The Development of a Digital Twin to Improve the Quality and Safety Issues of Cambodian Pâté: The Application of 915 MHz Microwave Cooking

Abstract

Foodborne diseases are common in Cambodia and developing good food hygiene practices is a mandatory goal. Moreover, developing a low-carbon strategy and energy efficiency is also a priority. This study focuses on pâté cooking, a very common food product in Cambodia. In this paper, the authors chose to develop a digital twin dedicated to perfectly predict the temperature for cooking in a 915 MHz single-mode cavity, instead of using a classical and energy-consuming steaming method. The heating strategy is based on a ramp-up heating and a temperature-holding technique (with Tylose^® as the model food and Cambodian pâté). The model developed with COMSOL^® Multiphysics software can accurately predict both local temperatures and global moisture losses within the pâté sample (RMSE values of 2.83 and 0.58, respectively). The moisture losses of Cambodian pâté at the end of the process was 28.5% d.b (dry basis) after a ramp-up heating activity ranging from 4 to 80 °C for 1880 s and a temperature-holding phase at 80 °C for 30 min. Overall, the accurate prediction of local temperatures within Cambodian pâté is mainly dependent on the external heat-transfer coefficient during the temperature-holding phase, and is specifically discussed in this study. A 3D model can be used, at present, as a digital twin to improve the temperature homogeneity of modulated microwave power inputs in the future.

Keywords: 915 MHz; Cambodian pâté; Lewis analogy; heat transfer; mass transfer; microwave.

Figure 1

Detailed view of the microwave system’s (A) cavity (B) and antenna (C).

Figure 2

Sample positions within the single-mode microwave cavity (view from the top of the microwave cavity).

Figure 3

Position of optical fiber sensors in the sample (A,B) and sensor holder (C) (the red stars are the measured location, which is named 1, 2 and 3).

Figure 4

Dielectric properties of Cambodian pâté as a function of temperature at 915 MHz (A): measured value of Ԑr’(T), (B): measured value of Ԑr″(T)).

Figure 5

Thermal conductivity of pâté at various temperatures.

Figure 6

Reflection coefficients of Tylose^® at positions A, B, C, and D following various SSC positions.

Figure 7

Reflection coefficients of pâté at position A for various SSC positions.

Figure 8

Temperature profiles of three points (1, 2 and 3) inside the Tylose^® sample during experimental heating at positions A and B (Exp) compared to simulation (Sim).

Figure 9

Surface-temperature cartography of Tylose^® during the ramp-up heating period at position A. (The blue line is the temperature sampling line used in Figure 10).

Figure 10

Experimental and predicted temperature profiles at Tylose^® sample’s surface along a cut-line during microwave heating during t = 0 to 5 min of microwave heating respectively.

Figure 11

Temperature profiles of three points inside the pâté sample during microwave heating at positions A (Exp) compared with simulations.

Figure 12

2D Temperature cartography at the end of the ramp-up heating (1880 s) process and temperature-holding phase (3680 s) (each plan passed through the centerline); 3D temperature map of the sample at 3680 s (simulation with hc₃ value).

Figure 13

Surface temperature cartography of pâté during the ramp-up heating period at position A (simulation with hc₂ value). (The blue line is the temperature sampling line used in Figure 14).

Figure 14

Experimental and predicted temperature profiles (using hc₃ value) on the pâté’s surface along a cut-line during ramp-up heating.

Figure 15

Water concentration profiles (% d.b.) along a central cut-line from the top surface to the bottom (A), and global moisture loss during cooking (B) (hc₁ = 3.5 W/(m²·K), hc₂ =6 W/(m²·K), and hc₃ = 8.4 W/(m²·K)).

Figure 16

Two-dimensional plan of water concentration levels (% d.b.) at t = 1880 s and t = 3680 s for various heat-transfer coefficients on the surface of the pâté sample.