title: Levels of essential and non-essential metals in ginger (Zingiber officinale) cultivated in Ethiopia.
abstract: BACKGROUND
  Ginger (Zingiber officinale Roscoe) is a common condiment for various foods and beverages and widely used worldwide as a spice. Its extracts are used extensively in the food, beverage, and confectionary industries in the production of products such as marmalade, pickles, chutney, ginger beer, ginger wine, liquors, biscuits, and other bakery products. In Ethiopia, it is among the important spices used in every kitchen to flavor stew, tea, bread and local alcoholic drinks. It is also chiefly used medicinally for indigestion, stomachache, malaria, fevers, common cold, and motion sickness. The literature survey revealed that there is no study conducted on the determination of metals in ginger cultivated in Ethiopia. Hence it is worthwhile to determine the levels of essential and non-essential metals in ginger cultivated in Ethiopia.
  
  
  METHODS
  The levels of essential (Ca, Mg, Fe, Zn, Cu, Co, Cr, Mn, and Ni) and non-essential (Cd and Pb) metals in ginger (Zingiber officinale Roscoe) cultivated in four different regions of Ethiopia and the soil where it was grown were determined by flame atomic absorption spectrometry. 0.5 g of oven dried ginger and soil samples were digested using 3 mL of HNO3 and 1 mL of HClO4 at 210°C for 3 h and a mixture of 6 mL aqua-regia and 1.5 mL H2O2 at 270°C for 3 h, respectively.
  
  
  RESULTS
  The mean metal concentration (μg/g dry weight basis) ranged in the ginger and soil samples, respectively, were: Ca (2000-2540, 1770-3580), Mg (2700-4090, 1460-2440), Fe (41.8-89.0, 21700-46900), Zn (38.5-55.2, 255-412), Cu (1.1-4.8, 3.80-33.9), Co (2.0-7.6, 48.5-159), Cr (6.0-10.8, 110-163), Mn (184-401, 1760-6470), Ni (5.6-8.4, 14.1-79.3) and Cd (0.38-0.97, 0.24-1.1). The toxic metal Pb was not detected in both the ginger and soil samples.
  
  
  CONCLUSIONS
  There was good correlation between some metals in ginger and soil samples while poor correlation between other metals (Fe, Ni, Cu). This study revealed that Ethiopian gingers are good source of essential metals and free from toxic metal Pb while containing negligible amount of Cd.
authors: Department of Chemistry, College of Natural Sciences, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia.
authors: Yohannes
authors: Y
authors: Wagesho
authors: Department of Chemistry, College of Natural Sciences, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia.
authors: Bhagwan Singh
authors: BS
authors: Chandravanshi
keywords: Essential metals; Ethiopia; Ginger; Non-essential metals; Soil; Zingiber officinale