Content Of Individual Phenolic Compounds Research Articles

Improving Soluble Phenolic Profile and Antioxidant Activity of Grape Pomace Seeds through Fungal Solid-State Fermentation.

Grape pomace seeds contain abundant phenolic compounds, which are also present in both soluble and insoluble forms, similar to many other plant matrices. To further increase the extractable soluble phenolics and their antioxidant activities, grape pomace seeds were fermented with different fungi. Results showed that solid-state fermentation (SSF) with Aspergillus niger, Monascus anka, and Eurotium cristatum at 28 °C and 65% humidity had a significantly positive impact on the release of soluble phenolics in grape pomace seeds. Specifically, SSF with M. anka increased the soluble phenolic contents by 6.42 times (calculated as total phenolic content) and 6.68 times (calculated as total flavonoid content), leading to an overall improvement of antioxidant activities, including DPPH (increased by 2.14 times) and ABTS (increased by 3.64 times) radical scavenging activity. Furthermore, substantial changes were observed in the composition and content of individual phenolic compounds in the soluble fraction, with significantly heightened levels of specific phenolics such as chlorogenic acid, syringic acid, ferulic acid, epicatechin gallate, and resveratrol. Notably, during M. anka SSF, positive correlations were identified between the soluble phenolic content and hydrolase activities. In particular, there is a strong positive correlation between glycosidase and soluble phenols (r = 0.900). The findings present an effective strategy for improving the soluble phenolic profiles and bioactivities of grape pomace seeds through fungal SSF, thereby facilitating the valorization of winemaking by-products.

HPLC-Mass spectrometry analysis of phenolics comparing traditional bilberry and blueberry liqueurs

The purpose of this study was to investigate the differences between the phenolics compositions of bilberry and blueberry liqueurs, to determine whether these are comparable. Both bilberry and blueberry liqueurs have the same name on the market, however they differ in phenolic composition and content. A total of 43 compounds were identified, 36 in the bilberry liqueur, and 21 in the blueberry liqueur. High performance liquid chromatography coupled with mass spectrometry (HPLC-MS) was used to identify and quantify these compounds, where they were fragmented to the MS4 fragments. Anthocyanins were the major phenolics group detected in the bilberry liqueurs, but only the second most abundant phenolics group in the blueberry liqueurs. The most abundant phenolics group in the blueberry liqueurs was hydroxycinnamic acids. The lowest content of individual phenolic compounds was for blueberry liqueur made from whole fruit. This study will provide valuable data to consumers in their choice of a more expensive bilberry liqueur or a cheaper blueberry liqueur.

Influence of the content of biologically active phenolic compounds in the fruits of Malus Mill. on their quality indicators

The article presents the results of an analytical review of Russian and foreign literature sources devoted to the study of the influence of the composition and functions of phenolic compounds in apple fruits on their quality indicators (appearance, pulp density, nutritional value). Studies of the biochemical composition of apple fruits are currently relevant and are being carried out with the aim of in-depth study of the assortment of fruit crops and assessment of its potential use in breeding to increase the content of biologically active compounds. The prospects of the search for plants that accumulate phenolic compounds in tissues, which have a protective antioxidant function and nutritional value, have been confirmed. The issue of the role of accumulation, the dynamics of the content of individual phenolic compounds and the total content of phenolic compounds in various metabolic processes that determine the properties of apple fruits is considered. Analysis of the results of thematic scientific works on changes in the composition and content of phenolic compounds will allow targeted research leading to the use of fruits as a potential source of phenolic compounds, as well as identifying sources of accumulation of biologically active substances for practical use in breeding. The creation of new varieties of apple trees is necessary to obtain useful secondary phenolic metabolites contained in fruits, while the range of use of fruits includes the production of processed products. The expediency of carrying out breeding work aimed at increasing the content of phenolic compounds in fruits is confirmed by a number of recent publications by Russian and foreign scientists.

Natural Deep Eutectic Solvent-Based Matrix Solid Phase Dispersion (MSPD) Extraction for Determination of Bioactive Compounds from Sandy Everlasting (Helichrysum arenarium L.): A Case of Stability Study.

In the present study, vortex-assisted matrix solid-phase dispersion (VA-MSPD) extraction was used to isolate the major bioactive compounds from H. arenarium. To reduce the negative environmental impact of the conventionally used organic solvents, four different choline chloride-based natural deep eutectic solvents (NADES) were investigated as possible eluents. The most influential VA-MSPD extraction parameters: stationary phase (adsorbent), adsorbent/sample ratio, vortex time, and volume of extraction solvent were systematically optimized. Ultrasound-assisted extraction with 80% MeOH was used as the standard method for the comparison of results. The stability of the obtained extracts was studied over a period of 0 to 60 days at three different temperatures (-18 °C, 4 °C, and 25 °C). All extracts were evaluated both spectrophotometrically (determination of total phenolic content (TPC) and antioxidant activity by ABTS and FRAP assay) and chromatographically (HPLC-UV). NADES based on choline chloride and lactic acid (ChCl-LA) was selected as the most effective extractant, with a determined TPC value of its extract of 38.34 ± 0.09 mg GA/g DW (27% higher than the methanolic VA-MSPD extract) and high antioxidant activity. The content of individual phenolic compounds (chlorogenic acid, dicaffeoylquinic acid isomers, naringenin isomers, and chalcones) in the ChCl-LA extract, determined by HPLC-UV, was comparable to that of the conventionally obtained one. Moreover, the stabilization effect of ChCl-LA was confirmed for the studied compounds: chlorogenic acid, naringenin-4'-O-glucoside, tomoroside A, naringenin-5-O-glucoside, isosalipurposide, and naringenin. The optimum VA-MSPD conditions for the extraction of H. arenarium polyphenols were: florisil/sample ratio of 0.5/1, a vortex time of 2 min, and an elution volume of ChCl-LA of 10 mL.

Chemical composition and bioactivity of oilseed cake extracts obtained by subcritical and modified subcritical water

Recovery of bioactive compounds from biowaste is gaining more and more interest in circular economy models. The oilseed cakes are usually insufficiently exploited by most technologies since they represent valuable matrices abundant in proteins, minerals, and phytochemicals, but their use is mostly limited to feed ingredients, fertilizers or biofuel production. This study was thus focused on the exploration of new valorization pathways of oilseed cakes by subcritical water, representing a safe and economic alternative in the creation of value chains. Pumpkin, hemp, and flax seed cakes were treated with subcritical water in nitrogen and carbon-dioxide atmospheres, as well as in nitrogen atmosphere with the addition of acid catalyst. The degradation of carbohydrate fraction was studied by quantifying sugars and sugar degradation products in the obtained extracts. The extracts obtained under different conditions were further compared chemically with respect to total phenols and flavonoids, as well as to the content of individual phenolic compounds. Furthermore, the effects of subcritical water treatment conditions on antioxidant, antiradical and cytotoxic properties of thus obtained extracts were defined and discussed.Graphical

Impact of Different Drying Temperatures onIn VitroAntioxidant and Antidiabetic Activities and Phenolic Compounds of Wild Guava Leaves Collected in the Central Highland of Vietnam

Most biologically natural compounds are very sensitive and easily degradable under drying conditions. This study aimed to investigate the effect of drying temperature on the contents of phenolic compounds and in vitro antioxidant and antidiabetic activities of wild guava leaves. Wild guava leaves were dried at 40 °C, 50 °C, 60 °C, 70 °C, and 80 °C, as well as sun drying (SD). The total phenolic and flavonoid contents (TPC and TFC) were measured using the colorimetric method. Antioxidant activity was determined by the 2,2-diphenyl-2-picrylhydrazyl hydrate (DPPH) and 2,2-azino-bis(3-ethylbenzothazoline-6-sulfonic acid (ABTS) radical scavenging activity assays. In vitro antidiabetic activity was measured by assessing α-glucosidase and α-amylase inhibitory activities. The contents of individual phenolic compounds were determined using ultra-performance liquid chromatography (UPLC). The principal component analysis (PCA) results revealed that hot air drying at different temperatures had significantly different effects on the bioactive compounds and biological properties of guava leaves. Drying at high or low temperatures resulted in a higher degradable rate of bioactive compounds leading to a weakening of the biological properties. Drying at 50 °C resulted in high TPC and TFC as well as the highest in vitro antioxidant and antidiabetic activities. Furthermore, the highest contents of gallic acid, catechin, rutin, quercetin, apigenin, quercitrin, vitexin, and apigenin-7- O-D-glucopyranoside were found in samples dried at 50 °C, whereas the highest contents of chlorogenic acid, epicatechin, and ellagic acid were observed in samples dried at 60 °C. Therefore, drying at 50 °C was the suitable temperature for retaining valuable biological compounds in wild guava leaves.

Application of different cooking methods to improve nutritional quality of broccoli (Brassica oleracea var. italica) regarding its compounds content with antioxidant activity

The analysis of the effect of different cooking methods (boiling, steaming, and microwaving) and cooking times (0, 1, 3, 5 and 10 min), in phenolic compounds and ascorbic acid concentration and their antioxidant activity in broccoli samples were investigated in this study. The results show that total polyphenol content increased to 12% on microwaving at 5 min and decreased to 60% in boiling at 10 min. Regarding the content of individual phenolic compounds, boiling showed a significant decrease in all the analyzed compounds, while steaming at 10 min showed a significant increase in four compounds. With respect to total ascorbic acid, the highest loss was observed for boiling broccoli at 1, 3, 5, and 10 min (10, 18, 42 and 55%, respectively). DPPH, ABTS and FRAP evaluation in steaming at 10 min, showed an increase in antioxidant activity of 15, 6 and 7%, respectively. Positive correlations were found between phenolic compounds and total ascorbic acid content, and antioxidant activity in broccoli samples. This study presents interesting results about common cooking methods and their effect on improving the nutritional quality of broccoli.

Alleviation of postharvest rib-edge darkening and chilling injury of carambola fruit by brassinolide under low temperature storage

Carambola fruit produced in the tropical and subtropical region could easily suffer the postharvest loss in low temperature storage and cold chain logistics owing to the hazard of chilling injury (CI). Here, the effects of brassinolide (BR) on phenolic metabolism, rib-edge darkening and CI of carambola fruit were studied. The present results showed that BR treatment effectively delayed the CI and weight loss, maintained peel color and flesh firmness, and inhibited the increases of electrolyte leakage, malondialdehyde and reactive oxygen species production, induced total phenols and proline accumulation. Moreover, BR treatment raised the activities of antioxidant enzymes and higher content of individual phenolic compounds, inhibited membrane lipid peroxidation and safeguard cellular membrane integrity. This study for the first time demonstrated that BR could alleviate CI in carambola fruit during low temperature storage and cold chain circulation.

Phenolic compound profiles in Finnish apple (Malus × domestica Borkh.) juices and ciders fermented with Saccharomyces cerevisiae and Schizosaccharomyces pombe strains

The phenolic compounds in juices and ciders made with Saccharomyces cerevisiae or Schizosaccharomyces pombe from eleven Finnish apple cultivars were analyzed using liquid chromatographic and mass spectrometric methods combined with multivariate data analysis. In general, the ciders contained less phenolic compounds than corresponding apple juices. In the studied apple juices and ciders, hydroxycinnamic acids were the most predominant, accounting for around 80% of total phenolic compounds. Apple juices contained more flavonol glycosides and dihydrochalcones whereas cider processing resulted in increased amount of free hydroxycinnamic acids. The contents of individual phenolic compounds were more dependent on the apple cultivars than the yeast species. Certain cultivars contained remarkably higher contents of dihydrochalcones and hydroxycinnamic acids when comparing with other cultivars. Ciders made using S. pombe remained higher contents of procyanidins and (+)-catechin while S. cerevisiae ciders contained higher individual hydroxycinnamic acids, such as 5-O-caffeoylquinic acid, 4-O-caffeoylquinic acid, 3-O-p-coumaroylquinic acid, and 4-O-p-coumaroylquinic acid.

Comparative analysis of the composition and content of phenolic compounds in fruits of wild species of Malus native to eastern Siberia and the Far East

Comparative analysis of the composition and content of phenolic compounds (PC) in the fruits of three wild species of Malus: Malus mandshurica, Malus chamardabanica, Malus sachalinensis, native to Eastern Siberia and the Far East, was carried out. It was established that the tissues of the fruits of the three species, on the whole, had a qualitative composition of PC characteristic of the genus Malus. Quantitative differences in the content of individual PC were found between the species. The fruits of M. chamardabanica showed a high content of anthocyanins and low flavans. A characteristic feature of the fruit of M. sachalinensis was a high content of dihydrochalcones — more than 50% of the total PC content of. A high (about 80%) content of flavans was found in the fruits of M. mandshurica. At the same time, about 20% of their total amount was was accounted for procyanidin B2, which was not found in the other two species studied. Principal component analysis (PCA) revealed that two principal components (PC1, PC2,) together accounted for more than 99% variation of the total observed variations. PC1 strongly integrated with phloridzin. The data obtained may be of interest for pharmacology, selection of agriculturally valuable traits for breeding new apple varieties, as well as for the study of chemosystematics of the genus Malus.

Relationship between Phenolic Compounds, Antioxidant Properties, and the Allergenic Protein Mal d 1 in Different Selenium-Biofortified Apple Cultivars (Malus domestica).

Notable parts of the population in Europe suffer from allergies towards apples. To address this health problem, the analysis of the interactions of relevant allergens with other substances such as phenolic compounds is of particular importance. The aim of this study was to evaluate the correlations between the total phenolic content (TPC), polyphenol oxidase (PPO) activity, antioxidant activity (AOA), and the phenolic compound profile and the content of the allergenic protein Mal d 1 in six apple cultivars. It was found that the PPO activity and the content of individual phenolic compounds had an influence on the Mal d 1 content. With regard to the important constituents, flavan-3-ols and phenolic acids, it was found that apples with a higher content of chlorogenic acid and a low content of procyanidin trimers and/or epicatechin had a lower allergenic potential. This is probably based on the reaction of phenolic compounds (when oxidized by the endogenous PPO) with proteins, thus being able to change the conformation of the (allergenic) proteins, which further corresponds to a loss of antibody recognition. When apples were additionally biofortified with selenium, the composition of the apples, with regard to TPC, phenolic profile, AOA, and PPO, was significantly affected. Consequently, this innovative agronomic practice seems to be promising for reducing the allergenic potential of apples.

Volatile and phenolic composition of monovarietal red wines of Valpolicella appellations

The volatile and phenolic compositions of nine monovarietal wines from the following grape varieties allowed in the Valpolicella appellation were investigated: Corvina, Corvinone, Rondinella, Molinara, Oseleta, Raboso, Croatina, Sangiovese and Cabernet-Sauvignon. Different clones were also investigated for Corvina and Corvinone, the two main varieties of the appellation. All grapes were harvested from a single experimental block and vinified following a standard protocol. Wines from different clones of Corvina were characterised by higher monoterpenols content, including linalool, α-terpineol and geraniol, as well as by a peculiar pattern of C6-alcohols. Relatively high levels of monoterpene alcohols were also found in Corvinone wines, while Oseleta showed the highest concentration of terpinen-4-ol and cis- and trans- isomers of linalool oxide. The evaluation of the wine aroma profile by means of different aromatic series indicated higher values for the “floral”, “fruity” and “ripe fruit” series for Corvina and Corvinone wines. Major differences in phenolic composition were found between the different varieties of wine. The total phenolics and total tannins values for Corvina, Corvinone, Rondinella and Molinara wines indicated relatively low phenolic content in comparison with Croatina, Oseleta, Cabernet-Sauvignon. There were also major differences in the content of individual phenolic compounds, in particular anthocyanins, between the monovarietal wines.

Bioactive compounds, antioxidant activity and sensory properties of Tarhana, a traditional fermented food, enriched with pickling herb (Echinophora tenuifolia L.)

SummaryThe addition of pickling herb (Echinophora tenuifolia L.; PHET) resulted in increase in the total phenolic and flavonoid contents in Tarhana in both free and bound fractions' extracts. The antioxidant activity of Tarhana containing 2%, 6% and 18% PHET was 81.45–81.72% in bound fraction whereas in free fraction it was up to 88.27% (6% PHET). The gallic acid contents of Tarhana with PHET in free fraction were between 0.49 mg L−1 (10%) and 2.75% (14%) and that in bound fraction varied between 0.36 mg L−1 (10%) and 3.61 mg L−1 (18%). Statistically significant differences (with control) were observed among the contents of individual phenolic compounds in free and bound fractions of Tarhana depending on PHET concentrations. The addition of higher PHET contents in Tarhana showed negative effects hence, a low concentration (2%) of PHET is recommendable for Tarhana with enhanced nutritional properties.

Effect of N Fertilization on the Content of Phenolic Compounds in Jerusalem Artichoke (Helianthus tuberosus L.) Tubers and Their Antioxidant Capacity

Three cultivars of Jerusalem artichoke Albik, Rubik and Gute Gelbe were grown under different nitrogen fertilization regimens: 0, 80 and 120 kg N·ha−1. Phenolic compounds were extracted from tubers using 80% (v/v) methanol. The total phenolics were determined with the Folin–Ciocâlteu reagent and antioxidant activity was assessed using the ABTS (2,2’-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)), FRAP (ferric-reducing antioxidant power), and DPPH (2,2-diphenyl-1-picrylhydrazyl) assays. The content of individual phenolic compounds was determined by HPLC. The effect of nitrogen fertilization on the total phenolics content was observed for the Albik cultivar. In the Rubik variety the lowest content was recorded at fertilization zero, and in the Gute Gelbe variety at this fertilization level the content of phenols was the highest. At fertilization 120 kg N·ha−1, the highest ABTS test results were noted for all cultivars. For the Albik variety no effect of fertilization on the FRAP test results was noted; for the Rubik variety at zero nitrogen fertilization, the value for FRAP was the lowest, and it was the highest Gute Gelbe. The results of the DPPH test in the Gute Gelbe variety did not depend on the fertilization used. In the other two varieties, the lowest DPPH results were obtained at zero nitrogen regimen. Three main phenolic compounds were determined using HPLC. One of them was chlorogenic acid and the other two were derivatives of caffeic acid. The content of chlorogenic acid in tubers of the Gute Gelbe variety depended on nitrogen fertilization; the highest content of this compound was found in the case of fertilization zero. Statistical analysis showed a correlation between the content of phenolic compounds in tubers and their antioxidant potential. The results of this study suggest great potential for using Jerusalem artichoke tubers as a rich source of phenolic compounds with high antioxidant capacity.

Effect of nano-SiO2 packing on postharvest quality and antioxidant capacity of loquat fruit under ambient temperature storage

Effect of nano-SiO2 packing on postharvest quality and antioxidant capacity of two different loquat cultivars (white-flesh ‘Qingzhong’ and red-flesh ‘Dawuxing’) were determined. Results showed that nano-SiO2 packing significantly inhibited internal browning, retarded the decline of total soluble solids, titratable acidity, ascorbic acid content and extractable juice in both cultivars. Decay index of nano-SiO2 packing in ‘Dawuxing’ and ‘Qingzhong’ was 53.25% and 42.84% lower than control after the day 12, respectively. Meanwhile, nano-SiO2 packing enhanced the contents of individual phenolic compounds and soluble sugar compounds, induced higher superoxide dismutase and catalase activities, which contributed to improving 1,1-diphenyl-2-picrylhydrazyl and hydroxyl radical scavenging capacity. Furthermore, the contents of total soluble solids, ascorbic acid and soluble sugar were higher in ‘Qingzhong’ than those in ‘Dawuxing’, which dedicated to better quality. These results indicated that nano-SiO2 packing was a promising approach in inhibiting decay, maintaining quality and expanding shelf life of loquats.

Inoculation of Lupinus albus with the nodule-endophyte Paenibacillus glycanilyticus LJ121 improves grain nutritional quality

Metabolic changes occurring in white lupine grain were investigated in response to Plant Growth Promoting Rhizobacteria (PGPR) root inoculation under field condition. We precisely targeted lipids and phenolics changes occurring in white lupine grain in response to Pseudomonas brenneri LJ215 and/or Paenibacillus glycanilyticus LJ121 inoculation. Lipids and phenolic composition were analyzed using an Ultra High-Performance Liquid Chromatography/Tandem Mass Spectrometry Methods. As compared to grain of un-inoculated control plant, Paenibacillus glycaniliticus inoculation highly increased the total lipids content (from 232.55 in seeds of un-inoculated control plant to 944.95mg/kg) and the relative percentage of several fatty acid such as oleic acid (+20.95%) and linoleic acid (+14.28%) and decreased the relative percentage of glycerophospholipids (- 13.11%), sterol (- 0.2% and - 0.34% for stigmasterol and campesterol, respectively) and prenol (- 17.45%) class. Paenibacillus glycaniliticus inoculation did not affect total phenolic content, while it modulated content of individual phenolic compounds and induced the accumulation of "new" phenolics compounds such as kaempferol. Paenibacillus glycanilyticus LJ121 can be a useful bio-fertilizer to enhance nutritional quality of white lupine grain.

Biochemical markers of vital biodestruction in common oak (Quercus robur)

The wood of the common oak (Quercus robur L.) has high mechanical strength, elasticity and resistance to fracture. However, constitutional stability is not always able to provide the plants with reliable protection from wood-decay fungi, and the initial stages of biodegradation are difficult to determine. Therefore, this study concerns research on appropriate biochemical markers for early diagnostics of wood defects. The total content of phenolic compounds in leaves and wood was determined by a spectrophotometer Optizen Pop using Folin & Ciocalteu’s phenol reagent; the flavonoid content in leaves – by adding solutions of aluminum chloride and sodium acetate to methanolic extracts; catechins content – by the reaction with vanillin reagent; the concentration of phenolic antioxidants – by Brand Williams; chlorophyll and carotenoids’ contents in leaves – by the formula for methanol extracts; the qualitative composition of phenolic compounds – by high performance liquid chromatography and highly effective thin-layer chromatography. During the planned felling of oak trees on the territory of the Boyar Forest Research Station, trees were found with signs of brown streak and biodestruction of wood. Brown streak in wood is caused by a polycondensation of phenolic compounds, which are deposited on the internal surfaces of tracheal elements. In cases of an increase in the total amount of oxidized polyphenols, the cell walls are also stained. Active oxidation processes in wood have a systemic nature for the plants and affect the physiological state of the assimilation apparatus. We determined that in leaves of the trees with signs of brown streak the total phenol content increases in comparison with the control by 1.6 times, as well as flavonoid and catechin content. Our research has shown that the complex of plastid pigments in common oak leaves does not significantly change in the early stages of destructive processes. Increase of brown streak and appearance of rot in wood are associated with slight increase in chlorophyll a to b ratio in leaves. Chromatographic profiling of the leaves showed that the presence of brown streak changes the content of individual phenolic compounds. The trees with brown rot have more substances with UV spectrum characteristic for kaempferol glycosides compared to the control. The results have shown that the biochemical profiles of the trees with signs of brown streak and brown rot differ from the control by the composition of low and medium polar compounds. The absence or presence of some individual phenolic components and their ratio in the leaves are considered as biochemical markers of hidden wood defects.

Extraction of polyphenols and antioxidants from pomegranate peel using ultrasound: influence of temperature, frequency and operation mode

SummaryThe objective of this research was to investigate the effects of temperature (40–70 °C), frequency (37 and 80 kHz) and ultrasonic operation mode (normal, pulse and sweep), and their interactions on the recovery of phenolic compounds and antioxidants present in pomegranate peel using ultrasound‐assisted extraction. The content of individual phenolic compounds, total phenolic compounds (TPC), antioxidant capacity (AC) and total extract yield (X0) were analysed. Significant effects were observed between some sources of variation in recovery of individual compounds at TPC and X0, and no significant effect was observed for AC. The process and conditions studied shown to be interesting to extract antioxidants, since a high antioxidant capacity was verified in the extracts. Temperatures around 50–60 °C, using 37 kHz frequency, and normal or pulse modes were the conditions that provided better yields of phenolic compounds and X0. Regarding AC, the best condition observed was at 70 °C, 80 kHz frequency and continuous mode.

Impact of elevated carbon dioxide and temperature on strawberry polyphenols.

The strawberry cultivars 'Albion' and 'San Andreas' ('SA') were grown under various combinations of day temperature (25 and 30 °C) and carbon dioxide [CO2 ] (400, 650 and 950 μmol mol-1 ) conditions. The influence of different growth combinations on the polyphenol, flavonoid, anthocyanin, antioxidant, and individual phenolic compound content of fresh strawberry fruits was studied. The content of individual phenolic compounds of fresh strawberry fruits was quantified using high-performance liquid chromatography-ultraviolet (HPLC-UV). Elevated [CO2 ] and higher temperature caused significant increases in total polyphenol, flavonoid, anthocyanin and antioxidants in both strawberry cultivars when compared with plants grown under ambient conditions. Results of HPLC-UV analysis also revealed that individual phenolic compounds of fruits were also increased with increasing [CO2 ] and temperature. However, the responses were significantly altered by the interaction of elevated [CO2 ] and higher temperature. The individual and interaction effects of [CO2 ] and temperature were also significantly cultivar dependent. The largest amounts of flavonoid (482 ± 68 mg kg-1 FW) and antioxidant (19.0 ± 2.1 μmol g-1 FW) were detected in 'Albion' grown at 30 °C and under 950 μmol mol-1 , and total polyphenol (3350 ± 104 mg GAE kg-1 FW) and anthocyanin (332 ± 16 mg kg-1 FW) in 'San Andreas' grown at 25 °C and 950 μmol mol-1 . Strawberry fruit was rich with polyphenols and antioxidants when grown under elevated [CO2 ] and higher temperature. There were also interactions between [CO2 ] and temperature affecting the fruits' content. An increase in the polyphenol and antioxidant content in strawberry fruits would be highly beneficial to human health. © 2019 Society of Chemical Industry.

Effect of extraction solvent on the phenolic compounds content and antioxidant activity of Ramon nut (Brosimum alicastrum)

Ramon nut (Brosimum alicastrum) is a vegetable product of significant importance in the Mayan culture given that it is a part of their diet; however, it has not yet been fully studied. The effect of seven solvent systems on the content of total phenolic compounds (TPC), extraction yield, total flavonoids (TF) and antioxidant activity was evaluated and the content of individual phenolic compounds of Ramon nut was analyzed by HPLC. The results reveal that the type of solvent and its polarity has a significant effect on the extraction of antioxidants and on the quantitative analysis of the Ramon nut. Of all the solvents used, the ethanol/water extract (1:1, v/v) (S6) was identified as the most efficient solvent in the extraction process, with a higher TPC content, greater antioxidant activity (with the reduction power assay) and a higher content of gallic acid, chlorogenic acid and vanillic acid. A high correlation was found between TPC and TF vs antioxidant activity, suggesting the possible contribution of the phenolic compounds in the antioxidant activity of the Ramon nut. The Ramon nut extraction with S6 reduced the TBARS content of cooked hamburger meat, stored at 4 °C for 14 days.