Quality chracterization of functional soy-based yoghurt incorporated with scent leaf (Ocimum gratissimum) essential oil microcapsules

Scent leaf (Ocimum gratissimum) essential oil (OGEO) have been proven to possess antioxidants, antiseptics, antibacterial and antifungal activities. This study evaluated the effect of inclusion of OGEO microcapsule on the quality of soy based yoghurt. OGEO was encapsulated using high speed homogenizer, followed by freeze drying while gum arabic serves as the emulsifying agent or binder. The antioxidant and physicochemical properties of the soy-based yoghurt incorporated with the OGEO microcapsules were carried out. The flavonoid content of the control soy-based yoghurt increased from 0.11mg/100g to 0.35mg/100g, FRAP content from 20.01mg/100g to 27.51mg/100g, and iron chelating from 7.50% to 11.08%, phenolic content from 3.34mgGAE/g to 5.94mgGAE/g, the DDPH from 50.90% to 56.88% with increased incorporation of the OGEO microcapsules. The water holding capacity of the soy based yoghurt increased by almost 2%, the pH reduced from 4.75 to 4.15, acidity increased from 0.71 to 0.99%, while the degree of syneresis reduced from 26.44 to 23.03% over a period of five days storage at room temperature. The bacteria count of the soy-based yoghurt without OGEO microcapsule increased from none at day 0 to 4.3.33 × 104 cfu/100ml by day 5, while soy-based yoghurt incorporated with OGEO microcapsule had no count by day 3 and 3.62 × 103 cfu/100ml by day 5. There were no yeast and mould counts for the soy-based yoghurt incorporated with OGEO microcapsules for the five days storage whereas, the sample without the microcapsule recorded 2.4 × 104cfu/100ml by day 5. Incorporation of soy-based yoghurt with OGEO microcapsule improved the antioxidant and physicochemical properties as well as improved the shelf life of the product.