What Active Ingredient Is in Ginger Extract Powder?

Ginger (Zingiber officinale Roscoe) is a perennial herb in the family Zingiberaceae. It is one of the world's most important condiments and is cultivated in Asia, Africa and Latin America. China is one of the world's largest exporters of ginger, and it is now widely used in the pharmaceutical, food and spice industries. Research into the functional ingredients of ginger has long been a focus of study for relevant academics. After nearly a century of research, people have a relatively clear understanding of the functional ingredients of ginger.

1 Functional ingredients of ginger extract powder

The active ingredients in ginger extract powder are complex. Research results show that the sensory properties and antioxidant properties of ginger are mainly attributed to three types of components: the aroma and some of the flavour of ginger are determined by its volatile oil – essential oil; the characteristic spicy flavour of ginger mainly comes from the non-volatile oil – gingerol; and diphenylheptane. It can be seen that cellulose, volatile oil and gingerol are the traditional Chinese medicine indicators for measuring the processing characteristics of ginger, while the amount of ginger essential oil and gingerol is the determining factor in the quality of ginger processing products [1].

1. 1 Ginger essential oil

Essential oil refers to the volatile oil extracted from the ginger rhizome by steam distillation. It contains almost no high boiling point components and has a strong aromatic odor. Essential oil is a transparent, light yellow to orange liquid with a complex mixture of components. Its refractive index is 1.488 0~1.494 0 and optical rotation is 28. ~45. The density is 0.871~0.882. The physical parameters of ginger essential oil obtained by steam distillation of ginger with different storage periods are roughly the same.

The first study on the composition of ginger essential oil was reported in the late 19th century. In 1900, Soden and Rojahn first isolated the important sesquiterpene hydrocarbon component α-zingerone.

important sesquiterpene hydrocarbon component, α-zingiberene. In 1950, Eschenmoser and Schintz elucidated the structure of this compound.

In 1952, Eschenmoser and Schintz elucidated the structure of this compound. In 1952, Mills and in 1954 Agrigoni and Jeger identified its three stereochemical isomers. By 1980, 60 components had been reported. Today, more than 100 components have been found in ginger oil[2]. The main components are sesquiterpene hydrocarbons 50% to 60%, oxidized sesquiterpenes 17%, and the rest mainly monoterpene hydrocarbons and oxidized monoterpenes.

1.2 Zingerone

Ginger oleoresin is a viscous semi-fluid substance obtained by extracting the ginger rhizome with an (organic) solvent and then recovering the (organic) solvent. The main component is gingerol. The gingerol structure contains a 3-methoxy-4-hydroxyphenyl functional group. According to the different fatty chains attached to this functional group, gingerols can be divided into different types, such as gingerols (Gingerols), shogaols (Shogaols), zingerone (Zingerone), gingerdiones (Gingerdiones), gingerdiols (Gingerdiols), etc.

1.3 Diarylheptanoids

Diarylheptanoids are a general term for a class of compounds with 1,7-disubstituted phenyl groups and a heptane backbone as the parent structure. They can be divided into linear diarylheptanoids and cyclic diarylheptanoids. These compounds are mainly distributed in the rhizomes and flower buds of plants in the Zingiberaceae family, such as Zingiber officinale, Curcuma longa and Zingiber mioga. Kikuzaki et al. isolated 13 compounds in 1991, with numbers 1 to 6 and 11, 12, and 13 being the first new compounds to be isolated. and the antioxidant activity of these compounds was tested; in 1996, Kikuzaki et al. isolated five new cyclic diphenylheptane compounds from a dichloromethane extract of ginger [3].

1.4 Ginger protease

Ginger protease is a new plant protease discovered after papain and bromelain. It has great homology in structure and properties with the above proteases and is considered to be another new member of the papain family. Ginger protease-II can specifically hydrolyze peptides and proteins in which the P2 position is proline. This specificity for Pro makes ginger protease a very promising tool enzyme for protein sequencing and identification of stable structural domains in proteins.

2 Extraction method

2. 1 Extraction of ginger essential oil

The content and composition of essential oil in ginger varies greatly depending on the plant variety and growing region. Ginger oil is usually stored in the spaces between the angular cells of the rhizome, and is distributed both on the surface and inside the rhizome. However, the essential oil is more abundant in the epidermal tissue, so an important factor affecting the yield of essential oil is whether the ginger is peeled or not. In addition, before ginger oil is extracted, different drying treatments of ginger have a significant effect on the composition and quality of the ginger oil obtained. When fresh ginger is dried to make dried ginger, many low-boiling terpenes are lost. A reasonable drying method can help to preserve high-quality monoterpenes.

The method of extracting volatile essential oils from ginger has always been steam distillation, with a yield of 1.5% to 2.5%. This method is easy to operate and requires little investment, but the disadvantages are long distillation times and a low oil yield. In recent years, supercritical fluid technology and short-path molecular distillation technology have been developed, which can efficiently separate and extract target components under mild conditions. The extraction of ginger essential oil is theoretically much superior to traditional methods and is well worth trying in practice.

2.2 Extraction of ginger oleoresin

Ginger oleoresin is a product obtained by solvent extraction. The yield, aroma, flavour and pungency of the product are related to the source of the ginger, the harvest period, the solvent and the extraction method. Currently, there are mainly the following methods for extracting ginger oleoresin.

2.2.1 Solvent extraction

Solvent extraction methods include direct solvent maceration and Soxhlet extraction. The chemical composition of the ginger oleoresin extracted depends heavily on the solvent used. Most extractions are carried out using highly polar solvents such as ether, acetone, methanol, ethanol and ethyl acetate. Of these, continuous Soxhlet extraction with ethanol can be used to obtain the total oil content of ginger. This method can obtain more ginger oleoresin than acetone.

2.2.2 Pressing method

The pressing method is a method of extracting ginger oleoresin by directly treating washed ginger with mechanical means of pressing. In addition to the quality of the ginger itself, the amount of ginger oil obtained by this method is also related to the pre-treatment of the ginger and the operating conditions of the pressing facilities.

2.2.3 Supercritical carbon dioxide extraction method

High-pressure liquid carbon dioxide is used as the extraction solvent, which can simultaneously obtain volatile and non-volatile ginger oils. The reaction conditions are mild and the extraction efficiency is high. The ginger oleoresin extracted by this method has a high-quality flavor and contains the aromatic odor produced by light molecular fine components. In addition, because of its highly selective separation characteristics, it is conducive to distinguishing flavor components and developing new products, while its mild operating conditions provide the possibility of further utilizing its waste corners. This process also opens up new functional uses for ginger oleoresin in commercial applications.

2.3 Extraction of ginger protease

There are many methods for extracting proteases. The crude separation and extraction methods include organic solvent precipitation, dialysis, salting-out, adsorption, ultrafiltration, etc., which are mainly used for the concentration and enrichment of proteases. Gel filtration, ion exchange chromatography, hydrophilic chromatography and other chromatographic methods are fine separation methods that can be used to extract high-purity proteases. Spray drying and freeze drying are more suitable for industrial mass production of protease extraction.

3 Application of ginger extract

3. 1 Pharmacological effects [4]

Ginger has long been used in traditional Chinese medicine. Traditional Chinese medicine considers ginger to be a fine medicine, and it has been used to prevent and treat colds, coughs, vomiting, urticaria, loss of appetite, chilblains and other diseases. Its medicinal products include dried ginger, ginger peel, ginger, ginger charcoal and other types.

3.1.1 Antioxidant effect

The main antioxidant active substances in ginger extract are gingerols, shogaols and certain related phenol and ketone derivatives, which can remove superoxide anions and phenyl free radicals. Ginger can regulate lipid peroxidation and oxidation in rats, and reduce lipid peroxides in the body. Petroleum ether extract of ginger can inhibit the rate and extent of oxidation of red blood cells, and has a certain inhibitory effect on LPO in mouse liver microsomes. The inhibitory effect increases with increasing concentration. Li Aihua added an 80% ethanol extract of ginger to edible fats and oils and demonstrated that it has a very significant antioxidant effect. The addition of citric acid, ascorbic acid, and tocopherol had a synergistic effect.

3.1.2 Anti-inflammatory effect

Ginger essential oil can significantly inhibit the increase in capillary permeability caused by histamine and acetic acid in mice, significantly inhibit otitis caused by xylene, and significantly inhibit granulation tissue hyperplasia. Administration of ginger ethanol extract into the abdominal cavity can inhibit the swelling of rat toes and skin edema caused by carrageenan and 5-hydroxytryptamine (5-HT), suggesting that its anti-inflammatory mechanism is related to blocking 5-HT receptors [5]. 6-Gingerol has a concentration-dependent inhibitory effect on cyclooxygenase, which is effective not only against inflammation but also against allergies.

3.1.3 Anti-atherosclerotic effect

Ginger extract can prevent the infiltration of atherosclerotic lipoproteins into the arterial wall. Damaged cholesterol is converted into free cholesterol and transported to the liver by high-density lipoproteins for catabolism. 6 - Gingerol can promote the excretory function of the gallbladder and is an inhibitor of atherosclerosis [6].

3.1.4 Enhances immune function

Gingerol extract administered by gavage to tumor-bearing mice significantly increased organ index, improved macrophage phagocytosis, and increased the positive rate of α-ANAE and IgM levels, indicating that gingerol extract can significantly improve the immunocompromised state of tumor-bearing mice and play a role in preventing and treating tumors [7].

3.1.5 Antimicrobial effect [5]

Ginger water extract has varying degrees of inhibitory or killing effects on typhoid bacillus, cholera vibrio, trichophyton violaceum and vaginal trichomonas, and has the effect of preventing and treating schistosome egg hatching and killing schistosomes. Ginger ethanol extract diluted to a certain concentration with liquid Sabouraud agar has a very significant bacteriostatic and bactericidal effect on the common dermatophytes in the culture medium.

3.1.6 Antiemetic effect

When ginger acetone, 50% ethanol and water extracts were given intravenously to non-healthy mixed-breed dogs along with 3 mg/kg cisplatin, the ginger acetone and ethanol extracts had a significant antiemetic effect, while the water extract was ineffective against cisplatin-induced vomiting. Therefore, ginger can be used as an effective and inexpensive antiemetic during chemotherapy [6].

3.1.7 Cholesterol-lowering effect

Feeding (E)-8β-17-epoxy-12-ene-l5,16-dialdehyde (ZT) to mice with hypercholesterolemia induced by Trilon WR-1339 was found to reduce cholesterol biosynthesis in mouse liver homogenates. In addition, feeding ZT to mice with excised livers also resulted in a decrease in cholesterol biosynthesis [7].

3.2 Application in the food industry

In the food industry, ginger has been used to process and dye ginger sprouts, pickled ginger sprouts, pickled ginger, canned ginger, ginger sauce, sweet and sour ginger, ginger chips, ginger wine, ginger beer, seasoned ginger juice, ginger jellies, high-foaming ginger juice and many other ginger products that use ginger as the main ingredient. Ginger is also used in cooking, baked goods, curry powder, etc. In these applications, ginger is used not only as a seasoning, but also the antioxidant substances it contains are essential to ensure the flavor and quality of these foods. In recent years, ginger extract has been studied for use in producing edible flavored oils and preservatives [8].

3.3 Application in the spice industry

In the spice industry, ginger is mainly used to produce ginger oil and oleoresin, which are used to make food flavors and oriental cosmetics for men. A large amount of research has been done on the aromatic substances in ginger. A representative example is Chen Chu-chin (1986), who used supercritical carbon dioxide (SC-CO2) technology to extract oleoresin from ginger. High-pressure liquid chromatography, mass spectrometry and other analytical methods were used to confirmed that the pungent substances in ginger account for 16% of the total ginger oleoresin, and that gingdrol can be converted into shogaol, which has a stronger pungent taste, under acidic conditions, and into gingerone, which has a weaker pungent taste than gingdrol, under alkaline conditions. From a molecular perspective, these pungent substances all have phenolic groups, hydroxyl groups or alkenyl chains with antioxidant properties. Chen Chu-chin (1988) used SC-CO2 extracts and GC/MC analysis to isolate 168 compounds, of which the chemical structures of 90 components have been determined, laying the foundation for research on the natural antioxidants contained in ginger.

4 Problems and prospects

At present, the methods used to extract ginger essential oil and essential oil resin are becoming increasingly refined, and significant progress has been made in the compositional analysis of ginger oil. However, there have been few reports on the systematic study of the differences in the composition of the resulting ginger oil under different process conditions. There have been relatively few comparisons of the differences in the functional properties of ginger oil resin, such as its antioxidant and antibacterial properties, obtained under different process conditions. The research on the microencapsulation of ginger oil products is not yet in-depth, such as the process conditions and the release model and stability of the product capsules. However, the solution of these problems will be conducive to the further promotion and utilization of ginger oil products in the food processing industry.

The comprehensive processing and utilization technology of ginger still needs to be improved. For example, the ginger residue after ginger juice extraction can be crushed and used to extract natural ginger antioxidants, and ginger residue can also be used to prepare ginger dietary fiber.

References:

[1] Chen Yan, Ni Yuanying, Cai Tongyi. Research progress on ginger extract – essential oil and oleoresin [J]. Food Science, 2000, 21 (8): 6-8.

[2] [2]Weiss E A. Essential Oil Crops[M]. Australia：Eaglemont，1997 ：539- 567.

[3]Kikuzaki  H.  Cycilic  Diarylheptanoids  from  Rhizomes  of Zingiber offcinale[J]. Phyto-  chemistry， 1996 ，43 （1）： 273.

[4] Wang Ying, Li Dongwei. Research progress on ginger [J]. China Pharmaceutical Industry, 2006, 15 (9): 62-63.

[5] Wu Caixia, Ding Hua. Research progress on the pharmacological effects of ginger [J]. Journal of Linyi Medical College, 2004, 26 (6): 445-447.

[6] Liu Xuemei. Research progress on the pharmacological effects of ginger [J]. Chinese Patent Medicine, 2002, 24 (7): 539-540.

[7] Liu Hui. Effects of gingerol extract on the immune function of tumor-bearing mice [J]. Health Research, 2002, 31 (3): 208-210.

[8] Huang Xuesong. Research status of natural antioxidants in ginger [J]. Chinese Condiments, 1997 (8): 2-4.