Evaluation of Antioxidant and Chelating Activities of Ginger Extract

Subject Areas : Microbiology

zahra  kamali rosta ¹ (دانش آموخته کارشناسی ارشد دانشگاه آزاد اسلامی، واحدعلوم وتحقیقات، گروه علوم وصنایع غذایی، تهران، ایران)
maryam  gharachorloo ² (استادیار دانشگاه آزاد اسلامی، واحد علوم وتحقیقات، دانشکده علوم ومهندسی صنایع غذایی، تهران، ایران)
amirhosein  elhami rad ³ (استادیاردانشگاه آزاد اسلامی، واحدسبزوار، ایران)
reza  azizi nezhad ⁴ (استادیار دانشگاه آزاد اسلامی، واحد علوم وتحقیقات، دانشکده کشاورزی ومنابع طبیعی، تهران، ایران)

Received: 2009-09-20 Accepted : 2010-04-27 Published : 2014-06-22

Keywords: antioxidant, Chelating Agent, Extracts, Ginger,

Abstract :

Introduction: Oxidation of oils and fats might be considered as the main factor affecting the quality of the food in general. This process might be controlled by the application of different methods and means. Antioxidants are regarded as a tool to achieve this aim. Although the application of synthetic antioxidants due to their possible side effects might not be desirable, the application of natural antioxidants present in various food namely spices that have been consumed by man for years might be suitable alternatives. Therefore the aim of present investigation is to understand the antioxidant and chelating activities of chemical compounds present in ginger.Materials and Methods: Ginger extracts (Zingiber officinale Rosceo) were prepared by cold extraction using acetone and methanol as extracting solvents. Total phenolic compounds were determined and the extracts were added to tallow; a substrate free of natural antioxidants at concentrations of 0.02, 0.04, 0.06, 0.08 and 0.10 %. Peroxide value and induction period measurements were employed as means to determine the antioxidant activities of the extracts were compared to TBHQ, the synthetic antioxidant. The chelating activities of the extracts were determined by the application of copper in the form of 4-cyclohexyl butyric acid copper salt followed by the determination of peroxide value and induction period of the substrate.Results: The results indicated that the antioxidant activities of the extracts are concentration dependent and as concentration is increase better activity is observed. The acetone extract at 0.1% should a good activity ever better than the addition of 0.01% TBHQ. The acetone extract also exhibited chelating activity at 0.1%.Conclusion: Both methanol and acetone extracts of ginger exhibited antioxidant and chelating activities when added to tallow a substrate free of natural antioxidants