Secondary Metabolites of Brassica juncea (L.) Czern and Coss: Occurence, Variations and Importance

Abstract

There are numerous secondary plant metabolites found in the crop B. juncea, especially glucosinolates. Isothiocyanates, the by-products of glycosinolate breakdown, are beneficial to human health. A number of studies have also called attention to phenolic compounds and carotenoids, both well known for their anti-oxidant properties. A notable feature is that the profiles and concentrations of secondary plant metabolites vary greatly between varieties and that genetic factors are thought to be the most significant factors. In addition, environmental and agronomic factors have also been noted to change the concentrations of secondary plant metabolites. Secondary plant metabolites are primarily produced for defense purposes. Consequently, the intrinsic quality of Indian mustard, including color, aroma, taste, and medicinal properties, is profoundly influenced by its secondary metabolite profile. The health benefits of glycosinolates and the cancer prevention properties of their breakdown products make them of specific interest. Plant cells that have been injured undergo enzymatic decomposition of glucosinolate by endogenous enzymes such as myrosinase, which releases degradation products such as nitriles, epithionitriles, or isothiocyanates. The main phenolic compounds found in B. juncea are flavonoids and hydroxycinnamic acid derivatives. A diverse secondary metabolite pool is also essential for plant-environment interactions.

1. Introduction

Among the largest groups of autotrophs on this planet are plants. There are many organisms that feed on them, including bacteria, fungi, invertebrates, and vertebrates. It is remarkable that plants are able to support such a large group of organisms. In spite of this, some plants still manage to survive on this earth, even in very hostile environments. In order to defend themselves against herbivores and attackers, they possess a variety of mechanisms [1]. Indian mustard (Brassica juncea), an annual herb that belongs to the brassicaceae family, is one such plant. Affordable, healthy foods like mustard contain bioactive ingredients like glucosinolates, their breakdown products, and polyphenols. It is also high in ascorbic acid, fibre, chlorophyll, minerals, and volatile organic compounds. Mustard is utilised as a spice because of its strong, fiery, pungent flavour. The leaves of the mustard plant are used as stimulants, expectorants, and diuretics in folk medicine [2].

2. Chemical compounds in mustard

There are several important molecules present in mustard leaves, including chlorophyll, beta-carotene, ascorbic acid and potassium [3]. Mustard seeds include a lot of dietary fibre and lipids in addition to carbohydrates and proteins. Furthermore, they contain vitamin K and C, electrolytes such as sodium and potassium and trace minerals such as Mg, Ca, Mn, Fe, Zn, Cu, and Se [4, 5]. Varieties, locations, growing areas, and methods of processing influence mustard’s specific nutrients and content. The lower and upper leaves of mustard have similar nutrient contents [6]. Compared to the rest of the plant, seeds have higher protein, carbohydrate, and fat content, while dietary fibre content is lower [5]. Indian mustard, or B. juncea L., is an oilseed as well as leafy vegetable crop bearing seeds that are high in both protein and oil (37–49%) with promising possibilities [7, 8].

2.1 Polyphenol types and contents in mustard

An important group of secondary metabolites in plants, polyphenols are found in cortex, skin, roots, fruits, and leaves of plants. They are phenolic compounds with multiple hydroxyl groups. A polyphenolic compound is a hydrophilic compound in the cell, and when combined with carbohydrates, it is predominantly a glycosidic compound. Polyphenols, which comprise flavonoids and tannins, have been proven to have anticancer and antioxidant properties [9, 10]. It is evident that mustard variety, plant part, preparation techniques, and detection technique all had a significant impact on the types and contents of polyphenols. The Mustards’ total phenolic content range between 404.33 and 3.26 milligrams of gallic acid equivalent/g [9]. Various mustards contain polypheonols, including epigallocatechin gallat, proanthocyanidins, epicatechin gallat, rutin, naringin, protocatechuic acid, p-hydroxybenzoic acid, catechin, chlorogenic acid, vanillic acid, gallic acid, sinapic acid, caffeic acid, p-Coumaric acid, ferulic acid, vanillin, and p-hydroxybenzaldehyde. There is substantial variation in the polyphenol content of mustard greens. Mustard greens were found to have the greatest content of sinapic acid and then chlorogenic acid. In general, lateral buds were found to have more polyphenols than other parts of the plant [11]. Various plant sections have different polyphenol contents, which are arranged in the following order: seeds, leaves, roots, and stems [12, 13]. Furthermore, mustard contains a high level of flavonoids. Indian mustard (B. juncea) contained flavonoids in amounts ranging from 56 to 2893 μg kaempferol-3-O-hydroxyferuloyldiglucoside-7-O-glucoside equivalents/g [14]. There was a large variation in flavonoids content between mustard varieties and detection methods.

Polyphenols can be detected in mustard by several methods, including: 1. high-performance liquid chromatography (HPLC) [15], 2. Reversed-phase HPLC (reverse-phase high-performance liquid chromatography) [16], 3. Qualitative HPLC-ESI-MSn analysis [13], 4. UHPLC-DAD-ESI-MSn analysis and quantification [17], 5. Folin-Ciocalteu reagent [18], 6. Ultra-sonication [19], 7. spectrophotometry methods, 8. Others- paper chromatography, Column chromatography and thin-layer chromatography [16]. Microwave extraction, Soxhlet water bath extraction, and ultrasonic extraction are the methods used to extract mustard’s total polyphenols [17, 20, 21]. Using three solvents, Huang et al. [22] extracted mustard polyphenols. Overall, ethanol extracted polyphenols were higher than methanol extracted polyphenols followed by water extracted polyphenols. About 8000 different polyphenolic compounds have been identified in Indian mustard [23]. As new technology and further research are developed, it will be possible to find more polyphenols in mustard.

2.2 Types and contents of glucosinolates and their degradation products in mustard

Glycosinolates are mostly made up of three components (sulfonium sulfonate, D-glucose and an amino acid side chain R) in plants. The glucosinolates are categorised as aliphatic, aromatic, and Indole glucosinolates based on the difference in R, i.e., functional group [24, 25]. Three components are involved in glucosinolate biosynthesis: lengthening of the side chains of amino acids, the development of core structures, and alteration of secondary side chains [26]. In addition to various biological functions, glucosinolates play a vital role in determining how cruciferous vegetables smell and taste. The non-volatile flavour precursors nitriles, thiocyanates, isothiocyanates, and glucosinolates are what gives mustard its spicy flavor [27, 28]. Glucoseglucoside can result in isothiocyanate breakdown products with fresh, aromatic, or bitter and spicy flavours through the three degradation processes of enzymatic, chemical, and thermal degradation [29].

Kim et al. [21] detected 13.0 mg of glucosinolates per gram of mustard. It has been found that sinigrin is present in all mustards reported to date [12]. According to Sun et al. [11], Sinigrin made up 41.7% of the total glucosinolates in Korean leaf mustard (B. juncea var. Integrifolia). The study of Nugrahedi et al. [30] concluded that over 90% of the glucosinolate content in fresh mustard was sinigrin, which was reduced by 95% after 3 days of fermentation, while the levels of neo glucobrassicin and 4-methoxy glucobrassicin dropped to 80–90%.

It was found that Potherb Mustard (B. juncea) contained progoitrin and gluconapin as the main glucosinolates [31]. Nutrient composition and content differed significantly between plant organs/tissues. Compared to other baby mustard edible portions, the skin of B. juncea var. gemmifera contains more aromatic glucosinolates. Korean Dolsan Leaf mustard (B. juncea) seeds were more likely to contain sinigrin than stems, roots, and leaves, according to Tsukamoto et al. [12]. Mustard has also been qualitatively found to comprise other glucosinolates and their breakdown products [26], including progoitrin, glucoerucin, and glucoraphanin. More mustard types need to be explored, along with the glucosinolate alterations and processes in mustard processing.

In cruciferous vegetables, there are over 200 known glucosinolates [29], but no systematic study has been conducted on mustard glucosinolates.

3. Developments in the research of mustard’s medicinal properties

Consumption of mustard leaves has been associated with several possible health advantages in Asia and Africa [32]. Literature reports that mustard extracts have antiinflammatory, antioxidant, antidepressant, antimutagenic, and antibacterial activities. The extract from mustard also inhibits angiotensin-converting enzymes, lowers blood cholesterol levels, increases HDL cholesterol levels, and protects against renal ischemia. There is also evidence that the risk of developing numerous malignancies, including breast, colon, lung, and gastric cancers, is decreased by the mustard extract.

3.1 Anticancer activity

Several bioactive components of mustard, including polyphenols, flavonoids, glucosinolates, and their degradation products, are believed to play a role in its antiproliferative and preventative effects on tumor cells. This is especially true for glucosinolates such as sulforaphane, indole-3-methanol, sinigrin, isothiocyanate allyl acid, and their degradation products. ACI/N rats were found to inhibit tongue cancer when administered sinigrin and inhibit liver cancer when administered sinigrin [33]. Further, Kim et al. [34] found that, especially for SNU-C4 and SNU-251 cells, red mustard had greater anticancer properties than green mustard. In this study, the glucosinolates of both Korean red and green mustard were tested against the cancer cells, SNU-251, SNU-C4, SNU-354, and MCF-7. In the red and green mustard extract, sinigrin was determined to be the primary active ingredient. As a result of glucosinolate degradation products [35, 36], studies have demonstrated that considerable inhibition of cancer cells of lung by phenethyl isothiocyanate, benzyl isothiocyanate, allyl isothiocyanate, and sulforaphane. Sulforaphane effectively suppressed the growth of esophageal adenocarcinoma cells [37], cancer cells of colon [38], and lung cancer cells [35]. As reported by Tanaka et al. [33], indole-3-methanol inhibits cancer cell of colon, breast, and tongue s in male ACI/N rats [38]. A study found that the ethyl acetate extract of B. juncea var. Raya is anti-cancerous and can prevent the spread of colon cancer cells, (HCT116), breast cancer cells (MCF-7, MDA-MB-231), lung cancer cells (A-549), cervical cancer cells (HeLa), and prostate cancer cells (PC-3). As a result, the extract has potential to supress the growth of cancer cells was dose-dependent, affecting the breast carcinoma cell line the most. Studies have shown that mustard extract has therapeutic potential in addition to its cacinopreventative properties. The extract causes cancer cell lines to undergo apoptosis, which kills them, as a result of reactive oxygen species being generated by the mitochondrial pathway. Several compounds were identified in B. juncea var. Raya. Among the isothiocyanates present in B. juncea var. Raya include allyl isothiocyanates (23%, degraded from sinigrin), 2-phethyl isothiocyanates (20%, generated from gluconasturiin) and 3-butyl isothiocyanates (18%, degraded from gluconapin). Additionally, it has been claimed that mustard extracts in methanol and water can suppress the growth of cancer cells [3, 39, 40], however, their main active components are unknown. It will be necessary to continue identifying the components of mustard extract, examine dose-resistance relationships, and examine how structure affects anticancer activity in order to advance in this field.

3.2 Antioxidant activity

A number of antioxidant compounds have been found in mustard [18], including phenolic compounds, vitamin A, glucosinolates, vitamin C, and other compounds. It was found that the 50% acetonitrile extract of Korean Dolsan Leaf mustard was shown to have somewhat better antioxidant activity than that of other sites in the study. In addition to ABTS, EDA, and FRAP (Ferric ion-reducing antioxidant power) were shown to have antioxidant activity. As shown in Oh, Kim et al. [21], it was linearly correlated with flavonoid concentration, indicating that flavonoids and polyphenols may act as mediators for their antioxidant activity. However, aerobic environment, temperature, fermentation time, solvent, and pH may affect the antioxidant activity of fermented mustard [15, 18, 41]. Several mustards have different antioxidant activities, and different mustards have various antioxidant capacities. Tests conducted in vivo and in vitro can identify antioxidant activity. A primary method for evaluating antioxidant activity in vitro is DPPH (2,2-Diphenyl-1-(2,4,6-trinitrophenyl) hydrazyl; 1,1-Diphenyl-2-picrylhydrazyl radical). For the determination of antioxidant activity in vivo, LPO is the most common method. Although Free radicals are scavenged by both methods, DPPH [42] is faster, simpler and more economical than other test methods. The antioxidant activity of mustard extracts may also be determined using the ABTS-free radical scavenging and iron reduction antioxidant capacity (FRAP) tests [13, 22]. A number of malignancies have been closely associated with excessive nitrate intake [19, 43].

The methanol-based mustard extract shows nitrite scavenging activity at a higher level than water extract and ethanol extract [18, 44]. In vitro pH value studies of microbiological thiobarbital acid-free fatty acids were also carried out to determine the antioxidant potential of mustard leaf ethanol extracts on raw meat lipid oxidation protection. The findings showed that while the samples’ pH declined after storage, their contents of free fatty acids and thiobarbital considerably rose significantly (P < .05).

In samples treated with ethanol extracts of mustard leaf pickles of 0.1% or 0.2%, bacteria were significantly less prevalent than in samples treated with control ascorbic acid (0.02% ascorbic acid), demonstrating mustard’s antioxidant properties [22, 32, 45]. Animals are often shielded from oxidative stress throughout testing in order to evaluate in vivo detection. Live mice were treated to oxidative stress brought on by urethane, cyclophosphamide, and mustard leaf extract, as well as new radiation-induced chromosomal damage. When given at 50–250 mg/kg body weight over the course of 7 days, mustard leaf extract decreases the micronuclei brought on by radiation and genotoxic substances. Furthermore, glutathione levels and glutathione S-transferase levels rose, shielding the mice against genotoxicity and chromosomal damage. In streptozotocin-induced diabetic rats, mustard BuOH extract fraction was also evaluated for its effect on oxidative stress. As a result of thiobarbituric acid fraction administration (100 or 200 mg/kg of body weight every day for 10 days), superoxide levels, glycosylated protein, serum glucose, thiobarbituric acid levels, and nitrite/nitrate both the amount of reactive substances and the amount of thiobarbituric acid-reactive compounds were dramatically decreased as well. As a result of reduced lipid peroxidation and oxygen-free radical levels in mustard leaf BuOH fractions, oxidative stress associated with diabetes is improved [46]. Several studies have examined the antioxidant potential of mustard extracts using various methodologies; however, further research is needed to determine the antioxidant components of mustard, their assimilation, metabolism, and anti-oxidant processes in the human body.

3.3 Anti-obesity

A limited amount of research has been conducted in this field, but some studies have shown, that B. juncea L. leaf extracts with 80% (v/v) ethanol had positive effects on obese Sprague-Dawley rats on a high-cholesterol diet. A number of lipid parameters were improved in rats, including serum and organ lipid levels. Gene/protein expression related to fat metabolism and cholesterol production was also regulated. In rats given the extract, the weight of the organs significantly decreased, and the bulk of the mesentery, epididymis, and total adipose tissue all decreased (p < 0.05). Those enzymes produced a significant amount of mRNA expression being given a dose of leaf extract from B. juncea.

Based on the findings, 80% (v/v) ethanol extract of B. juncea L. leaf has the potential to alleviate obesity, likely by inhibiting the expression of G6pdh, Acc, and Fas genes [47].

3.4 Anti-inflammatory, antiviral, and antibacterial properties

An antiviral effect is obtained from brassinosteroids, which are polyhydroxy steroids found in B. juncea extract [48]. In comparison to ethanol, n-hexane, and hot water extracts (80°C), mustard subcritical water extract showed higher antiviral activity. Mustard subcritical water extracts were reported to exhibit 50.35 percent antiviral activity in influenza A/H1N1 influenza virus-infected cells, whereas a milk extract containing 0.28 mg/mL subcritical water extract showed 39.62% antiviral activity [48]. B. juncea extract, when diluted to 1.25 mg/mL, showed strong antiviral activity against influenza virus A/H1N1, according to Lee et al. [45]. At a dosage of 1.25 mg/mL, mustard extract significantly reduced the spread of virus particles.

There was a selective antibacterial effect of crude Oriental mustard seed meal extracts and purified polyphenols on both Gram-negative and Gram-positive bacteria (Listeria monocytogenes and Staphylococcus aureus). The hydrolyzed extract was found to be effective against Bacillus subtilis, S. aureus, Escherichia coli, L. monocytogenes, and Pseudomonas fluorescens when the minimum inhibitory level was 0.1 g/L.

The mustard extract has also been shown to be a successful anti-inflammatory agent. B. juncea 50% ethanol extract has been demonstrated to lessen both acute inflammations (12-o-tetradecanoylphorbol-acetate (TPA) generated mouse ear edoema and arachidonic acid (AA) produced mouse ear edoema) and chronic inflammation (many applications of croton oil (CO) induced) in mice [49]. TPA-treated mice’s ears were found to be significantly thinner and MPO activity significantly decreased by extracts, as was mRNA and protein levels of IL-6. Researchers discovered that B. juncea has anti-inflammatory properties. Mustard ethyl acetate and n-butanol fractions have also been examined for their effects on peritoneal macrophages stimulated with lipopolysaccharide. Neither fraction produced nitric oxide (NO) or nitrite, and both inhibited nitric oxide (NO) generation. Compared with mustard leaf n-butanol, mustard leaf ethyl acetate appears to perform better as a protective agent against lipopolysaccharides and inhibits nitrite synthesis more strongly. A study demonstrated by Kim et al. [50] showed that mustard leaf inhibits the production of nitrites and nitric oxide, possibly contributing to its anti-inflammatory properties.

3.5 Therapeutic effect on diabetic cataract

Studies have been conducted on mustard extract and dietary cataract Albino Wistar rats administered streptozotocin. Scientists found that administering extracts to subjects for 8 weeks at doses of 250 and 500 mg/kg body weight prevented cataract development, as well as improving protection against diabetic cataracts at high concentrations [51]. In a study by Yokozawa et al. [52], The effectiveness of a mustard ethyl acetate (EtOAc) extract in preventing diabetes and its consequences was examined. Research was conducted on diabetic rats induced by streptozotocin. After oral treatment of EtOAc fractions (200 mg/kg body weight/d and 50 mg/kg body weight/d) for 10 days, a dose-dependent reduction in blood glucose glycosylated protein levels and thiobarbital acid reactive substance levels was seen. Additionally, serum, liver, and kidney mitochondrial levels of superoxide and nitrite/nitrate reduced. Based on these results [52], mustard leaf extract may be beneficial in reducing diabetic complications.

3.6 Anti-hyperglycemia effect

A study of extracts from green and red mustard leaves (B. juncea var. Integrifolia) examined their phenolic and glucosinolate concentrations as well as their blood sugar reducing abilities. According to the findings, green and red mustard leaves had total phenolic contents of 1228.48 36.81 and 850.75 28.88 mg/100 g, respectively, while green mustard leaves had sinigrin contents of 953.19 41.11 and 1319.62127.95 mg/100 g, respectively. Sinigrin is more abundant in red mustard leaves than green mustard leaves, which have a greater amount of total phenolic content. Red mustard leaves were shown to suppress the activity of -glucosidase but to have no influence on that of alpha-amylase. Accordingly, red mustard leaves reduce blood sugar levels more effectively than green mustard leaves [53].

3.7 Antidepressant effect

As a result of diabetes, rodents demonstrate changes in their behavior, brain structure, and biochemical characteristics [54]. B. juncea leaf methanolic extract has been studied because of its antidepressant properties. Tests for tail-hanging, behavioural despondency, learned helplessness, and motor activity were used to measure the therapeutic efficacy. Furthermore, serum levels of serotonin, norepinephrine and dopamine were determined following extract treatment. B. juncea was discovered to have anti-depressive properties in behavioural experiments using diabetic rats and mice as well as biochemical examinations., dopamine, norepinephrine, and Serotonin levels in the brain were elevated by mustard extract in a dose dependent manner in comparison to diabetic-depressed baseline values. In order to fight diabetes-related depression, B. juncea might prove to be a valuable nutritional alternative [54].

4. Genetic engineering methods to augment Glucosinolate content

Brassical plants contain glycosinolates, which contain nitrogen and sulfur. Myrosinases hydrolyze these glucosinolates into various compounds when plant tissue is damaged, such as by mechanical injury or by pathogens or insect pests attacking the plant. B. juncea is able to defend itself against pathogenic insects and pathogens using aromatic and indole glucosinolates [55]. Aside from its pungency, mustard oil also features distinctive flavors due to glucosinolates. It is this pungency that has made mustard oil so popular. Chemoprotective and anticancer properties have been observed for many glucosinolates and their degradation products. B. juncea seedmeal contains high levels of glucosinolates (80–120 mol/g) which are nutritional antagonists and reduce the palatability. As a result, seedmeal is not palatable to poultry. Augustine et al. [56] found that the degradation products of these compounds are also goitrogenic in nature.

Since Indian mustard seedmeal contains such high levels of glucosinolates, it is less expensive in the international market. Indian mustard breeding programs target glucosinolate content reductions to 30 mol/g of dry seed weight (DSW). As a result of negative linkage drag between seed glucosinolates and seed yield, whenever quality lines are developed through conventional breeding methods, yield penalty occurs. A genetic engineering approach was required to improve this trait. Using RNAi-based targeted suppression of the BjMYB28 transcription factor gene involved in aliphatic glucosinolate biosynthesis, A high-yielding Indian mustard cultivar Varuna was reduced in its glucosinolate content by Augustine et al. [57]. As low as 11.26 moles/g of DSW of glucosinolate-containing transgenic Indian mustard lines can be developed. However, the desirable non-aliphatic glucosinolate content and composition did not change following targeted silencing of BjMYB28 transcription factor. There are many anti-cancer properties found in the glucosinolates in Indian mustard that offer great health benefits.

Sulphoraphane, produced by glucosinolate glucoraphanin, has anticancer and healing properties. Glucosinolate glucoraphanin is converted in this process by the enzyme AOP as well as the enzyme GSL-ALK, which leads to certain undesirable degradation products like gluconapin and progoitrin, which are present in greater amounts in B. juncea. The GSL-ALK gene family has four functional homologs and Augustine and Bisht [56] used constitutive gene silencing to silence all four homologs. As a result, the transgenic B. juncea plants contained more glucoraphanin, a desirable glucosinolate, and fewer antinutritional glucosinolates. Transgenic mustard lines were also more resistant to Sclerotinia sclerotiorum, the fungus that causes stem rot. Indian mustard seeds contain various types of aliphatic glucosinolates, including sinigrin, which can be used medically and therapeutically in mammals. A Bju.CYP79F1 gene overexpression study by Sharma et al. [58] demonstrated that Bju.CYP79F1 gene is functionally important for sinigrin biosynthesis in a B. juncea line having high glucosinolate content in the seeds, but no sinigrin in them. Through overexpression of the Bju.CYP79F1 gene, transgenic mustard lines were able to synthesize sinigrin in their seeds. An antinutritional compound found in Indian mustard seedmeal is sinapine, a type of glucosinolate.

As a result, it gives chicken eggs a fishy flavour and contributes a gritty quality to meat, decreasing customer interest in both products. Sinapine levels in the germplasm of Brassica lines range from 6.7 to 15.1 mg/g of DSW. Kajla et al. [59] tried to silence two genes to reduce the amount of sinapine in Indian mustard. The three SGT-encoding enzymes that catalyse the crucial stages in the sinapine production pathway are sinapate glucosyltransferase, sinapoylglucose, and choline sinapoyltransferase. To stop the production of the target genes, they employed three distinct methods of gene silencing, including RNA interference (RNAi), antisense gene, and synthetic micro RNA. The RNAi gene silencing method was used to assess a decrease in seed sinapine content in these transgenic lines that ranged from 15.8% to 67.2%. A transgenic mustard line only contained 3.79 mg/g of DSW sinapine.

5. Conclusion

As a cruciferous plant and a primary raw material for kimchi, mustard (B. juncea) is widely used as a food and spice. The dietary fiber, minerals, chlorophyll, vitamins, glucosinolates and their degradation products, volatile components, polyphenols, and phytochemicals found in mustard are just some of the phytochemicals it contains. Varieties, growth environments, extraction technologies, and food processing affect the content and type of food. As well as anti-cancer properties, mustard also has antioxidative properties, anti-inflammatory properties, antibacterial properties, antiviral properties, anti-obesity properties, antidepressant properties, diabetes treatment, and cataract prevention and treatment. Currently, mustard seeds are fermented, fried, steamed, microwaved, and extracted from their oils. As mustard is primarily processed by fermentation, it does not have intensive processing or utilization, while the functional components of mustard do not get the best use. Most products do not have a high level of value-addition. The bioactive components of mustard include glucosinolates and polyphenols. The exact amount and structure of glucosinolates and polyphenols found in mustards are still unknown, despite extensive research on their qualitative determination. Based on the data, glucosinolates and polyphenols in mustards are not reported to change and degrade during processing. There have been many studies examining the anticancer and antioxidant effects of mustard extracts, but their exact mechanism of action and structure–activity relationship have not yet been determined. In addition to mastering the metabolic pathways of bioactive components, improving research into the degradation mechanism will ensure that bioactive components are retained during processing. Utilizing modern metabolomics to study and adjust specific components of plants to produce mustard plants that have stable genetic properties, are high in glucosinolates, polyphenols, and other beneficial chemicals. These products can be improved with novel technologies, and their applications can be expanded to include functional foods for health.

Conflict of interest

The authors declare no conflict of interest.

Acknowlegements

The first authors duly acknowledges the co-authors for active participation in deciding the contents, careful curation and their valuable inputs.