ASSESSMENT OF EXTRACTION PROCESSES, COLOR PROPERTIES AND DEGRADATION KINETICS OF ANTHOCYANIN FROM RED AMARANTH (Amaranthus gangeticus)
Date
2014-12
Authors
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Journal ISSN
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Publisher
HAJEE MOHAMMOD DANESH SCIENCE AND TECHNOLOGY UNIVERSITY, DINAJPUR
Abstract
There is a growing attention in natural colorants as an alternative of synthetic colorants
which have many biological activities and antioxidant potential on consumer health. The
present study deals with the assessment of extraction process and the effects of pH (1, 3,
and 5), extraction media (water and 50% ethanol) and storage condition (ambient and
refrigerated) on anthocyanin content, color values as well as degradation kinetics of total
anthocyanin in red amaranth. Maximum amount of anthocyanin content was obtained in
water and 50% ethanol (41.16+1.91 and 36.3840.28 mg/100g) at pH-3 followed by pH-1
and pH-5. Better results for thermal degradation parameters ( ti, %R) and hunter color
values (L*, a*, b*, AE) was noticed at lower pH for water followed by 50% ethanol at
refrigerated temperature. Anthocyanin degradation was accelerated at ambient
atmospheric temperature (30+2°C) than in refrigerated storage condition (4°C). P",
storage time and temperature affected the stability of anthocyanin. Experience of this
research work suggests that anthocyanin from red amaranth may be an excellent source to
meet up the increasing need of natural colorants.
Description
Vegetable is important for human well being. In Bangladesh there are lots of varieties of
vegetables such as Indian spinach, Tripatri leaves, Mustard green, Leaf amaranth,
Spinach, Goose foot and Water spinach are found throughout the year. Among all the
vegetables red amaranth (Amaranthus gangeticus) is commonly consumed and is known
as “LalShak’’. Red amaranth is available in winter season than in summer and spring
season. It is a source of large amount of vitamins (vitamin A, vitamin Be, vitamin K,
vitamin C, and riboflavin), minerals (calcium, potassium, iron, copper, magnesium,
phosphorus and especially manganese) folic acid, protein, dietary fibre and amino acids
(Khandaker et al., 2008). It is also an excellent source of health beneficiary bioactive
compounds such as betacyanin, polyphenols, anthocyanin and antioxidants (Khandaker et
al., 2008). The phenolic compounds or pigments anthocyanins are belonging to the family
named as flavinoid. There are only six anthocyanins found in food such as pelargonidin,
cyanidin, delphinidin, peonidin, pentunidin and malvinidin (Malacrida and Motta, 2005).
Anthocyanins are found in flowers, leaves, stems, fruits, seeds and the root tissue of
plants. Anthocyanin is free from toxicity. It may help to prevent cardiovascular disorder,
inflammatory response, cancer and deteriorative diseases. Anthocyanin also improves
neurotral and cognitive brain functions, ocular health as well as protects geomic DNA
integrity (He and Giusti, 2010).
Keywords
Sample collection and preparation, Chemicals and reagents, Extraction of anthocyanin, Determination of anthocyanin content