Content Of Individual Compounds Research Articles

Phytochemicals in recovered seed oils from by‐products of common quince (Cydonia oblonga) and Japanese quince (Chaenomeles japonica)

AbstractNearly 100% of Japanese quince (Chaenomeles japonica) and common quince (Cydonia oblonga) fruits are processed. It generates large amounts of seeds. One of the possible utilization of seeds is oil recovery. Seeds of both quinces were tested for their oil recovery using two methods—solvent‐free protocol by mechanical press and ultrasound‐assisted extraction (UAE) applying n‐hexane, and phytochemistry of obtained oils was studied. The oil yield was nearly twice higher from common quince than Japanese quince (20.9% and 11.2%, respectively) for UAE. Compared to UAE, screw‐pressed allowed for 67% oil recovery. In general, the phytochemical profile of both quince seed oils was similar with some differences in the content of individual compounds. The two quince seed oils were dominated by the same molecules in different compound groups: fatty acids—linoleic acid; tocochromanols—α‐tocopherol; phytosterols—β‐sitosterol, and triterpenoid—squalene. Common quince seed oil was richer in tocochromanols, squalene, and linoleic acid, whereas Japanese quince seed oil was richer in phytosterols. The present study showed the oil potential of fruit industry by‐products and the relatively high oil recovery by the environmentally friendly/healthy technique of extraction (solvent‐free) to achieve ultimately high‐quality products in a “Natural‐Safe‐Green” strategy.Practical applications: Production of fruit each year, especially those used for processing, for example, common quince (C. oblonga), has been increasing in recent years, likely, so has processing and amounts of generated by‐products, including seeds. To reduce the costs, CO2 emissions, and other environmental safety aspects of production, different techniques of plant oil recovery are considered. The extraction method affects oil yield as well as its phytochemical composition. The generated information in the present study can contribute to improved effectiveness of the use of plant material thereby providing environmental, health, and economic benefits.

QUANTITATIVE ANALYSIS OF KHELLACTONE AND OTHER COUMARINS IN PHLOJODICARPUS SIBIRICUS (APIACEAE)

Phlojodicarpus sibiricus (Fisch.) Koso-Pol. is a medicinal plant of the Apiaceae family, the underground organs of which accumulate various groups of coumarins, including simple coumarins, furocoumarins and angular dihydropyranocoumarins in the form of esters of kellactone (3′,4′-dihydroxy-3′,4′-dihydroseselin), which are the dominant group of secondary metabolites. Known methods for the analysis of rhizomes and roots of P. sibiricus determine the content of individual compounds (visnadin, dihydrosamidin), which does not allow obtaining complete information about the presence of coumarin compounds in the plant. In the present study, a method of quantitative analysis of coumarins was developed. It includes preliminary hydrolysis of raw materials in aqueous potassium hydroxide, which leads to deacylation of esterified derivatives of kellactone and lomatin, without affecting glycosides of simple coumarins, followed by analysis of hydrolysis products (sum of kellactones, lomatin, 6′-O-apiosyl skimmin) by HPLC. The developed technique is characterized by high analysis speed, satisfactory validation characteristics, and accuracy. Approbation of the technique was carried out on samples of rhizomes and roots of P. sibiricus collected in three regions of Siberia (Zabaikalsky Krai, Buryatia Republic, Sakha (Yakutia) Republic). The total content of coumarins in plant materials from the studied populations was 12.70–74.03 mg/g. The method can be used for quality analysis and standardization of P. sibiricus rhizomes and roots.

Bioactive compounds of Arctostaphylos uva-ursi wild-growing populations from Bulgaria

Arctostaphylos uva-ursi (L.) Sprengel (bearberry), Ericaceae is a valuable medicinal plant with diuretic and uroantiseptic action which is mainly due to arbutin. In Bulgaria the species is considered as rare. Content assessment of bioactive compounds of A. uva-ursi leaves from three natural populations from Bulgaria was the aim of the present study. Leaf samples were collected from Pirin, Vitosha, and Rhodope Mountains. Bioactive compounds in the methanolic extracts of the samples were analysed by GC/MS. Total phenolic content was determined using Folin–Ciocalteu reagent. Arbutin, quinic acid and gallic acid were detected in the highest amounts. Catechine, 4-hydroxybenzoic acid, chlorogenic acid, triterpenes (α- and β-amyrin, uvaol and lupeol) and other primary and secondary metabolites were found, also. Differences in the content of individual compounds between samples of different origin were established. The highest total phenolic (182.98 mg GAE g-1) and arbutin (8.4%) content was found in the sample from Vitosha Mountain. The presented data characterizes the profile of bioactive compounds in the Bulgarian bearberry raw material for the first time.

The Effect of Illumination Patterns during Mung Bean Seed Germination on the Metabolite Composition of the Sprouts

Mung bean (Vigna radiata (L.) Wilczek) sprouts are popular over the world because of their taste, nutritional value, well-balanced biochemical composition, and other properties beneficial for human health. Germination conditions affect the composition of metabolites in mung bean sprouts, so a detailed study into its variability is required. This article presents the results of a comparison of the metabolite composition in the leaves of mung bean sprouts germinated first in the dark (DS) and then in the light (LS). Gas chromatography with mass spectrometry (GC–MS) made it possible to identify more than 100 compounds representing various groups of phytochemicals. Alcohols, amino acids, and saccharides predominated in the total amount of compounds. The analysis of metabolomic profiles exposed a fairly high intra- and intervarietal variability in the metabolite content. DS and LS differed in the qualitative and quantitative content of the identified compounds. The intravarietal variability was more pronounced in DS than in LS. DS demonstrated higher levels of saccharides, fatty acids, acylglycerols, and phenolic compounds, while amino acids were higher in LS. Changes were recorded in the quantitative content of metabolites participating in the response of plants to stressors—ornithine, proline, GABA, inositol derivatives, etc. The changes were probably induced by the stress experienced by the sprouts when they were transferred from shade to light. The analysis of variance and principal factor analysis showed the statistically significant effect of germination conditions on the content of individual compounds in leaves. The identified features of metabolite variability in mung bean genotypes grown under different conditions will contribute to more accurate selection of an illumination pattern to obtain sprouts with desirable biochemical compositions for use in various diets and products with high nutritional value.

Chemical Composition and Antioxidant Capacity of the Fruits of European Plum Cultivar "Čačanska Lepotica" Influenced by Different Rootstocks.

We investigated the influence of different rootstocks on the content of sugars, organic acids, and antioxidant phenolic compounds in the whole fruit and fruit skin of the European plum cultivar “Čačanska Lepotica”. 1H NMR of the fruit extracts allowed for the identification of sucrose, α- and β-glucose, sorbitol, fructose, and malic and quinic acids, while LC–DAD–ESIMS showed the presence of neochlorogenic and chlorogenic acids, cyanidin-3-O-glucoside, cyanidin-3-O-rutinoside, peonidin-3-O-glucoside, peonidin-3-O-rutinoside, hyperoside, isoquercitrin, rutin, and unidentified quercetin-3-diglycoside. The quantitation of the sugars, malic and quinic acids by 1H NMR and phenolic compounds by HPLC–DAD revealed that the rootstock significantly influenced the content of the individual compounds in the fruit skin and fruit. The fruit grafted on “Wavit” rootstock was characterized by significant amounts of neochlorogenic acid, peonidin-3-O-rutinoside, cyanidin-3-O-rutinoside, and sucrose, while the fruit on “GXN-15” was characterized by high levels of sugars, cyanidin-3-O-glucoside, and malic and chlorogenic acids. The fruit skins of plums grafted on “Wavit” were the richest in sugars, organic acids, and phenolic compounds. A good correlation was observed between the content of total phenolics (TPC), flavonoids (TFC), anthocyanins (TAC), and individual phenolic compounds in the extracts of the fruit and the fruit skins and their antioxidant capacity (DPPH, ABTS, and FRAP).

Lemon Juice Formulations Modulate In Vitro Digestive Recovery of Spinach Phytochemicals.

Citrus limon (L.) Burm lemon juice is rich in many important natural chemical components (flavonoids, citric acid and vitamin C) and its use in traditional medicine is well known. Formulations of lemon juice with fruit polyphenols in beverages have been investigated, but there is very little information about their ability to modulate the digestive behaviour of polyphenols. The goal of this study is to determine the stability and digestive availability of spinach (Spinacia oleracea L.) polyphenols by adding different volume fractions of lemon juice (0, 2, 5, 10 and 20%) during in vitro digestion. The content of polyphenols and other abundant compounds including nitrates, oxalic acid and l-ascorbic acid in spinach formulation with various volume fractions of lemon juice were measured in predigested and digested samples using in vitro human digestion model. Antioxidant and α-amylase inhibitory activities of spinach lemon juice formulation were also measured. The highest increases in total polyphenols, total flavonoids, total phenolic acids, oxalic acid and nitrate content were noted in predigested and almost all digested spinach samples formulated with the highest volume fraction of lemon juice. In the same sample, the content of individual compounds significantly increased after salivary 
(l-ascorbic acid), initial (p-coumaric acid) and intestinal (quercetin) phase of digestion. High bioaccessibility of polyphenols and l-ascorbic acid in all phases of digestion was observed in almost all spinach lemon juice formulations, with the exception of nitrates in gastric and intestinal phases and oxalic acid in the intestinal phase, which had moderate bioaccessibility. For the first time the stability and digestive availability of spinach polyphenols, oxalic acid, nitrates and l-ascorbic acid were tested with the addition of different volume fractions of lemon juice. The pH of lemon juice and its 
l-ascorbic acid content increase the stability and availability of polyphenols in spinach lemon juice formulation during in vitro digestion. Antioxidant and α-amylase inhibitory activities increase in dose-dependent manner after lemon juice addition. Accordingly, spinach formulated with 20% of lemon juice appears as the best source of dietary polyphenols with antioxidant and antidiabetic activities and nitrates that may be used as a functional drink.

Qualitative and Quantitative Analysis of Secondary Metabolites in Morphological Parts of Paulownia Clon In Vitro 112® and Their Anticoagulant Properties in Whole Human Blood.

It is not easy to find data in the scientific literature on the quantitative content of individual phytochemicals. It is possible to find groups of compounds and even individual compounds rather easily, but it is not known what their concentration is in cultivated or wild plants. Therefore, the subject of this study was to determine the content of individual compounds in the new Paulownia species, Oxytree, developed in a biotechnology laboratory in 2008 at La Mancha University in Spain. Six secondary metabolites were isolated, and their chemical structure was confirmed by spectral methods. An analytical method was developed, which was then used to determine the content of individual compounds in leaves, twigs, flowers and fruits of Paulownia Clon in Vitro 112®. No flavonoids were found in twigs and fruits of Oxytree, while the highest phenylethanoid glycosides were found in twigs. In this study, we also focused on biological properties (anticoagulant or procoagulant) of extract and four fractions (A–D) of different chemical composition from Paulownia Clon in Vitro 112 leaves using whole human blood. These properties were determined based on the thrombus-formation analysis system (T-TAS), which imitates in vivo conditions to assess whole blood thrombogenecity. We observed that three fractions (A, C and D) from leaves decrease AUC10 measured by T-TAS. In addition, fraction D rich in triterpenoids showed the strongest anticoagulant activity. However, in order to clarify the exact mechanism of action of the active substances present in this plant, studies closer to physiological conditions, i.e., in vivo studies, should be performed, which will also allow to determine the effects of their long-term effects.

The Phenolic Compounds in the Young Shoots of Selected Willow Cultivars as a Determinant of the Plants' Attractiveness to Cervids (Cervidae, Mammalia).

Simple SummaryThe presented study examined the phenolic acids, flavonoids and salicylates contents in young, 3-month-old shoots of different willow (Salix spp.) cultivars. The contents of individual compounds were not identical and depended on the cultivar from which they were isolated. Then, the severity of foraging damage by deer to the analyzed willow cultivars was evaluated and correlated with the content of specific compounds from each analyzed group. The quantitative relationships of helicine and salicin from the group of salicylic compounds, and between ferulic, trans-cinnamic and synapinic acid from the group of phenolic acids, can determine the foraging attractiveness of willow shoots to cervids.This study examined the phenolic acids, flavonoids, and salicylates contents in young, 3-month-old shoots (including the leaves) of willow (Salix spp.). The cultivars were selected based on experiments carried out previously in Poland on fodder and energy willows. It was found, using the HPLC-MS/MS method, that the willow cultivars analyzed from three experimental plots, contained nine different phenolic acids, five salicylates and nine flavonoids, including four flavanols (quercetin, kaempferol, taxifolin and isorhamnetin), two flavanones (prunin, naringenin), two flavones (luteolin, apigenin) and one flavan-3-ol (catechin). The contents of individual compounds were not identical and depended on the cultivar from which they were isolated. The S. laurina 220/205 and S. amygdalina Krakowianka contained the greatest amounts of phenolic acids. The lowest quantities of these compounds were found in the S. viminalis Tur, S. pantaderana and S. cordata clone 1036. The highest concentration of flavonoids in young stems was found in S. fragilis clone 1043. The S. purpurea clone 1131 contained the highest amounts of salicylic compounds. Based on the results obtained from all experimental plots, it was shown that there is a negative correlation between the extent of browsing damage and the content of helicine and salicin from the group of salicylic compounds. A similar analysis between the phenolic acid concentration and the degree of willow browsing showed a positive correlation, especially between ferulic, trans-cinnamic, and synapinic acid. A negative correlation was found between the concentration of protocatechic acid content and browsing by cervids.

Changes of carotenoid content in carrots after application of pulsed electric field treatments

Under certain conditions, pulsed electric fields (PEF) can promote the accumulation of phytochemicals through a stress-mediated response in plant tissues. Likewise, electropermeabilization of cell membranes can also improve the extraction of intracellular compounds. The objective of this study was to evaluate the main causes driving the increase in carotenoids content in PEF-treated carrots and to study the impact of those treatments on their relevant quality attributes. Carrots were treated with PEF differing in electric field strength (E) (0.8, 2 and 3.5 kV/cm) and number of pulses (5, 12 and 30). Individual carotenoids content, colour, pH and total soluble solids (TSS) were determined after 0 h and 24 h after PEF treatment. Total and individual carotenoid contents (phytoene and β-carotene) increased just after applying E ≥ 2 kV/cm, whereas lutein concentration decreased, and that of α-carotene remained similar to that found in untreated carrots. After applying 2 and 3.5 kV/cm, TSS and pH remained unaltered, but cortical browning index increased, which was correlated to carotenoid content. Increase in total carotenoid content is likely related to better extractability, but differences in the content of individual compounds suggest that PEF may also act by modulating their biosynthesis or causing their degradation.

Sustainable ultrasound-assisted extraction of valuable phenolics from inflorescences of Helichrysum arenarium L. using natural deep eutectic solvents

In the present study, an analytical methodology based on natural deep eutectic solvents (NADESs) and ultrasound-assisted extraction (UAE) is demonstrated as an environmentally friendly protocol for the isolation of valuable phenolic compounds from inflorescences of Helichrysum arenarium L. For this purpose, 11 different NADESs containing choline chloride and selected hydrogen bond donors, including organic acids, polyols, sugars and an amide, were tailored and evaluated based on the content of individual compounds determined by HPLC-PDA-MSn. Choline chloride-lactic acid based NADES (NADES 1) showed the most promising extraction efficiencies for flavonoids (15.34 ± 0.10 mg g−1) and phenolic acids (5.10 ± 0.12 mg g−1) as the efficiencies were comparable to those obtained with 80 % methanol (15.60 ± 0.09 mg g−1 and 5.32 ± 0.18 mg g−1, respectively) and up to 54 % higher compared to water (9.94 ± 0.13 mg g−1 and 5.47 ± 0.22 mg g−1). Furthermore, three essential parameters of the proposed NADES 1 methodology (UAE time, water content in NADES, and NADES hydrogen donor/acceptor molar ratio) were optimized by Box-Behnken experimental design. Based on the statistically evaluated results the following conditions were determined to be optimal: an UAE time of 85 min, 38 % water in NADES 1, and a molar ratio of choline chloride:lactic acid of 1:4. The developed approach allows easy transfer of the proposed methodology to large-scale extraction, enabling clean production with minimal environmental impact.

The chromatographic analysis of extracts from poplar (Populus sp.) - Laying program GC-MS

The chromatographic analysis of extracts from poplar (Populus sp.) - Laying program GC-MS. The aim of the study was to develop the method of analysis by gas chromatography of the liquid obtained after extraction with cyclohexane of wood of different poplar varieties (Populus sp.). After applying an appropriate method, the application of gas chromatography with mass detector facilitates the analysis of the chemical composition of extracts from different types of lignocellulosic biomass. It is also possible to verify included compounds as well as to compare the content of individual compounds contained in the analysed sample. Moreover, this sample will make it possible to determine the significance of the influence of given substances on biofuel production processes based on lignocellulosic materials. One of the key chemical substances influencing the process of enzymatic hydrolysis and fermentation are extraction substances contained in lignocellulose materials used in 2nd and 3rd generation biofuels. These compounds can inhibit the whole process of producing biofuels from lignocellulosic biomass.

Phytochemical Composition and Antimicrobial Activity of Corydalis solida and Pseudofumaria lutea.

Corydalis and Pseudofumaria are two closely related genera from the Papaveraceae subfamily Fumarioideae with Corydalis solida (C. solida) and Pseudofumaria lutea (P. lutea) as two representative species. Phytochemical analysis revealed significant differences in the quality and quantity of isoquinoline alkaloids, phenolic compounds and non-phenolic carboxylic acids between aerial and underground parts of both species. Using the Liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) technique, 21 compounds were identified: five protoberberine derivatives, three protopine derivatives, four phenanthridine derivatives, as well as three carboxylic acids, two hydroxycinnamic acids, one chlorogenic acid, one phenolic aldehyde, and two flavonoids. Moroever, significant differences in the content of individual compounds were observed between the two studied species. The phytochemical profile of C. solida showed a higher variety of compounds that were present in lower amounts, whereas P. lutea extracts contained fewer compounds but in larger quantities. Protopine was one of the most abundant constituents in C. solida (440–1125 µg/g d.w.) and in P. lutea (1036–1934 µg/g d.w.). Moreover, considerable amounts of coptisine (1526 µg/g) and quercetin (3247 µg/g) were detected in the aerial parts of P. lutea. Extracts from aerial and underground parts of both species were also examined for the antimicrobial potential against S. aureus, P. aeruginosa and C. albicans. P. lutea herb extract was the most effective (MIC at 0.39 mg/L) against all three pathogens.

Effect of ultrasound combined with ultraviolet treatment on microbial inactivation and quality properties of mango juice.

This work explored the effect of ultraviolet-assisted ultrasound (US-UV) as an emerging non-thermal sterilization technology on mango juice in aspects of microbial growth and quality changes. The juice in the ice bath was subjected to US-UV treatment at different US powers (0-600W) and times (0-40min), and no pathogen bacteria could be detected after treatment, while the physicochemical features (particle size, suspension stability, color, content of total polyphenols, carotenoids, sugar, reducing sugar and protein) and antioxidant ability of treated juice was preserved or improved to some extent. Based on these results, we further validated its positive effects on the nutritional value (content of ascorbic acid and soluble dietary fiber, antioxidant ability) and quality parameters (titratable acid, sugar acidity, total soluble solids, rheological behavior, metal elements) of mango juice treated at the optimal US parameter (10min, 600W); Not only the inactivation of polyphenol oxidation enzyme, peroxidase and pectin methylesterase was achieved but also the treated juice has a significant different volatile profile compared with the fresh juice, which might offer the better color, texture, and smell. Importantly, through the HPLC-MSD-Trap-XCT (phenols) and UPLC-Q Exactive Orbitrap-MS (carotenoids) study, the US-UV treatment will not cause difference on compounds composition, but it was responsible for changes in content of individual compounds, especially the all-trans-β-carotene, became the main component of carotenoids in processed mango juice (increased from 43.72% to 75.15%, relative content), and the oxygenated carotenoids (xanthophylls) are highly sensitive to the US (reduced from 50.96% to 4.85%) while the carotenes show a strong resistance to the US (increased 49.04% to 95.15%). Thus, the overall safety and quality of mango juice were enhanced while the sensory characteristics remained stable, suggesting that this non-thermal combination sterilization processing may successfully be implemented in the commercial processing of mango juice.

Different extraction processes affect the metabolites in blue honeysuckle(Loniceracaerulea L. subsp. edulis) food products

Honeysuckle berries are becoming an attractive organically grown fruit with many aspects as a new functional food. They have the benefit of containing health-promoting compounds, such as saponins, ascorbic acid, iridoids, flavonoids, and anthocyanins. Fruit berries can be processed into many products with various contents of selected bioactive compounds. The contents of individual compounds were identified with the aid of high-performance liquid chromatography coupled with mass spectrophotometry. Their concentrations significantly differed among the various food products. Ascorbic acid had the highest values in blue honeysuckle spread (302.02 mg/100 g of dry weight), while infusion (119.17 mg/100 g) and juice (118.17 mg/100 g) had the lowest values. All the food products had low sugar contents. Of the health beneficial phenolic compounds honeysuckle spread had the highest content (1753.54 mg/100 g) and honeysuckle infusion (196.61 mg/100 g) had the lowest content. Honeysuckle liqueur and smoothie also had high total analyzed phenolic contents (1138.75 mg/100 g and 1108.25 mg/100 g, respectively).

Variability of composition of essential oil and coumarin compounds of Angelica archangelica L.

Summary The medicinal and culinary properties of Angelica archangelica L. have been known and valued since the Middle Ages. Ingredients of essential oil and coumarins found in this plant are to a large degree responsible for its pharmacological activity. This study is a review of the literature of the most important biologically active compounds present in herbal raw materials: root (rhizome with roots) and angelica fruits. Research shows that the content of individual compounds of the essential oil and coumarin fraction is variable, which may point to a large intraspecific variation. Therefore, these compounds may be good markers for identifying taxa or chemotypes in chemotaxonomic research valuable for the herbal medicine and pharmaceutical industry.

Effect of a variety of polyphenols compounds and antioxidant properties of rhubarb (Rheum rhabarbarum)

Rhubarb (Rheum spp.) is a plant characterized by very high antioxidant properties. It is very rich in many compounds that have a pro-health effect on the human body. Polyphenols are natural plant substances that can be a very important component in the prevention of various diseases. Therefore, the use of rhubarb as an interesting plant material in various industries has recently increased. The aim of the study was to determine the effect of the harvest date and rhubarb variety on the content of polyphenolic compounds. The quantitative determination of polyphenols was performed by liquid chromatography–mass spectrometry with quadrupole time-of-flight mass spectrometry. Rhubarb stalks of two Polish varieties Viktoria and Red Malinowy were used in the study. It was found that rhubarb is a source of flavan-3-ols (86.57–195.98 mg/100 gdm), flavonols (49.79–73.49 mg/100 gdm), anthocyanins (4.33–96.20 mg/100 gdm), and gallotannin (6.32–13.56 mg/100 gdm). Red Malinowy rhubarb from spring harvest was characterized by the highest and VA rhubarb was characterized by the lowest total antioxidant activity. It should be emphasized that the content of individual compounds depended on the variety and the date of harvest of rhubarb. Furthermore, the study revealed a high correlation between the polyphenol content and the total antioxidant capacity.

Antioxidant and Potentially Anti-Inflammatory Activity of Anthocyanin Fractions from Pomace Obtained from Enzymatically Treated Raspberries.

Raspberry pomace was obtained from raspberries subjected to enzymatic maceration using three commercial pectinolytic preparations (Pectinex Ultra SP-L, Pectinex Yield Mash, and Ultrazym AFP-L). Phenolic compounds were extracted and anthocyanin fractions were isolated using the SPE solid phase extraction technique. In the separated anthocyanin fractions, the content of individual compounds was determined by the HPLC technique and the antioxidant activity was assessed with four complementary methods (DPPH and ABTS radical scavenging activity, chelating Fe(II) power, and ferric reducing power). Potential anti-inflammatory properties were also identified as the ability to inhibit the activity of lipoxygenase and cyclooxygenase 2. For these enzymes, the type of inhibition was determined based on the Lineweaver–Burke plot.

Fractionation of sterols, tocols and squalene in flaxseed oils under the impact of variable conditions of supercritical CO2 extraction

This study analysed the impact of selected adjustable parameters in the SFE such as SC−CO2 flow rate (6–12 mL/min), temperature (40–80 °C) and extraction time (2–6 h) on the oil recovery and content and composition of tocols, sterols and squalene in flaxseed oils. To track changes in the content of individual compounds in the oil, the Box-Behnken design with RSM was employed. It was found, that the oil yield was positively correlated with the ratio of SC−CO2 to sample mass and was only slightly modified by extraction temperature variation. A low SC−CO2 flow rate and short extraction time favoured the accumulation in oil of larger amounts of β/γ-tocopherols, squalene, stigmasterol and campesterol. In turn, a high SC−CO2 flow rate and long extraction resulted in the highest concentration in oil of plastochromanol-8, 25-hydroxy-24-methylcholesterol and 24-methylenecycloartanol. The concentration of β-sitosterol and cyclolanost-23-ene-3,25-diol was the highest after extraction at the highest temperature by medium extraction time.

Profiling of main metabolites in root exudates and mucilage collected from maize submitted to cadmium stress.

The aim of this study was to characterize qualitatively and quantitatively the composition of the main rhizodeposits emitted from maize (Zea mays) under Cd stress, in order to discuss their role in Cd availability and tolerance. Maize was grown for 6weeks in sand at four Cd exposure levels (0, 10, 20, and 40μM Cd in nutrient solution) and two types of rhizodeposits were collected at the end of cultivation period. Mucilage and other molecules adhering to rhizospheric sand were extracted with a buffer before root exudates were collected by diffusion into water. Total carbon, proteins, amino acids, and sugars were analyzed for both rhizodeposit types and about 40 molecules were identified using GC-MS and LC-MS. Cadmium effect on plant morphology and functioning was slight, but consistent with previous works on Cd toxicity. However, rhizodeposition did tend to be impacted, with a decrease in total carbon, sugars, and amino acids correlating with an increasing Cd content. Such a decrease was not noticeable for proteins in root exudates. These observations were confirmed by the same trends in individual compound contents, although the results were generally not statistically significant. Many of the molecules determined are well-known to modify, whether directly or indirectly, Cd speciation and dynamics in the soil and could play a role in Cd tolerance.

Polyphenolic profiles in lettuce (Lactuca sativa L.) after CaCl2 treatment and cold storage

Lettuce (Lactuca sativa L.) is a popular vegetable with the health-enhancing properties determined by high levels of antioxidant polyphenols as chlorogenic acids and other derivatives of caffeic acid or flavonoids. In this study, changes in the phenolic compound profiles in the lettuce leaves induced by application of CaCl2 before harvest and cold storage were studied. For the first time quantitative analysis of individual phenolic compounds on the basis of standards isolated from lettuce leaves was performed. Compounds were identified using HPLC, LC-MS, 1H and 13CNMR techniques. The dominant compounds were 2,3-dicaffeoyltartaric (2,3-diCTA), 5-O-caffeoylquinic (5-OCQA) and caffeoyltartaric (CTA) acids, with content of 5.7, 2.5 and 0.981 mg/g DM, respectively. The levels of individual phenolic compounds, total phenolics and antioxidant activity (DPPH assay) in plants treated by CaCl2 were determined throughout the storage period (7 and 14 days) at 4 °C. To ascertain the relationship between the content of individual compounds, total phenols, antioxidant activities and storage time, Pearson’s correlation analysis was used. The best correlation between the storage length and compound concentration was observed for 2,3-diCTA (R2 = 0.866) and caffeoylmalic acid (CMA) (R2 = 0.750). Application of CaCl2 (0.05M) on lettuce resulted in an increase in the levels of CTA, 2.3-diCTA and 5-OCQA about 120, 65 and 57%, respectively, compared to the control stored for 7 days in the same conditions and had a favourable effect on the antioxidant activity (R2 = 0.985). The present paper shows that CaCl2 may be used as an agent that influences the stability of health-promoting compounds of cold-stored lettuce.