Green Tea Leaves Extract: Microencapsulation, Physicochemical and Storage Stability Study.

Area of Science:

• Food Science and Technology
• Nutraceuticals and Functional Foods
• Chemical Engineering

Background:

• Green tea polyphenols offer numerous health benefits but are unstable under processing conditions.
• Sensitivity to heat, pH, and oxygen limits the application of green tea extracts in the food industry.
• Developing stable green tea formulations is crucial for effective utilization of its bioactive compounds.

Purpose of the Study:

• To enhance the stability of green tea extracts using encapsulation techniques.
• To evaluate the impact of different carrier materials on the properties of encapsulated green tea polyphenols.
• To assess the storage stability and release characteristics of the microencapsulated green tea extracts.

Main Methods:

• Supercritical fluid extraction (SFE) was used to obtain green tea extracts from Malaysian Cameron Highlands leaves.
• Spray-drying encapsulation was performed using maltodextrin (MD), gum arabic (GA), and chitosan (CTS) as carrier materials.
• Physicochemical properties, encapsulation efficiency, antioxidant capacity, swelling ability, and storage stability were analyzed.

Main Results:

• Encapsulation efficiency ranged from 71.41% to 88.04%, with high total phenolic content and antioxidant capacity.
• Microparticles exhibited favorable characteristics including moisture content (2.31%-5.11%), water activity (0.28-0.36), and particle size (40.43-225.64 µm).
• Encapsulated extracts showed improved storage stability, with significantly longer half-lives at lower temperatures (231-288 weeks at 4°C).

Conclusions:

• Spray-drying encapsulation effectively improved the stability and shelf-life of green tea polyphenols.
• The choice of carrier material and storage temperature significantly impacts the stability of encapsulated green tea extracts.
• Storing microparticles below 25°C is recommended for optimal shelf-life stability and preservation of bioactive compounds.