Assessment of Meat Freshness via Optical Measurement of Carbon Dioxide Using Fluorescent Capillary Coating

This paper describes a unique method for quickly, accurately, and non-destructively determining the freshness of meat. During the spoilage of meat, CO₂ is evolved primarily through microbial respiration. The production of CO₂ is often a sign of active spoilage, which helps in determining the freshness and safety of meat consumption. The level of carbon dioxide evolved during meat spoilage was measured using a fluorescent material–coated capillary tube. A CO₂ sensing dye was immobilized in a hybrid sol–gel silica matrix followed by its deposition inside a glass capillary tube, which acts as the sensing medium. When the sensing medium is excited by a light source, it fluoresces. The intensity of the fluorescence emitted when meat samples are exposed to the capillary tube diminishes proportionally to the CO₂ concentration, thereby enabling quantification. The fluorescence intensity and CO₂ concentration were found to have a high linear correlation (R² > 0.95), demonstrating the method’s accuracy and dependability. A low response time of 12 s signifies the fast detection of changes happening in the evolution of CO₂ from meat. The recovery time is determined to be 17 s. Within this time, the sensor becomes ready to react to fresh stimuli for CO₂ detection. A short recovery time allows for more rapid successive measurements. This approach is environment-friendly and makes real-time measurements possible, making it ideal for on-site and in-line applications in the food sector. It provides the meat processing industry with an easy, affordable, and effective replacement for traditional methods, enabling quicker decision-making and quality control.