There are many applications in the food industry for which a lower concentration of ethanol is acceptable or often preferred. The ability of ethanol to denature proteins is maximized at 60-90% concentration. This feature of ethanol is critical for many applications, including its function as a bactericide. Any surface that comes into contact with food during processing requires sanitization with food grade reagents. Alcohol for use in hand sanitizer is also required to be food grade. The same goes for the anti-microbial properties of ethanol – relatively low concentrations are required, and the reagent must be food grade. For a long time, it was observed empirically in wine that fermentation slows and halts naturally around 12-15% ethanol as yeast activity dies off. Operating on the same principal, ethanol is commonly used to extend shelf-life of fruit and by inhibiting microbial activity.
The ability of ethanol to denature proteins is exploited in protein isolates. Denatured protein isolates demonstrate increased bioavailability, increased foaming capacity, and increased emulsifying capacity. Similar to disinfectant applications, the optimal concentration of ethanol for protein manipulation is generally around 70% or lower.
In all of the discussed applications, it is essential that the ethanol be USP/FCC compliant. Lower grades such as technical grade ethanol can contain contaminants such as acetaldehyde at concentrations that are up to 10-fold higher than USP/FCC-compliant reagents. In response to the alcohol shortage at the onset of the Covid-19 pandemic, the FDA temporarily permitted the use of non-pharmaceutical grade (USP) and non-food grade (FCC) alcohols for use in hand sanitizers, although the long-term toxicological effects had not been studied.< Back