Ultrasound-Assisted and Conventional Extraction of Betalains from Beetroot and Characterization of Freeze Dried Extract Powder.

Lee, Zhi Yee (2019) Ultrasound-Assisted and Conventional Extraction of Betalains from Beetroot and Characterization of Freeze Dried Extract Powder. Final Year Project (Bachelor), Tunku Abdul Rahman University College.

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Abstract

Betalains pigment is one of the functional phenolic compound derived from beetroot and it is often utilized in the food industry to replace synthetic red food colorants due to it promotes numerous health benefits such as anti-cancers, antioxidants, anti-inflammatory properties. An advanced ultrasound non-thermal technology had been used to assist the betalains extraction which investigated the effect of ultrasound treatment time on the betalains concentration and the extraction yield of beetroot juice extract. The increase in the ultrasound treatment time, increased the betalains concentrations in terms of betacyanins and betaxanthins, and extraction yield of beetroot juice extracts. The optimal ultrasound treatment time of 15 minutes was determined from the highest betacyanins (62.88 mg/L) and betaxanthins (28.02 mg/L) of beetroot juice extracts. Utilizing the optimized ultrasound treatment time for 15 minutes, the beetroot juice extracts by ultrasound-assisted extraction were freeze dried into powder and compared with the freeze dried beetroot juice extract powder sourced from the conventional extraction method that conducted at 33 ºC for 15 minutes. Ultrasound-assisted extraction of freeze dried powder showed significantly highest betacyanins (541.48 mg/L), betaxanthins (207.26 mg/L), total phenolic content (785.30 mg GAE/100g) and 2,2-diphenyl-1-pircryhydrazyl (DPPH) free radical scavenging activity (442.81 mg AAE/100g) with p < 0.05. Ultrasound is applicable to assist the betalains extraction from beetroot which gives better results in terms of betalains concentration total phenolic content and DPPH free radical scavenging activity as antioxidant activity than conventional extraction.