Diversity in antioxidant activity of amaranth (Amaranthus dubius (L.) and Amaranthus tricolor (L.)) and culantro (Eryngium foetidum (L.))

Date

4-2005

Degree

Bachelor of Science in Biology

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Adelina A. Barrion

Abstract

Utilizing the two methods: 2,2-diphenyl-l-picrylhydrazyl (DPPH) and the modified thiocyanate (MT) for the antioxidant activities (AoA), reflectometric ascorbic acid assay and Folin-Denis method for measuring the antioxidant concentrations involving ascorbic acid (AsA) and total phenolics, respectively, the five different harvesting periods caused variations in the AoA as well as the antioxidant concentrations involving AsA and total phenolics in the young leaves of four accessions of the two species of amaranth, Amaratuhus dubius (L.) and A. tricolor (L.) and in 19 accessions of culantro, Eryngium .fociicluiti (L.) at the Asian Vegetable Research and Development Center (AVRDC). For the DPP1-1 method, TOT 4303 from Bangladesh exhibited the highest AoA (57%) harvested 33 DAT while the least AoA (10%) was observed in TOT 4868 from Japan harvested 26 DAT. MT method showed the highest AoA (104%) in TOT 4141 from Vietnam harvested 33 and 48 DAT while TOT 4868 from Japan showed the least AoA (73%) which was harvested 33 DAT. With regards to antioxidant concentration, ascorbic acid content was highest (149 mg/100g FW) in TOT 4582 harvested 48 DAT while least (44 mg/ 100 g FW) in TOT 4868 harvested 26 DAT. Total phenolics content was highest (422 mg chlorogenic acid equivalent/ 100 g FW) in TOT 4303 from Bangladesh harvested 33 DAT while the least value (105 mg chlorogenic acid equivalent/ 100 g FW) was measured in TOT 4868 harvested 26 DAT. Variations due to different accessions were also evaluated wherein TOT 4303 had the highest AoA (57%) by DPPH method while TOT 4141 had the highest AoA (104%) by MT method. Antioxidant concentration for ascorbic acid was highest (149 mg/ 100 g FW) in TOT 4582 while the total phenolics was highest (422 mg chlorogenic acid equivalent) in TOT 4303. Significant differences in the variability of antioxidant activity and antioxidant concentrations may be due to genotypic differences, environmental growing conditions and maturity_ Correlation coefficients for the functional properties of E. foetidum were noted because significant differences in values obtained cannot be determined since only one sampling was done. Correlation coefficient between AsA and AoA by DPPH method was moderately positive (0.57) while AsA and AoA by MT method showed a negative interaction (-0.25). A very strong positive linear relationship (0.97) was computed for total phenolics and AoA by DPPH while total phenolics and AoA by MT method had a weak linear association (0.37). Based from the results, free radical scavenging effect of E. foetid., may be attributed to its total phenolic contents but the overall antioxidant activity of E. foetidun cannot be accounted by the ascorbic acid and total phenolic contents

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

Thesis

Document Type

Thesis

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