Wall rocket (Diplotaxis erucoides) is a wild edible herb traditionally consumed in the Mediterranean regions with a characteristic, pungent flavour. However, little is known about its acceptance as a potential new crop. In the present study, an hedonic test with 98 volunteers was performed in order to evaluate the potential of wall rocket as a new crop. Three products were tested corresponding to microgreens, seedlings and baby-leaves. The volatile constituents were also studied due to their probable influence on acceptance, and compared to Dijon's mustard and wasabi.The degree of acceptance was mainly related to taste and pungency. Microgreens were well accepted, whereas seedlings and baby-leaves were mainly appreciated by individuals that enjoy pungent tastes. The purchase intent was also highly related to the acceptance of taste and pungency.The volatiles profile revealed that wall rocket was rich in allyl isothiocyanate, like mustard and wasabi. This compound may be greatly responsible of the relationship between the acceptance of mustard, wasabi and wall rocket. Microgreens displayed the highest levels of isothiocyanates, although the quantity of product tested by panellists did not probably allow the appreciation of such compounds. In baby-leaves, a significant decrease in isothiocyanates GC area and relative abundances was observed. These results suggest that wall rocket microgreens would be accepted by a significant proportion of the general public since pungency is lowly perceived in the product, despite its high levels of isothiocyanates. By contrast, baby-leaves may become a crop for a cohort of consumers that enjoy pungent flavours.

Antiviral treatments inhibiting Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) replication may represent a strategy complementary to vaccination to fight the ongoing Coronavirus disease 19 (COVID-19) pandemic. Molecules or extracts inhibiting the SARS-CoV-2 chymotripsin-like protease (3CLPro) could contribute to reducing or suppressing SARS-CoV-2 replication. Using a targeted approach, we identified 17 plant products that are included in current and traditional cuisines as promising inhibitors of SARS-CoV-2 3CLPro activity. Methanolic extracts were evaluated in vitro for inhibition of SARS-CoV-2 3CLPro activity using a quenched fluorescence resonance energy transfer (FRET) assay. Extracts from turmeric (Curcuma longa) rhizomes, mustard (Brassica nigra) seeds, and wall rocket (Diplotaxis erucoides subsp. erucoides) at 500 µg mL−1 displayed significant inhibition of the 3CLPro activity, resulting in residual protease activities of 0.0%, 9.4%, and 14.9%, respectively. Using different extract concentrations, an IC50 value of 15.74 µg mL−1 was calculated for turmeric extract. Commercial curcumin inhibited the 3CLPro activity, but did not fully account for the inhibitory effect of turmeric rhizomes extracts, suggesting that other components of the turmeric extract must also play a main role in inhibiting the 3CLPro activity. Sinigrin, a major glucosinolate present in mustard seeds and wall rocket, did not have relevant 3CLPro inhibitory activity; however, its hydrolysis product allyl isothiocyanate had an IC50 value of 41.43 µg mL−1. The current study identifies plant extracts and molecules that can be of interest in the search for treatments against COVID-19, acting as a basis for future chemical, in vivo, and clinical trials.

Water celery (Apium nodiflorum) is a wild plant traditionally harvested in some Mediterranean areas for being consumed raw. Despite its appreciated organoleptic properties, the aromatic profile of the fresh vegetable remains to be studied. In the present study, volatile compounds from five wild populations were extracted by the headspace-solid phase microextraction technique, analysed by gas cromatography-mass spectrometry, and compared to related crops. The wild species had a high number of aromatic compounds. It was rich in monoterpenes (49.2%), sesquiterpenes (39.4%) and phenylpropanoids (9.6%), with quantitative differences among populations, in absolute terms and relative abundance. On average, germacrene D was the main compound (16.6%), followed by allo-ocimene (11.9%) and limonene (11.1%). Only in one population, the levels of limonene were greater than those of germacrene D. Among phenylpropanoids, dillapiol displayed the highest levels, and co-occurred with myristicin in all populations except one. These differences may have a genetic component, which would indicate the possibility of establishing selection programmes for the development of water celery as a crop adapted to different market preferences. On the other hand, comparison with related crops revealed some similarities among individual volatiles present in the different crops, which would be responsible of the common aroma notes. However, water celery displayed a unique profile, which was in addition quantitatively richer than others. Thus, this differentiation may promote the use of water celery as a new crop.

Wall rocket (Diplotaxis erucoides) is a wild vegetable with the potential to become a crop of high antioxidant quality. The main bioactive compounds include ascorbic acid (AA), sinigrin, and a high content of total phenolic compounds (TP). It also accumulates nitrates. Since these compounds are affected by environmental conditions, adequate crop management may enhance its quality. Eleven accessions of wall rocket were evaluated under field and greenhouse conditions during two cycles (winter and spring) and compared to Eruca sativa and Diplotaxis tenuifolia crops. The three species did not differ greatly. As an exception, sinigrin was only identified in wall rocket. For the within-species analysis, the results revealed a high effect of the growing system, but this was low among accessions. The highest contents of AA and TP were obtained under field conditions. In addition, the levels of nitrates were lower in this system. A negative correlation between nitrates and antioxidants was determined. As a counterpart, cultivation in the field–winter environment significantly decreased the percentage of humidity (87%). These results are of relevance for the adaptation of wall rocket to different growing conditions and suggest that the field system enhances its quality. The low genotypic differences suggest that intra-species selections in breeding programs may consider other aspects with greater variation.

Highlights Wall rocket leaf morphology is different from other rocket crops. Morphological differentiation can be used to enhance and promote it as new crop. Significant inter-and intra-population variation was detected among accessions. High environmental effects resulted in low heritabilities. Field cultivation promotes lobated, dark green leaves, commercially appreciated.

BackgroundFool’s watercress (Apium nodiflorum) is an edible vegetable with potential as a new crop. However, little information is available regarding the antioxidant properties of the plant and the individual phenolics accounting for this capacity are unknown.MethodsThe antioxidant properties of twenty-five wild populations were analysed and individual phenolics present in the species reported and compared with celery and parsley. The antioxidant activity was measured as the 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH) free radical scavenging capacity, and the total phenolics content (TPC) via the Folin-Ciocalteu procedure. The individual phenolics constituents were determined via high performance liquid chromatography (HPLC) as aglycones.ResultsThe average DPPH and TPC of fool’s watercress were 28.1 mg Trolox g−1 DW and 22.3 mg of chlorogenic acid equivalents g−1 DW, respectively, much higher than those of celery and parsley. Significant differences for both DPPH and TPC, which may be explained by either genotype or environmental factors, were detected among groups established according to geographical origin. Quercetin was identified as the major phenolic present in the leaves of the species, unlike parsley and celery, in which high amounts of apigenin and luteolin were determined. Quercetin represented 61.6% of the phenolics targeted in fool’s watercress, followed by caffeic acid derivatives as main hydroxycinnamic acids.DiscussionThe study reports the high antioxidant properties of fool’s watercress based on a large number of populations. Results suggest that quercetin accounts for an important share of the antioxidant capacity of this potential new crop. The study also provides a basis for future breeding programs, suggesting that selection by geographical locations may result in differences in the antioxidant properties.

Capsicum peppers are one of the most important vegetables and a plethora of cultivars can be found within common pepper, C. annuum. In this regard, Spain is a center of diversity for this crop. Many studies on bioactive compounds have been done in peppers, although very little is known about their mineral content. In the present work fruits from a comprehensive collection of Capsicum accessions, mostly C. annuum landraces, were grown in open ield in Valencia (Spain) and evaluated at both unripe and fully ripe stages for their content in several minerals: P, K, Ca, Mg and Fe. The effects of the genotype, fruit ripening stage, and the genotype×ripening stage were studied. A wide genotypic diversity was found for minerals. Thus, the difference between the lowest and highest genotype means was about twice in both ripening stages for P, Ca, and Mg and for K in fully ripe fruits. Finally, Fe levels were 0.7-3.1% in unripe fruits and 1.07-5.1% in fully ripe fruits. Our results indicate that C. annuum fruits are a good source of K, particularly when unripe. With very few exceptions, P, K and particularly Ca decreased on average and in most genotypes with the ripening process. By contrast, Mg showed a strong genotype×stage interaction. Here we found a wide diversity among C. annuum genotypes for the content in most minerals, particularly in P, Ca and Mg, as well as high levels of K. Moreover, unripe fruits usually show higher levels of these minerals than fully ripe fruits.

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