Improving the Antioxidant Activity of a Carbonated Lemon Soft Drink

The carbonated functional soft drinks are a new concept that provides health benefits for the consumers. The aim of this study was to improve the antioxidant activity of a carbonated lemon soft drink, while preserving its characteristic flavour, by blending the lemon oil (L) with oregano (Or) essential oil. The effect of different thickeners, usually used in formulation of the soft drinks, on release of the volatile compounds from simple model solutions was evaluated, separately. Blending lemon oil with oregano essential oil (1.5 µL Or /100 µL) improved the odour acceptability and increased the DPPH scavenging ability of lemon oil by 40%. Studying the effect of different thickeners indicated that the xanthan, Arabic gum and pectin at levels 0.05, 6.0 and 0.01 g/100 mL water, respectively, showed the highest release of limonene and citral, the most contributors to lemon aroma, from the simple model solutions. This finding was mainly correlated to the interaction between the thickeners. In view of this result a lemon soft drink was formulated. Carbonation of the soft drink improved the sensory characteristics, decreased the pH value, increased the acidity and showed insignificant changes (P > 0.05) in total soluble solids and total sugars.