Development of portable smart colorimetric device for on-site evaluation of microbial safety of milk

Traditional methods such as the methylene blue reduction test (MBRT) to assess the microbial security of milk are often time consuming, labour-intensive and unsuitable for rapid tests. This paper presents a smart, inexpensive and portable alternative. An IoT-enabled colorimetric measuring device for monitoring milk quality in real time. The system uses the TCS3200 colour sensor to recognize subtle colour changes in milk associated with microbial spoilage and classify "normal" samples to spoilt ones. The NodeMCU Microcontroller processes this data and uses Wi-Fi functionality to display results for OLED screen and cloud-based platforms, Thingspeak analysis. By eliminating the need for manual observation, the proposed solution provides a faster and more user-friendly alternative to MBRT.  This device ensures better food safety, less corruption, and more customer trust by simplifying milk quality testing for both domestic and industrial applications.