Effects of various treatments on the stability of pigments from beetroot (Beta Vulgaris) and dragon fruit (Hylocereus Polyrhizus)

Khor, Ruying (2010) Effects of various treatments on the stability of pigments from beetroot (Beta Vulgaris) and dragon fruit (Hylocereus Polyrhizus). Universiti Malaysia Sabah. (Unpublished)


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Betalains are of great taxonomic significance in higher plants and water-soluble nitrogenous pigments. Peel, crown, flesh of beetroot and peel, flesh of dragon fruit were separately analyzed in the present study. The overall aim of the study was to identify suitable conditions for the extraction and storage of betalains from this plant species for further detailed biochemical studies. Major compounds found in beetroot and dragon fruit were betacyanins and betaxanthins by using thin-layer chromatography. Water was more effective for optimum extraction of betalains compared to ethanol: water (80:20) extraction. Beetroot peel had the highest betalains concentration which was 84.97 ±0.266 mg/100g fresh weight while dragon fruit peel had the lowest betalains concentration whid7 was 11.81 ±0.280 mg/100g fresh weight for water extraction. The highest pigment loss was observed at pH 8.0 while the lowest was at pH 6.0 in 24 hours. For temperature effect, pigment loss was minimum at 4 and maximum at 100°C for 3 hours. 8etalains extracts showed highest pigment retention when stored at -4 ± 2°C compared to 30 ± 4°C (ambient temperature) in the dark for 4 weeks. Overall, the results showed that betalains extracted from by-product of beetroot and dragon fruit can be used as potential colorants in food.

Item Type: Academic Exercise
Uncontrolled Keywords: betalains, water-soluble nitrogenous pigment, extraction, storage of betalains, beetroot peel, dragon fruit, potential colorant
Subjects: T Technology > TX Home economics > Nutrition. Foods and food supply
Divisions: SCHOOL > School of Food Science and Nutrition
Date Deposited: 10 Jul 2013 06:42
Last Modified: 23 Oct 2017 06:41
URI: http://eprints.ums.edu.my/id/eprint/6531

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