Changes In Glucosinolates Research Articles

Effects of Postharvest SO2 Treatment on Longan Aril Flavor and Glucosinolate Metabolites.

SO2 fumigation treatment (commonly known as sulfur treatment, ST) is a key method in the postharvest preservation of imported and exported fresh longan fruits, effectively reducing pericarp browning and enhancing color. Nonetheless, distinctive aromas, often referred to as "sulfur flavor", may develop in the aril during the extended preservation period. This study employed "Caopu" longan as the test material and patented SO2-releasing paper (ZL201610227848.7) as a treatment to perform a 35-day low-temperature (5 °C) storage of the fruit. The changes in glucosinolates (GSLs) and associated metabolites in the aril of treated fruit (ST) were examined utilizing ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) detection and widely targeted metabolomics technology. The findings indicated that following 35 days of storage, nearly all control (CK) fruit pericarp turned to brown, resulting in an edible fruit rate of 75.41% and a commercial fruit rate of 0%. In contrast, the treated (ST) fruit demonstrated an edible fruit rate and a commercial rate of 99.44%, while the pericarp color changed from dark yellow-brown to light earthy yellow. The sulfur-containing metabolites identified in longan fruit aril predominantly consist of amino acids and their derivatives (60.44%), followed by alkaloids (15.38%), nucleotides and their derivatives (1.10%), and other types (23.08%), which include GSLs. SO2 treatment significantly reduced the content of oxidized glutathione in fruit aril but increased the content of GSLs and related amino acids and their derivatives. Via screening, 19 differential sulfur-containing metabolites were obtained between ST and CK, including 11 GSLs. The identified differential metabolites of GSLs were all increased, primarily comprising aliphatic GSLs, such as 1-hydroxymethyl glucosinolate, 2-Propenyl glucosinolate (Sinigrin), and 4-Methylsulfinylbutyl glucosinolate (Glucoraphanin). Pathway analysis showed that these differential metabolites were mainly involved in coenzyme factor synthesis, cysteine and methionine metabolism, and amino acid synthesis, among other pathways. To the best of our knowledge, this is the first study to reveal the causes of the special flavor of longan aril after SO2 treatment, which is a great concern for longan consumers. Moreover, this study provides a scientific basis for exploring the reasons and mechanisms for the development of the sulfur flavor in the SO2-treated fruits during postharvest storage.

A relationship between antioxidant activity and seasonal changes in glucosinolates and hydrolysis by-products ITCs in various kale varieties recently cultivated in two growing seasons, winter and autumn, in Egypt.

A relationship between antioxidant activity and seasonal changes in glucosinolates and hydrolysis by-products ITCs in various kale varieties recently cultivated in two growing seasons, winter and autumn, in Egypt.

Targeted editing of multiple homologues of GTR1 and GTR2 genes provides the ideal low-seed, high-leaf glucosinolate oilseed mustard with uncompromised defence and yield.

Glucosinolate content in the two major oilseed Brassica crops-rapeseed and mustard has been reduced to the globally accepted Canola quality level (<30 μmoles/g of seed dry weight, DW), making the protein-rich seed meal useful as animal feed. However, the overall lower glucosinolate content in seeds as well as in the other parts of such plants renders them vulnerable to biotic challenges. We report CRISPR/Cas9-based editing of glucosinolate transporter (GTR) family genes in mustard (Brassica juncea) to develop ideal lines with the desired low seed glucosinolate content (SGC) while maintaining high glucosinolate levels in the other plant parts for uncompromised plant defence. Use of three gRNAs provided highly efficient and precise editing of four BjuGTR1 and six BjuGTR2 homologues leading to a reduction of SGC from 146.09 μmoles/g DW to as low as 6.21 μmoles/g DW. Detailed analysis of the GTR-edited lines showed higher accumulation and distributional changes of glucosinolates in the foliar parts. However, the changes did not affect the plant defence and yield parameters. When tested against the pathogen Sclerotinia sclerotiorum and generalist pest Spodoptera litura, the GTR-edited lines displayed a defence response at par or better than that of the wild-type line. The GTR-edited lines were equivalent to the wild-type line for various seed yield and seed quality traits. Our results demonstrate that simultaneous editing of multiple GTR1 and GTR2 homologues in mustard can provide the desired low-seed, high-leaf glucosinolate lines with an uncompromised defence and yield.

Variation in glucosinolates and the formation of functional degradation products in two Brassica species during spontaneous fermentation

Vegetables from the Brassica species are excellent sources of glucosinolates (GLSs), the precursors of health-promoting isothiocyanates (ITCs). Fermentation enhances the biotransformation of GLSs into potential bioactive ITCs. To explore the biotransformation of GLSs during Brassica fermentation, the changes in GLSs during the fermentation of two Brassica species (i.e., cauliflower and broccoli); the formation of corresponding breakdown products; and the shifts in physicochemical parameters, bacterial communities, and myrosinase activities involved in GLSs degradation were systematically investigated. Nine aliphatic, three indolic, and two benzenic GLSs were identified in fermented cauliflower (FC) and fermented broccoli (FB). Aliphatic glucoiberin and glucoraphanin were the major forms of GLS in FC and FB, respectively; indolic glucobrassicin was also abundant in both FC and FB. The total GLS content decreased by 85.29% and 65.48% after 3 d of fermentation in FC and FB, respectively. After 2 d of fermentation, a significant increase in bioactive GLS degradation products (P < 0.05), including sulforaphane (SFN), iberin (IBN), 3,3-diindolylmethane (DIM), and ascorbigen (ARG), was observed in FC and FB compared to in fresh cauliflower and broccoli. Moreover, variations in pH value and titratable acidity in FC and FB correlated with Brassica fermentation and were accomplished by lactic acid bacteria, including Weissella, Lactobacillus-related genera, Leuconostoc, Lactococcus, and Streptococcus. These changes may enhance the biotransformation of GSLs to ITCs. Overall, our results indicate fermentation leads to the degradation of GLSs and the accumulation of functional degradation products in FC and FB.

Insights into profiling of glucosinolates and genes involved in its metabolic pathway accompanying post-harvest yellowing of broccoli

Postharvest yellowing is the main manifestation in the rapid deterioration of broccoli. Here, we monitored the composition and content changes of glucosinolates accompanying the yellowing process of broccoli to reveal the changes of characteristic bioactive substances along with the appearance changes process. Glucosinolates content was greatly reduced in parallel with the yellowing process. The most prominent reduction was among glucoraphanin and its hydrolysate sulforaphane that decreased by 37 % and 69 %, respectively, during slight yellowing, and up to 85 % and 93 %, respectively when severely yellowed. Among the genes involved in glucoraphanin metabolism pathway, the continuous down-regulation of BoCYP83A1, BoTGG1 and BoTGG2 genes had the most serious impact on the reduction of glucoraphanin and sulforaphane content. Postharvest yellowing influenced the appearance of broccoli commodity, while greatly reduced the nutritional value.

Changes in glucosinolates and their breakdown products during the fermentation of cabbage and prolonged storage of sauerkraut: Focus on sauerkraut juice

Sauerkraut juice has not gained much scientific attention to date. Therefore, this study aimed to track changes in glucosinolates (GLS) during fermentation of white cabbage and the formation of corresponding breakdown products in sauerkraut and sauerkraut juice separately and to evaluate their stability during prolonged storage of the final products.The results obtained indicate that both sauerkraut and sauerkraut juice are a good source of bioactive compounds: ascorbigen and isothiocyanates. The stability of individual compounds during storage varied, and the absolute content of phytochemicals depended on the content of native GLS in the raw material and its bacterial composition. The dominant compound was ascorbigen, stable in acidic pH in both sauerkraut and sauerkraut juice, even after prolonged storage. Sauerkraut juice was also found as a rich source of bioactive isothiocyanates. One 250 mL glass of sauerkraut juice (after two weeks) can deliver approx. 75 μmol of bioactive ascorbien and isothiocyanates, hence it can be considered as functional food, delivering beneficial health effects.

Methyl Jasmonate Treatment of Broccoli Enhanced Glucosinolate Concentration, Which Was Retained after Boiling, Steaming, or Microwaving

Exogenous methyl jasmonate (MeJA) treatment was known to increase the levels of neoglucobrassicin and their bioactive hydrolysis products in broccoli (Brassica oleracea var. italica), but the fate of MeJA-induced glucosinolates (GSLs) after various cooking methods was unknown. This study measured the changes in GSLs and their hydrolysis compounds in broccoli treated with MeJA and the interaction between MeJA and cooking treatments. All cooked MeJA-treated broccoli contained significantly more GSLs than untreated broccoli (p < 0.05). After 5 min of cooking (boil, steam, microwave), MeJA-treated broccoli still contained 1.6- to 2.3-fold higher GSL content than untreated broccoli. Neoglucobrassicin hydrolysis products were also significantly greater in steamed and microwaved MeJA-treated broccoli. The results show that exogenous MeJA treatment increases neoglucobrassicin and its hydrolysis compounds in broccoli even after cooking. Once the positive and negative effects of these compounds are better understood, the results of this experiment can be a valuable tool to help food scientists, nutrition scientists, and dieticians determine how to incorporate raw or cooked broccoli and Brassica vegetables in the diet.

Quantitative Analysis of Glucosinolate Content in Chinese Cabbages Under Different Storage Conditions

Glucosinolates (GSLs) is a class of well-studied metabolites found in cruciferous vegetables. GSLs are known for their beneficial effect on human health. It has been reported that the GSL content is greatly affected by growth conditions and post-harvest treatments, but the effect of the post-harvest storage process on GSL composition and total content is still limited. In this study, we purposed to investigate the changes in GSL in Chinese cabbages (Brassica campestris L. ssp. Pekinensis) by storage temperature and durations, and to determine the optimal storage conditions for expressing a high level of GSL. Based on the storage experiment under different three-level temperature, the change of GSL contents was measured. Also, as a statistical approach, analysis of variance and multiple regression was conducted to investigate and to predict the GSL content. The statistical analysis showed that the storage temperature and duration were significant factors affecting GSL content and suggested that the optimal condition for maintaining high levels of GSL content varies. This study provides practical information to generate high GSL-producing Chinese cabbages, while previous studies on Chinese cabbage generally focus on breeding.

Glucosinolate variability between turnip organs during development.

Turnip (Brassica rapa spp. rapa) is an important vegetable species, with a unique physiology. Several plant parts, including both the turnip tubers and leaves, are important for human consumption. During the development of turnip plants, the leaves function as metabolic source tissues, while the tuber first functions as a sink, while later the tuber turns into a source for development of flowers and seeds. In the present study, chemical changes were determined for two genotypes with different genetic background, and included seedling, young leaves, mature leaves, tuber surface, tuber core, stalk, flower and seed tissues, at seven different time points during plant development. As a basis for understanding changes in glucosinolates during plant development, the profile of glucosinolates was analysed using liquid chromatography (LC) coupled to mass spectrometry (MS). This analysis was complemented by a gene expression analysis, focussed on GLS biosynthesis, which could explain part of the observed variation, pointing to important roles of specific gene orthologues for defining the chemical differences. Substantial differences in glucosinolate profiles were observed between above-ground tissues and turnip tuber, reflecting the differences in physiological role. In addition, differences between the two genotypes and between tissues that were harvested early or late during the plant lifecycle. The importance of the observed differences in glucosinolate profile for the ecophysiology of the turnip and for breeding turnips with optimal chemical profiles is discussed.

Influence of silver nanoparticles on the enhancement and transcriptional changes of glucosinolates and phenolic compounds in genetically transformed root cultures of Brassica rapa ssp. rapa.

Glucosinolates (GSLs) and phenolic compounds (PCs) are biologically active and involved in the defense reaction of plants; these compounds have a beneficial effect on human health. In this study, we described the influence of biologically synthesized silver nanoparticles (Ag NPs) to enhance the phytochemicals (GSLs and PCs), their transcription levels, and their biological activities in genetically transformed root cultures (hairy root cultures) of Brassica rapa. The concentrations of silver and reactive oxygen species (malondialdehyde and hydrogen peroxide) were highly elevated in the Ag NP-elicited hairy roots (HRs). Glucosinolates (glucoallysin, glucobrassicanapin, sinigrin, progoitrin, gluconapin, 4-methoxyglucobrassicin, 4-hydroxyglucobrassicin, glucobrassicin, neoglucobrassicin, and gluconasturtiin) and their transcripts (MYB34, MYB51, MYB28, and MYB29) were significantly enhanced in the Ag NP-elicited HRs. Moreover, the phenolic compounds (flavonols, hydroxybenzoic, and hydroxycinnamic acids) were significantly enriched in the Ag NP-elicited HRs. Total phenolic and flavonoid concentrations and their transcripts (PAL, CHI, and FLS) were higher in the Ag NP-elicited HRs than in the non-elicited HRs. Additionally, biological (antioxidant, antimicrobial, and anticancer) activities were significantly higher in the Ag NP-elicited HRs than in the non-elicited HRs. The Ag NP-elicited HR cultures offered an efficient and promising in vitro method to increase the production of health-promoting bioactive compounds, which may be useful in nutraceutical and pharmaceutical industries.

Changes in Glucosinolates, Sinapine and Flavonols during Seed Development of Camelina sativa (L.) Crantz

Camelina sativa (L.) Crantz is an oilseed crop whose oil is used as biofuel and the meal as animal feed. While the seed composition is widely documented, little is known about variations in the concentration of some compounds during seed development of camelina. The aim of this study was to characterize changes in the content of glucosinolates, sinapine, sinapic acid and flavonols (quercetin and koempferol) at different stages of seed maturation. Glucosinolates are accumulated in camelina seed in the first 4 weeks after pollination, while the other substances were transiently accumulated during development and may play a role in seed development.

Cultivar-Specific Changes in Primary and Secondary Metabolites in Pak Choi (Brassica Rapa, Chinensis Group) by Methyl Jasmonate.

Glucosinolates, their hydrolysis products and primary metabolites were analyzed in five pak choi cultivars to determine the effect of methyl jasmonate (MeJA) on metabolite flux from primary metabolites to glucosinolates and their hydrolysis products. Among detected glucosinolates (total 14 glucosinolates; 9 aliphatic, 4 indole and 1 aromatic glucosinolates), indole glucosinolate concentrations (153–229%) and their hydrolysis products increased with MeJA treatment. Changes in the total isothiocyanates by MeJA were associated with epithiospecifier protein activity estimated as nitrile formation. Goitrin, a goitrogenic compound, significantly decreased by MeJA treatment in all cultivars. Changes in glucosinolates, especially aliphatic, significantly differed among cultivars. Primary metabolites including amino acids, organic acids and sugars also changed with MeJA treatment in a cultivar-specific manner. A decreased sugar level suggests that they might be a carbon source for secondary metabolite biosynthesis in MeJA-treated pak choi. The result of the present study suggests that MeJA can be an effective agent to elevate indole glucosinolates and their hydrolysis products and to reduce a goitrogenic compound in pak choi. The total glucosinolate concentration was the highest in “Chinese cabbage” in the control group (32.5 µmol/g DW), but indole glucosinolates increased the greatest in “Asian” when treated with MeJA.

Glucosinolates in seeds, sprouts and seedlings of cabbage and black radish as sources of bioactive compounds

Sarıkamış, G., Yıldırım, A. and Alkan, D. 2015. Glucosinolates in seeds, sprouts and seedlings of cabbage and black radish as sources of bioactive compounds. Can. J. Plant Sci. 95: 681–687. The glucosinolate content of seeds, sprouts and seedlings of white head cabbage and black radish were analyzed in order to determine changes in aliphatic and indole glucosinolates during seed germination and early seedling growth. Both species with distinct glucosinolate profiles exhibited higher levels of aliphatics and to a much lesser extent indoles. Glucosinolate content decreased in germinating seeds and seedlings upon imbibition, followed by a slight increase after 48 h of germination. Total glucosinolates were highest in young seedlings at true leaf stage compared with seeds and sprouts in both species. The findings of the present study demonstrate changes in glucosinolates from seed to sprout and seedling during germination and early seedling growth as a particularly prominent factor in maximizing the concentration of the bioactive compounds available for improved health benefits.

A Mechanistic Perspective on Process-Induced Changes in Glucosinolate Content in Brassica Vegetables: A Review

Brassica vegetables are consumed mostly after processing, which is expected to give beneficial effects on the vegetable properties, such as improved palatability and bioavailability of nutrients, or shelf life extension. But processing also results to various changes in the content of health promoting phytochemicals like glucosinolates. This paper reviews the effects of processing on the glucosinolates content by using a mechanism approach underlying processing method employed. Cultural differences between Eastern and Western preparation practices and their possible effect on glucosinolate retention are highlighted. Boiling and blanching considerably reduce the glucosinolate content mainly due to mechanisms of cell lysis, diffusion, and leaching, and partly due to thermal and enzymatic degradation. Steaming, microwave processing, and stir frying either retain or slightly reduce the glucosinolates content due to low degrees of leaching; moreover, these methods seem to enhance extractability of glucosinolates from the plant tissue. Fermentation reduces the glucosinolate content considerably, but the underlying mechanisms are not yet studied in detail. Studying the changes of glucosinolates during processing by a mechanistic approach is shown to be valuable to understand the impact of processing and to optimize processing conditions for health benefits of these compounds.

Leaf Spray: Direct Chemical Analysis of Plant Material and Living Plants by Mass Spectrometry

The chemical constituents of intact plant material, including living plants, are examined by a simple spray method that provides real-time information on sugars, amino acids, fatty acids, lipids, and alkaloids. The experiment is applicable to various plant parts and is demonstrated for a wide variety of species. An electrical potential is applied to the plant and its natural sap, or an applied solvent generates an electrospray that carries endogenous chemicals into an adjacent benchtop or miniature mass spectrometer. The sharp tip needed to create a high electric field can be either natural (e.g., bean sprout) or a small nick can be cut in a leaf, fruit, bark, etc. Stress-induced changes in glucosinolates can be followed on the minute time scale in several plants, including potted vegetables. Differences in spatial distributions and the possibility of studying plant metabolism are demonstrated.

Changes of Glucosinolates in Mixed Fresh‐Cut Broccoli and Cauliflower Florets in Modified Atmosphere Packaging

Glucosinolates of broccoli and cauliflower florets were assessed to determine the effect of modified-atmosphere packaging on postharvest glucosinolate dynamics in mixed florets of Brassica vegetables. Mixed-packaged broccoli and cauliflower florets stored in food trays sealed with 2 different microperforated biaxial-oriented polypropylene films for up to 7 d at 8 degrees C were analyzed. Both applied modified atmospheres (1% O(2)+ 21% CO(2); 8% O(2)+ 14% CO(2)) maintained aliphatic glucosinolates in cauliflower florets, whereas in broccoli florets, the aliphatic glucosinolate concentration decreased slightly in each modified atmosphere. In addition, total indole glucosinolate concentration for both broccoli and cauliflower florets was maintained, and even increased in cauliflower florets at 1% O(2)+ 21% CO(2) due to rising neoglucobrassicin concentration. Thus, to simultaneously maintain glucosinolates and external appearance as well as to prevent off-odor, a modified atmosphere of 1% O(2)+ 21% CO(2) provides a suitable environment for storage of this Brassica floret medley for up to 7 d at 8 degrees C.

Seasonal changes of glucosinolates in Isatis leaves, and effect of harvest regimen and post-harvest treatment

Seasonal changes of glucosinolates in Isatis leaves, and effect of harvest regimen and post-harvest treatment

Quality Determination of Red Radish by Nondestructive Root Color Measurement

A new approach for nondestructive quality assessment based on color measurement was developed for red radishes (Raphanus sativus L.). Postharvest changes in hue angle corresponded with changes in soluble and insoluble pectic substances linked to textural characteristics in `Nevadar' radishes. Changes in glucosinolates were related to changes in chroma and were associated with radish flavor. However, monosaccharides were not related to root color during the 4 days of postharvest period. Nevertheless, the data suggest that root color may be used as a rapid, inexpensive and reliable indicator of quality during the postharvest distribution of radish.

Local and systemic changes in glucosinolates in Chinese and European cultivars of oilseed rape (Brassica nap us L.) after inoculation with Sclerotinia sclerotiorum (stem rot)

SummaryFour Chinese Brassica napus lines, generated through a breeding programme to identify Sclerotinia sclerotiorum tolerant and susceptible lines, and three European varieties were analysed for changes in glucosinolates (qualitative and quantitative), and general host reactions, after localised inoculation with a UK S. sclerotiorum isolate. Plants at the fifth leaf stage were either singly inoculated (third leaf) or were inoculated once (third leaf) and then challenged a second time (seventh leaf) 7 days after the first inoculation. The results showed very distinct reactions in the different lines and cultivars to the fungus, both locally and systemically.Of the European lines B. napus cv. Bienvenu showed good resistance (small lesions and less host damage) both 3 and 7 days post‐inoculation. Capricorn was the most susceptible followed by Cobra; the third leaves of these cultivars were showing strong chlorotic and necrotic reactions by day 3 and lesions were well developed. By day 7 the third leaves of Capricorn were completely rotten whilst Cobra still had a little healthy tissue.Inoculation of the four Chinese lines showed that two had moderate resistance (014 and 020 — slightly less resistant than Bienvenu) and two were very susceptible (016 and 024 — similar reactions to Capricorn and Cobra), based on lesion size and host tissue damage. Glucosinolate induction in line 014 was good both locally and systemically, with clear local and systemic induction of indolylglucosinolates and 2‐phenylethylglucosinolate both 3 and 7 days post‐inoculation. Line 020 did not show no particular increases in glucosinolates after inoculation either locally or systemically. In line 016 there was a small local increase and a large systemic reduction in total glucosinolates. Inoculation of line 024 caused no major local changes in glucosinolates and again a big reduction in glucosinolates systemically.The dual inoculation system, with lines 014 and 016, produced comparable results, with line 014 showing good local and systemic induction of glucosinolates (after the first inoculation) and a further local and systemic induction after the second inoculation. This induction in pre‐inoculated line 014 plants was associated with a reduction in lesion size of the second inoculum. Line 016 responded poorly both locally and systemically, and there were no real decrease in the lesion size of the second inoculum. It appears that in line 014 glucosinolate induction may be an important part of resistance, whereas in line 020 there are clearly other non‐glucosinolate factors involved. The poor local and systemic induction of glucosinolates in lines 016 and 024, and subsequent susceptibility, implies that glucosinolate induction may be an important marker of resistance to S. sclerotiorum in oilseed rape.

Changes in glucosinolates during crop development in single‐ and double‐low genotypes of winter oilseed rape (Brassica napus): I. Production and distribution in vegetative tissues and developing pods during development and potential role in the recycling of sulphur within the crop

SummaryThe distributions of glucosinolates and sulphur were measured in the vegetative and reproductive tissues in a series of single‐ and double‐low cultivars of oilseed rape (Bienvenu, Ariana, Cobra and Capricorn) grown on a sulphur‐sufficient soil at Rothamsted in 1987/88, and in crops of the cv. Libravo grown with none or 40 kg/ha of sulphur on a sulphur‐deficient soil at Woburn in 1990/91.The glucosinolate measurements demonstrated large differences in the abilities of single‐ and double‐low cultivars to synthesise glucosinolates, and showed that the biosynthetic differences were associated more with the developing pods than the vegetative tissues. It indicated that potential contribution of intact glucosinolates from vegetative tissues to the seed was likely to be small, but did not preclude the possibility that the vegetative tissues were a source of glucosinolate precursors. The sulphur measurements showed that the glucosinolates contained only a small proportion of the crop's total sulphur and that they were unlikely to be a major source of recyclable sulphur, even under conditions of severe sulphur deficiency.