Kinetics of Popping of Popcorn

Abstract

The rate of popping of popcorn was measured in oil and in air. Kinetic data for lifetimes of individual kernels from a large population were obtained in oil at six constant temperatures (180–250°C) and also in an air‐popper at 202°C. The data are characterized by an induction period, which is, significantly, followed by a first‐order decrease in the number of unpopped kernels versus time. The activation energy for the first order process is 166.7 kJ/mol between 180 and 210°C, and 53.8 kJ/mol between 210 and 250°C. These data are consistent with a model that assumes 1) that the rate of heat transfer into a kernel follows Newton's law of cooling; 2) that in a sample of kernels there exists a distribution of critical pressures; 3) that for an individual kernel, the probability of popping is directly proportional to the difference between the internal aqueous vapor pressure and the kernel's critical pressure; and 4) that the measured rate constant at any temperature is an average overall of the kernels in the sample with critical pressures equal to or less than the internal aqueous vapor pressure. Minimum popping temperatures predicted by the model are 181 ± 2°C (oil) and 187 ± 2°C (air), in good agreement with previously reported direct measurements.

Popcorn: critical temperature, jump and sound

“…Instead, 96% of popcorn are popped at 1808C (48 out of 50), suggesting a well-defined critical temperature close to 1808C. This is consistent with previous measurements [6,20,21], i.e. in the range 17721878C.…”

Hot air expansion of potato starch pellets with different water contents and salt concentrations

“…Fig. 5a showed that the initial time to start the expansion trends in a similar way to a uni-molecular reaction; this agrees with the work done by Byrd and Perona (2005) on popcorn expansion. However, the total time to expand is somewhat temperature independent.…”

Context-sensitive synthesis of executable functional models of cyber-physical systems

“…In this particular example, the design rule specifies that any function bleeding hot air into the environment is compatible with any predecessor function transmit thermal energy that transmits heat to a gas. [6] and 100 kernels, these simulation results show that the model recycling hot air achieves a higher popping rate and significantly less cooking time than the model that bleeds hot air into the environment.…”