Zingiber officinale Roscoe. (ginger) is a widely distributed plant with a long history of cultivation and consumption. Ginger can be used as a spice, condiment, food, nutrition, and as an herb. Significantly, the polysaccharides extracted from ginger show surprising and satisfactory biological activity, which explains the various benefits of ginger on human health, including anti-influenza, anti-colitis, anti-tussive, anti-oxidant, anti-tumor effects.
1. Introduction
Ginger is a perennial herb of the Zingiberaceae family, scientifically named
Zingiber officinale Roscoe.
[1,2][1][2]. As early as the 18th century, Europeans began using ginger to make beer, candy, bread, biscuits, and so on. It is also an indispensable seasoning in Japanese cuisine, Korean food, and Chinese food
[3,4][3][4]. Therefore, it is a widely distributed plant with a long cultivation history. It is now mainly cultivated and used in India, Nigeria, China, Burma, Indonesia, Australia, Japan, Sri Lanka, Germany, Greece, Arabia, and other countries. Among them, India, Nigeria, and China are the main producers of ginger, according to the Food and Agriculture Organization of the United Nations statistical database (FAO) in 2022
[5,6][5][6]. As an important plant with economic, ornamental, and even edible and medicinal values, it has attracted attention from multiple scientific fields. It is a rich source of nutrients such as protein, vitamins, minerals, fat, and crude fiber
[7,8,9][7][8][9]. It has attracted increasing interest from nutrition researchers and health-conscious consumers.
In its long history of application and consumption, ginger has been fully utilized and deeply developed as a nourishing food and traditional oriental medicine
[10,11,12][10][11][12]. As a “medicinal food homology” plant, ginger and its active ingredients are not only used as delicious food, but also as effective empirical medicine
[13,14][13][14]. Ginger can be used as tea or health drinks and is traditionally used to treat diseases such as colds, vomiting, and fatigue
[15,16,17][15][16][17]. In Africa, ginger essential oil is commonly used to relax muscles or treat muscle and joint pain, swelling, and inflammation. It can also be dripped in water and gargled to relieve toothache. In addition, ginger is an important part of Ayurveda preparation “Trikatu”. Trikatu can be used in combination with other drugs to treat asthma, bronchitis, dysentery, fever, and intestinal infections
[18]. Due to its health benefits such as enhancing immunity and promoting energy metabolism, ginger is widely used as a restorative supplement or medicinal food in folk
[19,20][19][20]. Officially, the Chinese Pharmacopoeia 2020 version includes three related products, including Shengjiang (fresh ginger), Ganjiang (dried ginger), and Paojiang (fried ginger) (
Figure 1). Therefore, the nutritional and medicinal value of ginger has been widely recognized, meeting the needs of consumers for a healthy diet, nutritional intake, and dietary treatment.
Figure 1.
A plant image of
Zingiber officinale
Roscoe. (ginger). (
a
) Shengjiang (fresh ginger); (
b
) Ganjiang (dried ginger); (
c
) Paojiang (fried ginger).
It is widely believed that ginger can be used as a nutritious vegetable or natural functional food. As ginger contains important phytochemicals and biologically active ingredients, such as volatile oil, curcumin, flavonoids, and polysaccharides, it is increasingly popular in daily diet
[21,22,23,24][21][22][23][24]. Gingerol, as an important source of ginger’s pungent taste, endows ginger with a unique spicy taste and is also one of the main active ingredients in ginger, which is often the focus of researchers
[25,26,27][25][26][27]. However, the macromolecular compound polysaccharides obtained from ginger exhibit surprising and satisfactory biological activities, which may explain their various benefits to human health, including anti-influenza, anti-colitis, anti-tussive, anti-oxidant, and anti-tumor effects
[28,29][28][29]. Currently, various polysaccharides have been extracted from ginger through different extraction and purification methods. Due to the diversity of the chemical structure of polysaccharides in ginger, as well as their different physicochemical properties and biological activities, it has attracted more and more research interest. Ginger polysaccharides are considered safe and non-toxic. At the same time, they have a variety of beneficial functions for the body, and have a good development prospect in food, cosmetics, medicine, and other industries
[30,31][30][31].
2. Extraction and Purification Methods of Ginger Polysaccharides
2.1. Extraction Methods of Ginger Polysaccharides
Effective extraction and purification of ginger polysaccharides is the main premise for studying the structures and biological activities of polysaccharides. In order to maximize the extraction efficiency of bioactive macromolecular polysaccharides from ginger, researchers have carried out a series of explorations into various extraction strategies, including the traditional extraction method of solvent extraction method (SEE), the novel extraction methods of enzyme-assisted extraction (EAE), and ultrasonic-assisted extraction (UAE). The specific information of various extraction methods is summarized in
Table 1.
Table 1.
A summary of ginger polysaccharides extraction methods.
Polysaccharide Fraction |
Extraction Methods |
Time (min) |
Temperature (°C) |
Solid–Liquid Ratio (g/mL) |
Total Yield (%) |
Ref. |
Ginger polysaccharide (GPS) |
Complex-enzyme hydrolysis extraction |
60 min |
55 °C |
1:25 |
22.18% |
[45][32] |
Ginger pomace polysaccharides extracted by hot water (HW-GPPs) |
Hot water extraction |
120 min |
70 °C |
1:40 |
12.13 ± 1.15% |
[46][33] |
Ginger pomace polysaccharides extracted by ultrasonic–assisted (UA-GPPs) |
Ultrasonic assisted extraction |
17 min |
74 °C |
1:40 |
16.62 ± 1.82% |
[46][33] |
A neutral ginger polysaccharide fraction (NGP) |
Hot water extraction |
Rhizome |
Ginger polysaccharides UGP2 |
1296 kDa |
N/A |
[ |
54 |
] |
[ |
43 |
] |