**2. Description of ginger**

*Z. officinale* belongs to the Zingiberaceae plant family, which includes 1300 species and 49 genera, with 80–90 Zingiber species. It is native to East and Southern Asia. Its common name, Zingiber, derives from the Greek word zingiberis from the Sanskrit word singabera, which means "spice." The Latin word, Zingiber, means "horn-shaped," and refers to the roots' antler-like appearance. Ginger is a weedy perennial herbaceous plant that grows to a height of 2 meters and thrives in humid environment [9]. Some of the names given to ginger are Zenzero in Italian, Jeung or Sang Keong in Chinese, Aliah in Indonesia, Adrack in Urdu, Gember in Dutch, Jengibre in Spanish, Ingwar in German, and Gingembre in French [10]. Ginger was one of the first eastern spices introduced to Europe, and it is still in high demand today [10]. Zingiberaceae species typically have thickened rhizomes with secretory cells producing essential oil [11].

Ginger is traded in three basic forms - green (fresh), pickled or preserved and dry. Only dry ginger (whole, peeled, or sliced) is considered a spice; green or fresh ginger is primarily used as a vegetable, while pickled or preserved ginger is primarily used in the Chinese and Japanese culinary industries. In addition, ginger oil and oleoresins are also available for purchase. Despite the fact that ginger is grown in many countries, India and China are the top two exporters of dry ginger, followed by Nigeria, Sierra Leone, Australia, Fiji, Bangladesh, Jamaica, Nepal and Indonesia.

**Figure 1.** *Structure of 8-gingerol, 6-gingerol, 6-shogaol and 10-gingerol [14].*
