Simultaneous determination of gingerols and shogaol using capillary liquid chromatography and its application in discrimination of three ginger varieties from Indonesia

Gingerols and shogaols: A multi-faceted review of their extraction, formulation, and analysis in drugs and biofluids to maximize their nutraceutical and pharmaceutical applications

Gingerols represent the main bioactive compounds in ginger drugs mostly Zinigiber officinale (F. Zingebraceae) and account for the biological activities and the strong/pungent flavor in ginger. Ginger (Z. officinale) rhizome is one of the most valued herbal drugs for ailments' treatment in many ayurvedic medicine asides from its culinary applications as a spice. Gingerols and their dehydrated products shogaols are phenolic phytochemicals found in members of the Zingiberaceae family and account for most of their effects including anti-inflammatory and anticancer activities. This review entails most of the novel trends related to the extraction, optimization, and formulations of gingerols and shogaols to insure best recoveries and efficacies from their natural resources. Further, it presents a comprehensive overview of the different analytical approaches for the determination of gingerols/shogaols' levels in nutraceuticals to ensure highest quality and for their detection in body fluids for proof of efficacy.

Quality assessment of commercial dried ginger (Zingiber officinale Roscoe) based on targeted and non-targeted chemical profiles and anti-inflammatory activity

Dried ginger, a well-known medicine and food homologous production, has been widely circulated in China with high health benefits and economic value. Currently, there is still a lack of quality assessment on whether dried ginger in China exhibits chemically and biologically distinct properties, which creates a barrier to its quality control in commercial circulation. In this study, the chemical characteristics of 34 batches of common dried ginger samples in China were first explored using non-targeted chemometrics based on the UPLC-Q/TOF-MS analysis, leading to the identification of 35 chemicals that contributed to clustering into two categories, with sulfonated conjugates being the key chemically distinct components. By comparing the samples before and after sulfur-containing treatment and the further synthesis of a key differentiating component of [6]-gingesulfonic acid, it was then demonstrated that sulfur-containing treatment was the primary cause of the formation of sulfonated conjugates, as opposed to regional or environmental factors. Furthermore, the anti-inflammatory efficacy of dried ginger with high presence of sulfonated conjugates was significantly decreased. Consequently, for the first time, UPLC-QqQ-MS/MS was used to develop a targeted quantification method for 10 characteristic chemicals in dried ginger, allowing researchers to quickly determine whether dried ginger has been processed with sulfur and quantitatively evaluate the quality of dried ginger. These results provided an insight into the quality of commercial dried ginger in China and a suggested method for its quality supervision as well.

6-Gingerol contents of several ginger varieties of Northeast India and correlation of their antioxidant activity in respect to phenolics and flavonoids contents

INTRODUCTION

Ginger constitutes the rhizome part of the plant Zingiber officinale from the Zingiberaceae family. A large number of ginger varieties with high sensorial and functional quality are found in Northeast India. Hence, phytopharmacological screening of different ginger varieties is essential that will serve as a guideline in applied research to develop high-end products and improve economical margins.

OBJECTIVE

To determine the variation in total phenolics content (TPC), total flavonoids content (TFC), and antioxidant activities and correlate that with 6-gingerol contents of different ginger varieties collected from Northeast India using Pearson's correlation analysis.

MATERIALS AND METHODS

The TPC and TFC values were determined using standard methods. Antioxidant activities were measured using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radical scavenging assays, while reversed-phase high-performance liquid chromatography (RP-HPLC) analysis was utilised for quantitative determination of 6-gingerol content.

RESULTS

The result revealed that ginger variety 6 (GV6) contains the highest 6-gingerol content and TPC value showing maximum antioxidant activity, followed by GV5, GV4, GV9, GV3, GV2, GV8, GV1, and GV7. The findings also suggested that the antioxidant activity has much better correlations with TPC as compared with TFC values. Pearson's correlation analysis showed a significant correlation between 6-gingerol contents and TPC values.

CONCLUSION

This work underlines the importance of ginger varieties from Northeast India as a source of natural antioxidants with health benefits.

Antioxidant and Antimicrobial Properties of Hydrolysed Collagen Nanofibers Loaded with Ginger Essential Oil

Hydrolysed collagen obtained from bovine leather by-products were loaded with ginger essential oil and processed by the electrospinning technique for obtaining bioactive nanofibers. Particle size measurements of hydrolysed collagen, GC-MS analysis of ginger essential oil (EO), and structural and SEM examinations of collagen nanofibers loaded with ginger essential oil collected on waxed paper, cotton, and leather supports were performed. Antioxidant and antibacterial activities against Staphylococcus aureus and Escherichia coli and antifungal activity against Candida albicans were also determined. Data show that the hydrolysed collagen nanofibers loaded with ginger EO can be used in the medical, pharmaceutical, cosmetic, or niche fields.

A sense of ginger fraud: prevalence and deconstruction of the China-European union supply chain

As an important spice, ginger has been widely distributed in the Chinese and the European Union (EU) markets, the two largest trading areas, in various forms. The ginger supply chain between China and the EU is long and complex, providing opportunities for fraudsters to deceive consumers. However, limited attention has been given to food fraud in ginger, and there is a lack of research on this topic. In this review, ginger was used as an example for interpreting the fraud issues within low-priced and high-trade volume spice products. This review aims to summarize the open access information from food and food fraud databases, literature, and stakeholders about ginger fraud, and to map, deconstruct and analyse the food fraud vulnerability in the supply chain. In addition, potential testing strategies to detect ginger fraud were also discussed. The investigation of food fraud databases, a semi-structured literature review and online interviews with stakeholders revealed that adulteration is the major fraud type in ginger products. And the most vulnerable ginger products are ground ginger and finely processed ginger. The ginger supply chain from China to the EU comprises nine stages and is medium vulnerable to food fraud, both in regard to opportunities and motivational drivers. To ensure the integrity of the ginger supply chain, there is a need to apply fraud vulnerability tools in the companies of the industry. In addition, screening and confirmatory techniques based on the characteristics of ginger should be utilised for monitoring fraud issues in the supply chain.

Impact of drying and extractions processes on the recovery of gingerols and shogaols, the main bioactive compounds of ginger

Ginger extracts have anti-inflammatory, antioxidant, antitumor, and antibacterial activities mainly due to gingerols and shogaols. Extract composition and functionality can be affected by drying and extraction processes. Alternative methods to obtain ginger extracts based on high contents of gingerols and shogaols have been reported. However, there were no studies that present a broad overview of how these methods affect the composition and functionalities of ginger extracts. Based on literature data from 2011 to 2022, this review shows how drying, extraction, and complementary processes (i.e., enzymatic, acidic, and carbonic maceration) affect the composition and bioactivity of the ginger extract. Lower temperature processes, including freeze-drying, cold ultrasound-, or enzyme-assisted extraction, lead to extracts richer in phenolics, gingerols, and antioxidant activity. On the other hand, acidic solvents or "hot" processes including microwave-drying, pressurized liquid, and microwave-assisted extraction can favor higher shogaols concentrations, which have higher antitumor, anti-inflammatory, and antimicrobial activities than the gingerols precursors. Thus, in this review, we analyzed and discussed the relation between ginger processing and their bioactive compounds, focusing especially on gingerols and shogaols, as well as the main processes that increase the content of 6-shogaol without compromising other phenolic compounds to produce highly functional extracts for future applications in the food packaging sector.

Quality control and long-term stability study of ginger from different geographical origins using chemometrics

BACKGROUND

Ginger rhizome (Zingiber officinale) is a well-known spice and medicinal plant that is widely used in the Egyptian market as a spice, flavor and medicinal herb for different diseases. Since it is not cultivated as rhizomes in Egypt, ginger is imported from other countries, which may impact its quality. In this study, UV spectroscopy and high-performance liquid chromatography (HPLC) were applied as efficient available techniques for the discrimination and quality control of ginger collected from different geographical origins in combination with chemometrics. In addition, HPLC was applied to investigate the stability of ginger samples upon storage for 3 years to trace the changes in their main active constituents.

RESULTS

Data obtained from both UV and HPLC in combination with Principal Component Analysis (PCA) displayed proper discrimination of the samples according to their geographical origins. Regarding the stability study, ginger samples showed a significant decrease in quality after storage for 3 years, in which significant variation in the main pungent principles (6-, 8-, 10-gingerols and 6-shogaol) were observed. PCA failed to discriminate between ginger samples after long-time storage, so the applied model could discriminate between ginger samples before and after storage.

CONCLUSION

UV and HPLC in combination with chemometrics can be applied as a successful tool for the study of quality, stability and geographical discrimination of ginger. © 2020 Society of Chemical Industry.

Effect of heat treatment on thermal resistance, transparency and antimicrobial activity of sonicated ginger cellulose film

Transparent film with high thermal resistance and antimicrobial properties has many applications in the food packaging industry particularly packaging for reheatable food. This work investigates the effects of heat treatment on the thermal resistance, stability of transparency and antimicrobial activity of transparent cellulose film. The film from ginger nanocellulose fibers was prepared with chemicals and ultrasonication. The dried film was heated at 150 °C for 30, 60, 90, or 120 min. The unheated and sonicated film had the lowest crystallinity index and the lowest thermal properties. After heating, the film became brownish-yellow resulting from thermal oxidation. The reheated film had higher thermal resistance than unheated film. Heating led to further relaxation of cellulose network evidenced by shifting of the XRD peak positions toward lower values. The antimicrobial activity decreased due to heating. Average opacity value increases after short heating durations. It was relatively stable for further heating.

Comparison and HPLC quantification of antioxidant profiling of ginger rhizome, leaves and flower extracts

Background

In the present era, the attention of nutritionist diverted towards the bioactive entities present in natural sources owing to the presence of health boosting perspectives against lifestyle related disarrays.

Methods

In this context, different parts of ginger crop i.e. rhizome, leaves and flower of variety Suravi (ID no. 008) were used for the preparation of ginger extracts with 50% methanol, 50% ethanol and water via rotatory shaker for 45 min. After that, different phytochemical analysis and in vitro analyses were carried out to determine the antioxidant potential of these extracts. Lastly, the best selected extracts from each part was quantified through HPLC.

Results

The results of current investigated indicated that ethanol extract proved to have maximum quantity of phytoceutics as compared to methanol and water. The maximum TPC, flavonoids, flavonols, DPPH assay, antioxidant activity, FRAP assay, ABTS assay and metal chelating potential was observed in ginger leaves as 780.56 ± 32.78 GAE/100 g, 253.56 ± 10.65 mg/100 g, 49.54 ± 1.74 mg/100 g, 75.54 ± 3.17%, 77.88 ± 3.27%, 105.72 ± 4.44 μmole TE/g, 118.43 ± 4.97 μmole TE/g and 35.16 ± 1.48%, respectively followed by ginger flowers and ginger rhizome. The lowest antioxidant activity was estimated in ginger rhizome. On the basis of phytochemical profiling and in vitro analyses, ethanol extracts of ginger flowers, leaves and rhizome were selected for the quantification through HPLC.

Conclusion

The findings proved that maximum 6-gingerol was present in ginger leaves (4.9 mg/g) tackled by ginger flowers (2.87 mg/g) and ginger rhizome (1.03 mg/g).

Cross-talk between 10-gingerol and its anti-cancerous potential: a recent update

Since time immortal, ginger, as an ancient herb, has been used throughout the world in foods and beverages due to its typical strong and pungent flavor. Besides its use as a spice, it also serves as an excellent source of several bioactive phenolics, including nonvolatile pungent compounds, such as gingerols, paradols, shogaols, and gingerones. Gingerols constitute key ingredients in fresh ginger, with the most abundant being 6-gingerol (6-G), 8-gingerol (8-G), and 10-gingerol (10-G). Many studies have investigated the various valuable pharmacological properties of these ingredients and experimentally verified the mechanistic aspects of their health effects; however, to date, most research on the anti-cancerous activities of gingerols have focused largely on 6-G. Thus, the present article deals with the number of recent studies that have indicated and highlighted the role of 10-G with respect to its cancer prevention attributes in particular and its anti-inflammatory, anti-oxidant, anti-microbial, and gastrointestinal tract protective potential in general. The purpose of this review is to provide an overview of all the experimentally validated health benefits of 10-G for nutraceutical applications. The various findings have warranted the further investigation of 10-G and its possible use in various cancer treatments as well as its promising role as a chemo-preventive agent.

Discrimination of red and white rice bran from Indonesia using HPLC fingerprint analysis combined with chemometrics

HPLC fingerprint analysis combined with chemometrics was developed to discriminate between the red and the white rice bran grown in Indonesia. The major component in rice bran is γ-oryzanol which consisted of 4 main compounds, namely cycloartenol ferulate, cyclobranol ferulate, campesterol ferulate and β-sitosterol ferulate. Separation of these four compounds along with other compounds was performed using C18 and methanol-acetonitrile with gradient elution system. By using these intensity variations, principal component and discriminant analysis were performed to discriminate the two samples. Discriminant analysis was successfully discriminated the red from the white rice bran with predictive ability of the model showed a satisfactory classification for the test samples. The results of this study indicated that the developed method was suitable as quality control method for rice bran in terms of identification and discrimination of the red and the white rice bran.

Gingerols and shogaols: Important nutraceutical principles from ginger

Gingerols are the major pungent compounds present in the rhizomes of ginger (Zingiber officinale Roscoe) and are renowned for their contribution to human health and nutrition. Medicinal properties of ginger, including the alleviation of nausea, arthritis and pain, have been associated with the gingerols. Gingerol analogues are thermally labile and easily undergo dehydration reactions to form the corresponding shogaols, which impart the characteristic pungent taste to dried ginger. Both gingerols and shogaols exhibit a host of biological activities, ranging from anticancer, anti-oxidant, antimicrobial, anti-inflammatory and anti-allergic to various central nervous system activities. Shogaols are important biomarkers used for the quality control of many ginger-containing products, due to their diverse biological activities. In this review, a large body of available knowledge on the biosynthesis, chemical synthesis and pharmacological activities, as well as on the structure-activity relationships of various gingerols and shogaols, have been collated, coherently summarised and discussed. The manuscript highlights convincing evidence indicating that these phenolic compounds could serve as important lead molecules for the development of therapeutic agents to treat various life-threatening human diseases, particularly cancer. Inclusion of ginger or ginger extracts in nutraceutical formulations could provide valuable protection against diabetes, cardiac and hepatic disorders.