Characterization and quantification of flavonoids and hydroxycinnamic acids in curly kale (Brassica oleracea L. Convar. acephala Var. sabellica) by HPLC-DAD-ESI-MSn

Polyphenols in edible plant leaves: an overview of their occurrence and health properties

Edible plant leaves (EPLs) constitute a major renewable functional plant biomass available all year round, providing an essential source of polyphenols in the global diet. Polyphenols form a large family of antioxidant molecules. They protect against the harmful effects of free radicals, strengthen immunity and stimulate the body's natural defenses thanks to their antibacterial and antiviral functions. This study refers to phenolic compounds from 50 edible plant leaves divided into four categories: green leafy vegetables, underutilized leafy vegetables, leafy spices and leafy drinks. It provides data on the identification, occurrence and pharmacological functions of polyphenols contained in EPLs, and provides a better understanding of trends and gaps in their consumption and study. Certain EPLs, such as moringa (Moringa oleifera Lam.), tea (Camellia sinensis L.) and several leafy spices of the Lamiaceae family, reveal important characteristics and therapeutic potential. The polyphenol composition of EPLs makes them functional plants that offer relevant solutions in the fight against obesity, the management of food insecurity and the prevention of chronic diseases.

Iodine enriched kale (Brassica oleracea var. sabellica L.)-The influence of heat treatments on its iodine content, basic composition and antioxidative properties

Iodine deficiency in the diet globally continues to be a cause of many diseases and disabilities. Kale is a vegetable that has health-promoting potential because of many nutrients and bioactive compounds (ascorbic acid, carotenoids, glucosinolates and phenolic compounds). Brassica vegetables, including kale, have been strongly recommended as dietary adjuvants for improving health. The nutrient and health-promoting compounds in kale are significantly affected by thermal treatments. Changes in phytochemicals upon such activities may result from two contrary phenomena: breakdown of nutrients and bioactive compounds and a matrix softening effect, which increases the extractability of phytochemicals, which may be especially significant in the case of iodine-fortified kale. This study investigated changes of basic composition, iodine, vitamin C, total carotenoids and polyphenols contents as well as antioxidant activity caused by steaming, blanching and boiling processes in the levels of two cultivars of kale (green and red) non-biofortified and biofortified via the application to nutrient solutions in hydroponic of two iodoquinolines [8-hydroxy-7-iodo-5-quinolinesulfonic acid (8-OH-7-I-5QSA) and 5-chloro-7-iodo-8-quinoline (5-Cl-7-I-8-Q)] and KIO3. Thermal processes generally significantly reduced the content of the components in question and the antioxidant activity of kale, regardless of cultivar and enrichment. It was observed that the red cultivar of kale had a greater ability to accumulate and reduce iodine losses during the culinary processes. 8-hydroxy-7-iodo-5-quinolinesulfonic acid showed a protective effect against the treatments used, compared to other enrichments, thus contributing to the preservation of high iodine content.

Chemical profiling and quality evaluation of Liuweizhiji Gegen-Sangshen oral liquid by UPLC-Q-TOF-MS and HPLC-diode array detector fingerprinting

INTRODUCTION

Liuweizhiji Gegen-Sangshen (LGS) oral liquid is a Chinese patent medicine that is widely used for the prevention and treatment of alcoholic liver disease in clinical practice. However, the chemical complexity of LGS has not yet been investigated.

OBJECTIVE

The aim of this study was to rapidly identify chemical constituents of LGS and establish a quality control method based on fingerprint and quantitative analysis.

METHODOLOGY

A comprehensive strategy was used by combining qualitative analysis by ultra-performance liquid chromatography tandem quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) and fingerprint analysis by high-performance liquid chromatography with diode array detection (HPLC-DAD).

RESULTS

A total of 162 chemical components in LGS, including 91 flavonoids, 31 organic acids, and 20 phenolic compounds, were identified or preliminarily characterized in both positive and negative ion modes based on the UPLC-Q-TOF-MS results. Of these, 37 were confirmed with the reference standards. In fingerprint analysis, 23 peaks were chosen as common peaks and used to evaluate the similarity of different batches of LGS. Subsequently, a rapid quantification method was optimized and validated for the simultaneous determination of multiple chemical markers in LGS. The validated quantitative method was successfully used to analyze different batches of LGS samples.

CONCLUSION

The proposed comprehensive strategy combining HPLC-DAD fingerprinting and multi-component quantification demonstrated satisfactory results with high efficiency, accuracy, and reliability. This can be used as a reference for the overall quality consistency evaluation of Chinese patent medicines.

Rutin: Family Farming Products' Extraction Sources, Industrial Applications and Current Trends in Biological Activity Protection

In vitro and in vivo studies have demonstrated the bioactivity of rutin, a dietary flavonol naturally found in several plant species. Despite widespread knowledge of its numerous health benefits, such as anti-inflammatory, antidiabetic, hepatoprotective and cardiovascular effects, industrial use of rutin is still limited due to its low solubility in aqueous media, the characteristic bitter and astringent taste of phenolic compounds and its susceptibility to degradation during processing. To expand its applications and preserve its biological activity, novel encapsulation systems have been developed. This review presents updated research on the extraction sources and methodologies of rutin from fruit and vegetable products commonly found in a regular diet and grown using family farming approaches. Additionally, this review covers quantitative analysis techniques, encapsulation methods utilizing nanoparticles, colloidal and heterodisperse systems, as well as industrial applications of rutin.

The Vegetable 'Kale' Protects against Dextran-Sulfate-Sodium-Induced Acute Inflammation through Moderating the Ratio of Proinflammatory and Anti-Inflammatory LPS-Producing Bacterial Taxa and Augmenting the Gut Barrier in C57BL6 Mice

Kale (Brassica oleracea var. acephala), a food rich in bioactive phytochemicals, prevents diet-induced inflammation and gut dysbiosis. We hypothesized that the phytochemicals protect against the lipopolysaccharide (LPS)-induced acute inflammation which results from gut dysbiosis and loss of gut barrier integrity. We designed this study to test the protective effects of the whole vegetable by feeding C57BL/6J mice a rodent high-fat diet supplemented with or without 4.5% kale (0.12 g per 30 g mouse) for 2 weeks before administering 3% dextran sulfate sodium (DSS) via drinking water. After one week, DSS increased the representation of proinflammatory LPS (P-LPS)-producing genera Enterobacter and Klebsiella in colon contents, reduced the representation of anti-inflammatory LPS (A-LPS)-producing taxa from Bacteroidales, reduced the expression of tight junction proteins, increased serum LPS binding protein, upregulated molecular and histopathological markers of inflammation in the colon and shortened the colons. Mice fed kale for 2 weeks before the DSS regime had a significantly reduced representation of Enterobacter and Klebsiella and instead had increased Bacteroidales and Gram-positive taxa and enhanced expression of tight junction proteins. Downstream positive effects of dietary kale were lack of granuloma in colon samples, no shortening of the colon and prevention of inflammation; the expression of F4/80, TLR4 and cytokines 1L-1b, IL-6, TNF-a and iNOS was not different from that of the control group. We conclude that through reducing the proliferation of P-LPS-producing bacteria and augmenting the integrity of the gut barrier, kale protects against DSS-induced inflammation.

Evaluation of bioactive compounds, volatile compounds, drying process kinetics and selected physical properties of vacuum impregnation celery dried by different methods

We have developed a new healthy snack based on celery root enriched with vegetable juices. Vacuum impregnation was used the task of which was to introduce additional valuable substances, improving properties. Thus, prepared material was dried by various methods (sublimation, vacuum, convection) using optimal conditions for the process. In the tested sample, 41 bioactive compounds and 73 volatile compounds were identified. Vacuum impregnation of celery root in the juices of onion, kale and celery stalks significantly affected the profile of bioactive compounds, Volatile Organic Compounds (VOCs), total phenolic content, antioxidant properties, drying process kinetics and physical properties of the dried products. The highest nutrient values were recorded in celery samples after impregnation with kale and onion juice. Due to its good functional and nutritional properties, the material such as celery obtained as a result vacuum impregnation process can be envisioned as the future in creating novel functional foods.

Bioactive Compounds from Leaf Vegetables as Preservatives

Trends toward a healthier diet are increasing attention to clean-label products. This has led to the search for new ingredients that avoid the use of chemical additives. Food industries are responding to these demands by incorporating natural preservatives into their products, which consumers perceive as healthy. Leafy vegetables would fit this strategy since they are common components of the diet and are associated with beneficial health effects. The objective of this chapter is to offer an overview of the large number of bioactive compounds (phenolic acids, flavonoids, anthocyanins, glucosinolates, and sulfur compounds) present in these plants, which would be responsible for their activity as potential preservatives. Its incorporation into food would improve the quality and extend the shelf life by reducing oxidative processes and inhibiting or retarding the microbial growth that occurs during processing and storage without reducing the organoleptic characteristics of the product.

Salivary flow and turbidity development inconsistently associated with lower taste intensity of vegetables and juices

The same phytochemicals that stimulate aversive sensations are often also responsible for purported health benefits in fruits and vegetables. Prior work indicates that some salivary proteins may reduce aversiveness of phytochemicals. In rodents, the salivary binding proteins have been shown to reduce bitter taste of polyphenols and alkaloids, but work in humans has focused primarily on polyphenol astringency (dry, rough, or puckery sensations). In this study, we tested if tastes of vegetable products might correlate to either salivary flow rate or the polyphenol binding capability of saliva, as measured by turbidity development when saliva is mixed with tannic acid. Participants (N=26) provided chewing-stimulated saliva samples and rated five juices and two chopped vegetables for bitterness, sourness, and sweetness intensity. Saliva was mixed with tannic acid and light absorbance was measured for quantification of haze development. Greater absorbance corresponded to less bitterness for one green vegetable juice blend, less sweetness for two green vegetable juices and chopped kale, and less sourness from cranberry juice. Greater salivary flow corresponded to less bitterness from chopped brussels sprouts, and less sweetness from one green vegetable juice blend and chopped kale. These findings indicate that greater salivary flow rate and presence of certain salivary binding proteins is not universally associated with lower aversive tastes from phytochemical-containing foods. Whether associations between these salivary properties are ingredient specific or simply not robustly related to taste in commercial products should be further investigated.

Anti-inflammatory effects of Athyrium yokoscense extract via inhibition of the Erk1/2 and NF-κB pathways in bisphenol A-stimulated A549 cells

Bisphenol A is an environmental endocrine disruptor that has similar functions to estrogen in humans. However, few studies have investigated pulmonary inflammation induced by BPA, and the effect of Athyrium yokoscense extract on this inflammatory response is unknown. In this study, we investigated this effect in A549 human alveolar epithelial cells. BPA at concentrations higher than 100 µM were cytotoxic to A549 cells at 24 and 48 h after treatment; however, AYE (100 µg/mL) had a protective effect against BPA-induced cytotoxicity. AYE also inhibited the generation of intracellular reactive oxygen species, expressions of cyclooxygenase-2 and extracellular signal-regulated kinase1/2 proteins, activities of phospholipase A2, COX-2, nuclear factor kappa-light-chain-enhancer of activated B cells, and proinflammatory mediators including prostaglandin E2, tumor necrosis factor-α, and interleukin-6 induced by BPA in A549 cells. This study demonstrated that BPA, which induces chronic lung disease, causes oxidative stress and inflammatory response in lung epithelial cell line, and found that AYE reduces BPA-induced oxidative stress and inflammatory response by down-regulating the Erk1/2 and NF-κB pathways.

The Impact of Dietary Flavonols on Central Obesity Parameters in Polish Adults

Background: Central obesity is defined as the excessive fat tissue located in abdominal region accompanied by systemic inflammation, which drives to cardiovascular disease. Flavonols are antioxidative agents present in food. The aim of this study was investigating the relationship between dietary flavonols intake and central obesity. Methods and results: 80 participants (40 central obese and 40 healthy controls) were administered a food frequency questionnaire dedicated to flavonols intake assessment. Body composition was measured with bioelectrical impedance analysis. The analysis showed significant differences between central obese participants and healthy controls in total flavonol (p = 0.005), quercetin (p = 0.003), kaempferol (p = 0.04) and isorhamnetin (p < 0.001) habitual intake. Among central obese participants, there was a moderate inverse correlation between fat mass (FM) and total flavonol (R = −0.378; 95% CI: −0.620 to −0.071; p = 0.02), quercetin (R = −0.352; 95% CI: −0.601 to −0.041; p = 0.03), kaempferol (R = −0.425; 95% CI: −0.653 to −0.127; p = 0.01) and myricetin intake (R = −0.352; 95% CI: −0.601 to −0.041; p = 0.03). BMI was inversely correlated with total flavonol (R = −0.330; 95% CI: −0.584 to −0.016; p = 0.04) and quercetin intake (R = −0.336; 95% CI: −0.589 to −0.023; p = 0.04). Waist circumference was inversely correlated with total flavonol (R = −0.328; 95% CI: −0.586 to −0.009; p = 0.04), quercetin (R = −0.322; 95% CI: −0.582 to −0.002; p = 0.048) and myricetin intake (R = −0.367; 95% CI: −0.615 to −0.054; p = 0.02). Among flavonols’ dietary sources, there was an inverse correlation between black tea consumption and FM (R: −0.511; 95% CI: −0.712 to −0.233; p < 0.001) and between coffee and waist circumference (R: −0.352; 95% CI: −0.604 to −0.036; p = 0.03) in central obese participants. Conclusions: The higher flavonol intake could play a protective role in abdominal obesity development. What is more, total and selected flavonol dietary intakes are inversely correlated with the parameters used for obesity assessment in central obese participants. The habitual consumption of products rich in flavonols, mainly tea and coffee, could possibly have a preventive role in abdominal obesity development.

Metabolic diversity in a collection of wild and cultivated Brassica rapa subspecies

Brassica rapa (B. rapa) and its subspecies contain many bioactive metabolites that are important for plant defense and human health. This study aimed at investigating the metabolite composition and variation among a large collection of B. rapa genotypes, including subspecies and their accessions. Metabolite profiling of leaves of 102 B. rapa genotypes was performed using ultra-performance liquid chromatography coupled with a photodiode array detector and quadrupole time-of-flight mass spectrometry (UPLC-PDA-QTOF-MS/MS). In total, 346 metabolites belonging to different chemical classes were tentatively identified; 36 out of them were assigned with high confidence using authentic standards and 184 were those reported in B. rapa leaves for the first time. The accumulation and variation of metabolites among genotypes were characterized and compared to their phylogenetic distance. We found 47 metabolites, mostly representing anthocyanins, flavonols, and hydroxycinnamic acid derivatives that displayed a significant correlation to the phylogenetic relatedness and determined four major phylometabolic branches; 1) Chinese cabbage, 2) yellow sarson and rapid cycling, 3) the mizuna-komatsuna-turnip-caitai; and 4) a mixed cluster. These metabolites denote the selective pressure on the metabolic network during B. rapa breeding. We present a unique study that combines metabolite profiling data with phylogenetic analysis in a large collection of B. rapa subspecies. We showed how selective breeding utilizes the biochemical potential of wild B. rapa leading to highly diverse metabolic phenotypes. Our work provides the basis for further studies on B. rapa metabolism and nutritional traits improvement.

Changes in the content of glucosinolates, polyphenols and carotenoids during lactic-acid fermentation of cruciferous vegetables: a mini review

•

Cruciferous vegetables as fermented products has been used since ancient times.

•

During fermentation of cruciferous vegetables complete fermentation of glucosinolates occur.

•

Fermentation decrease the content of complex polyphenols, while increase the content of polyphenols in free form.

•

Carotenoid content decrease during fermentation of cruciferous vegetables.

Cruciferous vegetables are considered functional foods because of their content of health-related compounds. They are grown and consumed in various cultures around the world. Fermentation as a preservation method for cruciferous vegetables has been used since ancient times. This process results in fermented products that have a unique flavour and odour, high bioactivity, and a distinctly different phytochemical profile than raw vegetables. In this mini review, we summarize data on changes in phytochemical content during lactic-acid fermentation of various cruciferous vegetables. The main focus was on the changes in the group of glucosinolates, polyphenols and carotenoids.

Identification and Quantification of Glucosinolates and Phenolics in a Large Panel of Brassica napus Highlight Valuable Genetic Resources for Chemical Ecology and Breeding

Glucosinolate (GLS) and phenolic contents in Brassicaceae contribute to biotic and abiotic stress responses. Breeding crop accessions harboring agroecologically relevant metabolic profiles require a characterization of the chemical diversity in Brassica germplasm. This work investigates the diversity of specialized metabolites in 281 accessions of B. napus. First, an LC-HRMS2-based approach allowed the annotation of 32 phenolics and 36 GLSs, revealing 13 branched and linear alkyl-GLSs and 4 isomers of hydroxyphenylalkyl-GLSs, many of which have been rarely reported in Brassica. Then, quantitative UPLC-UV-MS-based profiling was performed in leaves and roots for the whole panel. This revealed striking variations in the content of 1-methylpropyl-GLS (glucocochlearin) and a large variation of tetra- and penta-glucosyl kaempferol derivatives among accessions. It also highlighted two main chemotypes related to sinapoyl-O-hexoside and kaempferol-O-trihexoside contents. By offering an unprecedented overview of the phytochemical diversity in B. napus, this work provides a useful resource for chemical ecology and breeding.

Phenolic and Volatile Composition and Antioxidant Properties of the Leaf Extract of Brassica fruticulosa subsp. fruticulosa (Brassicaceae) Growing Wild in Sicily (Italy)

In continuation of research conducted on species of the spontaneous flora of Sicily (Italy) belonging to the Brassicaceae family, Brassica fruticulosa subsp. fruticulosa was selected. It is an edible species utilized in Sicilian traditional medicine. In this study, for the first time, the phenolic and the volatile compounds and the antioxidant properties of the hydroalcoholic extract obtained from the leaves of B. fruticulosa subsp. fruticulosa were characterized. Through HPLC-PDA/ESI-MS analysis, a total of 22 polyphenolic compounds (20 flavonoids and 2 phenolic acids) were identified, with 3-hydroxiferuloylsophoroside-7-O-glucoside (1.30 mg/g ± 0.01) and kaempferol-3-O-feruloylsophoroside-7-O-glucoside (1.28 mg/g ± 0.01) as the most abundant compounds. Through SPME-GC/MS several volatiles belonging to different chemical classes were characterized, with nitriles and aldehydes accounting for more than 54% of the whole volatile fraction. The extract of B. fruticulosa subsp. fruticulosa showed moderate activity in the DPPH assay (IC50 = 1.65 ± 0.08 mg/mL), weak reducing power (17.47 ± 0.65 ASE/mL), and good chelating properties (IC50 = 0.38 ± 0.02 mg/mL), reaching approximately 90% activity at the highest tested concentration. Lastly, the extract was non-toxic against Artemia salina, indicating its potential safety. According to the findings, it can be stated that B. fruticulosa subsp. fruticulosa represents a new valuable source of bioactive compounds.

Multitherapeutic Efficacy of Curly Kale Extract Fabricated Biogenic Silver Nanoparticles

Purpose

Due to the biomedical applications universally, the Ag nanoparticles are one of the most commonly investigated nanoparticles (NPs). Curly kale (BroL) leaves contain numerous beneficial nutrients and phytochemicals. The aim of the current study is the fabrication of the Ag nanoparticles using the extracts of curly kale and to investigate their biological potentials.

Methods

The characterization of the generated BroLAgNPs was done through UV-Vis spectro study, Fourier-transform infrared spectro study, scanning electron microscope analysis, energy-dispersive X-ray study, distribution of size and zeta potential investigation, and X-ray powder diffraction study, and their biological effects were evaluated by antidiabetic, antioxidant, antibacterial and cytotoxicity effect.

Results

BroL-Ag nanoparticle displayed surface plasmon resonance at 432 nm. The Zeta potential of BroL (-26.6) AgNPs displayed a highly negative charge. In antidiabetic assay, BroL-AgNPs was highly effective with IC50 value 2.29 µg/mL at 1.0 µg/mL concentration. In cytotoxicity assay, BroL-AgNPs displayed strong activity at 10.0 µg/mL concentration. It showed inhibitory action against three food-borne pathogenic bacteria (9.29-11.44 mm inhibition zone) and displayed moderate antioxidant potential.

Conclusion

This study as a whole report an eco-friendly green synthesis of AgNPs using leafy vegetable aqueous extract and its multi-biological effects which could serve as a promising candidate in pharmacological and related industries.

Understanding the Functional Activity of Polyphenols Using Omics-Based Approaches

Plant polyphenols are the main category of natural active substances, and are distributed widely in vegetables, fruits, and plant-based processed foods. Polyphenols have a beneficial performance in preventing diseases and maintaining body health. However, its action mechanism has not been well understood. Foodomics is a novel method to sequence and widely used in nutrition, combining genomics, proteomics, transcriptomics, microbiome, and metabolomics. Based on multi-omics technologies, foodomics provides abundant data to study functional activities of polyphenols. In this paper, physiological functions of various polyphenols based on foodomics and microbiome was discussed, especially the anti-inflammatory and anti-tumor activities and gut microbe regulation. In conclusion, omics (including microbiomics) is a useful approach to explore the bioactive activities of polyphenols in the nutrition and health of human and animals.

Controlled fermentation of curly kale juice with the use of autochthonous starter cultures

The aim of this paper was to evaluate the influence of different indigenous lactic acid bacteria isolates - as a single culture or bacterial consortium - on the functional and physicochemical properties of fermented curly kale juice. All tested variants exhibited good growth parameters, manifested by efficient pH lowering, increases in acidity, and fructose and glucose metabolism, as well as a significant inhibition of pathogens. A slight increase in total phenolic content was observed, while antioxidant activity remained unchanged. L. sakei and MIX A were associated with an increase in riboflavin and pyridoxine content, while L. plantarum only contributed to an increase in vitamin B₆ content. Bioconversion of individual phenolic compounds, carotenoids, and glucosinolates strongly depended on the strain-specific metabolism. In the process, the levels of ferulic acid and other hydroxycinnamic acids were maintained, while the content of 9-cis lutein increased. Considering presented results and our previous research regarding probiotic features of LAB strains, among tested starter cultures - L. plantarum seemed to possess the best characteristics as a potential starter culture for controlled fermentation of curly kale juice.

Kale supplementation during high fat feeding improves metabolic health in a mouse model of obesity and insulin resistance

Cruciferous vegetables have been widely studied for cancer prevention and cardiovascular health. Broccoli is the cruciferous vegetable whose phytochemistry and physiological effects have been most extensively studied. Kale (Brassica oleracea var. acephala) appears on lists of 'healthiest, nutrient dense foods' but, there is paucity of data on kale as a functional food. In a 12-week study, we tested the effect of curly green kale on high fat diet (HFD) induced obesity and insulin resistance, lipid metabolism, endotoxemia and inflammation in C57BL/6J mice fed isocaloric diets. Kale supplementation did not attenuate HFD diet induced fat accumulation and insulin resistance (P = ns; n = 9) but, it lowered serum triglycerides, low density lipoprotein (LPL) cholesterol and prevented HFD induced increases in systemic endotoxemia and inflammation (serum LPS and Ccl2) (P<0.01; n = 9). In adipose tissue, kale enhanced the expression of genes involved in adipogenesis (P<0.01; n = 9), reduced the appearance of histologic markers of inflammation, downregulated both the gene expression and protein expression of the adipose tissue specific inflammation markers CD11c and F4/80 (P<0.001; n = 9) and reduced the gene expression of a battery of chemokine C-C motif ligands (Ccl2, Ccl6, Ccl7, Ccl8, Ccl9) and chemokine C-C motif receptors (Ccr2, Ccr3, Ccr5). We conclude that kale vegetable protects against HFD diet induced dysfunction through mechanisms involving lipid metabolism, endotoxemia and inflammation.

Volatiles, phenolic compounds, antioxidant and antibacterial properties of kohlrabi leaves

This work presents the volatile compounds and phenolic profile investigation of the leaves of Brassica oleracea L. growing in Tunisia, together with antioxidant and antibacterial properties. Volatile constituents were determined by HS-SPME coupled to GC/MS, and the results showed that α-pinene (31.6%) and limonene (16.9%) were the main volatiles. The phenolic profile was determined by HPLC analysis, the methanol extract revealed the presence of four hydroxycinnamic acids (chlorogenic, ferulic, p-coumaric and sinapic acids), two hydroxybenzoic acids (syringic and gallic acids), and four flavonoids (catechol, catechin hydrate, epigallocatechin and epicatechin 3-O-gallate). The methanol extract showed the best significantly antiradical activity by DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS ((2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) antioxidant assays, with EC₅₀ of 0.32 and 0.45 mg/mL, respectively. For antibacterial activity, the methanol extract inhibits all the tested strains. It can be concluded that kohlrabi leaves are rich in bioactive compounds and are a potential source of natural antioxidants and antibacterials.

Agronomic and Metabolomic Side-Effects of a Divergent Selection for Indol-3-Ylmethylglucosinolate Content in Kale (Brassica oleracea var. acephala)

Brassica oleracea var. acephala (kale) is a cruciferous vegetable widely cultivated for its leaves and flower buds in Europe and a food of global interest as a “superfood”. Brassica crops accumulate phytochemicals called glucosinolates (GSLs) which play an important role in plant defense against biotic stresses. Studies carried out to date suggest that GSLs may have a role in the adaptation of plants to different environments, but direct evidence is lacking. We grew two kale populations divergently selected for high and low indol-3-ylmethylGSL (IM) content (H-IM and L-IM, respectively) in different environments and analyzed agronomic parameters, GSL profiles and metabolomic profile. We found a significant increase in fresh and dry foliar weight in H-IM kale populations compared to L-IM in addition to a greater accumulation of total GSLs, indole GSLs and, specifically, IM and 1-methoxyindol-3-ylmethylGSL (1MeOIM). Metabolomic analysis revealed a significant different concentration of 44 metabolites in H-IM kale populations compared to L-IM. According to tentative peak identification from MS interpretation, 80% were phenolics, including flavonoids (kaempferol, quercetin and anthocyanin derivates, including acyl flavonoids), chlorogenic acids (esters of hydroxycinnamic acids and quinic acid), hydroxycinnamic acids (ferulic acid and p-coumaric acid) and coumarins. H-IM kale populations could be more tolerant to diverse environmental conditions, possibly due to GSLs and the associated metabolites with predicted antioxidant potential.

Ontogenetic Variation in the Mineral, Phytochemical and Yield Attributes of Brassicaceous Microgreens

Microgreens constitute novel gastronomic ingredients that combine visual, kinesthetic and bioactive qualities. The definition of the optimal developmental stage for harvesting microgreens remains fluid. Their superior phytochemical content against mature leaves underpins the current hypothesis of significant changes in compositional profile during the brief interval of ontogeny from the appearance of the first (S1) to the second true leaf (S2). Microgreens of four brassicaceous genotypes (Komatsuna, Mibuna, Mizuna and Pak Choi) grown under controlled conditions and harvested at S1 and S2 were appraised for fresh and dry yield traits. They were further analyzed for macro- and micromineral content using inductively coupled plasma optical emission spectrometry (ICP-OES), carotenoid content using high-performance liquid chromatography with a diode-array detector (HPLC-DAD), volatile organic compounds using solid-phase microextraction followed by gas chromatography-mass spectrometry (SPME-GC/MS), anthocyanins and polyphenols using liquid chromatography-high resolution-tandem mass spectrometry (LC-MS/MS) with Orbitrap technology and for chlorophyll and ascorbate concentrations, well as antioxidant capacity by spectrophotometry. Analysis of compositional profiles revealed genotype as the principal source of variation for all constituents. The response of mineral and phytochemical composition and of antioxidant capacity to the growth stage was limited and largely genotype-dependent. It is, therefore, questionable whether delaying harvest from S1 to S2 would significantly improve the bioactive value of microgreens while the cost-benefit analysis for this decision must be genotype-specific. Finally, the lower-yielding genotypes (Mizuna and Pak Choi) registered higher relative increase in fresh yield between S1 and S2, compared to the faster-growing and higher-yielding genotypes. Although the optimal harvest stage for specific genotypes must be determined considering the increase in yield against reduction in crop turnover, harvesting at S2 seems advisable for the lower-yielding genotypes.

Transepithelial Anti-Neuroblastoma Response to Kale among Four Vegetable Juices Using In Vitro Model Co-Culture System

Juicing vegetables is thought to be an anticancer treatment. Support exists for a rank order of anticancer greens (kale > dandelion > lettuce > spinach) based on degrees of bioavailability of different phytochemicals, also offset by some noxious molecules (i.e., calcium-oxalate). We developed a new in vitro transepithelial anti-neuroblastoma model system. The juices were diluted as predicted once in the small intestine. They were applied to apical Caco-2Bbe1 cells atop dividing SH-SY5Y neuroblastoma cells, and changes in transepithelial electrical resistance (TEER) and cell growth were considered with juice spectroscopies. Studied first in monoculture, kale and dandelion were the most cytostatic juices on SH-SY5Ys, lettuce showed no effect, and high (4.2%) spinach was cytotoxic. In co-culture, high (4.2%) kale was quickest (three days) to inhibit neuroblastoma growth. By five days, dandelion and kale were equally robust. Lettuce showed small anti-proliferative effects at five days and spinach remained cytotoxic. Spinach’s cytotoxicity corresponded with major infrared bands indicative of oxalate. Kale juice uniquely induced reactive oxygen species and S-phase cell cycle arrest in SH-SY5Y. The superiority of kale and dandelion was also apparent on the epithelium, because raising TEER levels is considered healthy. Kale’s unique features corresponded with a major fluorescent peak that co-eluted with kaempferol during high performance liquid chromatography. Because the anticancer rank order was upheld, the model appears validated for screening anticancer juices.

Kale Attenuates Inflammation and Modulates Gut Microbial Composition and Function in C57BL/6J Mice with Diet-Induced Obesity

Kale (Brassica oleracea var. acephala) is a vegetable common in most cultures but is less studied as a functional food compared to other cruciferous vegetables, such as broccoli. We investigated the effect of supplementing a high-fat diet (HFD) with kale (HFKV) in C57BL/6J mice. We particularly explored its role in metabolic parameters, gut bacterial composition and diversity using 16S rRNA sequencing, systematically compared changes under each phylum and predicted the functional potential of the altered bacterial community using PICRUSt2. Like other cruciferous vegetables, kale attenuated HFD-induced inflammation. In addition, kale modulated HFD-induced changes in cecal microbiota composition. The HFD lowered bacterial diversity, increased the Firmicutes: Bacteroidetes (F/B) ratio and altered composition. Specifically, it lowered Actinobacteria and Bacteroidetes (Bacteroidia, Rikenellaceae and Prevotellaceae) but increased Firmicutes (mainly class Bacilli). Kale supplementation lowered the F/B ratio, increased both alpha and beta diversity and reduced class Bacilli and Erysipelotrichi but had no effect on Clostridia. Within Actinobacteria, HFKV particularly increased Coriobacteriales/Coriobacteriaceae about four-fold compared to the HFD (p < 0.05). Among Bacteroidia, HFKV increased the species Bacteroides thetaiotaomicron by over two-fold (p = 0.05) compared to the HFD. This species produces plant polysaccharide digesting enzymes. Compared to the HFD, kale supplementation enhanced several bacterial metabolic functions, including glycan degradation, thiamine metabolism and xenobiotic metabolism. Our findings provide evidence that kale is a functional food that modulates the microbiota and changes in inflammation phenotype.

Flavonoid Glycosides in Brassica Species Respond to UV-B Depending on Exposure Time and Adaptation Time

Recently, there have been efforts to use ultraviolet-B radiation (UV-B) as a biotechnological tool in greenhouses. Leafy Brassica species are mainly considered for their ability to synthesize glucosinolates and are valued as baby salads. They also have a remarkable concentration of chemically diverse flavonoid glycosides. In this study, the effect of short-term UV-B radiation at the end of the production cycle was investigated without affecting plant growth. The aim was to verify which exposure and adaptation time was suitable and needs to be further investigated to use UV as a biotechnological tool in greenhouse production of Brassica species. It is possible to modify the flavonoid glycoside profile of leafy Brassica species by increasing compounds that appear to have potentially high antioxidant activity. Exemplarily, the present experiment shows that kaempferol glycosides may be preferred over quercetin glycosides in response to UV-B in Brassica rapa ssp. chinensis, for example, whereas other species appear to prefer quercetin glycosides over kaempferol glycosides, such as Brassica oleracea var. sabellica or Brassica carinata. However, the response to short-term UV-B treatment is species-specific and conclusions on exposure and adaptation time cannot be unified but must be drawn separately for each species.

Sensory analysis of curly kale produced under conventional and hydroponic systems

Abstract The consumption and cultivation of curly kale in Brazil is recent and information on production systems and their acceptance by the consumer are scarce. The aim of this work was to evaluate the sensory characteristics of curly kales cultivated using the conventional and hydroponic systems, considering the treatments: cultivation under the conventional system, without fertilization (A), conventional system with organic fertilizers (C, E) and hydroponic system (F). The harvests were performed at 60, 90 and 120 days after planting for the plants cultivated using the conventional system and at 30 days for the hydroponic system. The total chlorophyll index content and the sensory analyses of ranking of difference and acceptance were analyzed. The lowest chlorophyll index in the curly kales was verified for the one cultivated under the hydroponic system. In the ranking test, the darkest green color was obtained for the curly kale produced using the conventional system and for the attributes aroma, sweet and bitter taste and crunchiness, there was no significant difference.

Quantitative Analysis of UV-B Radiation Interception and Bioactive Compound Contents in Kale by Leaf Position According to Growth Progress

UV-B (280-315 nm) radiation has been used as an effective tool to improve bioactive compound contents in controlled environments, such as plant factories. However, plant structure changes with growth progress induce different positional distributions of UV-B radiation interception, which cause difficulty in accurately evaluating the effects of UV-B on biosynthesis of bioactive compounds. The objective of this study was to quantitatively analyze the positional distributions of UV-B radiation interception and bioactive compound contents of kales (Brassica oleracea L. var. acephala) with growth progress and their relationships. Short-term moderate UV-B levels did not affect the plant growth and photosynthetic parameters. Spatial UV-B radiation interception was analyzed quantitatively by using 3D-scanned plant models and ray-tracing simulations. As growth progressed, the differences in absorbed UV-B energy between leaf positions were more pronounced. The concentrations of total phenolic compound (TPC) and total flavonoid compound (TFC) were higher with more cumulative absorbed UV-B energy. The cumulative UV energy yields for TFC were highest for the upper leaves of the older plants, while those for TPC were highest in the middle leaves of the younger plants. Despite the same UV-B levels, the UV-B radiation interception and UV-B susceptibility in the plants varied with leaf position and growth stage, which induced the different biosynthesis of TFC and TPC. This attempt to quantify the relationship between UV-B radiation interception and bioactive compound contents will contribute to the estimation and production of bioactive compounds in plant factories.

Screening of Indian bee pollen based on antioxidant properties and polyphenolic composition using UHPLC-DAD-MS/MS: A multivariate analysis and ANN based approach

The present investigation aims to examine the polyphenolic composition and antioxidant capacity of bee pollen samples procured from various regions of India. Total phenolic (TPC) and flavonoid (TFC) content ranged from 15.50 ± 1.25-25.63 ± 1.42 mg GAE/g and 9.72 ± 0.28-15.61 ± 0.74 mg RE/g, respectively. Coriander pollen showed the significantly (p < 0.05) higher antioxidant activity than other samples, demonstrated by DPPH radical scavenging activity (93.75 ± 0.05%), ferric reducing antioxidant power (103.98 ± 0.82 mmol Fe²⁺/g), ABTS^+• radical scavenging activity (96.58 ± 0.65%) and metal chelating activity (84.62 ± 4.37%). The observed antioxidant properties were strongly correlated with TPC and effectively predicted using artificial neural network. Sixty polyphenolic compounds including 38 flavonoids and derivatives, 21 phenolic acid and derivatives and one glucosinolates were identified using UHPLC-DAD-MS/MS wherein the presence of daidzein and sinigrin was acknowledged for the first time. Further, principal component analysis identified three principal components, illustrating 91.24% of total variation to differentiate the pollen samples which were also classified by hierarchical cluster analysis.

Chemical Characterization of Three Accessions of Brassica juncea L. Extracts from Different Plant Tissues

Indian mustard or Brassica juncea (B. juncea) is an oilseed plant used in many types of food (as mustard or IV range salad). It also has non-food uses (e.g., as green manure), and is a good model for phytoremediation of metals and pesticides. In recent years, it gained special attention due to its biological compounds and potential beneficial effects on human health. In this study, different tissues, namely leaves, stems, roots, and flowers of three accessions of B. juncea: ISCI 99 (Sample A), ISCI Top (Sample B), and “Broad-leaf” (Sample C) were analyzed by HPLC-PDA/ESI-MS/MS. Most polyphenols identified were bound to sugars and phenolic acids. Among the three cultivars, Sample A flowers turned were the richest ones, and the most abundant bioactive identified was represented by Isorhamnetin 3,7-diglucoside (683.62 µg/100 mg dry weight (DW) in Sample A, 433.65 µg/100 mg DW in Sample B, and 644.43 µg/100 mg DW in Sample C). In addition, the most complex samples, viz. leaves were analyzed by GC-FID/MS. The major volatile constituents of B. juncea L. leaves extract in the three cultivars were benzenepropanenitrile (34.94% in Sample B, 8.16% in Sample A, 6.24% in Sample C), followed by benzofuranone (8.54% in Sample A, 6.32% in Sample C, 3.64% in Sample B), and phytone (3.77% in Sample B, 2.85% in Sample A, 1.01% in Sample C). The overall evaluation of different tissues from three B. juncea accessions, through chemical analysis of the volatile and non-volatile compounds, can be advantageously taken into consideration for future use as dietary supplements and nutraceuticals in food matrices.

Study on Human Urinary Metabolic Profiles after Consumption of Kale and Daikon Radish using a High-resolution Mass Spectrometry-Based Non-targeted and Targeted Metabolomic Approach

In the present study, urine samples were collected from healthy human volunteers to determine the metabolic fates of phenolic compounds and glucosinolates after a single meal of kale and daikon radish. The major glucosinolates and phenolic compounds in kale and daikon radish were measured. The urinary metabolome after feeding at different time periods was investigated. A targeted metabolite analysis method was developed based on the known metabolic pathways for glucosinolates and phenolic compounds. Using a targeted approach, a total of 18 metabolites were found in urine: 4 from phenolic compounds and 14 from glucosinolates. Among these metabolites, 4-methylsulfinyl-3-butenyl isothiocyanate, 4-methylsulfinyl-3-butenyl isothiocyanate-cysteine, and 4-methylsulfinyl-3-butenylglucosinolate-N-acetyl cysteine were reported for the first time in human urine. The combination of non-targeted and targeted metabolomic approaches can gain a full metabolite profile for human dietary intervention studies.

Does selenium fortification of kale and kohlrabi sprouts change significantly their biochemical and cytotoxic properties?

BACKGROUND

The sprouts of Brassica vegetables are known from their nutritional and chemopreventive values. Moreover, sprouts fortification with some trace elements, like selenium, may increase their importance in human diet. Thus, the aim of our study was to examine if selenium enrichment of kale and kohlrabi sprouts may influence their biochemical properties (phenolic acids and L-tryptophan content, antioxidant potential) or cytotoxic activity. Additional aim of the study was to evaluate the profile of selenium compounds and to describe the multidimensional interactions between the mentioned parameters.

METHODS

Selenium content in the sprouts was evaluated by double-channel atomic fluorescence spectrometer AFS-230 with the flow hydride-generation system. Separation of selenium species in water soluble fraction was performed by size-exclusion LC-ICP-MS. The identification and quantification of phenolic acids and L-tryptophan was performed by HPLC. For antioxidant activity DPPH and FRAP methods were used. Cytotoxic activity of the sprouts extracts on a panel of human metastatic carcinoma cells was evaluated by MTT test.

RESULTS

Selenium content in the fortified sprouts was several orders of magnitude higher than in the unfortified ones. Only small percentage of supplemented selenium (ca. 10 %) was incorporated into the sprouts as seleno-L-methionine, while the other detected selenium species remained unidentified. Selenium fortification differently stimulated the production of phenolic acids (sinapic, chlorogenic, isochlorogenic and caffeic acid) in the tested sprouts, depending on the particular species, selenium dose and the investigated compound. PCA analysis revealed strong correlation between antioxidant parameters and phenolic acids and L-tryptophan, while Se correlated only with caffeic acid. The sprouts extracts (≥1 mg/mL) showed cytotoxic potency to all the studied cancer cell lines (SW480, SW620, HepG2, SiHa), regardless the selenium supplementation.

CONCLUSION

Se-fortified kale and kohlrabi sprouts are good candidates for functional food ingredients. Moreover, these results indicate that the sprouts enriched with sodium selenite show higher nutritional value, without significant changes in their cytotoxic activity.

Spatial and Temporal Bioactive Compound Contents and Chlorophyll Fluorescence of Kale (Brassica oleracea L.) Under UV-B Exposure Near Harvest Time in Controlled Environments

UV-B irradiation has been used to enhance the secondary metabolite content in plants, but its spatial effect on plants has not been considered. The objective of this study was to compare spatial photosynthetic traits and bioactive compound accumulation in kale (Brassica oleracea L. var Acephala) according to the distribution and length of UV-B exposure near harvest. Plants were exposed to UV-B of 0-3, 3-6 and 6-9 W m^-2 for 4 h per day at 5 days (Exp. 1) and 4.2 W m^-2 at 5, 4, 3, 2 or 1 days (Exp. 2) before harvest. In spatial distribution, the higher the UV-B intensity, the lower the mean F_v /F_m (maximal photochemical efficiency of PSII) and the higher the concentration of total flavonoid compound (TFC). With UV-B stress, F_v /F_m and fluorescence transient parameters decreased except for DI₀ /CS (dissipated energy flux per cross section) and PI_abs (performance index of PSII). When exposed to UV-B radiation for 2 days before harvest, the total phenolic compounds and TFC per plant were highest, not always proportional to the local F_v /F_m but affected by dry weight. Short-term UV-B stress near harvest would be more efficient for the accumulation of bioactive compounds by minimizing the loss of plant weight.

Side Streams of Broccoli Leaves: A Climate Smart and Healthy Food Ingredient

Human consumption of fruits and vegetables are generally below recommended levels. Waste from the production, e.g., of un-used parts such as broccoli leaves and stem when producing broccoli florets for food, is a sustainability issue. In this study, broccoli leaves were analyzed for the content of various dietary fibre and phenolics, applying the Uppsala method and HPLC analyses, respectively. The results showed that broccoli leaves had comparable levels of dietary fibre (26%-32% of dry weight (DW)) and phenolic compounds (6.3-15.2 mg/g DW) to many other food and vegetables considered valuable in the human diet from a health perspective. A significant positive correlation was found among soluble dietary fibre and phenolic acids indicating possible bindings between these components. Seasonal variations affected mainly the content of conjugated phenolics, and the content of insoluble dietary fibre. This study verified the importance of the use of broccoli production side streams (leaves) as they may contribute with health promoting components to the human diet and also socio-economic and environmental benefits to the bioeconomic development in the society.

Phenolic Constitution, Phytochemical and Macronutrient Content in Three Species of Microgreens as Modulated by Natural Fiber and Synthetic Substrates

The present study examined the modulatory effects of natural fiber substrates (agave fiber, coconut fiber and peat moss) and synthetic alternatives (capillary mat and cellulose sponge) on the nutritive and phytochemical composition of select microgreens species (coriander, kohlrabi and pak choi) grown in a controlled environment. Polyphenols were analyzed by UHPLC-Q-Orbitrap-HRMS, major carotenoids by HPLC-DAD, and macro-minerals by ion chromatography. Microgreens grown on peat moss had outstanding fresh and dry yield but low dry matter content. Natural fiber substrates increased nitrate and overall macro-mineral concentrations in microgreens compared to synthetic substrates. The concentrations of chlorophylls, carotenoids and ascorbate were influenced primarily by species. On the contrary, variability in polyphenols content was wider between substrates than species. Out of twenty phenolic compounds identified, chlorogenic acid and quercetin-3-O-rutinoside were most abundant. Hydroxycinnamic acids and their derivatives accounted for 49.8% of mean phenolic content across species, flavonol glycosides for 48.4% and flavone glycosides for 1.8%. Peat moss provided optimal physicochemical conditions that enhanced microgreens growth rate and biomass production at the expense of phenolic content. In this respect, the application of controlled stress (eustress) on microgreens growing on peat moss warrants investigation as a means of enhancing phytochemical composition without substantial compromise in crop performance and production turnover. Finally, nitrate deprivation practices should be considered for microgreens grown on natural fiber substrates in order to minimize consumer exposure to nitrate.

Determination of the Metabolite Content of Brassica juncea Cultivars Using Comprehensive Two-Dimensional Liquid Chromatography Coupled with a Photodiode Array and Mass Spectrometry Detection

Plant-based foods are characterized by significant amounts of bioactive molecules with desirable health benefits beyond basic nutrition. The Brassicaceae (Cruciferae) family consists of 350 genera; among them, Brassica is the most important one, which includes some crops and species of great worldwide economic importance. In this work, the metabolite content of three different cultivars of Brassica juncea, namely ISCI Top, “Broad-leaf,” and ISCI 99, was determined using comprehensive two-dimensional liquid chromatography coupled with a photodiode array and mass spectrometry detection. The analyses were carried out under reversed-phase conditions in both dimensions, using a combination of a 250-mm microbore cyano column and a 50-mm RP-Amide column in the first and second dimension (²D), respectively. A multi (three-step) segmented-in-fraction gradient for the ²D separation was advantageously investigated here for the first time, leading to the identification of 37 metabolites. In terms of resolving power, orthogonality values ranged from 62% to 69%, whereas the corrected peak capacity values were the highest for B. juncea ISCI Top (639), followed by B. juncea “Broad-leaf” (502). Regarding quantification, B. juncea cv. “Broad-leaf” presented the highest flavonoid content (1962.61 mg/kg) followed by B. juncea cv. ISCI Top (1002.03 mg/kg) and B. juncea cv. ISCI 99 (211.37 mg/kg).

Blue Light Treatment but Not Green Light Treatment After Pre-exposure to UV-B Stabilizes Flavonoid Glycoside Changes and Corresponding Biological Effects in Three Different Brassicaceae Sprouts

Ultraviolet-B (UV-B; 280-315 nm) radiation induces the biosynthesis of secondary plant metabolites such as flavonoids. Flavonoids could also be enhanced by blue (420-490 nm) or green (490-585 nm) light. Flavonoids act as antioxidants and shielding components in the plant's response to UV-B exposure. They are shown to quench singlet oxygen and to be reactive to hydroxyl radical. The aim was to determine whether treatment with blue or green light can alter flavonoid profiles after pre-exposure to UV-B and whether they cause corresponding biological effects in Brassicaceae sprouts. Based on their different flavonoid profiles, three vegetables from the Brassicaceae were selected. Sprouts were treated with five subsequent doses (equals 5 days) of moderate UV-B (0.23 kJ m^-2 day^-1 UV-B_BE), which was followed with two subsequent (equals 2 days) doses of either blue (99 μmol m^-2 s^-1) or green (119 μmol m^-2 s^-1) light. In sprouts of kale, kohlrabi, and rocket salad, flavonoid glycosides were identified by HPLC-DAD-ESI-MSⁿ. Both Brassica oleracea species, kale and kohlrabi, showed mainly acylated quercetin and kaempferol glycosides. In contrast, in rocket salad, the main flavonol glycosides were quercetin glycosides. Blue light treatment after the UV-B treatment showed that quercetin and kaempferol glycosides were increased in the B. oleracea species kale and kohlrabi while-contrary to this-in rocket salad, there were only quercetin glycosides increased. Blue light treatment in general stabilized the enhanced concentrations of flavonoid glycosides while green treatment did not have this effect. Blue light treatment following the UV-B exposure resulted in a trend of increased singlet oxygen scavenging for kale and rocket. The hydroxyl radical scavenging capacity was independent from the light quality except for kale where an exposure with UV-B followed by a blue light treatment led to a higher hydroxyl radical scavenging capacity. These results underline the importance of different light qualities for the biosynthesis of reactive oxygen species that intercept secondary plant metabolites, but also show a pronounced species-dependent reaction, which is of special interest for growers.

Changes in low molecular weight carbohydrates in kale during development and acclimation to cold temperatures determined by chromatographic techniques coupled to mass spectrometry

Kale (Brassica oleracea) is a cool-season vegetable widely employed in the elaboration of diverse products such as tea and smoothies in USA or in the Northern German cuisine in wintertime. Besides, kale is gaining attention due to the diverse health benefits reported in the literature for its consumption, e.g. antigenotoxic and anticarcinogenic effect, protection of cardiovascular system and gastrointestinal tract. Low molecular weight carbohydrates (LMWC) are compounds directly related with kale flavour and nutritional quality. Despite different studies focusing on the chemical composition of kale, few information on LMWC is available. Thus, in this work a multianalytical approach was conducted in order to perform a comprehensive study of kale LMWC; their evolution during plant development and acclimation to cool temperatures was also evaluated. Gas chromatography coupled to mass spectrometry allowed the identification of 13 LMWC, being myo-inositol, galactinol, maltose and melibiose described for the first time in kale. Eight major LMWC were quantified in three different commercial kale cultivars using hydrophilic interaction liquid chromatography coupled to mass spectrometry to monitor possible differences in their content during plant development and as consequence of plant acclimation to cold temperatures. Overall, for all types of kales under study, the content of maltose and sucrose decreased during the plant development while the concentration of fructose, melibiose, maltose, raffinose and galactinol was increased in all kale types exposed to low temperatures. These results underline the importance of controlling the temperature during kale cultivation in order to obtain products with a high nutritional value.

Characterization and Quantification of Major Flavonol Glycosides in Ramps (Allium tricoccum)

The ramp (Allium tricoccum) is a traditional plant in the eastern Appalachian Mountains. Ramps have been used in traditional medicine for their health-promoting roles in lowering blood pressure and cholesterol. Information on the chemical composition of the potentially bioactive components in ramps is limited. Therefore, the aim of this work was to characterize and quantify major flavonols in ramps. Flavonoids were extracted in 50% methanol and 3% acetic acid. Characterization was conducted using UHPLC-PDA-MS and MS/MS, and quantification was performed using UHPLC-PDA detection. The major flavonol glycosides were kaempferol sophoroside glucuronide, quercetin sophoroside glucuronide, kaempferol rutinoside glucuronide, quercetin hexoside glucuronide, quercetin sophoroside, and kaempferol sophoroside. All conjugates were detected in leaves. Quercetin and kaempferol sophoroside glucuronide conjugates were detected in the stem, but no flavonol glycosides were detected in the bulb. The total amounts of the identified quercetin and kaempferol conjugates in whole ramps were 0.5972 ± 0.235 and 0.3792 ± 0.130 mg/g dry weight, respectively. Flavonol conjugates were concentrated in the leaves. To our knowledge, this work is the first to identify and quantify the major flavonol glycosides in ramps. Our findings suggest that specifically the leaves may harbor the potentially bioactive flavonols components of the plant.

Long-Term Intake of Glucoraphanin-Enriched Kale Suppresses Skin Aging via Activating Nrf2 and the TβRII/Smad Pathway in SAMP1 Mice

Sulforaphane, a potent antioxidant compound, is unstable at ambient temperature, whereas its precursor glucoraphanin is stable and metabolized to sulforaphane. Thus, we hypothesized that glucoraphanin-rich diet could effectively induce antioxidant enzyme activities and investigated the protective effects of long-term intake of a glucoraphanin-enriched kale (GEK) diet on skin aging in senescence-accelerated mouse prone 1 (SAMP1) mice. The senescence grading score was significantly lower after treatment with GEK for 39 weeks than that of the control mice. GEK also suppressed the thinning of the dorsal skin layer. Moreover, the GEK treatment enhanced the collagen production and increased the nuclear translocation of Nrf2 and HO-1 expression level in the skin tissue. TβRII and Smad3 expressions were clearly higher in the GEK-treated group than in the control group. Thus, GEK suppressed senescence in SAMP1 mice by enhancing the antioxidant activity and collagen production via the TβRII/Smad3 pathway, suggesting its practical applications for protection against skin aging.

Preparative mass-spectrometry profiling of minor concentrated metabolites in Salicornia gaudichaudiana Moq by high-speed countercurrent chromatography and off-line electrospray mass-spectrometry injection

Salicornia species have just been introduced to the European market as a vegetable named 'samphire', 'green asparagus', or 'sea asparagus'. Due to its increasing attention, and associated value, minor compounds of Salicornia gaudichaudiana Moq were investigated. The use of countercurrent chromatography and mass spectrometry enabled the search for known, as well as potentially novel natural products. Their identification was achieved based on molecular weights and mass-spectrometric fragmentation data. Low detection limits enabled the visualization of all compounds with their identification in almost real time close to the preparative countercurrent chromatography experiment. A list of known natural products from Salicornia genus guided the identification process of compounds occurring in Salicornia gaudichaudiana Moq by tandem mass spectrometry fragment comparison. The natural product classes were divided into four groups: chlorogenic acid derivatives; flavonoid derivatives; pentacyclic triterpenoid saponins; and other compounds.

Bioconversion of Kaempferol and Quercetin Glucosides from Plant Sources Using Rhizopus spp

Fermentation with filamentous fungi is known for the ability to convert bioactive compounds. The aim of this research was to investigate the metabolism of glycosidic derivatives of kaempferol and quercetin during fungal fermentation of extracts from cauliflower outer leaves and onion by Rhizopus oryzae and R. azygosporus. The highest release of kaempferol and quercetin was observed after 2 days and 1 day of fermentation with R. oryzae, respectively. It was proposed that glycosidic compounds were initially deglycosylated to form kaempferol-3-glucoside and quercetin-3-glucoside and then further metabolized into their aglycones. Clear differences in conversion efficiency towards the aglycones were observed between the two Rhizopus strains. Although both flavonoids only differ in one hydroxyl group, the metabolism of the glycosides towards their respective aglycones, kaempferol or quercetin, was different. It is concluded that the fermentation with R. oryzae and R. azygosporus could be considered as a way to produce kaempferol and quercetin aglycone from their glycosidic derivatives.

Functional quality in novel food sources: Genotypic variation in the nutritive and phytochemical composition of thirteen microgreens species

Compositional variation was examined across 13 microgreens species/subspecies representing Brassicaceae, Chenopodiaceae, Lamiaceae, Malvaceae and Apiaceae, grown in controlled environment. Macro-mineral concentrations were determined by ion chromatography, chlorophyll and ascorbate concentrations, and hydrophilic/lipophilic antioxidant potentials by spectrophotometry, and major carotenoids by HPLC-DAD. Nitrate hyper-accumulators and wide genotypic differences in Na, K and S concentrations were identified. Antioxidant capacity was highest in brassicaceous microgreens and significant genotypic variation was demonstrated in chlorophyll and carotenoid concentrations. High phenolic content was confirmed in Lamiaceae microgreens, with significant varietal differences, and alternative phenolics-rich microgreens from the Apiaceae were identified. Twenty-eight phenolic compounds were variably detected and quantitated through Orbitrap LC-MS/MS with flavonol glycosides, flavones and flavone glycosides, and hydroxycinnamic acids representing 67.6, 24.8 and 7.6% of the mean total phenolic content across species, respectively. The obtained information is critical for selecting new species/varieties of microgreens that may satisfy demand for both taste and health.