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Abstract Background In the search for new alternatives to avoid the problems associated with the use of synthetic chemical fungicides in agriculture, the use of green manure (GrM) could help combat fungal diseases of crops, such as those produced by the necrotrophic pathogen Rhizoctonia solani. In the case of the use of Brassica tissues as GrM, it could have an elicitor capacity for systemic plant resistance. Results We used kale leaves as a GrM and applied it to pepper plants infected with R. solani. The application of freeze-dried kale tissues to the roots of pepper plants produced a systemic activation of foliar defences via the salicylic acid (SA) and ethylene (ET) pathways, significantly reducing pathogen damage. In addition, this systemic response led to the accumulation of secondary defence metabolites, such as pipecolic acid, hydroxycoumarin and gluconic acid, in leaves. Remarkably, pepper plants treated with lyophilised kale GrM accumulated glucosinolates when infected with R. solani. We also confirmed that autoclaving removed part of the glucobrassicin (85%) and sinigrin (19%) content of the kale tissues. Conclusions GrM kale tissues can activate systemic defences in bell pepper against foliar pathogens through SA/ET hormonal pathways, accumulating secondary defence metabolites.

Background: In the search for new alternatives to avoid the problems associated with the use of synthetic chemical fungicides in agriculture, the use of green manure (GrM) could help combat fungal diseases of crops, such as those produced by the necrotrophic pathogen Rhizoctonia solani. In the case of the use of Brassica tissues as GrM, it could have an elicitor capacity for systemic plant resistance. Results: We used kale leaves as a GrM and applied it to pepper plants infected with R. solani. The application of freeze-dried kale tissues to the roots of pepper plants produced a systemic activation of foliar defences via the salicylic acid (SA) and ethylene (ET) pathways, significantly reducing pathogen damage. In addition, this systemic response led to the accumulation of secondary defence metabolites, such as pipecolic acid, hydroxycoumarin and gluconic acid, in leaves. Remarkably, pepper plants treated with lyophilised kale GrM accumulated glucosinolates when infected with R. solani. We also confirmed that autoclaving removed part of the glucobrassicin (85%) and sinigrin (19%) content of the kale tissues. Conclusions: GrM kale tissues can activate systemic defences in bell pepper against foliar pathogens through SA/ET hormonal pathways, accumulating secondary defence metabolites. [ABSTRACT FROM AUTHOR]

Hydrolysis of glucobrassicin by plant or bacterial myrosinase produces multiple indoles predominantly indole-3-carbinol (I3C) and 3,3’-diindolylmethane (DIM), which show promise in clinical trials as effective cancer chemopreventive agents. This work aimed to study the capacity of two human gut bacteria; Escherichia coli VL8 and Enterococcus casseliflavus CP1 to hydrolyze glucobrassicin from yellow mustard (Sinapis alba) seeds. Myrosinase-positive bacteria from enrichment culture were cultured in media containing 0.1 mM glucobrassicin for 16 h. The HPLC results showed that E. casseliflavusCP1 was able to degrade glucobrassicin by 73% at 16 h, whilst E. coliVL8 gave 47% degradation. The putative glycosyl hydrolase (GH) enzymes from E. casseliflavus CP1 involved in the hydrolysis were predicted based on the UniProt database, cloned, inserted into the pET28b(+) vector and expressed in E. coli BL21(DE3) as recombinant enzymes using IPTG inducer. All the tested recombinant GH enzymes did not exhibit myrosinase activity towards glucosinolate substrate; however, some displayed GH and/or β-glucosidase activity towards various sugars using GOD-PERID and β-glucosidase assays. These enzymes may be inactive in the pH buffers used or activity only occurs in intact cells where the integrity of transport/phosphorylation system is intact. In spite of some caveats in this work, the findings would still be useful to better understand glucosinolate metabolism by human gut bacteria which is liked with chemopreventive benefits.

Here, the impact of 300 mg L-1 slightly acidic electrolyzed water ice (SAEWI) on postharvest senescence, glucosinolate and sulforaphane contents, and the expression levels of key genes in the glucosinolate metabolic pathway in broccoli was investigated. Results indicated that SAEWI delayed yellowing senescence by slowing the decline of chlorophyll content. Moreover, SAEWI upregulated the expression of genes involved in aliphatic and indole glucosinolate synthesis. Specifically, after 1 d of shelf life, the SAEWI-treated group exhibited 1.01–1.96 times higher expression levels of BoMYB28 , BoSUR1 , BoST5 , BoMYB51 , BoCYP79B2 , and BoCYP83B1 compared to the control group. Similarly, the expression levels of BoCYP79F1 , BoUGT74B1 , and BoFMO GS-OX2 were 2.51–8.67 times higher in the SAEWI-treated group. Consequently, the SAEWI treatment resulted in elevated concentrations of glucoraphanin, glucoiberin, and 4-Methoxy-glucobrassicin, contributing to an overall increase of more than 40% in the total glucosinolate content. Additionally, the expression level of BoMYR in the SAEWI-treated group exceeded that of the control group after 1 d of shelf life, accompanied by enhanced myrosinase activity. These changes led to higher sulforaphane content in the SAEWI-treated group, which was found to be 2.65–4.33 times higher than that of the control group. In conclusion, the findings suggest that SAEWI treatment in the cold chain circulation model not only delays postharvest quality decline but also boosts the accumulation of active substances in broccoli. • SAEWI slows down postharvest aging of broccoli. • SAEWI upregulates the expression of key genes involved in GLS. • SAEWI increases the content of sulforaphane in postharvest broccoli. [ABSTRACT FROM AUTHOR]

Abstract Background Glucobrassicin (GBS) and its hydrolysis product indole-3-carbinol are important nutritional constituents implicated in cancer chemoprevention. Dietary consumption of vegetables sources of GBS, such as cabbage and Brussels sprouts, is linked to tumor suppression, carcinogen excretion, and cancer-risk reduction. High-performance liquid-chromatography (HPLC) is the current standard GBS identification method, and quantification is based on UV-light absorption in comparison to known standards or via mass spectrometry. These analytical techniques require expensive equipment, trained laboratory personnel, hazardous chemicals, and they are labor intensive. A rapid, nondestructive, inexpensive quantification method is needed to accelerate the adoption of GBS-enhancing production systems. Such an analytical method would allow producers to quantify the quality of their products and give plant breeders a high-throughput phenotyping tool to increase the scale of their breeding programs for high GBS-accumulating varieties. Near-infrared reflectance spectroscopy (NIRS) paired with partial least squares regression (PLSR) could be a useful tool to develop such a method. Results Here we demonstrate that GBS concentrations of freeze-dried tissue from a wide variety of cabbage and Brussels sprouts can be predicted using partial least squares regression from NIRS data generated from wavelengths between 950 and 1650 nm. Cross-validation models had R2 = 0.75 with RPD = 2.3 for predicting µmol GBS·100 g−1 fresh weight and R2 = 0.80 with RPD = 2.4 for predicting µmol GBS·g−1 dry weight. Inspections of equation loadings suggest the molecular associations used in modeling may be due to first overtones from O–H stretching and/or N–H stretching of amines. Conclusions A calibration model suitable for screening GBS concentration of freeze-dried leaf tissue using NIRS-generated data paired with PLSR can be created for cabbage and Brussels sprouts. Optimal NIRS wavelength ranges for calibration remain an open question.

Traditional Chinese medicine (TCM) belongs to the most elaborate and extensive systems of plant‐based healing. The herb Northern Ban Lan (Isatis tinctoria) is famous for its antiviral and anti‐inflammatory activity. Although numerous components isolated from I. tinctoria have been characterized so far, their modes of action have remained unclear. Here, we show that extracts from I. tinctoria exert anti‐microtubular activity. Using time‐lapse microscopy in living tobacco BY‐2 (Nicotiana tabacum L. cv Bright Yellow 2) cells expressing green fluorescent protein‐tubulin, we use activity‐guided fractionation to screen out the biologically active compounds of I. tinctoria. Among 54 fractions obtained from either leaves or roots of I. tinctoria by methanol (MeOH/H2O 8:2), or ethyl acetate extraction, one specific methanolic root fraction was selected, because it efficiently and rapidly eliminated microtubules. By combination of further purification with ultra‐high‐performance liquid chromatography and high‐resolution tandem mass spectrometry most of the bioactivity could be assigned to the glucosinolate compound glucobrassicin. Glucobrassicin can also affect microtubules and induce apoptosis in HeLa cells. In the light of these findings, the antiviral activity of Northern Ban Lan is discussed in the context of microtubules being hijacked by many viral pathogens for cell‐to‐cell spread. [ABSTRACT FROM AUTHOR]

Hydrolysis of glucobrassicin by plant or bacterial myrosinase produces multiple indoles predominantly indole-3-carbinol (I3C). I3C and its major in vivo product, 3,3'-diindolylmethane (DIM), are effective cancer chemopreventive agents in pre-clinical models and show promise in clinical trials. The pharmacokinetics/pharmacodynamics of DIM have been studied in both rodents and humans and urinary DIM is a proposed biomarker of dietary intake of cruciferous vegetables. Recent clinical studies at Oregon State University show surprisingly robust metabolism of DIM in vivo with mono- and di-hydroxylation followed by conjugation with sulfate or glucuronic acid. DIM has multiple mechanisms of action, the most well-characterized is modulation of aryl hydrocarbon receptor (AHR) signaling. In rainbow trout dose-dependent cancer chemoprevention by dietary I3C is achieved when given prior to or concurrent with aflatoxin B1, polycyclic aromatic hydrocarbons, nitrosamines or direct acting carcinogens such as N-methyl-N'-nitro-nitrosoguanidine. Feeding pregnant mice I3C inhibits transplacental carcinogenesis. In humans much of the focus has been on chemoprevention of breast and prostate cancer. Alteration of cytochrome P450-dependent estrogen metabolism is hypothesized to be an important driver of DIM-dependent breast cancer prevention. The few studies done to date comparing glucobrassicin-rich crucifers such as Brussels sprouts with I3C/DIM supplements have shown the greater impact of the latter is due to dose. Daily ingestion of kg quantities of Brussels sprouts is required to produce in vivo levels of DIM achievable by supplementation. In clinical trials these supplement doses have elicited few if any adverse effects. Sulforaphane from glucoraphanin can act synergistically with glucobrassicin-derived DIM and this may lead to opportunities for combinatorial approaches (supplement and food-based) in the clinic.

Brassica vegetables may modulate cancer risk by regulation of xenobiotic metabolizing enzymes (XMEs). In a randomized crossover study, the effect of kale consumption on CYP1A2, CYP2A6, XO, and NAT2 activity was determined by urinary caffeine metabolite ratios, UGT1A1 activity by serum bilirubin concentrations, and GSTA protein and GST activity in blood by ELISA. Adults (n = 25) consumed a basal diet supplemented with kale and radish for 14 days or control vegetables. The kale diet increased CYP1A2 activity by 16.4% on day 8 and 15.2% on day 15 compared to control. Conjugated bilirubin was reduced by the kale diet, decreasing from 19.4 to 14.3 to 9.5% of total bilirubin on days 1, 8, and 15, respectively, which may be explained by induction of MRP2. Other XMEs were not affected by diet. The implications of these results for cancer risk will be clarified as the functions of these XMEs become better understood.

Recent improvements in light-emitting diode (LED) technology afford an excellent opportunity to investigate the relationship between different light sources and plant metabolites. Accordingly, the goal of the present study was to determine the effect of different LED (white, blue, and red) treatments on the contents of glucosinolates (glucoiberin, gluconapin, sinigrin, gluconasturtiin, 4-methoxyglucobrassicin, 4-hydroxyglucobrassicin, glucobrassicin, and neoglucobrassicin) and phenolic compounds (4-hydroxybenzonate, catechin, chlorogenic acid, caffeate, gallate, sinapate, and quercetin) in Brassica juncea sprouts. The sprouts were grown in a growth chamber at 25 °C under irradiation with white, blue, or red LED with a flux rate of 90 ^mol m-2 s-1 and a long-day photoperiod (16 h light/8 h dark cycle). Marked differences in desulfoglucosinolate contents were observed in response to treatment with different LEDs and different treatment durations. In addition, the highest total desulfoglucosinolate content was observed in response to white LED light treatment, followed by treatment with red LED light, and then blue LED light. Among the individual desulfoglucosinolates identified in the sprouts, sinigrin exhibited the highest content, which was observed after three weeks of white LED light treatment. The highest total phenolic contents were recorded after one week of white and blue LED light treatment, whereas blue LED irradiation increased the production of most of the phenolic compounds identified, including 4-hydroxybenzonate, gallate, sinapate, caffeate, quercetin, and chlorogenic acid. The production of phenolics decreased gradually with increasing duration of LED light treatment, whereas anthocyanin accumulation showed a progressive increase during the treatment. These findings indicate that white LED light is appropriate for glucosinolate accumulation, whereas blue LED light is effective in increasing the production of phenolic compounds in B. juncea sprouts. [ABSTRACT FROM AUTHOR]

Glucosinolates are phytochemicals with important health and nutritional benefits. This study reports the use of high-performance liquid chromatography (HPLC) and mid-infrared (MIR) spectroscopy to characterise and differentiate between broccoli varieties and systems of production (organic vs. non-organic) depending on their glucosinolate content and infrared fingerprint. Broccoli samples (n = 53) from seven varieties were analysed using MIR spectroscopy and HPLC. Differences in the MIR spectra of the individual broccoli varieties were observed in the carbohydrate fingerprint region (950–1100 cm-1) and between 1340 and 1615 cm-1 assigned to specific glucosinolates. Principal component analysis (PCA) of the MIR fingerprint spectra enabled the differentiation between samples with relatively high (200–500 mg/100 g DW) and low (< 200 mg/100 g DW) glucobrassicin content. Linear discriminant analysis (LDA) and PCA-LDA were used to classify broccoli varieties according to the system of production (organic vs. non-organic) and variety (common vs. Tenderstem® broccoli). The classification rates indicated that > 70 % of the samples were correctly classified as organic and non-organic, while > 90 % of the samples were correctly classified as common broccoli and Tenderstem®. This study demonstrates that MIR spectroscopy could be used as a potential tool to classify and monitor broccoli samples according to their variety and system of production. • HPLC and MIR spectroscopy were used to characterise seven broccoli varieties. • PCA and LDA classification models were used on broccoli HPLC and MIR data. • MIR was able to differentiate between samples high or low in glucobrassicin content. • LDA of MIR correctly classified 96 % of samples as common broccoli or Tenderstem®. [ABSTRACT FROM AUTHOR]

Individual glucosinolates (GSLs) were assessed to select cabbage genotypes for a potential breeding program. One hundred forty-six cabbage genotypes from different origins were grown in an open field from March to June 2019; the cabbage heads were used for GSL analyses. Seven aliphatics [glucoiberin (GIB), progoitrin (PRO), epi-progoitrin (EPI), sinigrin (SIN), glucoraphanin (GRA), glucoerucin (GER) and gluconapin (GNA)], one aromatic [gluconasturtiin (GNS)] and four indolyl GSLs [glucobrassicin (GBS), 4-hydroxyglucobrassicin (4HGBS), 4-methoxyglucobrassicin (4MGBS), neoglucobrassicin (NGBS)] were found this study. Significant variation was observed in the individual GSL content and in each class of GSLs among the cabbage genotypes. Aliphatic GSLs were predominant (58.5%) among the total GSLs, followed by indolyl GSL (40.7%) and aromatic GSLs (0.8%), showing 46.4, 51.2 and 137.8% coefficients of variation, respectively. GIB, GBS and NGBS were the most common GSLs found in all genotypes. GBS was the most dominant GSL, with an average value of 3.91 µmol g−1 (0.79 to 13.14 µmol g−1). SIN, GIB, PRO and GRA were the other major GSLs, showing average values of 3.45, 1.50, 0.77 and 0.62 µmol g−1, respectively. The genotypes with relatively high contents of GBS, SIN, GIB and GRA warrant detailed studies for future breeding programs since the hydrolysis products of these GSLs have several anti-cancer properties.

This study identified glucosinolate (GLS) breakdown products and determined the relationships between such products and parent GLS in boiled Brussels sprouts. This is the first ever study to analyse all groups of GLS breakdown products (aliphatic, aralkyl and indole) in boiled vegetables. In the examined boiled Brussels sprouts, isothiocyanates were not determined in the edible parts or cooking water. The presence of seven breakdown products was determined as indole-3-acetonitrile, indole-3-carbinol, ascorbigen and 3,3'-diindolylmethane released form glucobrassicin, 3-butenylnitrile released from sinigrin, 4-methylsulfinylbutanenitrile released from glucoiberin, and 2-phenylacetonitrile released from gluconasturtiin. In the edible parts, the content of indole-3-acetonitrile and 3-butenylnitrile was particularly high at approximately 30 and 16 µmol/100 g FW, which was equivalent to 54 and 9% of the initial value of the parent GLS, respectively.

Irrigation with moderately saline water is a necessity in many semi-arid areas of the Mediterranean Basin, and requires adequate irrigation management strategies. Broccoli ( Brassica oleracea var. italica ), a crop moderately sensitive to salinity stress, was used to evaluate the effects of the application of saline (S) and non-saline (NS) irrigation water during two growth phases in terms of plant growth, water status, floret yield, glucosinolate profile, and quality. Use of S-water (4 dS m −1 ) from transplanting to appearance of the inflorescence, alternated with NS-water (2 dS m −1 ) from inflorescence appearance to harvest and vice versa were compared with continuous use of S- or NS-water. Irrigation with S-water during the first growth-phase decreased leaf water and osmotic potential, net CO 2 assimilation rate, and favoured Na + and Cl − accumulation at toxic levels causing ion imbalances and reducing broccoli plant growth. Application of S-water exclusively after inflorescence appearance caused a 22.2% decrease of the head dry biomass compared to NS-NS plants. Regardless of application timing, irrigation with S-water decreased broccoli yield and head mean fresh weight compared to NS-NS plants by 20% and 24%, respectively. Use of S-water in one or both growth stages improved broccoli dry matter and soluble solid content, while had no impact on total glucosinolate concentration. However, application of S-water during the first growth-phase resulted in an increase of indolic glucosinolates (glucobrassicin and neoglucobrassicin) and potential effects on broccoli nutritional properties and flavour. [ABSTRACT FROM AUTHOR]

Glucobrassicin, a quantitatively significant constituent of Brassica vegetables, gives rise to indole-3-carbinol (I3C) and its dimer di-indolylmethane (DIM) when the vegetables are chewed. I3C and DIM have been extensively studied with respect to their anti-carcinogenic properties. However, the presumed intermediate isothiocyanate in their formation, indole-3-methyl isothiocyanate (IMITC), has to our knowledge never been observed, despite the fact that isothiocyanates derived from cruciferous vegetables are known to have anti-carcinogenic properties. Therefore, we investigated the formation and presence in human urine of IMITC by analyzing for its N -acetylcysteine conjugate, IMITC-NAC, in order to gain a more complete understanding of the biochemical pathways leading to formation of I3C and DIM upon consumption of vegetables rich in glucobrassicin. Standard IMITC-NAC was synthesized and its structure confirmed by NMR and MS. IMITC-NAC was identified in extracts of Brussels sprouts chopped in the presence of N -acetylcysteine. An LC-ESI–MS/MS-SRM method for analysis of IMITC-NAC, with [ 13 C, 15 N]IMITC-NAC as internal standard, was developed and validated. Then, ten subjects (7 females) consumed a salad of Brussels sprouts and cabbage (containing 100–500 μmol glucobrassicin) once daily for 3 days. Urine was collected at intervals up to 24 h after vegetable consumption. Levels of IMITC-NAC in the urine of these 10 subjects ranged from 0.2 to 30.2 pmol/mL urine. These results provide the first evidence for the presumed intermediacy of IMITC in the formation of I3C and DIM in humans who consumed Brussels sprouts and cabbage as a source of glucobrassicin. [ABSTRACT FROM AUTHOR]

Multiple lepidopteran larvae feed successfully on plants containing glucosinolates despite the diverse array of toxic and deterrent breakdown products, such as isothiocyanates (ITCs), formed upon plant damage. While much is known about how specialist lepidopterans metabolize and tolerate glucosinolates, there is little information about the metabolic fate of these plant defense compounds in specialized herbivores. Employing 13C- and 14C-labeled 4-methylsulfinylbutyl glucosinolate (glucoraphanin), we identified and quantified the major detoxification products of glucosinolates and ITCs in selected specialized and generalist larvae. While specialists prevented glucosinolate hydrolysis or diverted hydrolysis to form nitriles, hydrolysis in generalists proceeded to toxic ITCs, of which a portion were conjugated to glutathione. However, a large amount of ITCs remained unmodified, which may have led to the observed negative effects on growth and development. The performance of two generalist-feeding caterpillars, Spodoptera littoralis (African cotton leafworm) and Mamestra brassicae (cabbage moth) on Arabidopsis thaliana Col-0 and various glucosinolate-deficient mutants was investigated from hatching until pupation. We found that glucosinolates negatively affected larval growth and development, but not survival, with aliphatic glucosinolates having stronger effects than indolic glucosinolates, and the combination of the two glucosinolate types being even more detrimental to growth and development. Curiously, last instar larvae grew better on wild type than on non-glucosinolate-containing plant lines, but this could not be attributed to a change in detoxification rate or feeding behavior. Glucosinolates thus appear to be effective defenses against generalist lepidopteran herbivores at least during most stages of larval development. Nevertheless, the reversal of negative effects in the oldest instar is intriguing, and further investigation of this phenomenon may shed light on how generalists adjust their physiology to feed on diets with many different types of plant defense compounds.

Multiple lepidopteran larvae feed successfully on plants containing glucosinolates despite the diverse array of toxic and deterrent breakdown products, such as isothiocyanates (ITCs), formed upon plant damage. While much is known about how specialist lepidopterans metabolize and tolerate glucosinolates, there is little information about the metabolic fate of these plant defense compounds in specialized herbivores. Employing 13C- and 14C-labeled 4-methylsulfinylbutyl glucosinolate (glucoraphanin), we identified and quantified the major detoxification products of glucosinolates and ITCs in selected specialized and generalist larvae. While specialists prevented glucosinolate hydrolysis or diverted hydrolysis to form nitriles, hydrolysis in generalists proceeded to toxic ITCs, of which a portion were conjugated to glutathione. However, a large amount of ITCs remained unmodified, which may have led to the observed negative effects on growth and development. The performance of two generalist-feeding caterpillars, Spodoptera littoralis (African cotton leafworm) and Mamestra brassicae (cabbage moth) on Arabidopsis thaliana Col-0 and various glucosinolate-deficient mutants was investigated from hatching until pupation. We found that glucosinolates negatively affected larval growth and development, but not survival, with aliphatic glucosinolates having stronger effects than indolic glucosinolates, and the combination of the two glucosinolate types being even more detrimental to growth and development. Curiously, last instar larvae grew better on wild type than on non-glucosinolate-containing plant lines, but this could not be attributed to a change in detoxification rate or feeding behavior. Glucosinolates thus appear to be effective defenses against generalist lepidopteran herbivores at least during most stages of larval development. Nevertheless, the reversal of negative effects in the oldest instar is intriguing, and further investigation of this phenomenon may shed light on how generalists adjust their physiology to feed on diets with many different types of plant defense compounds. [ABSTRACT FROM AUTHOR]

Environmental stress hinders growth of plants and commonly results in the accumulation of carbon-based defense compounds. However, the dynamics of nitrogen (N)-containing defense compounds are less predictable under environmental stress. The impact of nutrient deficiency on plant defenses that require the metabolic conversion of a less toxic compound to a more potent toxin is even more poorly understood. We evaluated the effects of nitrogen (N) and potassium (K) deficiency and simulated herbivory on the concentration of metabolites including glucosinolates (GSLs), on the conversion of GSLs to more toxic isothiocyanates (ITCs), and on the activity of myrosinase (MYR) in leaves of Brassica juncea and Brassica nigra. Both species contained GSLs, predominantly sinigrin, but also derivatives of glucobrassicin. Compared to the control, N deficiency increased the sinigrin concentration in both species. Methyl jasmonate (MeJA) application increased sinigrin production in B. junceae, whereas in B. nigra MeJA increased sinigrin only under K-deficiency. Compared to the aliphatic-glucosinolates, MeJA application produced a greater compositional change in the profiles of indolic-glucosinolates. In both species the increase in sinigrin content of the tissue was associated with a decrease in its overall nutritive value as assessed by the content of sugars and amino acids. In B. juncea, application of MeJA decreased the conversion of sinigrin to allyl isothiocyanate (AITC) under both N and K deficiency. The potential activity of MYR decreased in both species under N deficiency. The reduced conversion of sinigrin to AITC and the lower activity of MYR suggest that the GSL-ITC defense system might have a limited efficiency in deterring generalist herbivores under environmental stress. [ABSTRACT FROM AUTHOR]

Smoothies represent an excellent and convenient alternative to promote the daily consumption of fruit and vegetables in order to obtain their health-promoting benefits. Accordingly, a green fresh vegetables smoothie (77.2% cucumber, 12% broccoli and 6% spinach) rich in health-promoting compounds was developed. Soluble solids content, pH and titratable acidity of the smoothie were 4.3 ± 0.4°Bx, 4.49 ± 0.01 and 0.22 ± 0.02 mg citric acid 100−1 g fw, respectively. Two thermal treatments to reduce microbial loads and preserve quality were assayed: T1 (3 min at 80 ℃) and T2 (45 s at 90 ℃). Fresh blended unheated samples were used as control (CTRL). The smoothie presented a viscoelastic behaviour. T1 and T2 treatments reduced initial microbial loads by 1.3–2.4 and 1.4–3.1 log units, respectively. Samples were stored in darkness at 5 and 15 ℃. Colour and physicochemical changes were reduced in thermal-treated samples throughout storage, which were better preserved at 5 ℃ rather than at 15 ℃. Vitamin C changes during storage were fitted with a Weibullian distribution. Total vitamin C losses of T1 and T2 samples during storage at 15 ℃ were greatly reduced when they were stored at 5 ℃. Initial total phenolic content (151.1 ± 4.04 mg kg−1 fw) was 44 and 36% increased after T1 and T2 treatments, respectively. The 3-p-coumaroyl quinic and chlorogenic acids accounted the 84.7 and 7.1% relative abundance, respectively. Total antioxidant capacity (234.2 ± 20.3 mg Trolox equivalent kg−1 fw) remained constant after the thermal treatments and was better maintained during storage in thermal-treated samples. Glucobrassicin accounted the 81% of the initial total glucosinolates content (117.8 ± 22.2 mg kg−1 fw) of the smoothie. No glucosinolates losses were observed after T2 treatment being better preserved in thermal-treated samples. Conclusively, a short time–high temperature mild thermal treatment (T2) showed better quality and bioactive compounds retention in a green fresh vegetable smoothie during low temperature storage. [ABSTRACT FROM AUTHOR]

BACKGROUND The content of individual and total glucosinolates in 65 mashua tuber accessions ( Tropaeolum tuberosum) from the germplasm bank at Universidad Nacional de Colombia was determined by reverse phase high-performance liquid chromatography on enzymatically desulfated extracts. The predominant glucosinolate was identified and the possible structure of the glucosinolate present in lower proportion was postulated from evidence obtained by high-performance liquid chromatography/mass spectrometry, 1H and 13C nuclear magnetic resonance and bi-dimensional experiments. The biological action of the hydrolysis products generated from the glucosinolates in the accessions that showed a higher content of these compounds was assessed in the presence of Fusarium oxysporum f. sp. dianthi, Rhizoctonia solani and Phytophthora infestans. RESULTS The total content of glucosinolates ranged between >3.00 × 10−1 and 25.8 µmol g−1 dry matter. p-Methoxybenzyl glucosinolate was identified as the predominant glucosinolate in Colombian mashua accessions; besides, the possible presence of p-hydroxybenzyl glucosinolate was postulated. In vitro assays established an important fungal growth inhibition of the potato pathogen P. infestans. CONCLUSION The biological action from p-methoxybenzyl glucosinolate and p-hydroxybenzyl glucosinolate found in Colombian mashua accessions depends on their concentration, with the Tt30 accession, characterized for showing the highest content of glucosinolates, being the most promising to control the assessed pathogens. © 2016 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The aim of this research was to evaluate the profile and concentration of individual glucosinolates (GSL), and the total phenol content (TPC), total flavonoid content (TFC), ascorbic acid content, and antioxidant activity of broccoli florets and flower stalks (10 commercial cultivars, 19 F1 hybrids, and 20 inbred lines). All broccoli heads were harvested at their marketable stage, and their flower stalks and florets were subjected to phytochemical analysis. GSL, TPC, TFC, and ascorbic acid content varied significantly depending on broccoli genotype. Altogether, nine GSLs were identified, four of which (glucoraphanin, progoitrin, glucoerucin, and glucobrassicin) were the most common in both broccoli flower stalks and florets. In florets, glucobrassicin was the most abundant GSL (4.46 μmol·g DW), followed by glucoraphanin (1.93 μmol·g DW), whereas glucoraphanin was the most abundant in flower stalks (1.47 μmol·g DW). The concentrations of total GSLs, TPC, and TFC in florets were relatively higher than those in the flower stalks, whereas the concentration of ascorbic acid was higher in the flower stalks than the florets. Almost all F1 hybrids and inbred lines exhibited higher TPC, TFC, ascorbic acid concentration, and antioxidant activities than those in the commercial cultivars. Three F1 hybrids; 5075, 5078, and 5079, and one inbred line (5308) had the highest glucoraphanin and total GSL content. Three inbred lines, 5307, 5311, and 5409 had the higher concentration of glucobrassicin and total GSLs, superior antioxidant activity with low PRO+EPI content. These results suggest that these genotype selections had desirable compositions of individual GSLs and higher nutritional value for commercialization as functional vegetables. [ABSTRACT FROM AUTHOR]

The aim of the study was to investigate the effect of storage on the contents of glucosinolates (GLS) and their degradation products in a boiled white cabbage. A 24 h storage at 4 °C resulted in a decrease in GLS content (20–40%, depending on the cooking time applied) in the edible parts. The most significant losses were observed for sinigrin (20–45%), and the least for glucobrassicin (12–32%). Storage had a diversified effect on GLS breakdown products (indole-3-acetonitrile, indole-3-carbinol, ascorbigen and 3,3′-diindolylmethane released from glucobrassicin and 4-methylsulfinylbutanenitrile released from glucoiberin) in the boiled cabbage. The increase in the content of indole-3-acetonitrile, especially considerable within the first 24 h of storage (and a simultaneous decrease in glucobrassicin) clearly indicates that degradation of GLS may occur during storage or cooling to 4 °C. [ABSTRACT FROM AUTHOR]

The relationship between the total glucosinolate (GSL) concentration calculated from the total sulfur concentration which had been measured by means of X-ray fluorescence spectroscopy and the content of glucobrassicanapine, glucobrassicine, gluconapine, napoleiferine, progoitrine and 4-hydroxiglucobrassicine in the seeds which were measured by chromatographic methods was determined in the line of quality assessment studies of oilseed rape standard reference materials. The constant ratio between individual aliphatic GSLs which is independent of the total GSL content allows to emulating the concentration of individual GSLs from the total GSL content on basis of the total S content. As indol GSLs represent a constant background value of the total GSL content their estimated concentration is added to the calculated sum of aliphatic GSLs in order to obtain an emulated total GSL content. In a simple program written in BASIC the typical background variability of individual GSLs can be randomly added to the results which yields different chromatograms that are statistically not different from true HPLC chromatograms. This may assist in distinguishing true experimental effects in studies targeting effects on individual GSLs from those of background analytical error variability. The program may also be used for an independent verification of HPLC chromatograms of GSLs in oilseed rape as it allows backtracking of a given total GSL content to its expected individual GSL concentrations in chromatographic analysis. [ABSTRACT FROM AUTHOR]

A systematic investigation was carried out on the influence of fermentation on glucosinolates and their degradation products from fresh raw cabbage, throughout fermentation at 20 °C and storage at 4 °C. Glucosinolates were degraded dramatically between Day 2 and 5 of fermentation and by Day 7 there was no detectable amount of glucosinolates left. Fermentation led to formation of potential bioactive compounds ascorbigen (13.0 μmol/100 g FW) and indole-3-carbinol (4.52 μmol/100 g FW) with their higher concentrations from Day 5 to Day 9. However, during storage indole-3-carbinol slowly degraded to 0.68 μmol/100 g FW, while ascorbigen was relatively stable from Week 4 until Week 8 at 6.78 μmol/100 g FW. In contrast, the content of indole-3-acetonitrile decreased rapidly during fermentation from 3.6 to 0.14 μmol/100 g FW. The results imply a maximum of health beneficial compounds after fermentation (7–9 days) in contrast to raw cabbage or stored sauerkraut. [ABSTRACT FROM AUTHOR]

This study identified glucosinolate (GLS) breakdown products and determined the relationships between such products and parent GLS in boiled Brussels sprouts. This is the first ever study to analyse all groups of GLS breakdown products (aliphatic, aralkyl and indole) in boiled vegetables. In the examined boiled Brussels sprouts, isothiocyanates were not determined in the edible parts or cooking water. The presence of seven breakdown products was determined as indole-3-acetonitrile, indole-3-carbinol, ascorbigen and 3,3'-diindolylmethane released form glucobrassicin, 3-butenylnitrile released from sinigrin, 4-methylsulfinylbutanenitrile released from glucoiberin, and 2-phenylacetonitrile released from gluconasturtiin. In the edible parts, the content of indole-3-acetonitrile and 3-butenylnitrile was particularly high at approximately 30 and 16 µmol/100 g FW, which was equivalent to 54 and 9% of the initial value of the parent GLS, respectively. [ABSTRACT FROM AUTHOR]

Most Brassicaceae plants produce glucosinolates (GSLs), which are hydrolyzed to form isothiocyanates (ITCs) that contribute to a stimulative flavor and antibiotic activity beneficial to human health. Three glucosinolates (GSLs), gluconapin, glucoibarin and glucobrassicin, were isolated from plants of Cardamine fauriei Maxim. (Brassicaceae; Ezo-wasabi in Japanese), a wild, edible herb originating from Hokkaido, Japan. These GSLs comprise two types: aliphatic (gluconapin and glucoibarin) and indolic (glucobrassicin). Total GSL concentration in the leaf blade, petiole and root of the plant grown in natural light were 62.81, 43.94 and 17.63 mg g −1 dry mass, respectively. When the plants were grown under various wavelengths of light supplied by LEDs, total GSL content in the leaf blade was highest when plants were irradiated by red + blue light. In addition, the ratio of the content of the indolic GSL to that of aliphatic GSL was greater after irradiation with by red or green alone rather than blue alone, red + blue, or white (red + blue + green). Because the last three types of irradiation include blue wavelengths, aliphatic GSL content can be increased by irradiation with blue light wavelengths, whereas the indolic GSL levels decreased. The results indicate that it is possible to control the GSL component ratio in C. fauriei by irradiating plants with particular wavelengths. [ABSTRACT FROM AUTHOR]

Broccoli is grown around the world at a wide range of photoperiods and temperatures, which may influence both sensory quality and phytochemical contents. Florets produced in phytotron and at two semi-field sites (70°N and 58°N) were examined for effects of contrasting temperatures and photoperiods on sensory quality and contents of glucosinolates, flavonols and vitamin C. Growth conditions associated with high northern latitudes of low temperature and long photoperiods, produced bigger floral buds, and florets with sweeter taste and less colour hue than more southern conditions. The contents of vitamin C did not vary, while the response of individual glucosinolates varied with temperature and day length, and contents of quercetin and kaempferol were lower in phytotron than under semi-field conditions. Thus, our results show that contrasting temperatures and photoperiods influence the sensory quality of broccoli florets, while contents of different bioactive phytochemicals are not influenced in a unidirectional pattern. [ABSTRACT FROM AUTHOR]

BACKGROUND Broccoli and other cruciferous vegetables contain a number of bioactive compounds, in particular glucosinolates and polyphenols, which are proposed to confer health benefits to the consumer. Demand for organic crops is at least partly based on a perception that organic crops may contain higher levels of bioactive compounds; however, insufficient research has been carried out to either support or refute such claims. RESULTS In this study we examined the effect of conventional, organic, and mixed cultivation practices on the content of total phenolics, total flavonoids, and total and individual glucosinolates in two varieties of broccoli grown over 2 years in a split-plot factorial systems comparison trial. Levels of total phenolics and total flavonoids showed a significant year-on-year variation but were not significantly different between organic and conventional production systems. In contrast, levels of the indolyl glucosinolates glucobrassicin and neoglucobrassicin were significantly higher ( P < 0.05) under fully organic compared to fully conventional management. CONCLUSION Organic cultivation practices resulted in significantly higher levels of glucobrassicin and neoglucobrassicin in broccoli florets; however, other investigated compounds were unaffected by production practices. © 2014 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Four loose-curd cauliflower varieties, and one common cauliflower cultivar, were studied to investigate the appearance, antioxidant capacity, and levels of ascorbic acid, chlorophylls, carotenoids and glucosinolates in the florets. The loose-curd cauliflower was typically characterized by a loose curd and long florets with green pedicels and a yellow surface. The levels of total glucosinolates, sinigrin, and neoglucobrassicin were lower in the loose-curd cauliflower varieties than in the common cauliflower. The amount of glucoiberin, major aliphatic glucosinolate, present in loose-curd cauliflower varieties, was 147 to 241 nmol/g dry weight (average: 147 nmol/g dry weight). In contrast, the common cauliflower contained a much higher amount of sinigrin (249 nmol/g dry weight) than glucoiberin (56 nmol/g dry weight). All cauliflower varieties contained minor amounts of progoitrin and neoglucobrassicin. Furthermore, the loose-curd cauliflower varieties exhibited comparably higher levels of ascorbic acid, chlorophylls, and carotenoids, than total phenolics. The ferric reducing antioxidant power values in the loose-curd varieties ranged from 92 ± 7 to 107 ± 8 μmol Fe2+/g dry weight, which were also higher than that in the common cauliflower. The results indicated that the loose-curd cauliflower can provide higher levels of health-promoting compounds than the common cauliflower. [ABSTRACT FROM AUTHOR]