Assessing the Relative Volatility and Beta Radioactivity of Ethanol as a Preliminary Verification of Varietal Authenticity in Philippine Wines and Liquors with Tourism Implications

Alcoholic beverages in the Philippines show significant variation in ethanol content and feedstock, influencing their relative volatility, α, which serves as a strong indicator of the ease of ethanol separation during distillation. This variability arises from differences in the vapor-liquid pseudo-binary equilibrium of the beverages. By constructing a pseudo-binary ethanol-water plot, the ease of dehydrating ethanol was analyzed from a thermodynamic perspective. Using Dalton’s, Raoult’s, Clapeyron, and Trouton’s laws, the study derived the equation: logα=TA​−TB​8.9×Δt​ where TATA​ and TBTB​ are the boiling points of ethanol and the residual liquid in Kelvin, respectively. It was found that the relative volatility increases with higher solute concentration in the mixture. Among the selected beverages, lambanog demonstrated the highest ease of producing 89.5 mole percent ethanol purity, followed by basi, tapuey, and tuba. In addition, the study confirmed that the 14C content in plant-derived ethanol from tuba, tapuey, basi, and lambanog ranged between 12-16 disintegrations per minute per gram carbon (dpm/gC), consistent with atmospheric levels at the time the plants were growing. Fossil or synthetic ethanol, by contrast, exhibited zero 14C activity. Thus, β-radioactivity measurement of carbon in ethanol provides a reliable method for detecting the illegal adulteration of authentic liquors with synthetic ethanol. This methodology is essential for ensuring the authenticity and quality of traditional alcoholic beverages in the Philippines.