Heat priming improved heat tolerance of photosynthesis, enhanced terpenoid and benzenoid emission and phenolics accumulation in Achillea millefolium.

The mechanism of heat priming, triggering alteration of secondary metabolite pathway fluxes and pools to enhance heat tolerance is not well understood. Achillea millefolium is an important medicinal herbal plant, rich in terpenoids and phenolics. In this study, the potential of heat priming treatment (35°C for 1 hr) to enhance tolerance of Achillea plants upon subsequent heat shock (45°C for 5 min) stress was investigated through recovery (0.5-72 hr). The priming treatment itself had minor impacts on photosynthesis, led to moderate increases in the emission of lipoxygenase (LOX) pathway volatiles and isoprene, and to major elicitation of monoterpene and benzaldehyde emissions in late stages of recovery. Upon subsequent heat shock, in primed plants, the rise in LOX and reduction in photosynthetic rate (A) was much less, stomatal conductance (gs ) was initially enhanced, terpene emissions were greater and recovery of A occurred faster, indicating enhanced heat tolerance. Additionally, primed plants accumulated higher contents of total phenolics and condensed tannins at the end of the recovery. These results collectively indicate that heat priming improved photosynthesis upon subsequent heat shock by enhancing gs and synthesis of volatile and non-volatile secondary compounds with antioxidative characteristics, thereby maintaining the integrity of leaf membranes under stress.

Composition and Antibacterial Effect of Mint Flavorings in Candies and Food Supplements.

Mint flavorings are widely used in confections, beverages, and dairy products. For the first time, mint flavoring composition of mint candies and food supplements (n = 45), originating from 16 countries, as well as their antibacterial properties, was analyzed. The flavorings were isolated by Marcusson's type micro-apparatus and analyzed by GC-MS. The total content of the mint flavoring hydrodistilled extracts was in the range of 0.01 - 0.9%. The most abundant compounds identified in the extracts were limonene, 1,8-cineole, menthone, menthofuran, isomenthone, menthol and its isomers, menthyl acetate. The antimicrobial activity of 13 reference substances and 10 selected mint flavoring hydrodistilled extracts was tested on Escherichia coli and Staphylococcus aureus by broth dilution method. Linalool acetate and (-)-carvone, as most active against both bacteria, had the lowest MIC90 values. (+)-Menthyl acetate, (-)-menthyl acetate, and limonene showed no antimicrobial activity. Three of the tested extracts had antimicrobial activity against E. coli and 8 extracts against S. aureus. Their summary antimicrobial activity was not always in concordance with the activities of respective reference substances.

Antibacterial and antioxidative properties of different parts of garden rhubarb, blackcurrant, chokeberry and blue honeysuckle.

BACKGROUND: It is important to find plant materials that can inhibit the growth of Listeria monocytogenes and other food-spoiling bacteria both in vitro and in situ. The aim of the study was to compare antibacterial and antioxidative activity of selected plant-ethanol infusions: leaves and berries of blackcurrant (Ribes nigrum L.), berries of chokeberry (Aronia melanocarpa (Michx.) Elliott) and blue honeysuckle (Lonicera caerulea L. var. edulis); petioles and dark and light roots of garden rhubarb (Rheum rhaponticum L.) for potential use in food matrices as antibacterial and antioxidative additives. RESULTS: The strongest bacterial growth inhibition was observed in 96% ethanol infusions of the dark roots of rhubarbs. In 96% ethanol, nine out of ten studied plant infusions had antibacterial effect against L. monocytogenes, but in 20% ethanol only the infusions of dark rhubarb roots had a similar effect. Chokeberry and other berries had the highest antioxidative activity, both in 20% and 96% ethanol infusions. CONCLUSION: The combination of dark rhubarb roots or petioles and berries of black chokeberry, blackcurrant or some other anthocyanin-rich berries would have potential as both antibacterial and antioxidative additives in food. © 2018 Society of Chemical Industry.

Comparative study of microbiological, chemical and sensory properties of kefirs produced in Estonia, Latvia and Lithuania.

In the current study the microbiological, sensory and chemical properties of 24 kefirs (12 producers) from Estonian, Latvian and Lithuanian retail market were determined using gas chromatography (GC), high performance liquid chromatography (HPLC-MS/MS-Q-TOF and LC-ion trap MS/MS), spectrophotometry and other methods. Antihypertensive, angiotensin-converting enzyme (ACE) inhibiting, antioxidant and antibacterial peptides were found in the kefir samples. According to the results of principal component analysis of 200 most abundant compounds obtained with HPLC-MS/MS-Q-TOF analysis, Estonian kefirs differed from the rest. Kefirs of Latvian and Lithuanian origin showed similarities in several characteristics, probably related to the starter cultures and technological processes. The fatty acids composition of all Baltic kefirs was uniform. The antioxidant capacity of the kefirs varied slightly, whereas intermediate positive correlation (r = 0.32, P < 0.05) was found between antioxidativity and total bacterial count. The lipid oxidation level, estimated as the content of linoleic and oleic acid primary oxidation products, oxylipins, was very low in all studied kefirs. Only one third of analysed kefirs met the requirements of the minimum sum of viable microorganisms, indicated in the Codex Standard for Fermented Milks.

Beetroot (Beta vulgaris L.) and naturally fermented beetroot juices from organic and conventional production: metabolomics, antioxidant levels and anticancer activity.

BACKGROUND: The aim of the paper was to determine the level of antioxidants and metabolomic fingerprinting in both raw beetroots and naturally fermented beetroot juices from organic (ORG) versus conventional (CONV) production. In addition, the anticancer properties of the fermented beetroot juices were evaluated. RESULTS: The obtained results showed that ORG fresh beetroots contained significantly more dry matter, vitamin C and some individual phenolic compounds than CONV beetroots. The content of total phenolic acids was significantly higher in CONV beetroots compared with the ORG ones. The level of flavonoids was similar in ORG and CONV beetroots. There were only slight differences in the chemical composition of ORG and CONV beetroot juices. Metabolomic analysis provided a possibility to distinguish clearly between ORG and CONV fermented beetroot juices. However, this method was less useful in the case of fresh whole beetroots. It was found that anticancer activity was stronger in the case of ORG fermented juices when compared with CONV ones. CONCLUSION: The obtained results indicate that ORG- and CONV-produced beetroots and fermented beetroot juices have different chemical properties and different impacts on cancer cells. It is necessary to continue research on this topic in order to confirm and understand the achieved results.

The Effect of Fruit and Berry Pomaces on the Growth Dynamics of Microorganisms and Sensory Properties of Marinated Rainbow Trout.

Plant pomaces in suitable forms (powders, extracts) can be used in foods of animal origin to increase the nutritional value and safety of these foods. In the present study, water extracts of apple, black currant, rhubarb and tomato pomaces were used in fish marinade solutions to evaluate their effect on the growth dynamics of microorganisms and the growth potential of Listeria monocytogenes by challenge testing. The results showed that mesophilic aerobic microorganisms, Pseudomonas spp., yeasts and moulds remained at acceptable levels throughout the predetermined storage period. The challenge test results showed that the overall growth potential of L. monocytogenes in all marinated rainbow trout samples remained at ≤0.5 log10 cfu/g during the study period, and none of the marinated fish samples supported the growth of L. monocytogenes. In addition, the effect of fruit and berry pomaces on the sensory properties of marinated rainbow trout samples was evaluated. The results revealed that it is possible to effectively use fruit and berry pomaces in marinated fish products, ensuring food safety, high microbiological quality, acceptable sensory characteristics and a sufficiently long shelf life of the products.

The Phytochemical Profile and Anticancer Activity of Anthemis tinctoria and Angelica sylvestris Used in Estonian Ethnomedicine.

The aerial parts of Anthemis tinctoria L. and Angelica sylvestris L. and the roots of A. sylvestris have been used as traditional anticancer remedies in Estonian ethnomedicine. The aim of this study was to investigate content of essential oils (by gas chromatography) and polyphenolic compounds (using two different methods of high performance liquid chromatography-mass spectrometry (HPLC-MS)) of both plant species, as well as the in vitro anti-cancer effects of their essential oils and methanolic extracts. The average (n = 5 samples) yield of essential oils was 0.15%, 0.13%, and 0.17%, respectively. The principal compounds of the essential oil from the aerial parts of A. tinctoria were palmitic acid (15.3%), p-cymene (12.6%), and α-muurolene (12.5%), and α-pinene (45.4%), p-cymene (15.5%), and ß-myrcene (13.3%) in aerial parts of A. sylvestris, while isocaryophyllene oxide (31.9%), α-bisabolol (17.5%), and α-pinene (12.4%) were the main constituents in the roots. The most abundant phenolic compounds in aerial parts were the derivatives of caffeic acid, quinic acid, and quercetin; the main compounds in roots of A. sylvestris were chlorogenic acid, quinic acid, and naringenin. The strongest anticancer effects were observed in essential oils of A. sylvestris roots and aerial parts on human carcinoma in the mouth cells (KB, IC50 19.73 µg/mL and 19.84 µg/mL, respectively). The essential oil of A. tinctoria showed a strong effect on KB and LNCaP cells (27.75-29.96 µg/mL). The methanolic extracts of both plants had no effect on the cancer cells studied.

Lipid oxidation inhibition capacity of plant extracts and powders in a processed meat model system.

A meat model system was used for screening lipid oxidation inhibiting capacity of diverse horticultural plant materials. In the model, heme-containing sarcoplasmic proteins from the meat water-phase were homogenized with linoleic acid and thiobarbituric reactive substances (TBARS) were measured. 23 Plant materials were investigated at three high (50, 100, and 200 ppm) concentrations and five plant extracts were tested at three low (5, 10, and 20 ppm) concentrations over time. In the high concentration sets, summer savory freeze-dried powder, beetroot leaves extracted with 50% ethanol, and an olive polyphenol powder extracted from wastewater, inhibited oxidation the most effectively. After two weeks and at 200 ppm concentration, oxidation was reduced to 17.2%, 16.6% and 13.5% of the blank sample with no added antioxidants respectively. In the low concentration set, spray dried rhubarb juice inhibited oxidation the most after two weeks at 5 ppm where oxidation was reduced to 68.3% of the blank sample with no added antioxidants.

Trans-resveratrol alone and hydroxystilbenes of rhubarb (Rheum rhaponticum L.) root reduce liver damage induced by chronic ethanol administration: a comparative study in mice.

The hepatoprotective effects and pharmacokinetics of trans-resveratrol and hydroxystilbenes of the garden rhubarb (Rheum rhaponticum L., R. rhaponticum) root ethanol extract were studied. Ethanol was administered to male BALB/c mice for 35 days in an inhalation chamber. During this time vehicle, trans-resveratrol (20 mg/kg per day) or R. rhaponticum extract was intraperitoneally (i.p.) administered and mice were sacrificed for the collection of liver and blood. In an additional experiment, the level of parent compounds and metabolites was estimated in the blood after acute i.p. administration of trans-resveratrol or R. rhaponticum extract. The levels of hydroxystilbenes, their metabolites and fatty acid oxy-metabolites (oxylipins) were studied by LC-tandem DAD-MS/MS. Ethanol induced hepatotoxicity, as evidenced by histological changes and accumulation of oxylipins in the blood. Both trans-resveratrol and R. rhaponticum extract reduced the extent of these changes. The pharmacokinetics of trans-resveratrol was characterized by a rapid removal from the blood and metabolism to sulfates and glucuronides. After the administration of R. rhaponticum extract, in addition to trans-resveratrol glucoside and its metabolites, several other hydroxystilbenes were found. Inhibition of oxidation of polyunsaturated fatty acids is proposed as a basis of the hepatoprotective effect of both trans-resveratrol and R. rhaponticum extract.

Polyphenolic composition of roots and petioles of Rheum rhaponticum L.

INTRODUCTION: Various species of the genus Rheum (Polygonaceae) are known for their high content of medicinally important hydroxyanthraquinones. However, little information is available concerning the polyphenolic composition of garden or dietary rhubarb Rheum rhaponticum L. (R. rhaponticum). OBJECTIVE: Determination of further polyphenols in the roots and petioles of R. rhaponticum. METHODOLOGY: The dried plant material was extracted with 10-fold excess (v/w) of methanol and subsequently diluted five times with methanol-water (1:1) and analysed by reversed-phase liquid chromatography using tandem UV-photodiode array and mass selective detection (RP-HPLC-UV-ESI/MS(2)). Polyphenols were identified using either HPLC-ESI/MS(2) data obtained for respective commercial standards or by comparison of a parent ion fragmentation picture with the respective MS(2 )spectrum from the literature. RESULTS: The roots of R. rhaponticum were very rich in various hydroxystilbenes and contained four main substance groups--derivatives of trans-piceatannol, trans-resveratrol, trans-rhapontigenin and trans-deoxyrhapontigenin. Additionally, pterostilbene acetylglucosides and a number of hydroxyanthraquinones and their glycosides were identified in the root samples. The profile of polyphenols in the petioles of R. rhaponticum was similar to that of the roots but the content of individual substances was remarkably lower. The petioles of the R. rhaponticum additionally contained significant amounts of derivatives of flavonol quercetin, which is a good antioxidant. CONCLUSION: The study has shown that roots of R. rhaponticum contain a wide variety of hydroxystilbenes and deserve further consideration as a source of medicinally interesting compounds.

Antimicrobial and Antioxidative Effects of Plant Powders in Raw and Cooked Minced Pork.

It is a challenge for scientists to find new plant-based food constituents simultaneously possessing antimicrobial and antioxidative properties to prolong the shelf life of meat products. In this study, various plant powders and their blends were added to minced pork to carry out a complex study of their effect on sensory characteristics, microbial growth, and lipid oxidation of the meat in raw and cooked forms during storage. Microbiological shelf life parameters were evaluated by determining the total counts of microorganisms, yeasts, and molds. The growth potential of Listeria monocytogenes was estimated by challenge testing. The impact on lipid oxidation processes was assessed using thiobarbituric acid reactive substances (TBARS) and high performance liquid chromatography (HPLC) methods. The results showed that the blend of rhubarb petioles and tomato powder added a pleasant color and a combined taste to the product, similar to the taste of salt. In raw samples, considerable microbial growth inhibition was achieved with rhubarb petioles, tomato, and their mixture. Nine treatments of cooked samples had a stronger inhibitory effect on microbial growth compared to control treatments. Among all plant powders, tomato was the most effective inhibitor of yeast and mold growth. However, the challenge test revealed that L. monocytogenes growth in cooked samples was not inhibited during shelf life. In raw samples, rhubarb roots combined with blackcurrant or chokeberry berries effectively inhibited lipid oxidation, and in cooked samples, rhubarb petioles showed a similar effect. In conclusion, it was found that powdered plant materials are well suited for use as antimicrobial and antioxidative agents in minced meat products.

Valorization of Wild Apple (Malus spp.) By-Products as a Source of Essential Fatty Acids, Tocopherols and Phytosterols with Antimicrobial Activity.

The amplified production of fruit as well as burgeoning demand for plant-made food products have resulted in a sharp increase of waste. Currently, millions of tons of by-products are either being discarded or utilized rather ineffectively. However, these by-products may be processed and further incorporated as functional ingredients in making high-value food products with many physiological and biochemical effects. The chemical analysis of pomace oils using gas chromatography-mass spectrometry (GC/MS) and reversed-phase-liquid chromatography coupled with fluorescence detector (RP-HPLC/FLD) systems led to the identification and quantification of 56 individual lipophilic compounds including unsaturated, polyunsaturated and saturated fatty acids, as well as phytosterols and four homologs of tocopherol. The oils recovered from by-products of Malus spp. (particularly cv. "Ola") are rich in fatty acids such as linolenic (57.8%), α-linolenic (54.3%), and oleic (25.5%). The concentration of total tocopherols varied among the Malus species and dessert apples investigated, representing the range of 16.8⁻30.9 mg mL-1. The highest content of total tocopherols was found in M. Bernu prieks, followed by M. cv. "Ola", and M. × Soulardii pomace oils. A significantly higher amount of δ-tocopherol was established in the oil of M. Bernu prieks, indicating that this species could be utilized as a natural and cheap source of bioactive molecules. ß-Sitosterol was the prevalent compound determined in all tested pomace oils with a percentage distribution of 10.3⁻94.5%. The main triterpene identified in the oils was lupeol, which varied in the range of 0.1⁻66.3%. A targeted utilization of apple pomace would facilitate management of tons of by-products and benefit the environment and industry.

Bioactive components of the hop strobilus: comparison of different extraction methods by capillary electrophoretic and chromatographic methods.

In the present study, the composition of the hop strobilus extract by using different extraction methods under different solvent conditions was analysed and compared. Several separation methods were applied to obtaining detailed information about the hop extract: capillary zone electrophoresis (CZE), high-performance liquid chromatography-mass-spectrometry (HPLC-MS/MS) and gas chromatography-mass-spectrometry (GC-MS). The electropherograms of different extracts varied dramatically. The oxidation reaction of the hop strobilus extract was examined.

Blood serum metabolome of atopic dermatitis: Altered energy cycle and the markers of systemic inflammation.

Atopic dermatitis is a chronic inflammatory disease which usually starts in the early childhood and ends before adulthood. However up to 3% of adults remain affected by the disease. The onset and course of the disease is influenced by various genetic and environmental factors. Although the immune system has a great effect on the outcome of the disease, metabolic markers can also try to explain the background of atopic dermatitis. In this study we analyzed the serum of patients with atopic dermatitis using both targeted and untargeted metabolomics approaches. We found the most significant changes to be related to phosphatidylcholines, acylcarnitines and their ratios and a cleavage peptide of Fibrinogen A-α. These findings that have not been reported before will further help to understand this complex disease.

Changes in Polyphenols Contents and Antioxidant Capacities of Organically and Conventionally Cultivated Tomato (Solanum lycopersicum L.) Fruits during Ripening.

Polyphenols of fruits and vegetables form an important part of human dietary compounds. Relatively little is known about accumulation of phenolics during fruits ripening process. The goal of this work was to study the changes in antioxidant activity and in content of 30 polyphenols during ripening of tomato fruits. Five organically and conventionally grown tomato cultivars were investigated at three different ripening stages. Phenolic compounds were extracted with methanol and extracts were analyzed by HPLC-DAD-MS/MS. During ripening, four different changing patterns were observed: (1) high level in green fruits with minimal changes; (2) continuous increase with maximum level in red-ripe fruits; (3) decrease; (4) increase and achieving maximum level at half-ripe stage. Similar change patterns were found for organic and conventional fruits. The accumulation patterns of phenolic compounds were similar in standard-type tomatoes but differed in several cases in cherry-type cultivar. Although contents of some polyphenols decreased during ripening, total phenolics and free radical scavenging activity increased in all studied cultivars and in case of both cultivation modes. The changes in content of phenolic compounds during ripening were greatly influenced by cultivars, but cultivation mode had only minor impact on dynamics in polyphenols contents in tomato fruits.

Survey of grapevine Vitis vinifera stem polyphenols by liquid chromatography-diode array detection-tandem mass spectrometry.

Grapes and red wine prepared from Vitis vinifera L. contain a variety of polyphenols. Some information is available about the polyphenols of the seeds and leaves of grapevine, but considerably less is known about the polyphenols of woody stems. In this paper, we describe the results of a study of polyphenolic compounds in grapevine stems. We demonstrate how a combination of reversed phase high-performance liquid chromatography with ultraviolet-diode array detection and electrospray ionization-tandem mass spectrometry ion-trap detection enables characterization of a phytochemical mixture of considerable complexity. As the polyphenol source, the stems of three frost-hardy grapevine varieties [Hasaine (Hasansky) sladki, Zilga, and Yubilei Novgoroda] were used. The main group of methanol-extractable polyphenols of stems consists of trans-resveratrol and its derivatives including oligomers and glucosides. As minor components of the extract, stilbenoid piceatannol as well as a number of nonstilbenoid polyphenols, mostly flavan-3-ols and phenolic acids glucosides, were determined. The total polyphenol content of the grapevine stems depends on the variety, whereby the stems of cultivar Yubilei Novgoroda with white grapes contain significantly less of both groups of polyphenols.

Mint Flavorings from Candies Inhibit the Infectivity of Chlamydia pneumoniae.

The impact of solvent extracts from the distillation water (flavoring extracts) isolated from mint flavored candies on the infectivity of the intracellular bacterium Chlamydia pneumoniae was evaluated by an in vitro model of epithelial cell infections., The mint flavoring extracts were isolated from the candies by simultaneous hydrodistillation and their chemical composition, established by GC-MS, demonstrated menthol and limonene as the most abundant components. Results obtained by treating C. pneumoniae elementary bodies (EBs) with the flavoring extracts or pure reference compounds showed a significant decrease in EB infectivity, achieved with most of the extracts. This antichlamydial activity could be related to the relatively high menthol content of the extracts. Overall, the obtained data indicates that the flavorings present in the candies are able to target the metabolically quiet, non-replicating form of the bacterium and to suppress the spread of this respiratory pathogen from one cell to another.

Variability of procyanidin type A- and -B trimers content in aerial parts of some Vaccinium species and cultivars.

Based on the ethnopharmacological data showing that either wild bilberry leaves or whole aerial parts of the plants have been used as antidiabetic drugs, it can be hypothesized that the controversial results of various clinical and animal investigations may be caused by different contents of the active principles in different aerial parts of the bilberry/blueberry (Vaccinium spp.) plants, as well as by their geographical and seasonal variability. The aim of this study was to compare the content of procyanidin type A- and -B trimers in different parts of wild bilberry (Vaccinium myrtillus L.) and northern highbush blueberry (V. corymbosum L.) cultivars. Stems (60 samples) and leaves (30 samples) of wild bilberries and northern highbush blueberry cultivars 'Ama' and 'North Blue' were collected at different locations in Estonia around the year, and analyzed for the concentration of the target polyphenols by HPLC-MS/MS. The highest content of type A doubly linked trimer, a known antidiabetic substance, was established in the stems of V. myrtillus. These contained up to 100 times more of the active substance than the leaves of V. myrtillus and at least 1000 times more than the leaves of V. corymbosum, whereas the seasonal/geographical variation was nearly tenfold. We suggest using stems of V. myrtillus for future animal and clinical investigations of bilberry preparations against diabetes.

Three-year comparative study of polyphenol contents and antioxidant capacities in fruits of tomato (Lycopersicon esculentum Mill.) cultivars grown under organic and conventional conditions.

In the present study, four tomato cultivars were grown under organic and conventional conditions in separate unheated greenhouses in three consecutive years. The objective was to assess the influence of the cultivation system on the content of individual polyphenols, total phenolics, and antioxidant capacity of tomatoes. The fruits were analyzed for total phenolic content by the Folin-Ciocalteau method and antioxidant capacity by the DPPH free radical scavenging assay. Individual phenolic compounds were analyzed using HPLC-DAD-MS/MS. Among 30 identified and quantified polyphenols, significantly higher contents of apigenin acetylhexoside, caffeic acid hexoside I, and phloretin dihexoside were found in all organic samples. The content of polyphenols was more dependent on year and cultivar than on cultivation conditions. Generally, the cultivation system had minor impact on polyphenols content, and only a few compounds were influenced by the mode of cultivation in all tested cultivars during all three years.

Toxicological issues associated with production and processing of meat.

Meat is a very complex and continuously changing ex vivo system of various high- and low-molecular substances that can be used for satisfying needs of the human organism for metabolic energy, building material and fulfilling of the other vital functions. A great majority of these substances are useful and safe for the consumer. Yet, meat and meat products may always contain substances exerting detrimental effects to the consumer's organism. The present paper is a literature review of the most important potentially toxic substances found in meat and meat products; their classification, ways of getting into the meat or formation during meat processing, undesirable physiological outcomes and biochemical mechanisms of their toxic effects, and methods for reduction of these responses.