Brassica foods are among the top 10 economic crops in the world (i.e. broccoli, kale, cauliflower and Chinese cabbage). These vegetables have been identified as important components of a healthy diet ...because of their high levels of nutrients and health‐promoting phytochemicals (i.e. phenolics, glucosinolates, vitamins and minerals). Epidemiological studies have shown that increased consumption of Brassica foods is strongly associated with a reduced risk of degenerative diseases, cancer, cardiovascular disease and immune dysfunction. Nevertheless, the nutritional content and profile in Brassica vegetables have been reported to vary considerably during the growth period due to agronomical factors including light, temperature, water availability and soil fertility among others. Moreover, the conditions of postharvest processing and cooking are also important factors on food quality. A better understanding of specific preharvest and postharvest conditions is essential to improve cultivars with value‐added nutritional quality. Thus, in this article are going to be addressed the effects of the most common crop management strategies and processes on the variation of nutritive compounds present within Brassica from the agri‐food perspective.
Mustard is a
vegetable that provides a number of phytonutrients. However, the phytonutrient profile of mustard has been relatively limited. We analyzed the glucosinolates and their hydrolysis ...products, carotenoids, total anthocyanin and phenolic contents, and antioxidant capacity of the leaves of 11 mustard cultivars grown in a greenhouse at the baby leaf and mature stages. An aliphatic glucosinolate sinigrin and its hydrolysis products allyl isothiocyanate and 1-cyano-2,3-epithiopropane were the major phytonutrients in the mustard leaves. Carotenoids β-carotene, lutein, violaxanthin, and neoxanthin were detected. We found phytonutrient concentration and their change with plant growth were cultivar-dependent. The %RDA value for vitamin A calculated using β-carotene content and retinol activity equivalents suggests that mustard cultivars used in this study can be a good source of vitamin A. Phenolic contents and antioxidant capacity also varied among cultivars and between physiological stages. Our results suggest that mustard leaves are rich in various phytochemicals and their composition depends on cultivar and the physiological stage. This is the first report on phytochemical composition in various mustard cultivars at different physiological stages.
Plant diseases are major contributing factors for crop loss in agriculture. Here, we show that Arabidopsis plants with high levels of novel glucosinolates (GSs) as a result of the introduction of ...single CYP79 genes exhibit altered disease resistance. Arabidopsis expressing CYP79D2 from cassava accumulated aliphatic isopropyl and methylpropyl GS, and showed enhanced resistance against the bacterial soft-rot pathogen Erwinia carotovora, whereas Arabidopsis expressing the sorghum CYP79A1 or over-expressing the endogenous CYP79A2 accumulated p-hydroxybenzyl or benzyl GS, respectively, and showed increased resistance towards the bacterial pathogen Pseudomonas syringae. In addition to the direct toxic effects of GS breakdown products, increased accumulation of aromatic GSs was shown to stimulate salicylic acid-mediated defenses while suppressing jasmonate-dependent defenses, as manifested in enhanced susceptibility to the fungus Alternaria brassicicola. Arabidopsis with modified GS profiles provide important tools for evaluating the biological effects of individual GSs and thereby show potential as biotechnological tools for the generation of plants with tailor-made disease resistance.
Glucosinolates, present in Brassica vegetables, are thought to contribute to human health prevention because of their enzymatically induced breakdown products, primarily isothiocyanates (ITCs). ITCs ...are reactive substances that readily react with nucleophilic (food) compounds. The reactivity of allyl-ITC and 4-(methylsulfinyl)butyl-ITC (sulforaphane) toward thiol and amino groups of cysteine and lysine derivatives was studied in buffered model systems as well as broccoli sprouts. The thiol group is the preferred reaction site, and it was demonstrated that even endogenously released sulforaphane is able to react very fast with cysteine in broccoli sprouts. Amino groups reacted slower and only under basic conditions. However, great differences in the reactivity between the different amino compounds were revealed. The aliphatic allylamine reacted very fast with allyl-ITC, forming N,N′-diallylthiourea, a compound identified as a main thermal degradation product of allyl-ITC.
Pre- and postharvest strategies have been developed during the last decades to increase yield, quality, and bioactive compounds of sprouts and microgreens. Depending on the growth stage, especially ...in the first stages, the phytochemicals amount differs and usually affects the sensory profile and consumer acceptability. The aim of this work was to compare key biocompounds content (organosulfur compounds and total phenolic content) with their sensory profile in two growing stages (sprouts and microgreens) of five Brassica species (kale, radish, rocket, broccoli, and mustard). A penalty analysis with consumer study data was also performed to optimize their harvest time by avoiding undesirable intensity of sensory descriptors. An online survey was conducted in two Mediterranean basin populations (Italy and Spain) to fix these product intentions and consumption preferences. Brassica sprouts were generally richer in organosulfur compounds than microgreens of the same species. This study confirms that some organosulfur compounds and/or their hydrolyzed compounds are linked with spicy/pungent sensory attributes in brassicas sprouts and microgreens. The results reported provide useful information for microscale vegetable farmers as a tool to determine their harvest time according to the content and composition of phytochemical compounds.
•Brassica sprouts contain higher organosulfur phytochemicals than their respective microgreens.•No significant differences were shown in sensory profile between sprouts and microgreens, except in radish.•Consumer acceptability depends on the growing stage and the brassica specie.•Some glucosinolates and/or their hydrolyzed compounds are linked with spicy attributes.
Soil salinity can have various negative consequences on agricultural products, from their quality and production to their aesthetic traits. In this work, the possibility to use salt-affected ...vegetables, that otherwise would be discarded, as a source of nutraceuticals was explored. To this aim, rocket plants, a vegetable featuring bioactive compounds such as glucosinolates, were exposed to increasing NaCl concentrations in hydroponics and analysed for their content in bioactive compounds. Salt levels higher than 68 mM produced rocket plants that did not comply with European Union regulations and would therefore be considered a waste product. Anyway, our findings, obtained by Liquid Chromatography-High Resolution Mass Spectrometry, demonstrated a significant increase in glucosinolates levels in such salt-affected plants. opening the opportunity for a second life of these market discarded products to be recycled as glucosinolates source. Furthermore, an optimal situation was found at NaCl 34 mM in which not only were the aesthetic traits of rocket plants not affected, but also the plants revealed a significant enrichment in glucosinolates. This can be considered an advantageous situation in which the resulting vegetables still appealed to the market and showed improved nutraceutical aspects.
► GLSs, mainly glucobrassicin have antioxidant activity in ORAC and SRSA assays. ► There is no synergy or antagonism between GLSs. ► Breakdown products of GLSs are far more active than the native ...GLSs. ► Contribution of GLSs to antioxidant activity of cauliflower seems low.
Glucosinolates (GLSs) are of great interest for their potential as antioxidant and anticancer agents. Our aim was to assess in vitro antioxidant activity of cauliflower GLSs and their derivatives, as well as to evaluate their contribution to the overall antioxidant capacity of cauliflower extracts using four different in vitro assays, 2,2′-azino-bis-(3-ethyl-benzothiazoline-6-sulphonic acid) radical cation (ABTS+), 2,2-diphenyl-1-picrylhydrazyl assay (DPPH), oxygen radical absorbance capacity assay (ORAC) and superoxide radical scavenging activity assay (SRSA). The antioxidant activities of GLSs determined using ABTS+ and DPPH assays were weak. In contrast, ORAC and SRSA assays showed significant antioxidant activity for GLSs. This activity was particularly important for glucobrassicin, which was the most effective GLS, and for glucoiberin and gluconapin. Mixtures of GLSs did not show either synergy or antagonism in general. Interestingly, the breakdown products, i.e. enzymatic hydrolysis-derived products (EHDP) of GLSs, were far more active than the native GLSs. The highest increases in antioxidant activity were obtained for EHDPs from progoitrin, sinigrin and glucoraphanin; progoitrin EHDP being the second most active derivative behind glucobrassicin EHDP. Antioxidant activities and GLS composition of different cauliflower by-product extracts were also determined. The contribution of different GLSs on measured antioxidant activity of cauliflower extracts was also discussed.
Gregarines are usually classified as parasites, but recent studies suggest that they should be viewed on a parasitism-mutualism spectrum and may even be seen as part of the gut microbiota of host ...insects. As such, they may also impact the consumption of their hosts and/or be involved in the digestion or detoxification of the host's diet. To study such effects of a gregarine species on those traits in its host, the mustard leaf beetle (
) was used. This beetle species feeds on Brassicaceae plants that contain glucosinolates, which form toxic compounds when hydrolyzed by myrosinases. We cleaned host eggs from gametocysts and spores and reinfected half of the larvae with gregarines, to obtain gregarine-free (G-) and gregarine-infected (G+) larvae. Growth and food consumption parameters of these larvae were assessed by rearing individuals on watercress (
, Brassicaceae). A potential involvement of gregarines in the glucosinolate metabolism of
larvae was investigated by offering G- and G+ larvae leaf discs of watercress (containing mainly the benzenic 2-phenylethyl glucosinolate and myrosinases) or pea (
, Fabaceae, lacking glucosinolates and myrosinases) treated with the aliphatic 4-pentenyl glucosinolate or the indole 1-methoxy-3-indolylmethyl glucosinolate. Larval and fecal samples were analyzed via UHPLC-QTOF-MS/MS to search for breakdown metabolites. Larval development, body mass, growth rate and efficiency to convert food into body mass were negatively affected by gregarine infection while the pupal mass remained unaffected. The breakdown metabolites of benzenic and aliphatic glucosinolates were conjugated with aspartic acid, while those of the indole glucosinolate were conjugated with glutamic acid. Gregarine infection did not alter the larvae's ability to metabolize glucosinolates and was independent of plant myrosinases. In summary, some negative effects of gregarines on host performance could be shown, indicating parasitism. Future studies may further disentangle this gregarine-host relationship and investigate the microbiome potentially involved in the glucosinolate metabolism.
•Glucosinolates, isothiocyanates and amino acids increase significantly over time.•Glucoraphanin is not significantly affected by harvesting and processing.•Sulforaphane significantly increases after ...processing in E. sativa cultivars.•Bacterial load of leaves is correlated with glucosinolate and amino acid abundance.•Commercial processing may increase the nutritional value of E. sativa to consumers.
Five cultivars of Eruca sativa and a commercial variety of Diplotaxis tenuifolia were grown in the UK (summer) and subjected to commercial growth, harvesting and processing, with subsequent shelf life storage. Glucosinolates (GSL), isothiocyanates (ITC), amino acids (AA), free sugars, and bacterial loads were analysed throughout the supply chain to determine the effects on phytochemical compositions.
Bacterial load of leaves increased significantly over time and peaked during shelf life storage. Significant correlations were observed with GSL and AA concentrations, suggesting a previously unknown relationship between plants and endemic leaf bacteria.
GSLs, ITCs and AAs increased significantly after processing and during shelf life. The supply chain did not significantly affect glucoraphanin concentrations, and its ITC sulforaphane significantly increased during shelf life in E. sativa cultivars. We hypothesise that commercial processing may increase the nutritional value of the crop, and have added health benefits for the consumer.
Butterflies, like many insects, use gustatory and olfactory cues innately to assess the suitability of an oviposition site and are able to associate colours and leaf shapes with an oviposition ...reward. Studies on other insects have demonstrated that the quality of the reward is a crucial factor in forming associative memory. We set out to investigate whether the large cabbage white Pieris brassicae (Linnaeus) has the ability to associate an oviposition experience with a neutral olfactory cue. In addition, we tested whether the strength of this association is dependent on the gustatory response to the glucosinolate sinigrin, which is a known oviposition stimulus for P. brassicae . Female butterflies were able to associate a neutral odour with an oviposition experience after a single oviposition experience, both in a greenhouse and in a semi-natural outdoor setting. Moreover, butterflies performed best when trained with concentrations of sinigrin that showed the strongest response by specific gustatory neurons on the forelegs. Our study provides novel insight into the role of both gustatory and olfactory cues during oviposition learning in lepidopterans and contributes to a better understanding of how these insects might be able to adapt to a rapidly changing environment.
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