Articles
Extraction and stability of betalains extracted from beetroot tubers and the fruit of eight cactus pear cultivars
Article number
1343_39
Pages
309 – 316
Language
English
Abstract
Betalains are red and yellow pigments found in red beetroot and many cactus pear cultivars.
The study aimed to develop the most ecologically friendly and time-efficient extraction method for betalains from red beetroot and eight cactus pear cultivars.
The cactus pear cultivars were selected from four different colours: green, orange, pink/red, and purple.
Chemical extraction consisted of extraction with water, 10-50% ethanol (EtOH), and 10-50% methanol (MeOH), respectively.
Secondly, pigments were heat-extracted with stovetop extraction at 60, 120, and 180 s as well as heating pigment extracts in the microwave oven for 10, 20, and 30 s (with and without ascorbic acid (AA)). Pigment stability against pH, temperature, and UV light was determined.
The results demonstrated that the extraction procedures had no effect on the total betalain content.
However, the relationship between cultivar and extraction method was significant, which suggests that certain cultivars performed better during certain extraction procedures.
The most heat-stable pigments were the red/purple pigmented fruit cultivars, namely beetroot and cactus pear.
In pH stability, all pigments were stable at pH 4.5 and unstable at pH 1. The UV-light results showed that sample colours and betalain contents did not show substantial changes before and after UV-light exposure.
The study aimed to develop the most ecologically friendly and time-efficient extraction method for betalains from red beetroot and eight cactus pear cultivars.
The cactus pear cultivars were selected from four different colours: green, orange, pink/red, and purple.
Chemical extraction consisted of extraction with water, 10-50% ethanol (EtOH), and 10-50% methanol (MeOH), respectively.
Secondly, pigments were heat-extracted with stovetop extraction at 60, 120, and 180 s as well as heating pigment extracts in the microwave oven for 10, 20, and 30 s (with and without ascorbic acid (AA)). Pigment stability against pH, temperature, and UV light was determined.
The results demonstrated that the extraction procedures had no effect on the total betalain content.
However, the relationship between cultivar and extraction method was significant, which suggests that certain cultivars performed better during certain extraction procedures.
The most heat-stable pigments were the red/purple pigmented fruit cultivars, namely beetroot and cactus pear.
In pH stability, all pigments were stable at pH 4.5 and unstable at pH 1. The UV-light results showed that sample colours and betalain contents did not show substantial changes before and after UV-light exposure.
Publication
Authors
V.N. Sigwela, M. de Wit, A. Du Toit, A. Hugo
Keywords
ecological, eco-friendly, extraction, pigments, pigment-stability, pH, stability, UV
Groups involved
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