Bioactive properties and oxidative stability of nutmeg oleoresin microencapsulated by freeze drying using native and OSA sorghum starches as wall materials

Microencapsulation is employed to protect bioactive ingredients in foods and is also used for their controlled release at targeted sites. The objectives of this study were to examine the bio active properties and stability of microcapsules containing nutmeg oleoresin encapsulated with different ratios (2:1, 1:1 and 1:2) of gum arabic and sorghum starch (native and OSA modified) prepared by freeze-drying. The properties of nutmeg microcapsules, including oxidation stability, antioxidant activity, total phenolic content and total flavonoid content were evaluated after sixty days storage trial. The finding revealed that freeze drying method had a spectacular effect on the retention of bioactive compounds during storage that consequently improved the storage stability of the all nutmeg encapsulated powders. The sample composed of 1:2 ratio of gum arabic with OSA starch resulted to have lowest peroxide value after 60 days of storage. Furthermore, the microcapsules were also observed through Fourier Transform Infrared spectroscopy and Scanning electron microscopy for advance analysis.