the difference in chocolate processing

The type of gas used in making chocolate can have a dramatic effect on taste and texture, say researchers from Nestlé.

The results of their study indicates to chocolate manufacturers that the processing choices they have to make between balancing desired taste and texture qualities in their products.

The results of their studies showed that chocolate produced using carbon dioxide and nitrous oxide had a distinctly better gas retention and contained larger bubbles, than the chocolates made with nitrogen or argon.

The sensory tests showed that the chocolates made with the argon and nitrogen were perceived as harder, less aerated, slower to melt in the mouth but with a higher overall cocoa flavour intensity.

The ones produced with argon and nitrogen were also judged to be creamier than the chocolates made with carbon dioxide and nitrous oxide, the scientists say in the latest edition of the Journal of Food Science.

The report was produced by two researchers from Nestlé and a scientist with the School of Food Biosciences at the University of Reading in the UK.

Bubbles formed by gas in foods impart unique textures, chew, and mouth-feel to products.

However, little is known about the relationship between structure of such products and consumer response in terms of mouth-feel and eating experience, the scientists stated.

The study investigated the sensory properties of four types of bubble-containing chocolates, produced by using combinations of carbon dioxide, nitrogen, nitrous oxide, or argon.

The researchers examined the structure of the chocolates, characterising them in terms of gas hold-up values determined by density measurements and bubble size distribution.

They also conducted a sensory study was undertaken by a non-expert panel of 20 subjects.

The results indicated that chocolates made from the four gases could be divided into two groups on the basis of bubble volume and gas hold-up.