Customer is the king of the market and manufacturers have to make products that satisfy the appetite of the king. Across the world, awareness on the benevolent health effects of natural products is on the rise. Then again, users are demanding the inclusion of specific flavours in the products they use.
Beers and alcoholic beverages with special flavours and low alcohol content are highly prized commodities in the present day market. Customers are willing to shell out a few more dollars for products containing specific ingredients.
Estimates place the global beer market at $805 billion at the end of 2024, after registering a CAGR of 6.2% from 2019 to 2024. Among the crucial factors driving up the prospects for the beer market are the changing customer preference for beers laced with special flavours and those with low alcohol content (by volume). Climbing disposable incomes of users, particularly youth, enables them to enjoy special brews. Similar trends are palpable in the alcohol market where financially better off users, particularly millennials, are spurring up the demand for premium alcoholic beverages.
In order to fulfil this demand, extraction techniques that isolate the required target molecule while leaving the others undisturbed are necessary. The supercritical fluid extraction (SCFE) technique is widely known and used to separate specific target molecules. It uses a supercritical fluid i.e. a fluid at a temperature and pressure respectively above its critical temperature and critical pressure.
When in the supercritical state, the fluid’s solvent power is highly customizable. Minor changes in pressure and temperature introduce large changes in its solvent power. The solvent power of a supercritical fluid rises and falls respectively with increase and decrease in density. Supercritical fluids have high density, similar to that of liquids. This lends then excellent solvent power.
Careful control over process pressure and temperature adjusts the density of the supercritical fluid and fine tunes its solvent power to isolate one particular molecule, the target molecule. The extracted target molecule is largely pure and requires minimal post processing.
If its density is like that of a liquid, its viscosity and surface tension are low – similar to that of a gas. This helps the supercritical fluid to penetrate deeper inside porous solids, and extract more of the required flavour.
Using carbon dioxide for SCFE further accentuates the natural advantages of the process. Purity of flavours is important as noted before. With a critical temperature of 31.1 deg-Celsius, CO2 is an ideal supercritical fluid as it keeps process temperatures near the room temperature and, thereby, avoids thermal distortion of the target molecule. Relatively lower temperatures translate into sustained integrity of the hop flavour, which also extends the shelf life of beer. Hop flowers provide the characteristic bitter taste to beer. The bitter flavour also plays a role in balancing the beer taste – in the absence of hop flavour, beer will taste repulsively sweet.