According to studies, many flavours lose their sensory profile after being used in a food product. Some of the fundamental causes of this loss are limited retentivity and excessive volatility in harsh surroundings. Furthermore, it presents significant problems for food processors because the flavour is the ultimate trigger for consumers to buy again and again. As a result, the flavour industry relies on cutting-edge technologies to give the flavour longer shelf life. One of the most common flavour encapsulation methods. It is the trapping of flavour in a food product to protect it from evaporation, reaction or migration. After then, the flavour is made available at the expected time and location of food consumption.
Encapsulation is described as the process of covering a desirable component with a protective wall material before releasing it at its intended target. The entrapped material is classified as core, active or payload material. Wall material can also be referred to as a carrier, shell, capsule or membrane. The following are the main advantages of encapsulated powder flavours:
- Thermal degradation protection
- Improved product functioning
- A longer shelf life
- Controlled flavour release
- Better masking qualities
What Is the Process of Encapsulating Flavour?
The literature lists a variety of flavour powder encapsulation processes, each of which produces different particle sizes and has its own set of benefits and drawbacks. Coacervation (20-200 microns), Extrusion (200-2000 microns), Spray drying (1-50 microns), Spray chilling (20-200 microns), and Fluidised bed drying (>100 microns) are only a few of them. Spray drying is the most widely used technology in the flavour business because it is more cost-effective and convenient for many heat-labile components.
First, a slurry mixture is formed by combining the carrier with a suitable emulsifier (e.g., gum) in water. After that, the flavour is spread throughout the mixture to form a stable emulsion. Water connects to the hydrophilic end of the emulsifier, while concentrated food flavour essence adheres to the hydrophobic end. The emulsion is atomised as a droplet in the dryer via a nozzle atomiser and exposed to hot air (temperature 160°C). Water vaporises, and gum shrinks as a result of the quick heating. The carrier triggers film development at the air-liquid interface by releasing moisture. Encapsulation occurs when the increasing solid content is entrapped in this film. The generated microcapsules are then transferred to a cyclone separator for air recovery and separation.
Flavour retention during encapsulation is determined by the physicochemical properties of the carrier and active material, emulsion stabilisation, carrier film-forming ability, solid content of the drier, processing temperature and ultimate moisture content. The wall material should be non-reactive, easy to handle, stable and effective in a targeted release. For greater retention, choosing a suitable carrier is essential. Modified starches such as maltodextrin (film-forming ability/ bulking agent/ filler), cyclodextrin (encapsulant), gum acacia or lecithin (emulsifier) and others are commonly used carriers. A mix of the above carriers is advised for optimal results.
Maltodextrin with a DE (Dextrose Equivalent) of 10 has been found to have greater retention in several experiments. Gelatin can be added to the slurry mixture to improve flavour retention. The sodium caseinate was also discovered to be a good wall material for retaining orange oil and dairy flavours.
What Method Is Used to Release Flavour?
Melting (heating of the wall material), degradation or erosion of the wall material, fracturing the wall material via swelling or diffusion are some of the mechanisms that release the entrapped flavour. Two factors primarily control the rate of flavour release from the food product. Thermodynamics is one of them (comparative volatility of flavour in the food matrix and its surrounding under equilibrium conditions). The kinetic factor is the second (the resistance to mass transfer from food matrix to surrounding). The controlled flavour release allows for a longer release time. It prevents flavour compounds from being lost during food processing, resulting in a superior profile.
In high-heating bakery and confectionery goods, encapsulated flavours provide superior stability, decreasing the need for overdosage. It can also be used when the liquid flavour is being suppressed by yeast fermentation. Another category where encapsulated flavours can be used is extruded foods subjected to high pressure. Long shelf life is necessary; powder beverage manufacturers can consider it. Encapsulated flavours are also functioning well in pharmaceutical goods.
Uses of Encapsulated Flavours
In the food sector, extruded encapsulated flavours are used as ingredients in quick desserts, cakes, biscuits, tea bags, loose tea, coffee, instant drinks and confectionery. For example, they are also used to compress active substances into tablets or cosmetic goods directly.
Flavours are expensive and delicate materials used as food additives (volatile, light-sensitive, easily oxidised and reactive). Aromatic molecules must be protected – or “encapsulated” – in an envelope that is further dissolved under specified conditions (solvent, temperature, etc.) and releases flavours in the destination medium.