**2. Uses of ginger essential oil**

### **2.1 As spice**

Globally, ginger is used as spice in foods in order to add flavour and nutrient to food. In many cultures, it is used in the making of several dishes, adding to them a hot and distinctive spicy flavour [24]. It may be used fresh or in the dried form and is an essential ingredient of most spice blends [25]. The inclusion of ginger oil in food has been demonstrated to improve the quality and flavour of the food [26].

### **2.2 As a herbal drug**

In ayurveda, Chinese or Tibb-Unani traditional medicine, ginger essential oil has been extensively employed [5, 27]. Indeed, spices from the family Zingiberacea, including ginger, are well utilised in traditional medicine for the management and treatment of several conditions and diseases such as stomach ailments and indigestion, respiratory disorders, infections and anxiety [3, 11]. In Iranian traditional medicine, it is believed that traditional medicine is more potent when formulated with ginger oil, as against when ginger rhizome is used in its formulation [8]. In Indian traditional medicine, it is used as stop excessive blood clotting while in Arabian traditional medicine, it is used as an aphrodisiac [28].

### **2.3 Antimicrobial agent**

The antimicrobial activity of ginger essential oil has been linked with the presence of abundant oxygenated compounds present [5]. At 12% V/V, it was found to be effective in reducing *Listeria monocytogenes* burden in food [1]. Its antifungal activity has also been demonstrated by [29]. Ginger essential oil may therefore act as a

preservative agent in food and its inclusion or marination into food may hence enhance the shelf life of food [26]. This has been found to be better achieved with the volatile oil encapsulated in protein fibres [30], thus enabling a gradual and controlled release of the oil into the food item, enhancement of solubility, as well as prevention of alteration in the food taste and thermal destruction of the oil [31].
