ANSWER

Encapsulation provides a significant protection against oxidation and heat degradation, thereby contributing to increase the shelf life of the encapsulated ingredients. Furthermore, encapsulation has the capability to mask undesirable taste and odor (Munin & Edwards-Levy, 2011).

A good encapsulating agent should possess several properties that includes low viscosity, non-hygroscopic, bland in flavour/tasteless, non-reactive with core materials, soluble in aqueous solvents, inexpensive, food-grade, flexible, hard, thin and pliable (Tan et al., 2015).

Encapsulating or carrier agents used in drying by spray drying can be carbohydrates (starch, maltodextrin, dextrans, sucrose, cellulose and derived), gums (Arabic gums, agar, carrageenan, etc.), lipids (wax, paraffin, diglycerides) and proteins (gluten, caseins, albumins, haemoglobin and peptides). It is common to use mixtures of maltodextrins with Arabic gum and modified starch as they offer good protection against oxidation (Costa et al., 2015).

However, no single encapsulating agent possesses all the above-mentioned properties. Therefore, two or more agents are often used in particular combinations. Maltodextrin and gum Arabic are two of the most commonly used encapsulating agents for spray-drying due to their low viscosity and good solubility in aqueous solutions. They are often used in combination because they complement each other well (Tan et al., 2015).

Modified starches are also widely used as encapsulating agents due to their excellent retention of volatiles (above 93%) and ability to stabilize emulsions & low viscosity. However, they exert low protection against oxidation during stocking (Costa et al., 2015).

References

Costa, S. S., Machado, B. A. S., Martin, A. R., Bagnara, F., Ragadalli, S. A. & Alves, A. R. C. (2015). Drying by spray drying in the food industry: Micro-encapsulation, process parameters and main carriers used. African Journal of Food Science, 9(9), 462-470. https://doi.org/10.5897/AJFS2015.1279

Munin, A. & Edwards-Levy, F. (2011). Encapsulation of Natural Polyphenolic Compounds; a Review. Pharmaceutics, 3(4), 793-829.

Tan, S. P., Kha, T. C., Parks, S., Stathopoulos, C. & Roach, P. D. (2015). Optimising the Encapsulation of an Aqueous Bitter Melon Extract by Spray-Drying. Foods, 4(4), 400-419. https://doi.org/10.3390/foods4030400