Popping candy, often known by various brand names, uses pressurised carbon dioxide gas trapped in a sugar matrix to cause popping noises and crackling sensations when the gas is released in the moisture and temperature of the mouth.
Popping candy was invented decades ago to be sold as confectionery. More recently, however, food manufacturers and chefs have been incorporating it into chocolate and other types of food to provide an additional point of interest. It is not only food that has benefited from the invention; the pharmaceutical industry is also becoming wise to this interesting ingredient.
As discussed in Confectionery News in July (2018), PFHIX has been working with companies that are developing products using popping candy as a drug delivery mechanism. The concept relies on the faster absorption of components from delivery systems that dissolve in the mouth (rather than the gut), and follows from the idea of using gummy sweets and chews to deliver medication to children and adults alike. Additionally, consumers are more likely to allow full dissolution of the crystals in the mouth as they enjoy the popping sensation than they would with a gummy sweet or pastel.
Popping candy begins to emit popping noises as soon as it is exposed to a drop of water, beginning with a vigorous cluster of pops that decrease in frequency over the course of a few minutes. This property can be quantitated simply using the Acoustic Envelope Detector by Stable Micro Systems along with Exponent software. A method has been developed to measure the frequency of pops generated in a controlled manner, with a cut-off frequency used to minimise the effect of background noise. As the noises emitted by popping candy are all of a high frequency, only high frequencies are of interest, so using this frequency cutoff helps to clean up the data. In the case of the two brands tested, this process helped to distinguish between two brands that were clearly different in the mouth but an untreated sound pressure level (SPL) measurement showed identical behaviour.
The following graph shows the acoustic data collected for the brand marketed as “super loud” and the chart shows the peak count for each 10 second segment of SPL for the two samples. As well as peak count, the macro also calculates the mean SPL and an estimation of sound energy released for each time segment.
Although this method showed good repeatability for the samples in question, even testing the product in bulk form with a repeatable test setup may not provide good repeatability between tests, as popping candy contains a large variation in CO2 bubble size and granule size. This may of course be the aim of the manufacturer – the creation of a random experience and the establishment of a method to measure this randomness. The statistical analysis of acoustic data offered in Exponent gives an automatic assessment of repeatability.
