Red Mustard Research Articles

Hormetic effect of UV-C radiation on red mustard microgreens growth and chemical composition

Brassica microgreens are rich in phytochemicals and are attractive crops for controlled vertical farming systems where the light spectrum can be precisely manipulated. Understanding the effects of pre-harvest hormetic UV-C light doses on plant composition and growth parameters represents a novel and largely unexplored area for precision agriculture and nutrition. Therefore, the objective of this work was to investigate the impact of exposing red mustard microgreens to low/hormetic doses of UV-C radiation on their growth, chemical composition and colour. Plants were grown in a controlled environment and exposed to 0.3 kJ m−2, 254 nm UV-C radiation at the end of the cultivation period. Treatments included a single pulse on day 7, or three pulses at days 7, 8, and 9 and harvest on day 10. UV-C radiation presented a hormetic effect, while 1 pulse of UV-C stimulated growth and productivity without significant colour changes in microgreens, 3 pulses of UV-C radiation to did not show significant effects when compared to controls (no UV-C exposure). Moreover, strong negative correlations were observed between growth parameters and chemical composition (p < 0.05). Microgreens with enhanced growth parameters showed a decrease in phenolic compounds content and antioxidant activity. Interestingly, regardless of quantification, untargeted metabolomics using UHPLC-Q-Orbitrap-MS/MS revealed that the secondary metabolites profile remained similar between control and microgreens treated with UV-C radiation.

Optimal Brassicaceae family microgreens from a phytochemical and sensory perspective

Microgreens, also called superfoods, emerge because of their high levels of nutrients, diverse flavour profiles, and sustainable cultivation methods, which make them culinary delights and valuable to a healthy and flavorful diet. The present study investigated Brassicaceae family microgreens, proposing a novel system (quality indices) that allows scoring among them. Fourteen Brassica microgreen species were morphological, phytochemical, and sensorial investigated. The morphological assessment revealed that radish microgreens exhibited the highest leaf area (p < 0.05), while red mizuna demonstrated superior yield. Cauliflower microgreens contained the highest concentrations of ascorbic acid (HPLC-DAD) and total phenolic content (p < 0.05). Phytochemical analysis using HPLC-MS/MS identified over 18 glucosinolates and phenolic compounds. Red mustard and red cabbage showed the highest glucosinolate content (p < 0.05). Watercress exhibited the highest phenolic compound content (p < 0.05), primarily flavonoids, while broccoli and radish contained the highest isothiocyanate levels. Cauliflower microgreens resulted in the most consumer-accepted variety. Appling quality indices scoring system identified radish, cauliflower, and broccoli microgreens as the most promising species. This study underscores the potential of Brassica microgreens as an excellent source of health-promoting phytochemicals with favorable market acceptance, providing valuable insights for both nutritional research and commercial applications.

Metabolite profiles and biological activities of different phenotypes of Chinese cabbage (Brassica rapa ssp. Pekinensis)

Chinese cabbage is considered as one of the most important cruciferous vegetables in South Korea because of its use in salads, kimchi, and Korean cuisine. Secondary metabolites were quantified in three Chinese cabbage varieties: 65065, interspecific hybrid of Chinese cabbage × red cabbage exhibiting a deep purple color; 85772, interspecific hybrid of Chinese cabbage × red mustard exhibiting a reddish-purple color; and a typical Chinese green cabbage cultivar “CR Carotene” (Brassica rapa subsp. pekinensis cv. CR Carotene). A total of 54 metabolites (2 amines, 2 sugar alcohols, 2 sugar phosphates, 6 carbohydrates, 18 amino acids, 13 organic acids, 8 phenolic compounds, and 3 carotenoids) were detected in 85772. Of them, 52 metabolites excluding β-carotene and 9-cis-β-carotene, and 51 metabolites excluding leucine, β-carotene, and 9-cis-β-carotene, were detected in 65065 and CR Carotene, respectively. Amino acid content was the highest in 85772, followed by 65065 and CR Carotene. The cultivars 65065 and 85772 contained high levels of phenolic compounds and total anthocyanins. Cyanidin-, pelargonidin-, and petunidin-type anthocyanins were detected in 65065 and 85772. However, delphinidin-type anthocyanins which typically impart a deep purple color were identified only in the deep purple phenotype 65065. Furthermore, the total anthocyanin content was the highest in 85772 (4.38 ± 0.65 mg g −1 dry weight) followed by that in 65065 (3.72 ± 0.52 mg g−1 dry weight). Antibacterial and antioxidant analyses revealed remarkable antibacterial effects of the purple cultivars against pathogens Vibrio parahaemolyticus (KCTC 2471), Bacillus cereus (KCTC 3624), Pseudomonas aeruginosa (KCCM 11803), Staphylococcus aureus (KCTC 3881), Chryseobacterium gleum (KCTC 2094), and Proteus mirabilis (KCTC 2510)] and methicillin-resistant pathogenic strains of Pseudomonas aeruginosa (0826, 0225, 0254, 1113, 1378, 1731, p01827, and p01828) compared with the antibacterial effects of CR Carotene. Furthermore, 65065 and 85772 exhibited significantly higher antioxidant activity than that of the CR Carotene. Therefore, the novel purple Chinese cabbages (65065 and 85772), derived from interspecific hybridization, are potentially favorable alternatives to the typical green Chinese cabbage, given the higher content of amino acids, phenolic compounds, anthocyanins, and carotenoids, as well as an increased ability to scavenge free radicals and inhibit pathogen growth.

Glucosinolate Accumulation and Hydrolysis in Leafy Brassica Vegetables Are Influenced by Leaf Age.

The health-beneficial effects of Brassica vegetables are mainly attributed to their high contents of glucosinolates and the products of their hydrolysis, especially isothiocyanates. Distribution of glucosinolates across plant organs can strongly vary. Here, we investigated the effect of leaf age on glucosinolate accumulation and hydrolysis in two leafy Brassica vegetables, pak choi and giant red mustard. We also evaluated the activity of the hydrolyzing enzyme myrosinase across the leaves. Finally, we assessed whether glucosinolates are transported from older leaves to younger leaves. Young leaves of both species contained more than 3-fold more glucosinolates than older ones. Accordingly, more isothiocyanates were released in the young leaves. Myrosinases fully hydrolyzed all of the amounts of glucosinolates regardless of the leaf age. Moreover, older leaves were observed to supply younger leaves with glucosinolates. Thus, this study suggests that consumers can improve the nutritional value of food by incorporating young leaves of leafy Brassicas in their diet.

Evaluation of the Effectiveness of Different LED Irradiators When Growing Red Mustard (Brassica juncea L.) in Indoor Farming

Investigation is devoted to the optimization of light spectrum and intensity used for red mustard growing. Notably, most of the studies devoted to red mustard growing were conducted on micro-greens, which is not enough for the development of methods and recommendations for making the right choices about the irradiation parameters for full-cycle cultivation. In this study, we tested four models of LED with different ratios of blue, green red and far red radiation intensity: 12:20:63:5; 15:30:49:6; 30:1:68:1, in two values of photon flux density (PFD)—120 and 180 µmol m−2 s−1—to determine the most effective combination for red mustard growing. The study was conducted in a container-type climate chamber, where the red leaf mustard was cultivated in hydroponics. On the 30th day of cultivation, the plant’s morphological, biochemical and chlorophyll fluorescence parameters, and reflection coefficients were recorded. The results indicated that the PFD 120 µmol m−2 s−1 had a worse effect on both mustard leaf biomass accumulation and nitrate concentration (13–30% higher) in the plants. The best lighting option for growing red mustard was the blue–red spectrum, as the most efficient in terms of converting electricity into biomass (77 Wth/g). This light spectrum contributes to plant development with a larger leaf area (60%) and a fresh mass (54%) compared with the control, which has a maximum similarity in spectrum percentage to the sunlight spectrum. The presence of green and far red radiation with the blue–red light spectrum in various proportions at the same level of PFD had a negative effect on plant fresh mass, leaf surface area and photosynthetic activity. The obtained results could be useful for lighting parameters’ optimization when growing red mustard in urban farms.

Germination and Seedling Growth Response of Sprouts and Leafy Vegetables after Applying Oxygen Nanobubble Water

Background and objective The nanobubbles remain stable in water, and it increased dissolved oxygen (DO) in the water that promotes the seed germination and the plant growth. We evaluated the seed germination and growth of sprouts (radish, wheat, and barley) and leafy vegetables (red mustard and pak choi) when irrigated with various DO of nanobubble water (NB). Methods The oxygen NB was generated by surface friction and treated in 4 levels: NB 0% (control, DO 9.21 mg·L−1), NB 20% (DO 15.40 mg·L−1), NB 33% (DO 20.93 mg·L−1), and NB 100% (DO 39.29 mg·L−1). Results The root length of radish and wheat increased more in NB 33% than the control plot. The fresh weight increased in NB 33% compared to the control plot in radish and wheat, and both fresh and dry weight increased more in NB 20%, NB 33%, and NB 100% than the control plot of barley. The leaf length and width of red mustard decreased more in NB 33% and NB 100% than the control plot and NB 20%, which indicated the leaf compactness. The fresh and dry weight of shoot and root increased more in NB 100% than the control plot in red mustard. In pak choi, the shoot fresh weight increased more in NB 100% than the control plot. In leafy vegetables, the germination rate of red mustard in NB 100% was higher than the control plot, however, it was not significantly different between oxygen NB plots in sprout vegetables. Conclusion The results showed that the root growth and biomass increased after applying NB 33% in sprout vegetables. The leaf growth properties as the number of leaves and leaf size were not significantly different or decreased in NB treatments compared to control plots, but NB 100% (DO 39.29 mg·L−1) effectively increased the root growth and plant biomass in leafy vegetables.

A Dynamic Study of Breakeven Output, Yield and Land-equivalent for Major Crops of Madhya Pradesh

Madhya Pradesh, one of the largest states in the country, has been lagging in private investment in agriculture since the 2000s. To investigate the reasons for this decline, breakeven analysis coupled with trend analysis was carried out using plot-level secondary data from DES, India, for the period 2000-01 to 2016-17 for sorghum, cotton, maize, chickpea/gram, black gram, red gram, lentil, rapeseed and mustard, soybean, paddy and wheat crops. The results revealed that the cotton, soybean and black gram were unsuitable for farmers with inadequate means while lentil was the most stable crop. Rice-wheat and Cotton-gram cropping pattern was found to be risky. Red gram, gram, sorghum, paddy, mustard, soybean and black gram had a horizontal trend of break-even output. Wheat was the only crop with a negative trend of breakeven output. Important policy suggestions include the adoption of custom hiring of machinery and rigorous yield improvement programmes for paddy, sorghum and maize.

Morphological and Physiological Responses in Basil and Brassica Species to Different Proportions of Red, Blue, and Green Wavelengths in Indoor Vertical Farming

Understanding the responses of plant growth and secondary metabolite synthesis to different light wavelengths is important for optimizing lighting conditions for vegetable production in indoor vertical farms. Basil (Ocimum basilicum) ‘Improved Genovese Compact’ (green leaf) and ‘Red Rubin’ (purple leaf), green mustard ‘Amara’ (Brassica carinata), red mustard ‘Red Giant’ (Brassica juncea), green kale ‘Siberian’ (Brassica napus var. pabularia), and red kale ‘Scarlet’ (Brassica oleracea), which are high-value and multifunctional culinary herbs and leafy greens, were used to characterize the effects of red (R), blue (B), and green (G) wavelengths on plant photosynthesis, morphology, biomass production, and secondary metabolites accumulation. Light quality treatments consisted of three R and B light combinations, R88B12 (the proportions of R and B wavelengths were 88% and 12%, respectively), R76B24, and R51B49, and two white light combinations, R44B12G44 (the proportions of R, B, and G wavelengths were 44%, 12%, and 44%, respectively) and R35B24G41. Experiments were conducted in a walk-in growth room with a photosynthetic photon flux density set at 224 μmol·m−2·s−1 and a 16-hour photoperiod. Results indicated that the net photosynthesis in purple basil and green kale were positively correlated with B proportions (BP), and that higher BP increased the relative chlorophyll concentration in purple basil and red kale. In contrast, higher BP suppressed stem elongation and leaf expansion and reduced shoot biomass in all tested species except red mustard. Higher BP increased phytochemical concentrations but decreased the total amounts of phytochemicals per plant. For all basil and brassica (Brassica sp.) cultivars, the inclusion of G wavelengths decreased shoot biomass compared with that of plants grown under R and B light combinations with similar BP. Inclusion of G wavelengths stimulated stem elongation in green basil and green mustard under 12% BP; whereas it suppressed stem elongation in purple basil, green kale, red kale, and green mustard under 24% BP. The effects on phytochemical accumulation were species-specific for the inclusion of G wavelengths. Considering biomass production, nutritional values, and working environment for growers, a white light with lower BP and G proportions is recommended for culinary herbs and Brassica leafy greens production at vertical farms.

Combined treatment of nut by-product extracts and peracetic acid against Listeria monocytogenes on red mustard and kale leaves

In this study, the antibacterial activities of nut by-product extracts (NBE), such as peanut skin or hull and walnut shell, against Listeria monocytogenes were examined. The applicability of a combined treatment using NBE and peracetic acid (PAA) for washing fresh-cut red mustard and kale leaves was also evaluated. Minimum inhibitory concentration and minimum bactericidal concentration tests indicated antimicrobial activities of NBE against L. monocytogenes. In addition, intracellular compound leakage and scanning electron microscopy images revealed that NBE caused bacterial cell death by disrupting cell wall and membrane permeability. Antibacterial activities against L. monocytogenes on red mustard and kale leaves established the effectiveness of an NBE treatment combined with PAA regardless of the fresh-cut produce type. In particular, the combination of 0.1% peanut skin extract and 80 mg/L PAA showed 1.6–1.9 log reductions in L. monocytogenes populations on vegetable leaves compared to water washing, showing higher microbial reduction than 200 mg/L of sodium hypochlorite washing. Furthermore, the combined treatment did not change the physicochemical properties of red mustard and kale leaves during storage. These results suggest that NBE is a good antimicrobial agent against L. monocytogenes and that a combined washing treatment with PAA is potentially efficient for disinfecting fresh-cut vegetables.

Zinc and Iron Agronomic Biofortification of Brassicaceae Microgreens

Insufficient or suboptimal dietary intake of iron (Fe) and zinc (Zn) represent a latent health issue affecting a large proportion of the global population, particularly among young children and women living in poor regions at high risk of malnutrition. Agronomic crop biofortification, which consists of increasing the accumulation of target nutrients in edible plant tissues through fertilization or other eliciting factors, has been proposed as a short-term approach to develop functional staple crops and vegetables to address micronutrient deficiency. The aim of the presented study was to evaluate the potential for biofortification of Brassicaceae microgreens through Zn and Fe enrichment. The effect of nutrient solutions supplemented with zinc sulfate (Exp-1; 0, 5, 10, 20 mg L−1) and iron sulfate (Exp-2; 0, 10, 20, 40 mg L−1) was tested on the growth, yield, and mineral concentration of arugula, red cabbage, and red mustard microgreens. Zn and Fe accumulation in all three species increased according to a quadratic model. However, significant interactions were observed between Zn or Fe level and the species examined, suggesting that the response to Zn and Fe enrichment was genotype specific. The application of Zn at 5 and 10 mg L−1 resulted in an increase in Zn concentration compared to the untreated control ranging from 75% to 281%, while solutions enriched with Fe at 10 and 20 mg L−1 increased Fe shoot concentration from 64% in arugula up to 278% in red cabbage. In conclusion, the tested Brassicaceae species grown in soilless systems are good targets to produce high quality Zn and Fe biofortified microgreens through the simple manipulation of nutrient solution composition.

Evaluation of the Bioaccessibility of Antioxidant Bioactive Compounds and Minerals of Four Genotypes of Brassicaceae Microgreens.

Microgreens constitute an emerging class of fresh, healthy foods due to their nutritional composition. In this study the content of minerals and antioxidant bioactive compounds, and for the first time bioaccessibility, were evaluated in broccoli (Brassica oleracea L. var. italica Plenck), green curly kale (Brassica oleracea var. sabellica L.), red mustard (Brassica juncea (L.) Czern.) and radish (Raphanus sativus L.) hydroponic microgreens. Macro- (K, Ca, Mg) and oligo-elements (Fe, Zn), ascorbic acid, total soluble polyphenols, total carotenoids, total anthocyanins, total isothiocyanates and total antioxidant capacity (Trolox Equivalent Antioxidant Capacity and Oxygen Radical Absorbance Capacity) were determined before and after the standardized simulated gastrointestinal digestion process. All microgreens provided relevant amounts of vitamin C (31–56 mg/100 g fresh weight) and total carotenoids (162–224 mg β-carotene/100 g dry weight). Mineral content was comparable to that normally found in hydroponic microgreens and the low potassium levels observed would allow their dietetic recommendation for patients with impaired kidney function. Both total soluble polyphenols and total isothiocyanates were the greatest contributors to the total antioxidant capacity after digestion (43–70% and 31–63% bioaccessibility, respectively) while macroelements showed an important bioaccessibility (34–90%). In general, radish and mustard presented the highest bioaccessibility of bioactive compounds and minerals. Overall, the four hydroponic Brassicaceae microgreens present a wide array of antioxidant bioactive compounds.

Iodine Biofortification of Four Brassica Genotypes is Effective Already at Low Rates of Potassium Iodate.

The use of iodine-biofortified vegetables may be a health alternative instead of iodine-biofortified salt for preventing iodine (I) deficiency and related human disorders. In this study, four Brassica genotypes (broccoli raab, curly kale, mizuna, red mustard) were hydroponically grown with three I-IO3− rates (0, 0.75 and 1.5 mg/L) to produce iodine-biofortified vegetables. Crop performances and quality traits were analyzed; iodine content was measured on raw, boiled, and steamed vegetables. The highest I rate generally increased I content in all Brassica genotypes, without plants toxicity effects in terms of reduced growth or morphological symptoms. After 21 day-iodine biofortification, the highest I content (49.5 µg/100 g Fresh Weight (FW)) was reached in broccoli raab shoots, while after 43 day-iodine biofortification, genotype differences were flattened and the highest I content (66 µg/100 g FW, on average) was obtained using 1.5 mg I-IO3/L. Nitrate content (ranging from 1800 to 4575 mg/kg FW) was generally higher with 0.75 mg I-IO3/L, although it depended on genotypes. Generally, boiling reduced iodine content, while steaming increased or left it unchanged, depending on genotypes. Applying low levels of I proved to be suitable, since it could contribute to the partial intake of the recommended dose of 150 µg/day: A serving size of 100 g may supply on average 24% of the recommended dose. Cooking method should be chosen in order to preserve and/or enhance the final I amount.

Lead Absorption by Radish Is Affected by Soil Texture and Cultivar

Lead (Pb) was detected in potential urban garden soil in Claremont Cali-fornia and was absorbed by radish cultivars and giant red mustard in a bioassay of the contaminated soil. Radish cultivars grown in two soils with two lead salts developed the same lead tissue concentrations. In a subsequent study, Cultivar “Rudolf” accumulated less lead nitrate than cultivars “French Breakfast” and “White Beauty”. Cultivar “Rudolf” grew the least biomass likely accounting for its reduced Pb accumulation. All radish cultivars accumulated more lead when grown in clay vs. sand soil and radish Pb accumulation increased when the concentration of lead was increased in either soil type. The solubility of the lead ion used was not associated with Pb uptake by radish.

Comparative analysis of glucosinolates and metabolite profiling of green and red mustard (brassica juncea) hairy roots.

Here, accumulation of glucosinolates and expression of glucosinolates biosynthesis genes in green and red mustard hairy roots were identified and quantified by HPLC and qRT-PCR analyses. The total glucosinolates content of green mustard hairy root (10.09µg/g dry weight) was 3.88 times higher than that of red mustard hairy root. Indolic glucosinolates (glucobrassicin, 4-methoxyglucobrassicin, and neoglucobrassicin) in green mustard were found at 30.92, 6.95, and 5.29 times higher than in red mustard hairy root, respectively. Conversely, levels of glucotropaeolin (aromatic glucosinolate) was significantly higher in red mustard than in green mustard. Accumulation of glucoraphasatin, an aliphatic glucosinolate, was only observed only in red mustard hairy roots. Quantitative real-time PCR analysis showed that the expression level of genes related to aliphatic and aromatic glucosinolate biosynthesis were higher in red mustard, exception BjCYP83B. The expression of BjCYP79B2, which encodes a key enzyme involved in the indolic glucosinolate biosynthetic pathway, was higher in green mustard than in red mustard. Additionally, to further distinguish between green mustard and red mustard hairy roots, hydrophilic and lipophilic compounds were identified by gas chromatography-mass spectrometry and subjected to principal component analysis. The results indicated that core primary metabolites and glucosinolate levels were higher in the hairy roots of green mustard than in those of red mustard.

In vitro and in vivo anti-hyperglycemic effects of green and red mustard leaves (Brassica juncea var. integrifolia)

Brassica juncea var. integrifolia, known as mustard leaf, is used as a medicinal plant in Asia, however, knowledge for their health benefits is limited. Here, we evaluate the total phenolic contents, phenolic profile, and antioxidant activity of green and red mustard leaves (EG and ER, respectively). Additionally, the inhibitory activity of EG and ER against rat intestinal α‐glucosidase and porcine‐pancreatic α‐amylase were investigated. The total phenolic contents of EG and ER were 1,228.48 ± 36.81 and 850.75 ± 28.88mg/100 g, respectively. The total phenolic contents correlated to the observed antioxidant activities. ER had significant α‐glucosidase but low α‐amylase inhibitory activity. Using an Sprague‐Dawley‐Rat model, ER appeared to have better glucose‐lowering effect when compared to EG, after a sucrose‐loading test. This is the first report evaluating mustard leaves for potential glucose‐lowering effects. Our observations suggest that ER has better potential for this bioactivity and this observation possibly correlates with the sinigrin contents observed in both extracts. PRACTICAL APPLICATIONS: Mustard seeds are widely used for the production of food products and have been evaluated for their health benefits. Currently, mustard leaves are considered a low‐value by‐product of the mustard plant and are significantly underutilized. To support the sustainable utilization of mustard plant, it is important to initiate the utilization of mustard leaves. Value addition in mustard leaves through research efforts that define possible health benefits of this resource will significantly assist toward the possible utilization of this low‐value, underutilized raw material to produce high‐value, health beneficial, food ingredients.

Growing fresh food on future space missions: Environmental conditions and crop management.

This paper deals with vegetable cultivation that could be faced in a space mission. This paper focusses on optimization, light, temperature and the harvesting process, while other factors concerning cultivation in space missions, i.e. gravity, radiation, were not addressed. It describes the work done in preparation of the deployment of a mobile test facility for vegetable production of fresh food at the Neumayer III Antarctic research station. A selection of vegetable crops was grown under varying light and temperature conditions to quantify crop yield response to climate factors that determine resource requirement of the production system. Crops were grown at 21 °C or 25 °C under light treatments varying from 200 to 600 μmol m-2 s-1 and simulated the dusk and dawn light spectrum. Fresh food biomass was harvested as spread harvesting (lettuce), before and after regrowth (herbs) and at the end of cultivation. Lettuce and red mustard responded well to increasing light intensities, by 35-90% with increasing light from 200 to 600 μmol m-2 s-1, while the other crops responded more variably. However, the quality of the leafy greens often deteriorated at higher light intensities. The fruit biomass of both determinate tomato and cucumber increased by 8-15% from 300 to 600 μmol m-2 s-1. With the increase in biomass, the number of tomato fruits also increased, while the number of cucumber fruits decreased, resulting in heavier individual fruits. Increasing the temperature had varied effects on production. While in some cases the production increased, regrowth of herbs often lagged behind in the 25 °C treatment. In terms of fresh food production, the most can be expected from lettuce, cucumber, radish, then tomato, although the 2 fruit vegetables require a considerable amount of crop management. Spread harvesting had a large influence on the amount of harvested biomass per unit area. In particular, yield of the 3 lettuce cultivars and spinach was ca. 400% than single harvesting. Increasing plant density and applying spread harvesting increased fresh food production. This information will be the basis for determining crop growth recipes and management to maximize the amount of fresh food available, in view of the constraints of space and energy requirement of such a production system.

건조방법에 따른 적겨자잎의 이화학적 성분 및 항산화효과 비교

This research investigated the physicochemical properties and antioxidant activities of hot air-dried red mustard (Brassica juncea L.) leaf (HR) and freeze-dried red mustard leaf (FR). Crude protein content was highest in FR, and crude fat and carbohydrate contents were highest in HR. However, moisture and crude ash contents were not significantly different between the two drying methods. Total free sugars were higher in HR compared with FR. Sucrose, fructose, and glucose were the major free sugars in both HR and FR. Contents of essential and non-essential amino acids were higher in HR compared with FR. The major organic acid of FR was malic acid, and the major organic acid of HR was malic acid. The contents of saturated and unsaturated fatty acids were higher in HR than in FR. Total mineral contents were higher in FR (10,187.22 ㎎%) compared with HR (9,815.80 ㎎%). Major minerals were K, Ca, and Na in the two drying methods. The contents of vitamins C and E in HR were higher than those in FR. Total polyphenol contents showed no significant difference between the two methods. However, total flavonoid contents in HR were higher than in FR. The ICSUB50/SUB values of FR and HR in ABTS assay were 0.89 ㎎/mL and 0.65 ㎎/mL, respectively. The results of all experiments suggest that HR and FR can be natural candidates as a rich source of antioxidants for further chemical investigation.

Inhibitory effect of plant essential oil nanoemulsions against Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella Typhimurium on red mustard leaves

Abstract In this study, essential oil (EO) nanoemulsions as an alternative to chlorine-based sanitizers for red mustard leaves were prepared, and their inhibitory effects against pathogenic bacteria were examined. Red mustard leaves spot-inoculated with Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella Typhimurium were treated with EOs alone, surfactants (SFs) (Tween 80 (T80), non-ionic; cetylpyridinium chloride (CPC), cationic) alone, and nanoemulsions formulated with EOs (0.02%) and SFs (0.002%). The results indicated that nanoemulsions containing CPC exhibited a higher inhibitory effect than those including T80. The reductions in all pathogens after treatment with nanoemulsions containing EOs and CPC were higher (0.1–0.6 log reductions) than those of 0.02% NaOCl. In addition, nanoemulsion treatment did not affect the sensory qualities of red mustard during storage. Therefore, nanoemulsions with EOs and CPC can become an effective substitute for chlorine-based sanitizers for fresh-cut produce if regulations allow the use of CPC. Industrial relevance Foodborne-illness outbreaks related to fresh-cut produce have increased globally. The use of chlorine-based sanitizers in the fresh-cut produce industry has been decreasing due to health-related problems. Thus, an alternative washing treatment is needed to control pathogenic bacteria contaminating fresh-cut produce. Nanoemulsions with EOs and cationic SF developed in this study can be a suitable washing agent for inactivating foodborne pathogens on fresh-cut produce.

Development of a Comprehensive Flavonoid Analysis Computational Tool for Ultrahigh-Performance Liquid Chromatography-Diode Array Detection-High-Resolution Accurate Mass-Mass Spectrometry Data.

Liquid chromatography and mass spectrometry methods, especially ultrahigh-performance liquid chromatography coupled with diode array detection and high-resolution accurate-mass multistage mass spectrometry (UHPLC-DAD-HRAM/MSn), have become the tool-of-the-trade for profiling flavonoids in foods. However, manually processing acquired UHPLC-DAD-HRAM/MSn data for flavonoid analysis is very challenging and highly expertise-dependent due to the complexities of the chemical structures of the flavonoids and the food matrixes. A computational expert data analysis program, FlavonQ-2.0v, has been developed to facilitate this process. The program first uses UV-vis spectra for an initial stepwise classification of flavonoids into classes and then identifies individual flavonoids in each class based on their mass spectra. Step-wise identification of flavonoid classes is based on a UV-vis spectral library compiled from 146 flavonoid reference standards and a novel chemometric model that uses stepwise strategy and projected distance resolution (PDR) method. Further identification of the flavonoids in each class is based on an in-house database that contains 5686 flavonoids analyzed in-house or previously reported in the literature. Quantitation is based on the UV-vis spectra. The stepwise classification strategy to identify classes significantly improved the performance of the program and resulted in more accurate and reliable classification results. The program was validated by analyzing data from a variety of samples, including mixed flavonoid standards, blueberry, mizuna, purple mustard, red cabbage, and red mustard green. Accuracies of identification for all samples were above 88%. FlavonQ-2.0v greatly facilitates the identification and quantitation of flavonoids from UHPLC-HRAM-MSn data. It saves time and resources and allows less experienced people to analyze the data.

Effect of pomegranate (Punica granatum) pomace extract as a washing agent on the inactivation of Listeria monocytogenes inoculated on fresh produce

SummaryPomegranate pomace extract (PPE) was used as a substitute to chlorinated water for washing of fresh produce. PPE contained punicalagins and ellagic acids, and it had a good inhibitory effect against Listeria monocytogenes based on the results of disc diffusion test and time‐kill assay. Red chard, beet, chicon and red mustard leaves were treated with 7 mg mL−1 PPE as a washing solution to inactivate L. monocytogenes inoculated on fresh produce and compared with 0.05 mg mL−1 NaOCl treatment. After the treatment, L. monocytogenes population on the four leafy vegetables was reduced by 1.96–2.97 log CFU g−1 compared to that on nontreated samples. The reductions in L. monocytogenes after PPE treatment were higher than those observed after NaOCl treatment. Further, the PPE treatment did not affect the surface colour of all fresh produce applied in this study. Thus, PPE can be used as an effective antimicrobial washing agent of fresh produce.