Journal of Experimental Agriculture International

Bananas are among the most widely produced and consumed fruits in the world, but their climacteric ripening physiology makes them highly susceptible to rapid postharvest quality loss, particularly under uncontrolled ambient storage. This paper reports an experimental case study in which a low-cost Internet of Things (IoT) sensing platform — combining a DHT22 temperature/humidity sensor, an MQ3 gas sensor, and a light-dependent resistor (LDR), interfaced through an Arduino UNO and NodeMCU ESP8266 to the Blynk cloud application — was used to track the day-by-day environmental and volatile-gas signature of a batch of bananas stored at room temperature over an eight-day observation period. Temperature, relative humidity, and gas-sensor readings were logged and compared with the visually assessed ripeness/spoilage stage of the fruit on each day, from fresh (Day 1) through edible (Day 3), near-spoilage (Day 5), to fully spoiled (Day 8). The results show a clear, monotonic rise in gas-sensor output coinciding with the visible transition from ripe to over-ripe fruit, with the sharpest gas-sensor gradient occurring between Days 5 and 8, while temperature and humidity remained comparatively stable under ambient room conditions. These findings are discussed in relation to the published optimal banana ripening envelope of approximately 16–20°C and 90–95% relative humidity, and to the broader postharvest-physiology and ethylene-sensing literature. The results support the feasibility of low-cost gas-sensor-based systems as an early-warning tool for household and small-retail fruit spoilage, while highlighting sensor-specificity and calibration issues that should guide future refinement.