Effect of different processing conditions on antioxidant activity of Gracilaria edulis(Rhodophyseae) in Sri Lanka

Umakanthan Ganeshamoorthy

doi:10.14738/jbemi.65.8007

Abstract

Gracilaria edulis is red marine algae currently cultivated in Sri Lanka but relatively low than other country such as China and Japan. This species are used to produce drugs and healthy delicious low calorie foods because of they are primary source of secondary metabolite and to be used as natural antioxidants and antimicrobials. The Purpose of this research investigates effect of different processing conditions on antioxidant activity of G.edulis (Rhodophyseae) by hydrogen peroxide scavenging activity assay. Absorbance at 230 nm, hydrogen peroxide scavenging assays were done. Different processed G.edulis such as fresh, steamed, boiled, dried and microwaved were extracted with methanol. Their antioxidant properties were compared to the L-ascorbic acid which used as positive control. The methanolic extracts of this red algae was prepared keeping methanol as a standard. Methanol was used as control. In minitab-15 statistical software package, Paired T-Test was clearly shown the absorbance, inhibition or hydrogen peroxide scavenging activity depend on the processing conditions of the G.edulis methanol extract. This statistical test did tell about the difference between the different processing conditions of the methanol extract of the G.edulis (p<0.05) and antioxidant activity and these were not independent factors such are depend on each other. Hence antioxidant activity or H2O2 scavenging activity was highly in boiled G.edulis, followed by fresh, microwaved, dried and steamed respectively. L-ascorbic acid was used as Positive control and its antioxidant activity was higher than dried and steamed but relatively lowers than microwaved, fresh and boiled G.edulis. Finally Boiled G.edulis sample was recorded prominent antioxidant activity due to leaching of less antioxidant compounds. In future this study is used to functional product development incorporation of dried followed by boiled G. edulis into bakery Products.

Highlights

Seaweeds are commonly called as marine algae which are broadly categorized into 45000 species in worldwide (Amin, 2002)
These results revealed all processed G.edulis sample were shown prominent antioxidant activity
This research paper finding was indicated that the processing conditions significantly influenced the antioxidant activity of G.edulis in order to find the most potent functional processed G.edulis

Summary

Introduction

Seaweeds are commonly called as marine algae which are broadly categorized into 45000 species in worldwide (Amin, 2002). Most of the consumable seaweeds especially under Rodophyceae, G.edulis was contained high level of dietary fiber, indigestible carbohydrates, vitamins, minerals and essential amino acids (Layase, et al, 2011). Such type of seaweeds contain bio active compounds that are used in food industries and pharmaceutical industries and used as diet in china and Japan compare to Europe and North America for cure the prostrate and breast cancer (skiboda, 2004). Oxidative stress cause ischemic injury, cancer aging inflammation, and neurodegenerative diseases (Parkinson’s and Alzheimers’s) Reactive oxygen species such as nitric oxide radical, superoxide radical, peroxyl radical and hydroxyl radical form extensive oxidative damage are associated with those diseases. Such reactive oxygen species attach with RNA and DNA, Lipids and enzymes leading to cell or tissue damage and carcinogenesis and which are associated with chronic diseases such as cerebrovascular and cardiac diseases (Reaven and Witzum, 1996; Aruoma, 1999)

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