Volatile Compounds of Selected Raw and Cooked Brassica Vegetables

Reduction of N-nitrosamine in cured ham using atmospheric cold plasma-treated cauliflower powder

The effects of cauliflower treated with atmospheric cold plasma (ACP), as a natural nitrite source, on the curing of ground ham and nitrosamine formation were investigated. Ground ham was prepared using sodium nitrite and ACP-treated cauliflower powder (PTCP) to achieve initial nitrite concentrations of 60 and 100 mg/kg, respectively. ACP treatment generated nitrite in cauliflower but significantly reduced the antioxidant activity (P < 0.05). As a nitrite source, PTCP had similar effects as sodium nitrite in the development of cured color in ground ham, with a comparable residual nitrite content (P ≥ 0.05). Three nitrosamines, N-nitrosodimethylamine (NDMA), N-nitrosodiethylamine (NDEA), and N-nitrosopyrrolidine (NPYR), were detected in ground ham. NPYR formation was significantly lower in ground ham treated with PTCP at an initial nitrite concentration of 100 mg/kg (P < 0.05). Therefore, the use of a natural nitrite source manufactured through ACP treatment can prospectively achieve suitable curing efficiency while simultaneously suppressing nitrosamine formation.

Recent advances in the contribution of glucosinolates degradation products to cruciferous foods odor: factors that influence degradation pathways and odor attributes

As one of the most important vegetables and oils consumed globally, cruciferous foods are appreciated for their high nutritional value. However, there is no comprehensive knowledge to sufficiently unravel the "flavor mystery" of cruciferous foods. The present review provides a comprehensive literature on the recent advances regarding the contribution of glucosinolates (GSL) degradation products to cruciferous foods odor, which focuses on key GSL degradation products contributing to distinct odor of cruciferous foods (Brassica oleracea, Brassica rapa, Brassica napus, Brassica juncea, Raphanus sativus), and key factors affecting GSL degradation pathways (i.e., enzyme-induced degradation, thermal-induced degradation, chemical-induced degradation, microwave-induced degradation) during different processing and cooking. A total of 93 volatile GSL degradation products (i.e., 36 nitriles, 33 isothiocyanates, 3 thiocyanates, 5 epithionitriles, and 16 sulfides) and 29 GSL (i.e., 20 aliphatic, 5 aromatic, and 4 indolic) were found in generalized cruciferous foods. Remarkably, cruciferous foods have a distinctive pungent, spicy, pickled, sulfur, and vegetable odor. In general, isothiocyanates are mostly present in enzyme-induced degradation of GSL and are therefore often enriched in fresh-cut or low-temperature, short-time cooked cruciferous foods. In contrast, nitriles are mainly derived from thermal-induced degradation of GSL, and are thus often enriched in high-temperature, long-time cooked cruciferous foods.

Application of Sorbent-Based Extraction Techniques in Food Analysis

This review presents an outline of the application of the most popular sorbent-based methods in food analysis. Solid-phase extraction (SPE) is discussed based on the analyses of lipids, mycotoxins, pesticide residues, processing contaminants and flavor compounds, whereas solid-phase microextraction (SPME) is discussed having volatile and flavor compounds but also processing contaminants in mind. Apart from these two most popular methods, other techniques, such as stir bar sorptive extraction (SBSE), molecularly imprinted polymers (MIPs), high-capacity sorbent extraction (HCSE), and needle-trap devices (NTD), are outlined. Additionally, novel forms of sorbent-based extraction methods such as thin-film solid-phase microextraction (TF-SPME) are presented. The utility and challenges related to these techniques are discussed in this review. Finally, the directions and need for future studies are addressed.

Determination of extractable pollutants from microplastics to vegetables: Accumulation and incorporation into the food chain

The presence and impacts of microplastics (MPs) are being extensively researched and reviewed, especially in the marine environment. However, mobility, transportation routes, and accumulation of leaching compounds such as additives in plastic waste including MPs are scarcely studied. Information regarding ecotoxicity and leachability of compounds related to MPs contamination in the environment is limited. Current work presents the levels of leachates from plastic materials in edible-root and non-edible root vegetables. Samples were analyzed by static headspace and gas chromatography-mass spectrometry (SHS-GC-MS) and the presence of 93 putative compounds was accurately monitored in the samples by the usage of Mass Spectrometry-Data Independent Analysis software. The application of chemometrics to the SHS-GC-MS dataset allowed differentiation between the levels of plastic related compounds in edible root and non-edible root vegetables, the former showing a higher content of plastic leachates. For SHS sampling, 3 g of the sample were incubated at 130 °C for 35 min in the HS vial and toluene and naphthalene were added as internal standards for quantification purposes. The developed SHS-GC-MS methodology is straightforward, reliable, and robust and allowed the quantification of sixteen plastic associated compounds in the samples studied in a range from 0.14 to 28800 ng g-1 corresponding to 2,4-di-tert-butylphenol and p,α-dimethylstyrene, respectively. Several of the quantified compounds pointed out to potential contamination of polystyrene and/or polyvinyl chloride MPs.

Isothiocyanate-Rich Extracts from Cauliflower (Brassica oleracea Var. Botrytis) and Radish (Raphanus sativus) Inhibited Metabolic Activity and Induced ROS in Selected Human HCT116 and HT-29 Colorectal Cancer Cells

Cruciferous vegetables such as cauliflower and radish contain isothiocyanates exhibiting chemoprotective effects in vitro and in vivo. This research aimed to assess the impact of cauliflower (CIE) and radish (RIE) isothiocyanate extracts on the metabolic activity, intracellular reactive oxygen species (ROS), and LDH production of selected human colorectal adenocarcinoma cells (HCT116 and HT-29 for early and late colon cancer development, respectively). Non-cancerous colon cells (CCD-33Co) were used as a cytotoxicity control. The CIE samples displayed the highest allyl isothiocyanate (AITC: 12.55 µg/g) contents, whereas RIE was the most abundant in benzyl isothiocyanate (BITC: 15.35 µg/g). Both extracts effectively inhibited HCT116 and HT-29 metabolic activity, but the CIE impact was higher than that of RIE on HCT116 (IC₅₀: 0.56 mg/mL). Assays using the half-inhibitory concentrations (IC₅₀) of all treatments, including AITC and BITC, displayed increased (p < 0.05) LDH (absorbance: 0.25-0.40 nm) and ROS release (1190-1697 relative fluorescence units) in both cell lines. BITC showed the highest in silico binding affinity with all the tested colorectal cancer molecular markers (NF-kB, β-catenin, and NRF2-NFE2). The theoretical evaluation of AITC and BITC bioavailability showed high values for both compounds. The results indicate that CIE and RIE extracts display chemopreventive effects in vitro, but additional experiments are needed to validate their effects.

Role of Sulfur Compounds in Vegetable and Mushroom Aroma

At the base of the food pyramid is vegetables, which should be consumed most often of all food products, especially in raw and unprocessed form. Vegetables and mushrooms are rich sources of bioactive compounds that can fulfill various functions in plants, starting from protection against herbivores and being natural insecticides to pro-health functions in human nutrition. Many of these compounds contain sulfur in their structure. From the point of view of food producers, it is extremely important to know that some of them have flavor properties. Volatile sulfur compounds are often potent odorants, and in many vegetables, belonging mainly to Brassicaeae and Allium (Amaryllidaceae), sulfur compounds determine their specific flavor. Interestingly, some of the pathways that form volatile sulfur compounds in vegetables are also found in selected edible mushrooms. The most important odor-active organosulfur compounds can be divided into isothiocyanates, nitriles, epithionitriles, thiols, sulfides, and polysulfides, as well as others, such as sulfur containing carbonyl compounds and esters, R-L-cysteine sulfoxides, and finally heterocyclic sulfur compounds found in shiitake mushrooms or truffles. This review paper summarizes their precursors and biosynthesis, as well as their sensory properties and changes in selected technological processes.

Valorisation of Broccoli By-Products: Technological, Sensory and Flavour Properties of Durum Pasta Fortified with Broccoli Leaf Powder

The aim of this study was to evaluate the effect of broccoli leaf powder (BLP) incorporation on the technological properties, sensory quality and volatile organic compounds (VOCs) of durum wheat pasta. Incorporation of BLP increased cooking loss; however, all pasta samples were found to be in the acceptable range of 8 g/100 g. The addition of BLP decreased optimal cooking time and water absorption but increased the swelling index. Firmness and total shearing force decreased with increased BLP content. The obtained pasta was greener than the control, with a higher content of minerals, and an increasing tendency with respect to protein was observed. The VOC profile of enriched pasta was richer and contained compounds typical of broccoli (e.g., dimethyl sulphide), affecting its aroma. The sensory evaluation results indicate that the addition of BLP did not affect the overall acceptance of pasta. Up to 5% BLP content afforded an interesting, more nutritious pasta without compromising its technological and sensory quality.

Improving the Antioxidant Activity and Flavor of Faba (Vicia faba L.) Leaves by Domestic Cooking Methods

Faba leaves are an unusual vegetable which contain not only a range of functional phytochemicals, but also certain undesirable flavors, which limit their consumption. In this study, several cooking methods (microwaving, roasting, steaming, and boiling), which are expected to reduce the odd flavors, were evaluated in terms of both health benefit effects and odd flavor factors, including antioxidant activities and the content of non-volatile and volatile organic compounds (VOCs). A cooking time of 5 min was selected because of the high content of l-dopa (l-3,4-dihydroxyphenylalanine) and aim of reducing the undesirable flavors of the cooked faba leaves. Microwaving and steaming significantly increased the l-dopa content by 24% and 19%, respectively. Roasting specifically increased the content of flavonols, exhibiting a 28% increase of kaempferol-3-O-arabinoside-7-O-rhamnoside, representatively, whereas boiling decreased about 50% of most phytochemicals evaluated. Microwaving and steaming treatments significantly increased the antioxidant activities. The l-dopa content and antioxidant activities of the processed faba leaves were strongly positively correlated with either an R2 = 0.863 of DPPH radical scavenging activity or an R2 = 0.856 value of ABTS radical scavenging activity, showing that l-dopa was a key antioxidant. All cooking methods potentially improved the flavor of the cooked faba leaves compared with that of the fresh leaves, because they significantly reduced the contents of VOCs such as alcohols, aldehydes, and ketones. These VOCs were the main components (>90%) in the fresh leaves. Adverse aromatic hydrocarbons were newly formed by the microwaving treatment, typically producing p-xylene, which is known to be a harmful dose-dependent compound, but they were not detected in leaves processed by the other cooking methods; therefore, although microwaving efficiently increased antioxidant activity, the chemical safety of the aromatic hydrocarbons produced need further study.

Red and white cabbages: An updated comparative review of bioactives, extraction methods, processing practices, and health benefits

Red and white cabbages (Brassica oleracea var. capitata f. alba and rubra, respectively) are two of the most commercially valued vegetables in crucifers, well-recognized for their unique sensory and nutritive attributes in addition to a myriad of health-promoting benefits. The current review addressed the differential qualitative/quantitative phytochemical make-ups for the first time for better utilization as nutraceuticals and to identify potential uses based on the chemical makeup of both cultivars (cvs.). In addition, extraction methods are compared highlighting their advantages and/or limitations with regards to improving yield and stability of cabbage bioactives, especially glucosinolates. Besides, the review recapitulated detailed action mechanism and safety of cabbage bioactives, as well as processing technologies to further improve their effects are posed as future perspectives. White and red cabbage cvs. revealed different GLSs profile which affected by food processing, including enzymatic hydrolysis, thermal breakdown, and leaching. In addition, the red cultivar provides high quality pigment for industrial applications. Moreover, non-conventional modern extraction techniques showed promising techniques for the recovery of their bioactive constituents compared to solvent extraction. All these findings pose white and red cabbages as potential candidates for inclusion in nutraceuticals and/or to be commercialized as functional foods prepared in different culinary forms.

Chemical Changes in the Broccoli Volatilome Depending on the Tissue Treatment

The storage of plant samples as well as sample preparation for extraction have a significant impact on the profile of metabolites, however, these factors are often overlooked during experiments on vegetables or fruit. It was hypothesized that parameters such as sample storage (freezing) and sample pre-treatment methods, including the comminution technique or applied enzyme inhibition methods, could significantly influence the extracted volatile metabolome. Significant changes were observed in the volatile profile of broccoli florets frozen in liquid nitrogen at -20 °C. Those differences were mostly related to the concentration of nitriles and aldehydes. Confocal microscopy indicated some tissue deterioration in the case of slow freezing (-20 °C), whereas the structure of tissue, frozen in liquid nitrogen, was practically intact. Myrosinase activity assay proved that the enzyme remains active after freezing. No pH deviation was noted after sample storage - this parameter did not influence the activity of enzymes. Tissue fragmentation and enzyme-inhibition techniques applied prior to the extraction influenced both the qualitative and quantitative composition of the volatile metabolome of broccoli.

A Review of the Analytical Methods for the Determination of 4(5)-Methylimidazole in Food Matrices

4(5)-Methylimidazole (4(5)MEI) is a product of the Maillard reaction between sugars and amino acids, which occurs during the thermal processing of foods. This compound is also found in foods with caramel colorants additives. Due to its prevalence in foods and beverages and its potent carcinogenicity, 4(5)MEI has received federal and state regulatory agency attention. The aim of this review is to present the extraction procedures of 4(5)MEI from food matrices and the analytical methods for its determination. Liquid and gas chromatography coupled with mass spectrometry are the techniques most commonly employed to detect 4(5)MEI in food matrices. However, the analysis of 4(5)MEI is challenging due to the high polarity, water solubility, and the absence of chromophores. To overcome this, specialized sample pretreatment and extraction methods have been developed, such as solid-phase extraction and derivatization procedures, increasing the cost and the preparation time of samples. Other analytical methods for the determination of 4(5)MEI, include capillary electrophoresis, paper spray mass spectrometry, micellar electrokinetic chromatography, high-performance cation exchange chromatography, fluorescence-based immunochromatographic assay, and a fluorescent probe.

Key Odorants of Raw and Cooked Green Kohlrabi (Brassica oleracea var. gongylodes L.)

Volatile compounds of raw and cooked green kohlrabi were investigated using a sensomics approach. A total of 55 odor-active compounds were detected and identified in raw and cooked green kohlrabi using GC-O. Twenty-eight odor-active compounds with high flavor dilution (FD) factors ranging from 64 to 1024 were quantitated, and odor activity values (OAVs) were determined. Eight compounds showed high OAVs in raw and cooked kohlrabi: five sulfur compounds (dimethyl trisulfide, methyl 2-methyl-3-furyl disulfide, and three isothiocyanates (1-isothiocyanato-3-(methylsulfanyl)propane, benzyl isothiocyanate, and 1-isothiocyanato-4-(methylsulfanyl)butane)), two lipid oxidation products (1-octen-3-one and trans-4,5-epoxy-(2E)-dec-2-enal), and 2-isopropyl-3-methoxypyrazine. Among these, the sulfur compounds contributed most to the overall smell of the raw and cooked vegetables. The quantitation analysis indicates that the eight odorants are the backbone compounds for raw and cooked kohlrabi. The OAVs for the backbone compounds and also for minor odorants are clearly higher in raw kohlrabi than in the cooked one. Differences can be explained by the influence of the cooking process.

Current Methods for the Extraction and Analysis of Isothiocyanates and Indoles in Cruciferous Vegetables

Cruciferous vegetables are characterized by the presence of sulfur-containing secondary plant metabolites known as glucosinolates (GLS). The consumption of cruciferous vegetables such as broccoli, cabbage, rocket salad, and cauliflower has been related to the prevention of non-communicable diseases. Their beneficial effects are attributed to the enzymatic degradation products of GLS, e.g., isothiocyanates and indoles. Owing to these properties, there has been a shift in the last few years towards the research of these compounds and a wide range of methods for their extraction and analytical determination have been developed. The aim of this review is to present the sample preparation and extraction procedures of isothiocyanates and indoles from cruciferous vegetables and the analytical methods for their determination. The majority of the references that have been reviewed are from the last decade. Although efforts towards the application of eco-friendly non-conventional extraction methods have been made, the use of conventional solvent extraction is mainly applied. The major analytical techniques employed for the qualitative and quantitative analysis of isothiocyanates and indoles are high-performance liquid chromatography and gas chromatography coupled with or without mass spectrometry detection. Nevertheless, the analytical determination of isothiocyanates presents several problems due to their instability and the absence of chromophores, making the simultaneous determination of isothiocyanates and indoles a challenging task.

Phytochemical Constituents, Antioxidant Activity, and Toxicity Assessment of the Aerial Part Extracts from the Infraspecific Taxa of Matthiola fruticulosa (Brassicaceae) Endemic to Sicily

In a project designed to investigate the specific and infraspecific taxa of Matthiola endemic to Sicily (Italy) as new potential sources of bioactive compounds in this work, the infraspecific taxa of Matthiola fruticulosa were studied, namely, subsp. fruticulosa and subsp. coronopifolia. HPLC-PDA/ESI-MS and SPME-GC/MS analyses of hydroalcoholic extracts obtained from the aerial parts of the two subspecies led to the detection of 51 phenolics and 61 volatile components, highlighting a quite different qualitative-quantitative profile. The antioxidant properties of the extracts were explored through in vitro methods: 1,1-diphenyl-2-picrylhydrazyl (DPPH), reducing power and Fe2+ chelating activity assays. The results of the antioxidant tests showed that the extracts possess a different antioxidant ability: particularly, the extract of M. fruticulosa subsp. fruticulosa exhibited higher radical scavenging activity than that of subsp. coronopifolia (IC50 = 1.25 ± 0.02 mg/mL and 2.86 ± 0.05 mg/mL), which in turn displayed better chelating properties (IC50 = 1.49 ± 0.01 mg/mL and 0.63 ± 0.01 mg/mL). Lastly, Artemia salina lethality bioassay was performed for toxicity assessment. The results of the bioassay showed lack of toxicity against brine shrimp larvae for both extracts. The data presented indicate the infraspecific taxa of M. fruticulosa as new and safe sources of antioxidant compounds.

Suitability Analysis of 17 Probiotic Type Strains of Lactic Acid Bacteria as Starter for Kimchi Fermentation

The use of probiotic starters can improve the sensory and health-promoting properties of fermented foods. This study aimed to evaluate the suitability of probiotic lactic acid bacteria (LAB) as a starter for kimchi fermentation. Seventeen probiotic type strains were tested for their growth rates, volatile aroma compounds, metabolites, and sensory characteristics of kimchi, and their characteristics were compared to those of Leuconostoc (Le.) mesenteroides DRC 1506, a commercial kimchi starter. Among the tested strains, Limosilactobacillus fermentum, Limosilactobacillus reuteri, Lacticaseibacillus rhamnosus, Lacticaseibacillus paracasei, and Ligilactobacillus salivarius exhibited high or moderate growth rates in simulated kimchi juice (SKJ) at 37 °C and 15 °C. When these five strains were inoculated in kimchi and metabolite profiles were analyzed during fermentation using GC/MS and ¹H-NMR, data from the principal component analysis (PCA) showed that L. fermentum and L. reuteri were highly correlated with Le. mesenteroides in concentrations of sugar, mannitol, lactate, acetate, and total volatile compounds. Sensory test results also indicated that these three strains showed similar sensory preferences. In conclusion, L. fermentum and L. reuteri can be considered potential candidates as probiotic starters or cocultures to develop health-promoting kimchi products.

A literature survey of all volatiles from healthy human breath and bodily fluids: the human volatilome

This paper comprises an updated version of the 2014 review which reported 1846 volatile organic compounds (VOCs) identified from healthy humans. In total over 900 additional VOCs have been reported since the 2014 review and the VOCs from semen have been added. The numbers of VOCs found in breath and the other bodily fluids are: blood 379, breath 1488, faeces 443, milk 290, saliva 549, semen 196, skin 623 and urine 444. Compounds were assigned CAS registry numbers and named according to a common convention where possible. The compounds have been included in a single table with the source reference(s) for each VOC, an update on our 2014 paper. VOCs have also been grouped into tables according to their chemical class or functionality to permit easy comparison. Careful use of the database is needed, as a number of the identified VOCs only have level 2-putative assignment, and only a small fraction of the reported VOCs have been validated by standards. Some clear differences are observed, for instance, a lack of esters in urine with a high number in faeces and breath. However, the lack of compounds from matrices such a semen and milk compared to breath for example could be due to the techniques used or reflect the intensity of effort e.g. there are few publications on VOCs from milk and semen compared to a large number for breath. The large number of volatiles reported from skin is partly due to the methodologies used, e.g. by collecting skin sebum (with dissolved VOCs and semi VOCs) onto glass beads or cotton pads and then heating to a high temperature to desorb VOCs. All compounds have been included as reported (unless there was a clear discrepancy between name and chemical structure), but there may be some mistaken assignations arising from the original publications, particularly for isomers. It is the authors' intention that this work will not only be a useful database of VOCs listed in the literature but will stimulate further study of VOCs from healthy individuals; for example more work is required to confirm the identification of these VOCs adhering to the principles outlined in the metabolomics standards initiative. Establishing a list of volatiles emanating from healthy individuals and increased understanding of VOC metabolic pathways is an important step for differentiating between diseases using VOCs.

Environmental Conditions and Agronomical Factors Influencing the Levels of Phytochemicals in Brassica Vegetables Responsible for Nutritional and Sensorial Properties

Recently, the consumption of healthy foods has been related to the prevention of cardiovascular, degenerative diseases and different forms of cancers, underlying the importance of the diet for the consumer’s health. Fruits and vegetables contain phytochemicals that act as protective factors for the human body, through different mechanisms of action. Among vegetables, Brassica received a lot of attention in the last years for the phytochemical compounds content and antioxidant capacity that confer nutraceutical value to the product. The amount of healthy bioactive compounds present in the Brassica defines the nutritional quality. These molecules could belong to the class of antioxidant compounds (e.g., phenols, vitamin C, etc.), or to non-antioxidant compounds (e.g., minerals, glucosinolates, etc.). The amount of these compounds in Brassica vegetables could be influenced by several factors, depending on the genotypes, the environmental conditions and the cultivation techniques adopted. The aim of this study is to highlight the main phytochemical compounds present in brassicas used as a food vegetable that confer nutritional and sensorial quality to the final product, and to investigate the main factors that affect the phytochemical concentration and the overall quality of Brassica vegetables.

Volatile Organic Compounds (VOCs) of Endophytic Fungi Growing on Extracts of the Host, Horseradish (Armoracia rusticana)

The interaction between plant defensive metabolites and different plant-associated fungal species is of high interest to many disciplines. Volatile organic compounds (VOCs) are natural products that are easily evaporated under ambient conditions. They play a very important role in inter-species communication of microbes and their hosts. In this study, the VOCs produced by 43 different fungal isolates of endophytic and soil fungi during growth on horseradish root (Armoracia rusticana) extract or malt extract agar were examined, by using headspace-gas chromatography-mass spectrometry (headspace-GC-MS) and a high relative surface agar film as a medium. The proposed technique enabled sensitive detection of several typical VOCs (acetone, methyl acetate, methyl formate, ethyl acetate, methyl butanol isomers, styrene, beta-phellandrene), along with glucosinolate decomposition products, including allyl cyanide and allyl isothiocyanate and other sulfur-containing compounds—carbon disulfide, dimethyl sulfide. The VOC patterns of fungi belonging to Setophoma, Paraphoma, Plectosphaerella, Pyrenochaeta, Volutella, Cadophora, Notophoma, and Curvularia genera were described for the first time. The VOC pattern was significantly different among the isolates. The pattern was indicative of putative myrosinase activity for many tested isolates. On the other hand, endophytes and soil fungi as groups could not be separated by VOC pattern or intensity.

Comparison of Three Extraction Techniques for the Determination of Volatile Flavor Components in Broccoli

To analyze aroma active components in a food product, the crucial step is to select a suitable extraction technique. It should provide isolation of all components responsible for aroma creation, without the formation of any artifacts during the procedure. Preferably, the extraction method should yield analyzed compounds in detectable levels. The presented study aimed to compare three popular extraction techniques used in flavor studies: solid-phase microextraction (SPME), solvent-assisted flavor evaporation (SAFE), and simultaneous distillation extraction (SDE) in order to isolate aroma components from broccoli (Brassica oleracea L. var. italica). Obtained extracts were analyzed by gas chromatography-olfactmetry (GC-O) to determine compounds with aroma activity as well as gas chromatography-mass spectrometry (GC-MS) and comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC×GC-ToFMS) to identify them. Thirty-four aroma active compounds were detected in broccoli by the applied techniques. SPME and SAFE together gave the full profile of aroma active components on chromatograms from GC-O, without artifacts that occurred in the SDE extract. SPME was particularly useful in the identification of early eluting compounds, while SAFE enabled isolating compounds with relatively low partition coefficients. Despite all the disadvantages of the SDE method, it leads to the identification of pyrazines, which were important contributors to the overall aroma.

Methyl jasmonate treated broccoli: Impact on the production of glucosinolates and consumer preferences

Applying methyl jasmonate can mimic the defense response to insect damage in broccoli and enhances the production of glucosinolates, especially inducible indolyl GS-neoglucobrassicin. Previous studies have suggested that glucosinolates and their hydrolysis products are anti-carcinogenic. Therefore, MeJA treatment may increase the nutritional quality of broccoli. However, there are few reports on the sensory evaluation and consumer acceptance of MeJA-treated broccoli. In this study, an untrained consumer panel could not detect any taste differences between steamed MeJA-treated and untreated broccoli, even though the steamed MeJA-treated broccoli contained 50% more glucosinolates than untreated broccoli. The partial least square-regression model suggested that neoglucobrassicin-derived hydrolysis compounds were the major metabolites that determined overall preference for raw MeJA-treated broccoli potentially due to their potential negative sensory qualities. The results imply that MeJA treatment can increase the nutritional quality of broccoli without sacrificing taste in precooked meals or frozen vegetables.