Designing iron-ethyl cellulose microparticles to prevent unwanted color changes during iron fortification of milk tea

Iron deficiency affects an estimated 1.62 billion individuals worldwide, while Asia and Africa bearing the highest burden. The widespread consumption, unique sensory properties and cultural significance of tea make it an appealing avenue for iron fortification. Obtaining microparticles for food fortification with acceptable organoleptic properties is key for consumer acceptability. Microcapsules were prepared with Aquacoat and various iron salts. The experiments were designed to understand the effect of formulation variables, i.e. type of iron salt, ratio of iron-to-coating, temperature and flow rate of the process. The iron compound significantly impacted yield, particle formation, and size distribution (5-15 μm). Post treatment by curing at specified relative humidity and temperature improved the colour in milk tea with ΔE reduced from 7 to 2 in NBS units. Microparticles from FeCl₃ exhibited superior morphology and colour-masking efficacy, inhibiting iron-polyphenol interaction in tea and show promise as iron fortificants for milky black tea.

Practical applications

Microencapsulation is a highly effective technique for encapsulating active iron cores within inert coating materials, ensuring the desired chemical and physical properties. Using spray drying, we can produce small and uniformly sized particles ranging from 1 to 20 μm. This can easily be utilized for fortification of beverage like hot tea/coffee or similar products. The success of the current process is evaluated based on several key factors, including process yield, encapsulation efficiency, and sensory properties of fortified tea.