total phenolics
Recently Published Documents

Abstract Fresh-cut Chinese water chestnuts (CWCs) are prone to quality deterioration during storage, which does not meet consumer demand. In this study, the effect of exogenous melatonin (5 mM) on the quality and potential mechanisms in fresh-cut CWC was investigated. The results showed that melatonin treatment alleviated the cut-surface discoloration of CWCs. Not only did this treatment significantly slow down the increase in browning degree and b* as well as the decrease in L*, but also significantly delayed the loss of weight and total soluble solids. Further investigations indicated that melatonin-treated fresh-cut CWCs exhibited significantly lower total phenolics and soluble quinones and suppressed the activities of phenylalanine ammonia-lyase, polyphenol oxidase, and peroxidase. Meanwhile, when fresh-cut CWCs were treated with melatonin, the total flavonoid concentration was significantly decreased compared to the control. Additionally, melatonin significantly inhibited the accumulation of H2O2 and malondialdehyde (MDA) as well as enhanced the activities of superoxide dismutase and catalase by promoting the production of O2 -·. In summary, melatonin treatment may delay the surface discoloration of fresh-cut CWCs by inhibiting phenolic compound metabolism and improving antioxidant capacity, thereby effectively maintaining the quality, and prolonging the shelf life of fresh-cut CWCs.

<p class="042abstractstekst">The aim of this study was to study the impact of crop load on the yield and grape quality of ‘Merlot’ and ‘Vranac’ (<em>Vitis vinifera</em> L.) in Trebinje vineyard. The crop load levels studied in this trial were 9 buds (V1) and 12 buds (V2) per vine at each variety trained on Lenz-Moser bilateral cordon system. The impact was determined by measurements of yield per vine and grape quality characterized by the contents of total soluble solids, titratable acidity, total phenolics, total flavonoids and by total antioxidant capacity. The measured parameters of grape quality of ‘Merlot’ and ‘Vranac’ were not influenced significantly by crop load levels. V2, compared to the V1, showed the potential for increasing grape yield only for Merlot variety under experimental conditions. The results of this study also showed a positive correlation between total phenolics/flavonoids and total antioxidant capacity of grape berries in both varieties, regardless of crop loads applied.</p>

<p class="042abstractstekst">The impact of combinations of plant growth regulators (PGRs) on callus culture of <em>Satureja sahendica </em>Bornm. was investigated. In nodal explants, the response of secondary metabolite production to different concentrations of PGRs was analyzed regarding the presence and absence of polyvinylpyrrolidone (PVP). The explants were cultured on MS media in presence of auxins (2,4-dichlorophenoxyacetic acid and naphthylacetic acid) and cytokinins (thidiazuron and kinetin); which were used in equal concentrations of 0.5, 1, and 2 mg l^-1. The treatment of 2 mg l^-1 2,4-D + 2 mg l^-1Kin (MD3) led to the highest production of total phenolics (4.303 ± 0.449 mg GAE g^-1) and flavonoids (24.903 ± 7.016 mg QE g^-1). Moreover, the effect of salicylic acid (SA) on the production of secondary metabolites in cell suspension culture of <em>Satureja sahendica</em> was evaluated. The cell suspension culture was established by culturing the nodal-derived friable callus in the liquid medium containing different concentrations of SA (0, 100, 150, 200 µM). An inverse relationship exists between the fresh mass and secondary metabolites contents. In addition, there was a significant difference among concentrations of SA in the production of total phenolics and flavonoid compounds. SA enhances secondary metabolites production and decreases cell fresh mass.</p>

Salt stress is one of the main limitations to Triticum aestivum productivity all around the world. An experiment was conducted to assess the effect of Trichoderma harzianum seed coating on germination and seedling development of wheat under salt stress (60 and 120 mM NaCl). The seeds of six wheat cultivars, namely Shafaq-06, Punjab-11, Millet, Seher, Pirsabik, and Aari were seed coated with Trichoderma (taken from NARC Pakistan) at the rate of 2 x 107 CFU using PelGel for 24 h. After air-drying at room temperature for 12 h, the coated seeds were sown in small pots. Experimentation was laid out in a completely randomized design with three replications. The data for various biochemical attributes were collected after 30 d of germination to test the seed and seedling vigor, respectively. Trichoderma harzianum seed coating reduced the amount of hydrogen peroxide, catalase, Malondialdehyde, and increased protein content, Ascorbate Peroidase, and total phenolics under salt stress advocating that its use is effective in the cultivation of crops in saline areas because it inhibits oxidative damage by triggering various phenolic compounds and scavenging proteins.

The bioactive extracts recovered from Curcuma longa (stem), Mentha aquatica (stem and leaves), Emblica officinalis (fruits), Nigella sativa (seeds), and Glycyrrhiza glabra (stem) using methanol and ethanol, were appraised for antioxidant (total flavonoid contents, total phenolic contents, DPPH free radical scavenging ability, inhibition of linoleic acid peroxidation and reducing power) and antimicrobial attributes. Total phenolics (16.89 ± 0.18 - 25.06 ± 0.31g GAE/100g) and total flavonoids (1.96 ± 0.07 - 13.54 ± 0.18 CE g/100g) contents of aqueous methanol extracts of tested plant materials were significantly (p < 0.05) lower than that of aqueous ethanol extracts (13.87 ± 0.12 - 28.63 ± 0.34 g GAE/100g) and (2.20 ± 0.10 - 8.71 ± 0.24 CE /100g), respectively. The percent inhibition of linoleic acid per oxidation by crude ethanol extracts of plants was in the range of 48.72 ± 1.24 - 70.79 ± 1.57 and crude methanol extract 35.90 ± 1.28 - 61.54 ± 2.14, while the range of DPPH free radical scavenging activity of ethanol extracts was (58.36 ± 1.98 - 80.55 ± 3.07) and methanol extracts (39.55 ± 1.52 - 79.64± 2.33). The reducing power of the tested extracts obtained by ethanol (at the concentration of 10 mg/mL) ranged 1.11 ± 0.12 – 1.53 ± 0.18 while for methanol extracts 0.98 ± 0.11 – 1.39 ± 0.12. Among the attributes analyzed, total phenolics, total flavonoids, and DPPH free scavenging activity were found to be varied significantly in all the tested medicinal plants. The extracts from all plants showed good antimicrobial potential against a penal of bacteria, including E. coli, P. multocida and S. aureus, and fungi including A. niger, A. flavus, A. alternate, and G. lucidium. Overall, the tested samples were found to be a good source of natural antioxidant and antimicrobial agents and thus can be explored for potential functional food and nutra-pharmaceutical applications.

Salicylic acid (SA) and methyl jasmonate (MeJa) are prominent phytohormones that are involved in stress reactions. Both compounds may influence the biosynthesis of secondary compounds; however, scientific experiments in vivo are rare and contradictive. This paper reports on a study on the elicitation of volatiles and total phenolics (TPC) by MeJa and SA. The subjects were four Lamiaceae species studied in open field conditions in Budapest (Hungary). According to the results, both elicitors provoked specific responses in each plant species depending on the dosage applied and the parameter studied; 2 mM of SA stimulated essential oil (EO) accumulation in marjoram and peppermint, while in hyssop 0.1 mM was optimal. MeJa proved to be effective only in marjoram and in basil. In marjoram, cis-sabinene hydrate was decreased and in hyssop, isopinocamphone was increased by both dosages of SA. In peppermint, pulegone content was reduced by 2 mM SA, but no significant change of the major components of basil EO was detected. SA was successful in increasing TPC and antioxidant activity (AC) in three of the experimental species, but not in hyssop. In marjoram, only 0.1 mM induced TPC and eventually AC, while in peppermint and basil both dosages of SA were effective. Optimalisation of the treatments is suggested in further in vivo experiments.

Stevia rebaudiana is an important medicinal plant that belongs to the Asteraceae family. The leaves of Stevia rebaudiana are a rich source of many health-promoting agents such as polyphenols, flavonoids, and steviol glycoside, which play a key role in controlling obesity and diabetes. New strategies such as the elicitation of culture media are needed to enhance the productivity of active components. Herein, the Cuscuta reflexa extracts were exploited as elicitors to enhance the productivity of active components. Cuscuta reflexa is one of the parasitic plants that has the ability to elongate very fast and cover the host plant. Consequently, it may be possible that the addition of Cuscuta reflexa extracts to adventitious root cultures (ADR) of Stevia rebaudiana may elongate the root more than control cultures to produce higher quantities of the desired secondary metabolites. Therefore, the main objective of the current study was to investigate the effect of Cuscuta reflexa extract as a biotic elicitor on the biomass accumulation and production of antioxidant secondary metabolite in submerged adventitious root cultures of Stevia rebaudiana. Ten different concentrations of Cuscuta reflexa were added to liquid media containing 0.5 mg/L naphthalene acetic acid (NAA). The growth kinetics of adventitious roots was investigated for a period of 49 days with an interval of 7 days. The maximum biomass accumulation (7.83 g/3 flasks) was observed on medium containing 10 mg/L extract of Cuscuta reflexa on day 49. As the concentration of extract increases in the culture media, the biomass gradually decreases after 49 days of inoculation. In this study, the higher total phenolics content (0.31 mg GAE/g-DW), total flavonoids content (0.22 mg QE/g-DW), and antioxidant activity (85.54%) were observed in 100 mg/L treated cultures. The higher concentration (100 mg/L) of Cuscuta reflexa extract considerably increased the total phenolics content (TPC), total phenolics production (TPP), total flavonoids content (TFC), total flavonoids production (TFP), total polyphenolics content (TPPC), and total polyphenolics production (TPPP). It was concluded that the extract of Cuscuta reflexa moderately improved biomass accumulation but enhanced the synthesis of phenolics, flavonoids, and antioxidant activities. Here, biomass’s independent production of secondary metabolites was observed with the addition of extract. The present study will be helpful to scale up adventitious roots culture into a bioreactor for the production of secondary metabolites rather than biomass accumulation in medicinally important Stevia rebaudiana.

Peaches (Prunus persica L.) are a popular and sought-after dessert fruit. This is mainly due to their flavour, aroma, attractive appearance, and high content of substances that play an important role in human nutrition. The present study was carried out to determine some important analytical properties (sugars/sucrose, glucose, fructose and sorbitol), total acid, total phenolics, flavonoids, antioxidant capacity, carotenoids and anthocyanins of 34 selected peach varieties. The analyses are also complemented by colorimetric measurements of peach skin colour using CIELAB and other chromatic parameters. The results show, for example, that all peach varieties are good sources of phenolic compounds (9.43–577 mg gallic acid equivalent (GAE).100 g−1), flavonoids (1.12–95.1 mg catechin equivalent (CAE).100 g−1), and antioxidant capacity (136–462 mg Trolox equivalent (TE).100 g−1).

Physicochemical analysis for simplicia and extract, respectively: water content 2.12–4% for simplicia; drying losses 3.93–5.47% and 8.51–19.76%; total ash 5.14–9.41% and 6.22–17.07%; total ash acid-insoluble content 0.29–5.41% and 0.52–3.82%; total ash water-soluble content 1.26–7.14% and 1.43–8.54%; water-soluble content 19.60–39.43% and 58.45–77.51%; ethanol-soluble content 13.99–33.76% and 59.79–75.39%. The phytochemical analysis showed that the extracts contain alkaloids, flavonoids, saponins, tannins, and terpenoids. Total flavonoids and total phenolics content were 9.86–15.74% QE/g and 6.67–7.65% GAE/g, respectively. Based on LC-MS results, the extract contained emodin, kaempferol, kaempferol-3,7-diglucoside, and kaempferol-3-O-β-D-glucopyranoside. The extracts possessed antibacterial activity against bacteria tested.

To feed the increased world population, sustainability in the production of crops is the need of the hour, and exploration of an effective symbiotic association of rhizobia with legumes may serve the purpose. A laboratory-scale experiment was conducted to evaluate the symbiotic effectiveness of twenty wild rhizobial isolates (MR1–MR20) on the growth, physiology, biochemical traits, and nodulation of mung bean to predict better crop production with higher yields. Rhizobial strain MR4 resulted in a 52% increase in shoot length and 49% increase in shoot fresh mass, while MR5 showed a 30% increase in root length, with 67% and 65% improvement in root fresh mass by MR4 and MR5, respectively, compared to uninoculated control. Total dry matter of mung bean was enhanced by 73% and 68% with strains MR4 and MR5 followed by MR1 and MR3 with 60% increase in comparison to control. Rhizobial strain MR5 produced a maximum (25 nodules) number of nodules followed by MR4, MR3, and MR1 which produced 24, 23, and 21 nodules per plant. Results related to physiological parameters showed the best performance of MR4 and MR5 compared to control among all treatments. MR4 strain helped the plants to produce the lowest values of total soluble protein (TSP) (38% less), flavonoids contents (44% less), and malondialdehyde (MDA) contents (52% less) among all treatments compared to uninoculated control plants. Total phenolics contents of mung bean plants also showed significantly variable results, with the highest value of 54.79 mg kg−1 in MR—inoculated plants, followed by MR5- and MR1-inoculated plants, while the minimum concentration of total phenolics was recorded in uninoculated control plants of mung bean. Based on the results of growth promotion, nodulation ability, and physiological and biochemical characteristics recorded in an experimental trial conducted under gnotobiotic conditions, four rhizobial isolates (MR1, MR3, MR4, and MR5) were selected using cluster and principal component analysis. Selected strains were also tested for a variety of plant-growth-promoting molecules to develop a correlation with the results of plant-based parameters, and it was concluded that these wild rhizobial strains were effective in improving sustainable production of mung bean.