A comparative study on chemical composition and antioxidant activity of ginger (Zingiber officinale) and cumin
Ahmed Hassan El-Ghorab1, Muhammad Nauman, Faqir Muhammad Anjum
1National Institute of Food Science and Technology, University of Agriculture, Faisalabad, Pakistan.
Abstract:
Spices are the building blocks of flavor in foods. This research work was focused on two important spices, i.e., ginger and cumin. Ginger and cumin both are recognized for their antioxidant properties. So, this study was designed to evaluate the chemical composition and antioxidant activity of ginger (Zingiber officinale) and cumin (Cuminum cyminum). The highest yield for volatile oil was obtained by the cumin sample, which was 2.52 +/- 0.11%, while the fresh ginger showed the lowest yield (0.31 +/- 0.08%). The analysis of volatile oils of fresh and dried ginger showed camphene, p-cineole, alpha-terpineol, zingiberene and pentadecanoic acid as major components, while the major components in cumin volatile oil were cuminal, gamma-terpinene and pinocarveol. In nonvolatile extracts the highest yield was obtained by the methanol extract of cumin (4.08 +/- 0.17% w/w), while the n-hexane extract of fresh ginger showed the lowest yield (0.52 +/- 0.03% w/w). Maximum total phenolic contents were observed in the methanol extract of fresh ginger (95.2 mg/g dry extract) followed by the hexane extract of fresh ginger (87.5 mg/g dry extract). The hexane extract of cumin showed the lowest total phenolic content (10.6 mg/g dry extract). The DPPH method showed the highest antioxidant activity for cumin essential oil (85.44 +/- 0.50%) followed by dried ginger essential oil (83.87 +/- 0.50%) and fresh ginger essential oil (83.03 +/- 0.54%). The FRAP of essential oils showed almost comparative results with DPPH. Cumin essential oil was found best in reducing Fe(3+) ions, followed by dried and fresh ginger. Our results suggest that both ginger and cumin can be used as potential sources of natural antioxidants in foods.
