Ginger Beer: An Overview of Health Beneﬁts and Recent Developments

: Since time immemorial, ginger has been widely used as a food spice, providing aromatic odor and pungent taste, and as a medicinal plant, with various therapeutic e ﬀ ects such as antioxidant, anti-inﬂammatory, and analgesic, among others. It has long been an integral constituent of most herbal medicines in Africa, China and India. Its medicinal properties are largely attributed to its outstanding amount of phenolics which include gingerols, paradols, zingerones, and many others. With consumer preference gradually and remarkably shifting from high-calorie towards low-calorie and functional beverages, the demand for ginger beer is ﬂourishing at a faster rate. Currently, the ginger beer market is dominated by the United States. The demand for ginger beer is, however, debilitated by using artiﬁcial ingredients. Nonetheless, the use of natural ginger extract enriches beer with putative bioactive phytoconstituents such as shagaol, gingerone, zingerone, ginger ﬂavonoids and essential oils, as well as essential nutritional components including proteins, vitamins and minerals, to promote general wellbeing of consumer. This paper presents an overview of the phytoconstituents of ginger as well as the overall biological activities they confer to the consumer. In addition, the market trend as well as the production technology of ginger beer using natural ginger extract is described here. nerolidol (2.0%) and α -phellandrene(1.0%) weredetected in dried ginger. Similarly, Yang, etal. compared threedi ﬀ erent extraction techniques including headspace solid-phase microextraction (HS-SPME), petrol ether extraction (PEE) and steam distillation extraction (SDE) for gas chromatography-mass spectrometry (GC-MS) of volatile constituents from ginger. The results revealed camphene (1.1%), myrcene (0.2%) β -phellandrene (3.3%), curcumene (4.9%), zingiberene (53.1%), farnesene (8.6%), β -bisabolene (6.0%), and β -sesquiphellandrene (13.0%) as the major volatiles detected by HS-SPME-GCMS, whereas camphene (3.0%), myrcene (0.6%), β -phellandrene (9.1%), curcumene (4.7%), zingiberene (39.0%), farnesene (7.6%), β -bisabolene (5.9%), and β -sesquiphellandrene (13.0%) were VOCs identiﬁed by PEE-GCMS. With regard to SDE-GCMS the VOCs reported were camphene (5.7%), myrcene (1.0%), β -phellandrene (15.1%), cineole (1.7%), (E)-citral (1.1%), curcumene (4.5%), zingiberene (35.1%), farnesene (6.5%), β -bisabolene (5.2%), and β -sesquiphellandrene (10.4%). The major VOCs reported in ginger oil are camphene, p-cineole, geranyl isobutyrate,


Introduction
Prehistorically, ginger was used as a medicinal plant which is classified under the Zingiberaceae family and scientifically known as Zingiber officinale Roscoe, native to Asia. It is a perennial plant with yellow flowers, pseudo-stem and tuberous rhizomes called ginger or ginger root. Ginger rhizome is utilized due to its aromatic odor and pungent taste [1]. Apart from its role as food aroma or spicy, other therapeutic values such as antimicrobial, anti-parasitic, antioxidant, anti-inflammatory, analgesic, aphrodisiac, anticancer, hepato-protective, digestive aid, immune stimulating properties etc. have been associated to ginger [2]. Ginger is composed of carbohydrates, lipids, water, fibers, proteins and minerals. For centuries, ginger has been the fundamental part of most traditional herbal medicines in Africa, China and India for managing/treating aliments such as headaches, colds, osteoarthritis, muscle pains, nervous diseases, gingivitis, toothache and asthma [3]. The health benefits associated with ginger are ascribed to its outstanding amount of various phenolics compounds which include gingerols, paradols, shogoals, and zingerones [4], as well as 3-dihydroshogaols, dihydroparadols, acetylated gingerol derivatives, gingerdiols, diaryl heptanoids and ferollic acid derivates.
It is speculated that ginger beer first originated from England in the mid-1700s and was highly patronized due to its low alcohol content. It was a common drink available even for children and considered safer than water which was frequently contaminated [5]. Moreover, a recent document

Biological Activities
Results of extensive studies give much information about the bioactive compounds, biological activity (i.e., antioxidant, anticancer, antidiabetic, and so on) as well the general health benefits of ginger [35]. Some of biological activities of are elaborated below:

Antioxidant Activity
Naturally, the mammalian system generates reactive oxygen species (ROS) such as superoxide, hydrogen peroxide, hydroxyl radical, hydroxyl ion, and nitric oxide as by-products during various reactions which involve the reduction in oxygen. Usually, cells actively eliminate some of these species, but at some point, these species overwhelmed the cell's ability, thus causing oxidative stress in various cells, tissues and organs leading to several diseases [4]. Studies have shown how plant extracts containing bioactive ingredients such as polyphenols, etc., act as antioxidants by donating hydrogen atoms or electrons to neutralize ROS [28]. Ginger rhizome is overwhelmed with antioxidants which aid to lessen lipid oxidation and diseases. The essential oils and oleoresins found in ginger displayed antioxidant activities which have been reported by various studies. 6-dehydroshogaol, 6-shogaol and 1-dehydro-6-gingerdione, present in ginger, were found to inhibit nitric oxide (NO) synthesis in activated macrophages. 6-shogaol exhibited potent antioxidant activity due to the presence of unsaturated ketone moiety [36,37]. Additionally, phenolic compounds in ginger have been reported to exhibit antioxidant activities on test subjects [37]. Aeschbach et al. [38] and Chang et al. [39] illustrated the antioxidant activity of ginger rhizome in the inhibition of lipid peroxidation by FeCl 3 with the ascorbate system and the inhibition of xanthine oxidation system, respectively. These systems are responsible for the release of ROS like superoxide anion [40]. In vitro and in vivo studies revealed that 6-shogaol rich extract from ginger enhanced the antioxidant defense mechanism by triggering the nuclear factor E2-related factor 2 (Nrf2). Interestingly, 95% of ethanolic extracts obtained at 80 • C showed better antioxidant response element pathway (ARE) reporter gene activity and Nrf2 expression in HepG2 cells than 95% ethanolic extracts obtained at room temperature [41]. Likewise, in vitro study (DPPH scavenging capacity assay) revealed that ethanol, methanol and aqueous extracts of ginger exhibit potent antioxidant activity with ethanolic extract being the most prominent (65.30 ± 2.74%) and aqueous extract being the least. The authors arrived at similar findings when they used Ferric reducing antioxidant potential (FRAP)-the maximum FRAP ability was exhibited in ethanolic extract (102.62 ± 4.28 µmol TE/g) as compared to methanolic (98.14 ± 3.3 µmol TE/g) and water extracts (94.86 ± 3.32 µmol TE/g) [30].

Anticancer Activity
The formation of cancer cells is a complex process triggered by physical, chemical, viral mechanisms, genomic and epidemic alterations which ultimately lead to the malignant conversion of a normal cell. The damage of macromolecular species like lipids, proteins, polysaccharides and nucleic acid leads to dysfunction of cellular metabolism which includes lipid peroxidation and induction of oxidative stress in healthy cells. This lipid peroxidation plays a vital role in carcinogenesis and may lead to the formation of several toxic products such as malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE). These products can attack cellular targets, thereby inducing carcinogenicity [42]. During carcinogenesis, cytokines are produced by the inflammatory cells, which promote the survival, growth, mutation, proliferation, and differentiation of tumor cells [43]. Habib et al. [43] studied the effect of ginger extract on cancer cells and found that the extract had a chemotherapeutic effect on infected cells. Similarly, a recent study has shown the chemopreventive effect of ginger against 7,12-dimethylbenz [a] anthracene-related skin tumors. Ginger anticancer properties are credited to 6-gingerol, 6-paradol, shogaols and zingerone constituents which inhibit cyclooxygenase and lipoxygenase activities, initiates apoptosis and elicits an antitumorigenic effect. Therefore, ginger has the potential of being used in cancer therapy to induce cell death in leukemic, skin, kidney, lung and pancreatic cancer cells [44]. Moreover, gingerol was potent in blocking cyclooxygenase-2 (COX-2) expression by inhibiting p38 MAPK-NF-κB (mitogen activated protein kinase-necrosis factor kappa B) signaling pathway [40,45]. Similarly, an in vitro study revealed that 6-Shogaol suppressed growth of ovarian cancer cells by inhibiting NF-kB activation as well as growth factor (VEGF) and IL-8 secretion [45,46]. A conventional anticancer drug β-elemene developed from ginger extract was effective in managing patients suffering from lung cancer [47]. In addition, ginger supplements boosted glutathione reductase (GR), glutathione Fermentation 2020, 6, 102 6 of 23 peroxidase (GPX), and glutathione -S-transferase (GST) which led to the inhibition of colon cancer [44]. Table 4 summarizes some potential anticancer mechanism of ginger and its components reported in various studies.

Antidiabetic Activity
Diabetes is a chronic disease marked by high levels of blood glucose or sugar (hyperglycemia) [58]. By numerous biochemical and physiological control mechanisms, the body maintains a constant blood glucose concentration within homeostatic state. A hormone called insulin synthesized in the pancreas (specifically by the β cells) regulates carbohydrate metabolism in the body and maintains the flow of glucose across cell membranes [59]. Diabetes occurs either by less or no production of insulin by the β cells (type 1) or as a result of insulin resistance (where insulin is synthesized but not functional due to a diminished response of tissues to insulin-type 2). Pregnancy, surgery, medication, hormonal dysfunction etc. may alter the level of blood glucose [60]. Numerous studies have examined the efficacy of ginger and its extracts in hyperglycemia control in both in vivo and in vitro trials. Li et al. outlined the various mechanisms involved in the antidiabetic activity of Zingiber officinale:

1.
Ginger inhibits prominent enzymes associated with hyperglycemia in the carbohydrate metabolism (that is α-amylase and α-glucosidase).

2.
Additionally, ginger enhances insulin release by β cells and sensitivity by promoting glucose clearances in insulin responsive peripheral tissues to aid in maintaining blood glucose homeostasis.
Other reports [62,63] showed that ginger extract exerted small but relevant blood glucose-lowering potentials in diabetic and non-diabetic animals. Oboh et al. [63] speculated that ginger is a good source of water-extractible phytochemical which can inhibit enzymes linked to type 2 diabetes. In an in vivo study using a streptozotocin (STZ)-induced type I diabetes, Akhani et al. [64] showed that ginger extract significantly decreases glucose levels and increase insulin in STZ-diabetic rats. Also, treatment decreased serum cholesterol, triglyceride and blood pressure in diabetic rats [64]. Orally feeding STZ-induced diabetic mice with ethanolic extract of ginger (200 mg/kg) for 20 days showed antihyperglycaemic effect (p < 0.01) on diabetic rats. In addition, treatment lowered the serum's total cholesterol, triglycerides and increased the high-density lipoprotein (HDL)-cholesterol levels compared with pathogenic diabetic rats (p < 0.01). Liver and pancreas thiobarbituric acid reactive substances (TBARS) values (p < 0.01) were also lowered in the treated group compared to the pathogenic diabetic rats. The results were comparable to the group treated with the reference drugs gliclazide (25 mg/kg, orally) [65]. Similarly, a significant (p < 0.05) decrease occurred in the serum glucose level of alloxan-induced diabetic rats after treatment with ginger extract (500 mg/kg BW). However, the blood glucose level of the control and diabetic rats remained unaltered [59]. Chukwudike and Mercy [66] documented a promising result where doses of 250, 500 and 1000 mg/kg b.w ginger extracts significantly lowered blood glucose levels to 120.83 ± 2.1, 89.8 ± 8.2, 90.5 ± 4.2 mg/dL in diabetes-induced (alloxan monohydrate solution; 150 mg/dL, intraperitoneally) male Wistar rats, respectively, compared to the control 168.2 ± 1.8 mg/dL.
Treating streptozotocin-induced diabetic (45 mg/kg body) Wistar Albino rats weighing between 150 and 200 g with either green tea or ginger extract and a combination further showed the sugar lowering potential of ginger. Green tea and ginger extract significantly decreased blood glucose from 176.5 ± 20, 210 ± 8.5 to 80 ± and 5.5 82 ± 14.7 mg/dL, respectively, whereas their combination exerted the highest hypoglycemic from 220 ± 8.5 to 59.1 ± 11.7 mg/dL when compared to diabetic rats (from 200.5 ± 25.5 to 187.3 ± 37.6) [67].

Anti-Hypercholesteremic Effect
Hypercholesteremia is a condition where there is a rise in the level of cholesterol and low-density lipoprotein (LDL) in the plasma and is linked with mutation of genes such as encoding low-density lipoprotein receptor (LDLR), encoding apolipoprotein B (APOB), etc. [71]. It is inherited genetically as an autosomal dominant syndrome which can cause xanthomas, arcus corneae, and premature coronary heart disease [72]. A significant reduction in total cholesterol and low-density lipoprotein (LDL-C) was reported after administering ginger supplement to patients compared to the placebo group [69]. Additionally, oral administration of aqueous ginger infusion (100,200 and 400 mg/kg) to hypercholesterolaemia-induced rats showed a significant reduction in serum cholesterol by 63.72, 60.78, 59.41% and by 70.85, 69.41, 77.46% after 2 and 4 weeks of treatment, respectively, compared to the positive control (atorvastatin at dose of 0.18 mg/kg) by 51.04 and 69.04%. With respect to serum triglyceride levels, the same dose mentioned above manifested a significant reduction by 34.01, 73.6, and 74.76% and by 42.53, 84.28, and 90.49%, respectively, after 2 and 4 weeks of treatment compared to the positive control which also exhibited a significant reduction by 43.41 and 76.79% after 2 and 4 weeks of treatment, respectively [73]. Elevated serum cholesterol level in hypercholesterolemia-induced rabbits, by feeding them 0.5 g cholesterol in 5 mL hydrogenated vegetable oil, decreases significantly by administering ethanolic ginger extract (200 mg:kg, p.o.). The reduction was similar when reference drugs gemfibrozil was used. In addition, serum triglycerides, very low-density lipoproteins (VLDL-C), and serum phospholipids decreased significantly, but not high-density lipoprotein (HDL-C). The author speculated that phytochemicals in the extracts may have triggered transformation of cholesterol to bile acids [74]. Thomson et al. [75] also reported a significant decrease in serum prosta-glandin-E2 (PGE2) when hypercholesterolemia rats were orally fed with aqueous extract of ginger (50 mg/kg). The higher dose (500 mg/kg) was potent in lowering PGE2 and thromboxane-B2 (TXB2). The lower dose had no effect on TXB2 synthesis. Neither dose was sufficient to alter the serum's triglyceride levels [75].

Anti-Inflammatory Effect
Sharma et al. [76] examined the anti-inflammatory activity of ginger oil (33 mg/kg) by injecting a suspension of dead mycobacterium tuberculosis to induce severe arthritis in male Srague-Dawley rats. The oil significantly reduced the paw and joint swelling compared to the control and group treated with eugenol [76]. Similarly, ginger essential oils (28 mg/kg/d) suppressed chronic joint inflammation by 38% in streptococcal cell wall (SCW)-induced arthritis in a female Lewis rat [77]. Yong-liang and colleagues [78] also found that ginger oil (0.25-1.0 g/kg) produced dose-dependent significant repression of the carrageenan-induced paw edema, adjuvant arthritis, and inflammatory mediators-induced vascular permeability in Male Sprague-Dawley rats (p < 0.05, 0.001). However, aspirin (0.5 g/kg) exhibited efficient anti-inflammatory activity compared to the ginger oil (0.5 g/kg) [78]. Table 5 shows extensive studies on anti-inflammatory potentials of ginger bioactive compounds.

Toxicological Aspect and Health Concern
Ginger rhizome and their products are Generally Recognized as Safe (GRAS) [85]. Chukwudike and Mercy [66] reported that administering ginger extract at a dose from 250 to 1000 mg/kg body weight per oris did not manifest any concerns, thus no mortality was recorded. During the 28 days of the evaluation, all the rats were active, alive and healthy [66]. Similarly, Wilkinson orally fed pregnant Sprague-Dawley rats with either 15 g/L, 20 g/L or 50 g/L aqueous extract of ginger rhizomes. The author observed no signs of toxicity in treated rats. In addition, the treated group showed similar total weight gain before, during, or after treatment as the control. Nonetheless, though ginger tea may increase early embryo loss it paradoxically increases growth in surviving fetuses [86]. Thus, the amount of ginger or their product consumed must be taken with caution, especially by pregnant women. Weidner and Sigwart [87] examined the teratogenicity of EV.EXT 33 (a patented ginger extract) at different concentrations (100, 333, and 1000 mg/kg) on Wistar SPF rats (Mol. Wist). The results reveled that EV.EXT 33 exert no toxic effect on all the parameters examined even under a daily dose of up to 1000 mg/kg body weight [87]. Rong et al. [88] also carried out an acute toxicity study of ginger on rats and the results revealed oral administration of ginger powder up to 2000 mg/kg did not manifest any mortalities or abnormalities in general conditions, behavior, growth, food and water consumption of the treated rats. Evidently, hematology and blood biochemistry of treated rats were not altered except a decrease in LDH in male rats which were similar to the control group. Necropsy analysis showed that all of the examined organs except the testes of rats treated by 2000 mg/kg of ginger are normal [88]. Acute toxicity analysis of fixed (0.02, 0.04, 0.06, 0.08 and 0.1 mL/kg body weight) and essential or volatile (0.2, 0.4, 0.6, 0.8, 1.0, 2.0, 4, 6, 8 and 10 mL/kg body weight) ginger oils revealed that rats treated with 0.2 mL/kg fixed oil died. Similarly, six out of the ten treated (with essential oils) rats survived. The authors found that ginger oil at a concentration of 0.002 mL/kg body weight altered the liver tests, AST and alkaline phosphatase (ALP) compared to the control (fed with corn oil) [89].
Jeena et al. [90] reported that treatment of ginger oil at doses of 100, 250, and 500 mg/kg per day for 13 weeks had no toxicity effects on rats. The no-observed-adverse-effect level (NOAEL) proposed was 500 mg/kg per day [90]. Different food spices which include ginger, clove, black pepper, red pepper in combination with lemon grass supplementation and a control (lemon grass) were fed to rats at different concentration. The results showed weight gain with regards to rats fed with ginger among other spices. A contrast group treated with the combination of all the spices (ginger, clove, black pepper, red pepper, lemon grass) lost weight. Histological analysis revealed that liver biomarkers were altered in the group treated with lemon grass in combination with all spices, clove, ginger black pepper and red pepper compared to the control group [91]. Thus, ginger and other food spices may be toxic at certain a concentration.

Production Technology of Ginger Beer
Ginger beer could be either brewed by the traditional fermentation using the native microflora (probiotic) already present in ginger or by a controlled fermentation which involves the pitching Saccharomyces cerevisiae [92]. The natural fermentation produces beverages with inconsistent qualities (i.e., aroma, foaminess, etc.). The quality of beer has always been attributed to the yeast, malt, and fermentation conditions among others.
An amount of milled malt is mixed with hot water (67 • C) in a mash tun for 60 min. The mash is stirred at a predetermined time to enhance the conversion of starch into fermentable sugars. The temperature is subsequently increased to 75 • C for 10 min to inactivate the malt enzymes (i.e., amylase, proteases, etc.). The mash is then allowed to cool and filtered to obtained wort. The spent grains could either be used to feed animals or as raw material for extracting valuable bioactive compounds of human health benefits. The wort is boiled for 45 min, where bitter hops are added at the beginning of the boiling process. The wort is clarified by a whirlpool and allowed to cool down to 15 • C, the trub discarded [7,11,[93][94][95][96]. The wort is diluted to lower the gravity (Plato) when NABLAB is to be brewed. However, earlier researchers brewed beer with fruits [7][8][9] and reported high alcohol content (% ABV), hence the reason to lower the wort gravity. Ginger extract could be obtained by sorting and cleaning raw ginger (finely chopped) before extracting juice, either by boiling or pressing. The extract is added into the low-density wort, aerated with the aid of aeration stones or other means. A certain concentration of yeast (cells/mL) is pitched and fermentation carried out at 20 • C for limited days. The fermentation trub is discarded and the green ginger beer transferred into a new fermenter with a small amount of sugar for secondary fermentation (conditioning) (Figure 1).
Ginger extract could be added into the green beer during conditioning [97]. The secondary fermentation could last for a week at a lower temperature. The product is then ready for bottling and consumption. Liu and colleagues developed unfermented ginger beverages by mixing ginger juice (14.57 g), sugar (6.05 g), and ginger oil (0.0034 g) in 100 g pure water. The beverage was divided into four parts for treatments; 1. without sterilization; 2. sterilized by Ultrahigh-temperature sterilization (UHT); 3. atmospheric pressure sterilization (AP); and 4. high-pressure sterilization (HP) and denoted by G1, G2, G3 and G4, respectively [98]. However, with regards to fermented ginger beer, sterilization will not be necessary since it is a product of fermentation and overwhelmed with acids in addition to alcohols which inhibits spoilage microorganisms.
The majority of ginger beers in the market are produced from carbonated water, sugar, ginger extract/syrup/flavors, citric acid, yeast, preservatives and ascorbic acid. obtained by sorting and cleaning raw ginger (finely chopped) before extracting juice, either by boiling or pressing. The extract is added into the low-density wort, aerated with the aid of aeration stones or other means. A certain concentration of yeast (cells/mL) is pitched and fermentation carried out at 20 °C for limited days. The fermentation trub is discarded and the green ginger beer transferred into a new fermenter with a small amount of sugar for secondary fermentation (conditioning) (Figure 1).

Composition of Volatile Organic Compounds (VOCs) in Ginger
The volatile compounds in ginger are numerous and most are yet to be classified. Gingerol is a common compound in ginger, which is known to be in the same family as capsaicin in chilies, and it is responsible for the characteristic burning taste of the fresh ginger. Gingerol is a yellow liquid which has a low boiling point and transformed to Shogaol upon the application of heat. The pungency in dried ginger is as a result of shogaols, zingerone, gingerone, etc [99]. Though they are present in fresh ginger, their concentration is meager compared to that in dried ginger. Zingerone is less pungent but exerts a sweet-spicy aroma in ginger. In addition, sesquiterpenoids, curcumin and diasyleheptanoids are also present in smaller amounts [19].

Volatile Characteristics of Ginger Beverages
A total of 53 VOCs was identified in unfermented ginger beverage by solid phase microextraction (SPME) GC-MS. Among the VOCs identified, 25 were alcohols, 16 terpenes, 9 aldehydes, 5 ketones, 3 esters and 1 acid (Table 6) [98]. According to Ding et al., alcohols and aldehydes significantly influenced ginger aroma, and imparts fruity, floral, gingery, and sweet notes [103], therefore could elicit similar aroma characteristics to ginger beer. Alcohol is a precursor for ester synthesis in addition to acyl-coenzyme A and alcohol acyltransferases. Esters are sweet fruity-flowery, candy and perfume-like aromas, synthesized in trace quantities, yet are the most important flavor in beverages [104][105][106]. However, few esters were detected [98] because the formulated beverage was not fermented, hence the necessary enzymes (from yeast) required to initiate ester synthesis were absent. Pinho et al. reported that volatile acids impart vinegary, mushy, and fatty smells to beverages [107]. Surprisingly, only one acid was detected [98]. According to the literature [108][109][110], terpenes are mostly originated from the resins and essential oils found in the bright yellow lupulin glands of flowering plants (i.e., hops). Richter et al. reported that terpenes, despite accounting for a small percentage of the overall sensory profile, played an important role in the flavor and aroma in beer [111]. Similarly, using different methods, namely headspace sorptive extraction (HSSE), stir bar sorptive extraction (SBSE), HS-SPME and solvent-assisted flavor evaporation (SAFE), 16 terpenes were detected in beer [112]. These VOCs are typically present in conventional beers [7,93] and other food condiments [113] and impart a pungent aroma to the products. According to a recent study, these flavors influence consumers' acceptance and patronage of products [95]. However, beer flavor is the result of the interaction between many chemical compounds and their perception of taste and olfactory receptors [114]. Analysis of variance of sensory evaluation of unfermented ginger beverage showed a significant difference between samples (p < 0.001) with regard to attributes (fruity, gingery, piquant, and cooked) indicating that the processing method influenced flavor intensities (Table 7). With regard to the fruity note, G1 was significantly different compared to G2, G3, and G4. Notably, no significant difference was register for floral note. However, G1, G3 and G4 were statistically different from G2 in term of the gingery note. All samples differed with regard to cooked notes [98] which may be attributed to the sterilization methods used. AP and HP led to significant loss of VOCs [98] which goes to support previous results [103]. On the other hand, the control and UHT samples retained most aroma from ginger. In terms of taste, specifically Piquant note, G1 and G3 were statistically different from G3 and G4. Surprisingly, treatment elicited no significant effects on sweet and sour notes of samples [98].  Tozetto and colleagues reported the sensory acceptability index values of beer supplemented with ginger juice as 95%, 90%, 90%, 86%, 96% and 92% for color, taste, aroma, bitterness, appearance and global acceptance, respectively [11]. Similarly, Husain et al. assessed the sensory attributes of "Sarabba Instan" a traditional "Bugis-Makassar" beverage produced from "Enrekang" or "Sunti" or "Emprit" ginger. The level of preference for the products was as follows for lecturers (90.91%), staff (85.72%) and students (66.68%) [115].

Study Limitations
In vitro (Caco-2 cells) and in vivo (animal studies) are efficient methods of assessing the efficacy of bioactive ingredients extracted from plants (i.e., ginger). The merits of these methods include: 1. low cost; 2. less time require to conduct an experiment; 3. rapid physiological response; 4. easy identification of biomarkers; etc. On the other hand, these methods are labor intensive and results obtained do not usually reflect the physiological and metabolic response of the human system. For instance, the biological and pharmacological effects of ginger extracts are largely reported based on in vitro and in vivo (animal studies, i.e., rats) studies which may not represent the efficacy it has on humans and their diseases. Dias et al. emphasized the relevance of in vitro and in vivo studies to understanding the effects of bioactive compounds, but also caution on the interpretation of such results, especially when human studies are not extensively involved. They further recommended the combination of in vitro, animal and human studies as an effective method of elucidating the effects of active compounds on test subjects [130]. Similar concerns were raised by Roberts and colleagues where they indicated that in vitro methods such as microtitre plate assays and flow cells do not accurately represent in vivo conditions [131]. Therefore, extensive human trial is needed to further confirm the health benefits that the consumer may derive consuming ginger beer.

Conclusions
Ginger is a widely used food spice, famous for its distinctive aromatic odor. Traditionally, it is acknowledged as a medicinal plant with various biological and pharmacological activities including antioxidant, anti-inflammatory, antimicrobial and analgesic activities and is used to manage ailments such as cold, headaches, toothaches etc. Its use as a medicinal plant is corroborated by extensive scientific studies which show that it has, in addition, anticancer, antidiabetic and anti-hypercholesteremic activities. The medicinal properties of ginger are directly linked to its phytoconstituents which include shogaols, zingerones, gingerols, gingerenones, etc. It is also rich in nutritive components, i.e., carbohydrates, proteins, vitamins and minerals. Following the ever-increasing consumer preference for healthy drinks and beverages, the market for ginger beer has blossomed. To further satisfy consumers' demand, products with fewer chemical additives and the use of natural ginger extract to produce ginger beer, as described in this text, is more desirable. Moreover, the use of natural ginger extract would enrich resulting beer with its bioactive and nutritional constituents which consequently could promote the general wellbeing of consumers.