Design and Development of A Semi-Autoclave for Packaged Food based on Arduino R4 WiFi and Internet of Things (IoT)

Sterilization is a crucial stage in maintaining the safety and quality of packaged food, yet access to efficient and affordable equipment remains a barrier for micro and small enterprises (MSEs). This study reports the design and development of a compact, low-cost semi-autoclave for packaged food based on an Arduino R4 WiFi microcontroller and the Internet of Things (IoT). A type K thermocouple (via a MAX6675 module) and a pressure transducer transmitter, both mounted on the vessel lid, monitor the process, while a 12V solenoid valve provides closed-loop automatic venting and a manual safety valve acts as a safeguard. Process data are shown on an I2C LCD and transmitted to the Blynk application in real time. Sensor performance was validated against a manual pressure gauge and a digital thermometer by the comparison method. The mean reading error was about 2.3% (maximum 5.0%) for pressure and 0.9% (maximum 2.0%) for temperature. The chamber reached the target conditions of 121°C and 15 psi in about 15 min, and the solenoid responded consistently to automatic thresholds and manual commands, with an IoT transmission delay of 533–1003 ms. The prototype demonstrates the feasibility of affordable IoT-based monitoring and control of the sterilization process for MSEs, microbiological validation of sterility was not performed and is identified as future work.