Development of Functional Lemongrass Drink: Determination of Physicochemical, Sensorial and Antioxidative Properties

Hong, Wan Ying (2016) Development of Functional Lemongrass Drink: Determination of Physicochemical, Sensorial and Antioxidative Properties. Final Year Project (Bachelor), Tunku Abdul Rahman University College.

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Abstract

In this study, lemongrass (Cymbopogon citratus) was used to develop functional drink. First of all, fresh lemongrass juice was extracted according to substrate-to-solvent ratio of 1:10, 1:15 and 1:20 through hot water and grinding-assisted method. A hedonic test was conducted by 60 panellists to choose the best substrate-to-solvent ratio from each treatment. The best-chosen substrate-to-solvent ratio of hot water and grinding-assisted extracted sample is 1:10 and 1:15 respectively. The selected formula was added with different types of sweetener (white sugar, brown sugar, sucralose and stevia). Among the samples, hot water extracted lemongrass drink sample with brown sugar possessed the highest total phenolic content (131.71 ppm gallic acid equivalent (GAE) ± 2.44), DPPH radical scavenging effect (34.26 ppm ascorbic acid equivalent (AAE) ± 0.78), ferric reducing antioxidant power (257.55 μM ferrous sulphate equivalent ± 6.06). Quantitative Descriptive Analysis (QDA) and hedonic test were performed by 20 trained panellists to evaluate the sensory quality difference among samples and degree of acceptability on samples. The lemongrass drink sample prepared through grinding-assisted method with white sugar attained the most intense lemongrass odour and pungency that accounts for the characteristics of lemongrass, contributed to the highest degree of acceptability. Aroma profiles were evaluated through Headspace-Solid Phase Microextraction coupled to Gas Chromatography-Mass Spectrometry (HS-SPME/GC-MS). A total of 308 volatiles constituents were identified. The aroma compounds that found to be dominant in all lemongrass drink samples are lemonal, neral, geraniol, linalool, nerol, caryophyllene and 6-methyl-5-hepten-2-one where the white sugar added grinded lemongrass drink contained highest amount of geranial, neral, (R)-citronellol, linalool and nerol. This showed the GC-MS results correlated well with the QDA and hedonic test results. In short, this finding elucidated great potential of the healthy lemongrass functional drink to be commercialized.