Investigating the rate of heat transfer through chocolate varieties

Abstract

This study investigates the effect of different chocolate fillings on the rate of conductive heat transfer through various chocolate bars. Using four varieties from Cadbury’s ‘Favourites’; Dairy Milk, Caramilk, Cherry Ripe, and Crunchie, the experiment used hotplates set to 70 °C to heat the chocolates, and IR cameras to measure both inner and surface temperatures as the chocolates were heated. The setup was designed to mimic a squat rectangular fin in order to allow for analysis based on Fourier’s law in order to estimate the heat flux through the chocolates. Data was collected through manual repositioning of the IR camera, however technical limitations in the IR camera software necessitated the use of linear interpolation to recover data. This encompassed both the Dairy Milk and Crunchie datasets, but only Dairy Milk could be successfully recovered. While limited, the results indicate that Cherry Ripe exhibits delayed heat conduction compared to chocolates with no filling such as Dairy Milk and Caramilk. Despite the uncertainties introduced by measurement variability, convective heat losses that were not accounted for, and the destruction of the Crunchie thermal data, the findings indicate that further research should be done into the thermal performance of filled versus non-filled chocolates in order to optimise manufacturing processes and improve the thermal resistance of chocolate products in warm environments.