Microencapsulation is a process by which solids, liquids or even gases may be enclosed in microscopic particles by formation of thin layer around substances. It is a process by which very tiny droplets or particles of liquid or solid material are surrounded or coated with a continuous film of polymeric material.
Microencapsulation includes bio-encapsulation which is more restricted to the entrapment of a biologically active substance generally to improve its performance &/or enhance its shelf life.
India suffers from HIDDEN HUNGER which is a condition in which an individual has multiple deficiencies of various nutrients like Folic Acid, Vitamin A, Iodine, Zinc, Iron etc. takes place. Thus Indian Government has taken an Initiative to fortify staples like wheat, oil, salt, rice and milk for combating leading micro-nutrient deficiencies. Thus microencapsulation plays a major break-through technology for fortification ingredients.
However, on the other hand food fortification (Direct mixing) with micronutrients might cause unwanted sensory changes and interaction with food components resulting in a lower bioavailability. Microencapsulation may be helpful to prevent unwanted sensory changes and diminish micronutrients interactions with wheat flour components.
The incorporation of minor nutrients causes changes in the sensory properties of the fortified food like off flavour and change in colour. These changes might be due to the additives or interactions between, the additives and components of the food vehicle. In a study it has been reported that direct addition of iron to whole wheat flour produces off flavour and colour changes in fortified chapattis. The interaction of iron and zinc with whole wheat flour components reduces protein and moisture contents. Hence, a suitable technology must be used to deliver fortificants into fortified foods Food fortification (Direct mixing) with micronutrients often causes unwanted sensory changes and interaction with food components resulting in a lower bioavailability.
Another factor is shelf life of all food commodities. Shelf life is the length of time that a food material may be stored without becoming unfit for use, consumption or sale. The shelf-life of foods is affected by several aspects, mainly chemical and microbial events, resulting in a considerable decline in consumer’s acceptance.
Microencapsulation may be helpful to prevent unwanted sensory changes and diminish micronutrients interactions with staple components. Microencapsulation is considered as an excellent approach to protect sensitive food ingredients from oxidative degradation, increase the retention of nutrients, and avoid interaction with food components and prevent undesirable changes in fortified food. It can help to maximise the bioactivity of the added compounds during processing and storage of the fortified food.
Another example is Yogurt (4, 7, and 10 mg iron/100 g yogurt) which is fortified with ferrous sulphate, iron whey protein complex, and microencapsulated iron whey protein complex. However, yogurt fortified with ferrous sulphate was highly oxidised and metallic taste developed. The flavour and overall quality of yogurt fortified with microencapsulated iron-whey protein complex was much better and there were no chances of oxidation which results into extension of the shelf life of the product.
Microencapsulation is both an art and a science. Thus Microencapsulation is a break-through innovative technology used these days which are indispensable for manufacturing any quality ingredient.