ABSTRACT
This study determined the optimal pressure and time conditions for the high pressure processing (HPP) of a lemongrass-lime mixed beverage. The physicochemical and microbiological characteristics, bioactive compounds, and antioxidant activity of the beverage treated under the optimal HPP conditions were evaluated immediately after processing and during 8 weeks of storage at 4 °C, compared to untreated (control) and thermally pasteurized beverages. HPP at 250 MPa for 1 min at 25 °C ensured microbiological safety, according to inactivation tests with Listeria innocua as the target microorganism, without significant losses of vitamin C and phenolic compounds. Immediately after processing, the HPP treated beverage retained its original bioactive compounds content and showed physicochemical characteristics that were closer to the untreated control compared with the thermally pasteurized beverage. In addition, HPP provided microbiological quality and improved the shelf life of the beverage, demonstrating that it represents a reliable alternative to thermal treatment of lemongrass-lime mixed beverages.
ABSTRACT
BACKGROUND: Lemongrass is an aromatic plant with antioxidant and antimicrobial properties, used for the preparation of medicinal tea and for essential oil production. Previous studies have shown that extracts of lemongrass leaves contain phenolic compounds associated with health benefits. Although essential oils have been widely used as flavoring agents, there is no scientific evidence regarding the use of lemongrass essential oils in beverages. Thus, the objectives of the present study were to develop blends with lemongrass derivatives (aqueous extract, lyophilized extract, and essential oil) and lime juice for the preparation of mixed beverages, to evaluate the antioxidant and physicochemical characteristics of blends, and to determine the sensory profile and acceptance of mixed beverages. RESULTS: The formulated blends showed favorable physicochemical characteristics such as acidity and color, and they contained bioactive compounds (phenolics and vitamin C) and important antioxidant properties. Mixed beverages prepared from blends containing aqueous extract or lyophilized extract plus essential oil, which showed higher intensity of lemongrass aroma and flavor, were more readily accepted. CONCLUSION: This study demonstrates that it is possible to make suitable blends with lemongrass derivatives and lime juice for the preparation of high-quality mixed beverages with sensory pleasantness, and potentially beneficial health components. © 2018 Society of Chemical Industry.
