Microwave Irradiation: Effects on Particle Size Distribution, Rheological and Fluorescent Characteristics of Wine

This study investigated the effects of microwave irradiation on the particle size distribution, rheological properties, fluorescent characteristics, and sensory characteristics of wine. Wine samples were treated under varying microwave power (100–500 W), temperature (20–60 °C), and time (1–5 min). Results indicated that microwave treatment modified the particle size distribution, especially the proportion of particles in the range of 0.3–0.5 μm, which increased with microwave power, temperature, and time. Rheological analysis indicated that the behaviour followed the Power-law model, with all samples exhibiting expansion fluid properties (n > 1). Fitting with the Casson model revealed that microwave treatment increased the yield stress (τ0) and viscosity coefficient (K), with optimal improvements observed at 300 W, 30 °C, and 3 min (τ0 = 0.7769 Pa, K = 2.9367 × 10−3 Pa s0.5). These changes contributed to enhanced leg phenomenon and thickening effect. Furthermore, microwave treatment elevated the fluorescence intensity of wine, indicating accelerated formation of fluorescent substances. Sensory evaluation demonstrated that microwave treatment, particularly at 400 W, 40 °C, and 3 min, significantly improved colour, clarity, and mouthfeel while reducing astringency and bitterness. In conclusion, microwave treatment effectively modifies the sensory characteristics of wine, offering a viable technological approach to accelerate wine ageing and supporting its potential application in winemaking.