Total Flavonol Content Research Articles

The effect of quercetin mediated photodynamic inactivation on apple juice properties at different temperature and its bactericidal mechanism

The inactivation efficacy, mechanism, and effect on apple juice properties of 405 nm blue light combined with quercetin in apple juice were investigated. At 60 J/cm2, Listeria monocytogenes and Escherichia coli O157:H7 cells experienced more than 5 log reduction at room temperature. The depolarized membrane potential and loss of succinate dehydrogenase enzyme activity showed that the membrane and protein were the targets of photodynamic inactivation (PDI). While all measured properties of apple juice were not significantly (P > 0.05) changed after PDI, the total phenolic and flavonol contents were significantly (P < 0.05) more preserved after PDI at 4°C than at room temperature. In conclusion, quercetin-mediated PDI can achieve an approximately 5 log bacterial reduction in apple juice and has no adverse effect on the juice properties. Therefore, quercetin-mediated PDI is a nonthermal technology that has the possibility of being an alternative to conventional nonthermal processing for juice.

Effect of Methyl Jasmonate and Methyl Jasmonate Plus Urea Foliar Applications on Wine Phenolic, Aromatic and Nitrogen Composition

Foliar application has been studied to enhance grape composition and, therefore, wine quality. This work examined, for first time, the effects of foliar applications of methyl jasmonate (MeJ) and methyl jasmonate plus urea (MeJ+Ur) to Tempranillo vineyard on wine phenolic, aromatic and nitrogen composition over two vintages (2019 and 2020). A reduction in alcoholic degree was observed in MeJ and MeJ+Ur wines. The effect of foliar treatments was season-dependent. MeJ and MeJ+Ur wines were characterized, in the first vintage, by a higher content of total acylated anthocyanins, but a low content of total esters, alcohols and acids when compared with control wines. MeJ+Ur wines presented a higher total amino acids content than control and MeJ wines. However, in the second vintage, MeJ and MeJ+Ur wines presented an increase in some non-acylated anthocyanins, but only MeJ+Ur treatment increased the total content of flavonols, flavanols, hydroxycinnamic acids, stilbenes and total amino acids when compared with control wines. MeJ wines presented a low content of esters and acids, whereas MeJ+Ur did not show differences with control wines. Overall, the effect of MeJ+Ur foliar treatment was greater than the effect of MeJ application in order to improve the wine chemical composition.

Interactive Effects of Water Deficiency and Endophytic Beauveria bassiana on Plant Growth, Nutrient Uptake, Secondary Metabolite Contents, and Antioxidant Activity of Allium cepa L.

The main aim of this research study was to assess the interactive effects of water deficiency and the inoculation of a growth medium with Beauveria bassiana on plant growth, nutrient uptake, secondary metabolite contents, and antioxidant capacity of Allium cepa. A. cepa seedlings were simultaneously exposed to one of three watering regime treatments (3-day, 5-day, and 7-day watering intervals) and B. bassiana or no-fungus treatment. While the longest watering interval induced reduced plant growth, plants inoculated with B. bassiana had better results than those in the no-fungus treatment. Significant interactive effects (DF = 2.0; p < 0.05) between fungus and the watering regime on P, K, and Fe contents were observed. Remarkably, at the 7-day watering interval, the polyphenol content (64.0 mg GAE/L) was significantly higher in the plants treated with B. bassiana than in the no-fungus-treated plants. The watering interval significantly affected (DF = 2, 6; F = 7.4; p < 0.05) total flavonol contents among the fungus-treated plants. The interaction of the watering interval and B. bassiana inoculation (DF = 2.0; F = 3.8; p < 0.05) significantly influenced the flavonol content in the onion bulbs and the antioxidant activities of onion bulbs in the FRAP assay (DF = 2.0; F = 4.1; p < 0.05).

Synergistic antioxidant activity of selected medicinal plants in Brunei Darussalam and its application in developing fortified pasta.

Developing functional foods by utilizing plants can often lead to compromised sensory properties. Thus this study investigates the combination of plants to produce synergistic effects and to incorporate these plant powders into a pasta formulation without affecting its sensory acceptance. Six common Brunei medicinal plants were evaluated for their in vitro antioxidant activity determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity (IC50 ), ferric reducing antioxidant power (FRAP) assay and 2,2'-azino-bis(3-ethylbenziazoline-6-sulfonic acid) (ABTS) radical scavenging assay. Aqueous extracts of Amaranthus tricolor, Breynia androgyna, Manihot esculenta, Polygonum minus, Apium graveolens and Coriandrum sativum were prepared. Breynia androgyna had the highest FRAP value of 74.3 ± 5.33 mg g-1 ascorbic acid equivalents (AAE), with DPPH IC50 antioxidant activity of 70.3 ± 3.14 μg mL-1 and ABTS scavenging activity of 44.0 ± 2.80 mg g-1 AAE. This correlates well with the total flavonoid, flavonol and phenolic content (50.5 mg g-1 gallic acid equivalents (GAE), 50.6 mg g-1 GAE and 24.3 mg g-1 GAE, respectively). Plant species powders were combined in pairs and evaluated for their synergistic antioxidant properties. With potential synergistic plant mixtures, fortification of these mixtures into functional food can be developed to improve its overall antioxidant capacity. Based on the synergistic IC50 results of these mixtures, three fortified pastas were formulated by incorporating selected plant powder combinations of Amaranthus tricolor + P. minus, Apium graveolens + P. minus, and P. minus + B. androgyna into wheat pasta at 1:100 (w/w). Fortification of pasta with the plant powder blends resulted a significant increase in DPPH antioxidant activity, while successfully maintaining indistinguishable features from the control pasta, including minimal cooking loss, agreeable measure of cohesiveness, springiness and chewiness, with good overall sensory acceptability. © 2022 Society of Chemical Industry.

Molecular docking supported investigation of antioxidant, analgesic and diuretic effects of Costus speciosus rhizome

ABSTRACT. The aim of the current study was to analyze the polyphenols and determines the antioxidant, analgesic and diuretic properties of the methanolic extract of C.speciosus rhizome. DPPH and ferric reducing antioxidant power (FRAP) assays were used to determine the antioxidant activity. Acetic acid-induced writhing and formalin-induced licking experiments were used to assess the analgesic effect. The total phenolic, flavonoid and flavonol contents were found 51.73± 0.25 mg GAE/g dry weight, 3.41± 0.07mg QE/g dry weights and 44.19± 2.24 mg QE/g dry weight, respectively. The plant extract exhibited weak antioxidant activity in the DPPH and FRAP assays, with an IC50 value of 1699±62 μg/mL and an EC50 value of 125±2 μg/mL, respectively. The extract significantly reduced the number of writhes at both doses (200 and 400 mg/kg body weight) as compared to the control. The extract (400 mg/kg) also significantly reduced the percent inhibition of licking by 31.96 and 62.69% compared to the control in the early and late phase, respectively. Compared to the standard drug furosemide, the plant extract also showed a weak diuretic effect. The docking study supported the analgesic activity of rhizome extract. The potent analgesic activity of the plant extract justifies the traditional and medicinal aspects.&#x0D; &#x0D; KEY WORDS: Costus speciosus, Analgesic activity, Diuretic effect, Molecular docking&#x0D; Bull. Chem. Soc. Ethiop. 2022, 36(3), 627-640. &#x0D; DOI: https://dx.doi.org/10.4314/bcse.v36i3.12&#x0D;

Effects of different iron treatments on wine grape berry quality and peel flavonoid contents.

In this study, eight-year-old wine grape plants (Cabernet Sauvignon) were subjected to five different iron treatments: ferrous sulfate, ferric ethylenediaminetetraacetic acid (EDTA-Fe), ferric citrate, ferric gluconate, and ferric sugar alcohol, and conventional fertilization. Foliar spraying with clear water was used as the control treatment. The effects of different iron treatments on berry quality and flavonoid accumulation in grape peels were explored. All five iron treatments affected the sugar, acid, and peel flavonoid contents of grape berries, but the contents varied greatly among the different iron treatments. Foliar spraying with iron increased berry sugar content and reduced acid content. In addition, foliar spraying with ferrous sulfate, EDTA-Fe, ferric gluconate, and ferric sugar alcohol reduced the total anthocyanin, flavanol, and flavonol contents in the peel. The unique flavonoid monomer content of the peel was significantly higher under ferric citrate treatment than under the control and other iron treatments. Moreover, the results showed that foliar spraying with ferric citrate balanced the berry sugar-acid ratio and also increased the anthocyanin, flavanol, and flavonol contents of the grape peel, thereby improving the overall nutritional status of the berries and the final wine quality. The results obtained in this study demonstrate that different iron treatments could improve grape berry quality and clarify the effects of different exogenous iron treatments.

Phytochemical constituent and oxidative potencies of acetone, methanol and aqueous leaf extracts of Acalypha Wilkesiana grown at the Kaura Namoda plant nursery

As a result of increased interest in the production of plant-based drugs for the treatment of many diseases has become a significant reason why people have become more coversant in the use of traditional medicine for the treatment of mild and serious illness. Due to increase in the thrust for the production of plant-based drugs, this present study was carried out to compare the phytochemical constituents and antioxidant potencies of acetone, methanol and aqueous leaf extracts of Acalypha wilkesiana collected from Kaura Namoda Botanical Garden in Zamfara State-Nigeria. The antioxidant activities was evaluated using various assays; The total phenolic content of aqueous, methanol and acetone leaf extract were 15.58 0.66 mg GAE/g, 14.10 2.17 mg GAE/g and 8.70 0.01 mg GAE/g respectively. Total flavonol contents; 207.10 11.53 mg QE/g, 196.08 5.53 mg QE/g and 112.04 8.27 mg QE/g respectively. Total flavonoid contents; 240.99 9.50 mg QE/g, 252.52 3.73 mg QE/g and 123.88 5.58 mg QE/g respectively. FRAP values were 679.14 0.45 mmol/g, 611.90 7.09 mmol/g and 292.07 11.38mmol/g respectively. ABTS activity of aqueous, methanol and acetone leaf extract were 24.30 5.86 mg AAE/g, 14.49 1.02 mg AAE/g and 7.00 0.57 mg AAE/g respectively, methanol leaf extract had the highest percentage DPPH Inhibition value of 42.64 5.13, followed by aqueous (31.77 4.08) at 0.25mg/ml while aqueous had the highest (52.63 0.67), followed by methanol extract (44.80 2.80) at 0.50mg/ml. Aqueous extract had the highest percentage inhibition of Nitric Oxide with a value of 59.74 1.30, followed by methanol extract (46.11 2.54) at 0.25mg/ml. inhibition for aqueous was also highest at 0.5 mg/ml. Aqueous extract had the highest percentage lipid peroxidation inhibition value of 22.66 2.93, followed by methanol leaf extract with the value of 18.89 0.80 while at 0.50mg/ml methanol leaf extract had the highest percentage inhibition of lipid peroxidation (39.42 3.10), followed by aqueous leaf extract with the value of 31.48 1.61. The results showed that aqueous and methanol leaf extract of Acalypha wilkesiana displayed potent antioxidant effects with the aqueous having an edge. This present study therefore supports the view that Acalypha wilkesiana can be used in the management of oxidative stress and other related diseases.

Key genes for phenylpropanoid metabolite biosynthesis during half-highbush blueberry (Vaccinium angustifolium×Vaccinium corymbosum) fruit development

BACKGROUND: Blueberry fruits contain large amounts of phenolic compounds derived from the phenylpropanoid pathway. Their biosynthesis is complex, involving many enzymes. OBJECTIVE: We sought to investigate the content of phenylpropanoid-derived compounds and identify key genes involved in the phenylpropanoid metabolite pathway during half-highbush blueberry fruit development. METHODS: Phenylpropanoid metabolite contents were determined by high-performance liquid chromatography (HPLC) and spectrophotometry. Gene expression was examined through reverse-transcription PCR. RESULTS: Phloretin, chlorogenic acid, total flavonol, quercetin, catechin, and proanthocyanidin contents were highest in small-sized green fruits; myricetin and epicatechin contents were highest in pink fruits; and lignin and anthocyanin were highest in blue fruits. Genes from the 4-coumarate CoA ligase (4CL) family regulate the biosynthesis of phenylpropanoid metabolites. Phenylalanine ammonia-lyase (PAL) and cinnamoyl-CoA reductase (CCR) are key genes in the lignin biosynthetic pathway. Flavonol synthase (FLS) is a key gene affecting total flavonols and the quercetin biosynthetic pathway. PAL and chalcone isomerase (CHI) are key genes in the epicatechin and anthocyanin biosynthetic pathways, respectively. CONCLUSION: Phenylpropanoid metabolites are regulated by multiple genes from the same or different families. Enzymes in different metabolic pathways compete for precursors to form a complex regulatory network for phenylalanine metabolism.

Non-Volatile and Volatile Bioactives of Salvia officinalis L., Thymus serpyllum L. and Laurus nobilis L. Extracts with Potential Use in the Development of Functional Beverages.

Functional beverages based on herbal extracts are highly demanded products due to the presence of bioactives with promising health benefits and interesting and characteristic sensory properties. Mediterranean medicinal and aromatic herbs contain a wide range of bioactives (non-volatile polyphenols, volatile terpenes) that are important constituents of herbal extracts and essential oils. The antioxidant capacity and potential health benefits of these bioactives could be associated with their synergistic effects. Therefore, this study aimed to characterize the non-volatile and volatile bioactives of sage (Salvia officinalis L.), wild thyme (Thymus serpyllum L.) and laurel (Laurus nobilis L.) aqueous extracts and their two- and three-component mixtures as well as their antioxidant capacity. The content of total phenols, flavonoids, hydroxycinnamic acids and flavonols was determined spectrophotometrically. Individual polyphenols were analyzed by LC-MS/MS, the volatiles were analyzed by HS-SPME/GC-MS, and the antioxidant capacity was analyzed by ORAC and DPPH assays. The results showed that aqueous extracts of all examined herbs and their mixtures contained a high content of phenolic compounds ranging from 0.97 to 2.79 g L−1 of the sample, among which the most common were flavonols. At the same time, mono- and sesquiterpenes were the main volatiles. All extracts showed high antioxidant capacity, especially L. nobilis (781.62 ± 5.19 μmol TE mL−1 of the sample in the DPPH assay; 1896.10 ± 8.77 μmol TE mL−1 of the sample in the ORAC assay) and the two-component mixture of L. nobilis and T. serpyllum (679.12 ± 5.19 μmol TE mL−1 in the DPPH assay; 1913.38 ± 8.77 μmol TE mL−1 in the ORAC assay). Mixtures of herbal extracts have been shown to possess additive or synergistic effects, consequently contributing to higher antioxidant capacity. Therefore, two-component mixtures of herbal extracts showed promising potential for the production of functional beverages.

Antioxidant potential of various extracts from 5 common European mosses and its correlation with phenolic compounds

Summary Introduction: This paper presents the results of research about the antioxidant properties of extracts from 5 moss species, namely Brachythecium rutabulum, Callicladium haldanianum, Hypnum cupressiforme, Orthodicranum montanum and Polytrichastrum formosum. The macerates of each above mentioned species in water and ethanol (50% and 96%) solutions were analysed. Objective: Total phenolic acids, total flavonoids and total flavonols concentrations and content of carotenoids was determined. Also some phenolic compounds were determined by HPLC. Methods: The 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activities and the advanced oxidation protein products (AOPP) formation inhibition were studied. Results: The obtained results showed that the extracts prepared with 50% ethanol had the strongest radical scavenging activities. Every 50% ethanol extract also inhibited formation of AOPP. 96% ethanol extracts had the lowest free radical scavenging activities, although B. rutabulum extract strongly inhibited protein oxidation. Pearson’s correlation showed that the radical scavenging effects of water extracts and extracts prepared with 50% ethanol are dependent on the presence of phenolic acids and flavonoids. Conclusion: The results suggest the moss extracts as materials for potential use in pharmacy or cosmetology.

PALYNOLOGICAL ANALYSIS, PHENOLIC COMPONENTS AND ANTI-INFLAMMATORY ACTIVITY OF SOME BEE POLLENS COLLECTED FROM THE NORTHEAST REGION OF ALGERIA

Bee pollen is multiplex blend of floral pollen and nectar agglutinated by bee salivary substances. It is famously known for being high in proteins, carbs, lipids, vitamins, and phenolic compounds, among other physiologically dynamic components. Its composition fluctuates incredibly agreeing to both botanical origins and edaphoclimatic conditions. In this work, the botanical origin, the phenolic components and the anti-inflammatory activity in vivo of eight bee pollens intended for human consumption were taken from distinctive apiaries in Algeria’s northeast, were determined and compared. All samples were detected heterofloral based on the identification of forty pollen types belonging to 22 botanical families. Total phenolic contents varied between 752.94 ± 17.78 and 12247.06 ± 40.04 mg GAE/ 100g, while the total flavonoid contents ranged from 2680.55 ± 12.02 to 8506.94 ± 15.56 mg QE/ 100g, and the total flavonol contents were in the interval between 4978.87 ± 33.39 and 7903.75 ± 24.39 mg QE/ 100g. The obtained results showed that the bulk of the ethanolic extracts had a good anti-inflammatory activity. As a conclusion, all the aforementioned heterofloral bee pollen samples could significantly be a wealthy source of polyphenols with a potential anti-inflammatory activity.

Determination of secondary metabolites including curcumin in Rheum ribes L. and surveying of its antioxidant and anticancer activity

Dry stem and root of Rheum ribes are used for the treatment of different diseases. In this study, the organic components in the root of R. ribes were extracted by three extraction methods (soxhlet, ultrasonic and maceration) and the efficiencies of these methods were calculated. To validate the existence of Curcumin, analysis such as UV–Vis (Ultraviolet–Visible), HPLC (High Performance Liquid Chromatography), GC (Gas Chromatography) and GC/Mass were performed and in order to separate Curcuminoids, TLC (Thin Layer Chromatography) technique was implemented on the extract which had the highest yield. Total phenolic, flavonoid and flavonol contents of three kinds of extract were measured. For studying antioxidant activity, DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging was done. Finally, for investigating anticancer activity, MTT (Methyl Thiazolyl Tetrazolium), NBT (Nitro Blue Tetrazolium) and DNA-Binding tests were done. The most yield was belonged to soxhlet extract. The results showed the presence of Curcumin in soxhlet extract has not been reported previously. Furthermore, the total phenolic, flavonoid and flavonol contents were belonged to ultrasonic extract. As well as the maximum antioxidants properties were belonged to ultrasonic and maceration extraction. The MTT assay showed the lowest IC50 in the ultrasonic extract. At NBT test, the highest NBT reduction percentage was belonged to maceration extraction. DNA-binding test revealed that all the extracts have shown some degree of fragmentation. Due to the presence of Curcumin in R. ribes and the notable features that the results showed, it can be a good source for Curcumin extraction and use in the drug industry.

Antioxidant Activity and Chemical Characteristics of Sambucus nigra L. Blossom from Different Regions in Bulgaria

The aim of the current study was to investigate some bioactive compounds from Sambucus nigra L. blossoms and to evaluate the antioxidant potential of the obtained extracts. In this study, samples from four different regions of Bulgaria /Rhodopes, Plovdiv, Strandzha and Dobrich region/ from Sambucus nigra L. were collected and analyzed for total phenols, flavonoids, sugars and amino acids. The antioxidant activity of the extracts was evaluated by four assays based on different mechanisms. The sweetness index and total sweetness index of the extracts were also evaluated. The carbohydrate composition of the leaves and the blossoms was determined, with glucose and fructose predominating in both cases, as their contents were not above 3%. Nineteen amino acids have been identified in the composition of Sambucus nigra L., and glutamic, leucine and asparagine acids are predominant. The highest antioxidant activity and total content of phenols (49.2 ± 1 mg GAE/g) and flavonols (18.6 ± 0.5 mgQE/g) were found in the sample from the Rhodope region. Therefore, the higher altitude and lower temperature in mountains could influence the accumulation of secondary metabolites in blossoms of Sambucus nigra L., which improves the antioxidant potential of the samples.

Badania jakościowe i ilościowe wyciągów z Inonotus obliquus

Introduction. Inonotus obliquus (Ach. Ex Pers.) Pilát is a fungus found in North America, Finland, Poland, Russia, China, Japan and Korea on the bark of trees, most often Betula pendula, B. pubescens, B. carpatica and Fagus sylvatica. Mushroom extracts show a number of biological activities, due to the presence of: polysaccharides, phenolic compounds (phenolic acids and flavonoids), triterpenes, ergosterol and its peroxide. Aim. Determination of the content of the sum of polyphenolic compounds, including the sum of phenolic acids, flavonoids and flavonols in water, methanol and methanol-water extracts, determination of antioxidant activity and qualitative determination of the composition of the chloroform extract from the fruiting body of Inonotus obliquus, collected from a natural site. Material and methods. The raw material for research was collected in the Noteć Forest in the Sieraków Landscape Park. The fruiting body was dried and then ground into a fine powder. Using spectroscopic methods, the sum of polyphenols with the Folin-Ciocalteu reagent, the sum of phenolic acids using the Arnov method, the sum of flavonols with aluminum chloride, the sum of flavonoids according to the method described in FP X, antioxidant activity with the DPPH radical and the composition of the chloroform extract using GC-MS were determined. Results. The methanol extract was characterized by the highest content of the sum of phenolic acids per coffee acid (0.127%), and the lowest content of water-methanol extract (0.047%). The highest content of the sum of polyphenols in terms of caffeic acid was determined in the aqueous extract (1.85%), and the lowest in the methanol extract (1.01%). The methanol extract was characterized by the highest content of the sum of phenolic acids expressed as coffee acid (0.127%), and the lowest content of water-methanol extract (0.047%). The content of total flavonoids and total flavonols was determined only in methanol extracts, because the precipitation made it impossible to perform the determinations in the remaining extracts. The lowest IC50 value was determined for the water-methanol extract. GC-MS analysis allowed to identify, among others: isovanillin, santalene, α-selinene, syringaldehyde, linoleic acid, thymol, α-bergamotene and lanosterol. Conclusions. The highest content of the sum of polyphenols was determined in the water extract of Inonotus obliquus, the sum of phenolic acids in the methanol extract; the water-methanol extract was characterized by the strongest antioxidant properties. GC-MS analysis revealed the presence of numerous compounds with confirmed biological activity.

Preharvest Application of Phenylalanine Induces Red Color in Mango and Apple Fruit's Skin.

Anthocyanins are secondary metabolites responsible for the red coloration of mango and apple. The red color of the peel is essential for the fruit’s marketability. Anthocyanins and flavonols are synthesized via the flavonoid pathway initiated from phenylalanine (Phe). Anthocyanins and flavonols have antioxidant, antifungal, and health-promoting properties. To determine if the external treatment of apple and mango trees with Phe can induce the red color of the fruit peel, the orchards were sprayed 1 to 4 weeks before the harvest of mango (cv. Kent, Shelly, and Tommy Atkins) and apple fruit (cv. Cripps pink, Gala and Starking Delicious). Preharvest Phe treatment increased the red coloring intensity and red surface area of both mango and apple fruit that was exposed to sunlight at the orchard. The best application of Phe was 2–4 weeks preharvest at a concentration of 0.12%, while a higher concentration did not have an additive effect. A combination of Phe and the positive control of prohydrojasmon (PDJ) or several applications of Phe did not have a significant added value on the increase in red color. Phe treatment increased total flavonoid, anthocyanin contents, and antioxidant activity in treated fruit compared to control fruits. High Performance Liquid Chromatography analysis of the peel of Phe treated ‘Cripps pink’ apples showed an increase in total flavonols and anthocyanins with no effect on the compound composition. HPLC analysis of ‘Kent’ mango fruit peel showed that Phe treatment had almost no effect on total flavonols content while significantly increasing the level of anthocyanins was observed. Thus preharvest application of Phe combined with sunlight exposure offers an eco–friendly, alternative treatment to improve one of the most essential quality traits—fruit color.

Quercetin-derivatives painting the yellow petals of American lotus (Nelumbo lutea) and enzymatic basis for their accumulation

American lotus (Nelumbo lutea) is one of the two species in Nelumbo and has only yellow flower. Identification of total flavonoids showed wild American lotus contained almost only flavonols with quercetin 3-O-glucuronide to be the dominant pigment. The variation tendency of the total flavonol content was coincident with yellow color variation of petals during flower development. To understand the mechanism of accumulation and constituent of pigments in petals, three pivotal genes, NlFLS1, NlFLS2 and NlFLS3, which were predicted to encode flavonol synthases were isolated and characterized by analyses of basic bioinformatics, temporal and spatial expression patterns and enzymatic activity. Their temporal expression levels showed the same variation tendency, which was also consistent with the development-dependent variation of total flavonol content. Spatial expression patterns indicated the three genes should function in petals. All the three proteins were demonstrated to be bifunctional dioxygenase, possessing both flavonol synthase activity and flavanone 3-hydroxylase activity. Besides, other flavonol biosynthesis related genes were also investigated on their expression levels to give more clues on the mechanism. Substrate preferences of the three FLSs, substrate competitions between the FLSs and other flavonol biosynthesis related enzymes, and the greatly differential expression levels between F3’H (flavonoid 3′-hydroxylase) and F3’5’H (flavonoid 3′,5′-hydroxylase) contributed to the flavonol constituent in the petals of America lotus, namely abundant quercetin-derivatives while very few kaempferol-derivatives and myricetin-derivatives.

Changes in Phenolic Profile and Antioxidant Activity of Horseradish Roots During Freezing and Frozen Storage

Abstract Freezing is one of the ways to preserve plant products, because it allows inhibiting natural degradation and transformation processes of the bioactive compounds. The aim of this study was to evaluate the effect of freezing on bioactive compounds of horseradish roots and their dynamics in long-term frozen storage. Horseradish roots were frozen at two different conditions (–18±2°C and –40 ± 2 °C) and further stored at –18 ± 2 °C for 12 months. Total phenolic content (TPC), total flavonoid content (TFC), total flavonol content (TFlC), total flavan-3-ol content (TF3C), total phenolic acid content (TPAC), and radical scavenging activity (RedPow, DPPHÿ, ABTSÿ+) were determined spectrophotometrically. Individual phenolic compounds were deremined by liquid chromatography. The dominant individual phenolic compounds were phenolic acids (gallic and sinapic) and flavonoids (kaempferol, luteolin, and rutin). Because of freezing, TPC, TFC, and DPPHÿ as well as RedPow increased in horseradish roots. During storage, the content of analysed bioactive compounds mainly decreased. After 12-month storage, it was not possible to say unambiguously which of the freezing methods turned out to be better in general.

Phenolic Content and Antioxidant Activity in Apples of the 'Galaval' Cultivar Grown on 17 Different Rootstocks.

Apple cultivars are one of the main factors setting the composition of bioactive compounds in apples and the quality of the fruit. However, research has been providing increasing amounts of data on the influence of rootstocks on the variations in the composition of bioactive compounds in apples. The aim of the study was to determine the influence of rootstocks on the changes in the qualitative and quantitative composition of phenolic compounds and their antioxidant activity in vitro in apple flesh and peel. HPLC analyses of phenolic compounds in apple samples were performed. The rootstock–scion combination had a significant effect on the composition and antioxidant activity of phenolic compounds in apple samples. Depending on the rootstock, the total content of phenolic compounds in apple flesh of the ‘Galaval’ cultivar could vary by 2.9 times, and in the peel by up to 90%. The genotype of the rootstock resulted in the highest variation in total flavan-3-ol content in apple flesh—by as much as 4.3 times—while the total content of flavonols varied by 2.1 times. In apple peel, on the contrary, the greatest variation was recorded for the total flavonol content (by 4.4 times), and the total flavan-3-ol content varied the least (by 1.8 times). A proper match of a cultivar and a rootstock can program a fruit tree to grow larger amounts of higher-quality, antioxidant-rich, and high-nutrition-value fruit.

Phytochemical content and antioxidant activity of extruded products made from yellow corn supplemented with apple pomace powder

The aimed of this study was quantified total phenols content, total flavonoids, and antioxidant activity in extruded ready-to-eat products made from yellow corn added with apple pomace powder. A central composite rotatable experimental design was used. The variables tested were exit die temperature (140-180 °C), feed moisture (14-20 g/100 g) and apple pomace concentration (0-30 g/100 g). The effect of the process variables on the total contents of phenols, flavonols, flavanols and flavonoids and antioxidant activity was evaluated using the response surface methodology. The data of each response were fitted to a second-order model with determination coefficients ≥ 0.71. The extruded product with no added apple bagasse showed the lowest values of the evaluated phytochemicals but had higher antioxidant activity by DPPH. The addition of apple pomace increased the phytochemical content and antioxidant activity in extruded ready-to-eat products made with yellow corn. This makes it possible to obtain a formulation of an extruded food rich in phenolic compounds with potential to contribute to prevention of oxidative stress, while making use of agro-industrial waste from apple juice extraction.

Phenolic Profile and Antioxidant Capacity of Selected Medicinal and Aromatic Plants: Diversity upon Plant Species and Extraction Technique

Phenolic content and antioxidant capacity (AC) was evaluated in extracts of bay, sage and thyme leaves, myrtle leaves and berries, and sea buckthorn berries obtained by conventional (CE) and advanced extraction techniques [ultrasound-assisted (UAE) and accelerated solvent extraction (ASE)] using 80% acetone (v/v) as extraction solvent. Extracts were analyzed for phenolic content using UPLC/ESI MS2 and AC by ORAC method. Results indicated the variations in the phenolic composition and concentrations among analyzed plant species and applied extraction methods. Flavonoids showed to be the predominant phenolic group represented by flavonols kaemferol-3-O-hexoside (182.58–321.45 mg 100−1 g dm) and quercetin-3-glucoside (253.05–315.67 mg/100 g dm) in bay leaves, by flavonol isorhamnetine-3-O-hexoside (27.76–45.16 mg/100 g dm) in sea buckthorn berries and by flavone luteolin-7-O-glucoside (470.27–781.78 mg/100 g dm) in sage leaves. Among the phenolic acids, hydroxybenzoic acids and their derivates were the predominant phenolic group in thyme leaves and myrtle. Statistical analysis showed that ASE contributed to the highest content of total flavonols, flavones, hydroxycinnamic and hydroxybenzoic acids as well as AC. CE was more efficient method for the extraction of total flavan-3-ols, while UAE showed the highest efficiency in extraction of total anthocyanins. Analyzed plant extracts proved to be a rich source of various phenolics and results indicated suitable extraction methods for target phenolic compounds characteristic for certain plant species.