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The aim of the present study was to evaluate the phenolic composition of crude lyophilized extracts (CLE) and partially purified (PPE) extracts of C. ternatea blue petals as well as the anthocyanin stability against pH, temperature and light in the presence and absence of fructooligosaccharides. Twelve compounds were tentatively identified by UHPLC-Q-TOF-MS/MS in CLE and PPE extracts. In direct/reverse spectrophotometric titration, anthocyanins showed colour changes between pH 2.25 to 10.20, and colour reversibility, maintaining antioxidant activity against the DPPH radical. The aqueous extracts at pH 3.6 and 5.4 exhibited thermal stability with the presence and absence of fructooligosaccharides with activation energy higher than 99 kJ/mol. The addition of fructooligosaccharides in the extracts at pH 5.4 exposed to light provided a protective effect against anthocyanin photodegradation. The data show the technological potential of aqueous extract of C. ternatea blue petals as a natural colourant in a functional beverage model system., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The aim of this study was to evaluate the effects of different solvents and maximize the extraction of bioactive compounds from jabuticaba (Myrciaria cauliflora) seeds. In general, the solvent system composed of water and propanone (52:48 v/v) modified the extract polarity and increased extraction yield of bioactive compounds. The optimized extract presented antioxidant capacity measured by different chemical and biological assays. The optimized extract exerted antiproliferative and cytotoxic effects against A549 and HCT8 cells, antimicrobial and antihemolytic effects, inhibited α-amylase/α-glucosidase activities and presented in vitro antihypertensive effect. Nonetheless, the optimized extract showed no cytotoxicity in a human cell model (IMR90). Vescalagin, castalagin and ellagic acid were the major phenolic compounds in the optimized extract. Our results show that jabuticaba seed may be a potential ingredient for the development of potentially functional foods., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The purpose of this study was to use a statistical approach to optimise the experimental conditions regarding the extraction of bioactive compounds, and to analyse the in vitro functional properties of crude lyophilized extracts (CLE) and partially purified (PPE) extracts of Clitoria ternatea petals. The results showed that the factors of temperature and time influenced the extraction of phenolic compounds, antioxidant activity and the physicochemical parameters. Simultaneous optimisation showed that the same levels of bioactive compounds were extracted when using temperatures from 11.7 to 68.3 °C and times from 8.47 to 51.12 min. Principal component analysis revealed the experimental conditions that provided the extraction producing the highest level of phenolic content (40 °C/30 min). The CLE showed antimicrobial activity; protective effect against hemolysis of erythrocytes; inhibition of α-amylase, α-glucosidase and angiotensin-I-converting (ACE-I) enzymes; and inhibition of lipid peroxidation. The CLE and PPE demonstrated oxygen radical absorption capacity; inhibition of DNA strand scission; inhibition of LDL cholesterol oxidation; intracellular antioxidant activity against reactive oxygen species (>100 μg/mL); and no cytotoxicity (IC 50 , GI 50 and LC 50  > 900 μg/mL) against A549, HCT8 and IMR90 cell lines., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

In this work, different chemometric tools were compared to classify n = 26 conventional (CONV) and n = 19 organic (ORG) coffees from the main Brazilian producing regions based on the chemical composition, physicochemical properties, and antioxidant activity. Principal component analysis separated ORG and CONV coffees but the distinction among the producing regions of Brazilian coffee was not possible. Partial least squares discriminant analysis classified all ORG and CONV coffees in the external validation. Similarly, linear discriminant analysis was able to discriminate 100% and 81% of ORG and CONV coffees in the external validation, respectively, in which total phenolic content (TPC), ferric reducing antioxidant activity, and caffeic acid were the main discriminant variables. Overall 100% of samples from Paraná, Minas Gerais, and blended samples were correctly classified, where TPC, flavonoids, inhibition of lipid peroxidation, caffeic acid, pH, and soluble solids were the main discriminant variables. Support vector machines classified 95% ORG and 88% CONV, 100% Coffea arabica, and 88% and 78% coffees produced in São Paulo and Minas Gerais. k-Nearest neighbors was effective in distinguishing 100% CONV, 89% ORG, 100% coffees from São Paulo, and 100% C. arabica coffees. Overall, HPLC data and simple physicochemical parameters allied to chemometrics were effective in authenticating the cultivation system and the botanical origin of Brazilian coffees. PRACTICAL APPLICATION: Coffee adulteration is a serious problem in the food chain as some fraudsters replace coffee powder by other cheaper products. In the case of organic coffee, this scenario is even worse as still there is not a universal method to differentiate conventionally grown coffee from its organic counterpart. In addition, Brazilian coffee is produced in different regions and the commercial value varies. Therefore, we analyzed some physicochemical, chemical, and antioxidant properties of Brazilian coffees from distinct origins and classified the samples using chemometrics. Our approach seems to be interesting for quality control purposes., (© 2019 Institute of Food Technologists®.)

Red chicory leaves are appreciated sensorially and their constituents contain bioactive properties. The objectives of this study were as follows: to use an experimental design to extract anthocyanins from red chicory in aqueous solution at pH 2.5; to determine the stability of the extracts in relation to temperature and pH; and to evaluate the antioxidant activity and in vitro cytotoxic effect of the lyophilized and purified extracts. The best extraction conditions for the bioactive compounds from red chicory were a temperature of 64.2 °C for 25 min; the anthocyanin content was 73.53 ± 0.13 mg per 100 g fresh weight basis sample. The EC 50 (Half maximal effective concentration) value for the antioxidant activity assay in relation to DPPH (2,2-diphenyl-1-picrylhydrazyl) with optimized extract was 0.363, which corresponds to a concentration of 39.171 µmol/L of anthocyanins. The activation energy for the degradation reaction of the anthocyanins from the red chicory extract was 84.88 kJ/mol. The optimized extract, which was rich in anthocyanins, showed chemical and biological antioxidant activity (protection against erythrocyte hemolysis) and inhibited lipid peroxidation in vitro. The Cichorium intybus L. extracts interfered on the levels of reactive oxygen species generation and the crude extract did not present procarcinogenic effect. PRACTICAL APPLICATION: Red chicory is basically consumed as a part of traditional dishes worldwide. Here, we developed a process to extract and purify the anthocyanins from Cichorium intybus leaves and test the extracts in terms of the chemical composition, thermal stability, antioxidant activity, and antiproliferative effects. The anthocyanin-rich extract presented antioxidant activity in chemical and biological assays and low cytotoxicity and cytoprotective effects in relation to HepG2, HCT8, and Caco-2 cell lines. Additionally, the red chicory extract protected human erythrocytes against hemolysis. This extract may be used as a natural colorant/antioxidant in foods., (© 2019 Institute of Food Technologists®.)

This study aimed to optimise the experimental conditions of extraction of the phytochemical compounds and functional properties of Centaurea cyanus petals. The following parameters were determined: the chemical composition (LC-ESI-MS/MS), the effects of pH on the stability and antioxidant activity of anthocyanins, the inhibition of lipid peroxidation, antioxidant activity, anti-hemolytic activity, antimicrobial, anti-hypertensive, and cytotoxic/cytoprotective effect, and the measurements of intracellular reactive oxygen species. Results showed that the temperature and time influenced (p ≤ 0.05) the content of flavonoids, anthocyanins, and FRAP. Only the temperature influenced the total phenolic content, non-anthocyanin flavonoids, and antioxidant activity (DPPH). The statistical approach made it possible to obtain the optimised experimental extraction conditions to increase the level of bioactive compounds. Chlorogenic, caffeic, ferulic, and p-coumaric acids, isoquercitrin, and coumarin were identified as the major compounds in the optimised extract. The optimised extract presented anti-hemolytic and anti-hypertensive activity in vitro, in addition to showing stability and reversibility of anthocyanins and antioxidant activity with pH variation. The C. cyanus petals aqueous extract exhibited high IC 50 and GI 50 (>900 μg/mL) values for all cell lines, meaning low cytotoxicity. Based on the stress oxidative assay, the extract exhibited pro-oxidant action (10-100 μg/mL) but did not cause damage or cell death., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Hibiscus sabdariffa calyx is a rich source of anthocyanins and other bioactive compounds but no study reported the effects of experimental conditions on the extraction of these chemical compounds. Therefore, the effects of time and extraction temperature on the bioactive compounds and antioxidant activity of Hibiscus sabdariffa calyx were evaluated. In addition, the effects of copigmentation and pH on the stability of anthocyanins were assessed and the cytotoxic effects (LC 50 , IC 50 , and GC 50 ) of the extracts were determined in relation to tumor cell lines - Caco-2, HepG-2, HCT8, and A549. The temperature significantly influenced the total anthocyanins and flavonoids contents. The interaction between time/temperature influenced the total phenolic content and ascorbic acid. The t 1/2 and the percentage of colour retention decreased markedly at temperatures above 80 °C. Variations in pH conserved the antioxidant activity of the anthocyanins, and the protonation-deprotonation process of the extract was reversible. The treatment of cells with purified anthocyanin extract or crude extracts at 5-800 μg mL -1 did not show significant cytotoxic effects on the cell lines, corroborating the chemical antioxidant effect of the extracts (DPPH assay). Cyanidin-3-glucoside, delphinidin-3-sambubioside, delphinidin-3-glucoside, and cyanidin-3-sambubioside were identified in the extracts by LC-ESI-MS., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

This work was aimed at assessing the time-temperature effects on the phenolic compounds and in vitro functional properties of aqueous extracts from red rooibos (Aspalathus linearis). The major phenolic composition (tannins, flavonoids, flavonols, ortho-diphenols, total phenolic content), antioxidant (ABTS and DPPH) and reducing capacities (FRAP and total reducing capacity), antimicrobial effects and inhibition of α-amylase/α-glucosidase were measured. Phenolic compounds were also determined by LC-ESI-MS/MS. Aqueous extracts did not inhibit the growth of Escherichia coli, Staphylococcus aureus, and Candida albicans between 7.81 and 1000mgL -1 . Rooibos extracted at 85°C for 10min showed a beneficial interaction with the human erythrocytes, reducing the hemolysis. The correlation analysis showed that the phenolic compounds responsible for the inhibition of α-amylase (IC 50 ) were isohrmanetin, isoquercitrin, luteolin, salicylic acid, and syringaldehyde, whereas the inhibition of α-glucosidase was correlated to syringaldehyde, isoquercitrin, and luteolin. Overall, rooibos extracted at 85°C had the highest antioxidant activity measured by all assays, higher contents of phenolic compounds (spectrophotometric and LC-ESI-MS/MS data), and lower IC 50 values for the digestive enzymes. On the other hand, rooibos extracted at 65°C had the opposite behavior, while rooibos extracted at 75°C presented mean intermediate values for the responses. This result clearly indicates that the extraction temperature is the main factor leading to a higher extraction of bioactive compounds from red rooibos., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

This study was aimed to assess the effect of time and temperature on the extraction of antioxidant compounds from jabuticaba seeds (Myrciaria cauliflora cv. Sabará), to optimize the solvent proportion (water, ethyl alcohol, and propanone), and to characterize the extract according to the chemical composition, antioxidant, and antimicrobial properties. Proximal composition, total phenolic content (TPC), antioxidant, and antimicrobial activities were analyzed. The optimized solvent ratio of 60% water and 40% propanone provided a mean TPC of 8.65 g GAE/100 g seeds and the antioxidant activity toward 2,2-diphenyl-1-picrylhydrazyl (DPPH) was 82.79% ± 0.50%. Time and temperature parameters did not influence the yield of TPC. The gross seed extract was partially purified and both exhibited a high antioxidant activity and antimicrobial potential toward Gram-positive and Gram-negative bacteria. The purified jabuticaba seed lyophilized extract contained a higher (P < 0.05) TPC, o-diphenols, flavonols, and antioxidant activity measured by the DPPH assay and total reducing capacity as compared to the gross lyophilized extract. Electrospray ionization coupled with tandem mass spectrometry (ESI-MS/MS) data showed the presence of ellagitannins and ellagic acid in the extracts, which are probably the responsible for the antimicrobial and antioxidant activities., (© 2016 Institute of Food Technologists®)

In the current study, response surface methodology (RSM) was used to assess the effects of extraction time and temperature on the content of bioactive compounds and antioxidant activity of purple basil leaf (Ocimum basilicum L.) extracts. The stability of anthocyanins in relation to temperature, light and copigmentation was also studied. The highest anthocyanin content was 67.40 mg/100 g extracted at 30 °C and 60 min. The degradation of anthocyanins with varying temperatures and in the presence of light followed a first-order kinetics and the activation energy was 44.95 kJ/mol. All the extracts exposed to light showed similar half-lives. The extracts protected from light, in the presence of copigments, showed an increase in half-life from 152.67 h for the control to 856.49 and 923.17 h for extract in the presence of gallic acid and phytic acid, respectively. These results clearly indicate that purple basil is a potential source of stable bioactive compounds.

This study was aimed the extraction of total flavonoids, anthocyanins and phenolics, as well as the antioxidant activity of black rice (Oryza sativa) and to study the stability in relation to pH, light and copigmentation. Variations in temperature (10-50°C), time (20-80min), and solid-solvent ratio (1:15-1:45) were studied using a Box-Behnken design. The regression models were significant (P<0.001) and determination coefficients ⩾0.900. Extraction at 34.7°C for 80min using a solid:solvent ratio of 1:30 rendered an extract with 51.26mg 100g(-1) of flavonoids, 116.58mg 100g(-1) of anthocyanins, 520.17mg 100g(-1) of phenolics and 46.50% inhibition of the DPPH radical. A decrease in the color intensity was observed when pH values were changed while anthocyanins were reversible in the process of protonation/deprotonation. The addition of glucose, phytic and gallic acids in the optimized extract exposed to light displayed an intermolecular copigmentation. The main anthocyanin identified in black rice was cyanidin-3-glucoside., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Inositol hexaphosphate (InsP6) is present in cereals, legumes, nuts and seed oils and is biologically active against some tumor and cancer cells. Herein, this study aimed at evaluating the cellular toxicity, antiproliferative activity and effects on cell cycle progression of free InsP6 and InsP6-Ni(II) of leukemic T (Jurkat) and normal human cells. Treatments with InsP6 at concentrations between 1.0 and 4.0mM significantly decreased the viability of Jurkat cells, but showed no cytotoxic effect on normal human lymphocytes. Treatment with InsP6-Ni(II) complex at concentrations between 0.05 and 0.30 mM showed an anti-proliferative dose and a time-dependent effect, with significantly reduced cell viability of Jurkat cells but showed no cytotoxic effect on normal human lymphocytes as compared to the control. Ni(II) free ion was toxic to normal cells while InsP6-Ni(II) had no cytotoxic effect. The InsP6-Ni(II) complex potentiated (up to 10×) the antiproliferative effect of free InsP6 on Jurkat cells. The cytometric flow assay showed that InsP6 led to an accumulation of cells in the G0/G1 phase of the cell cycle, accompanied by a decrease in the number of cells in S and G2/M phases, whereas InsP6-Ni(II) has led to an accumulation of cells in the S and G2/M phases. Our findings showed that InsP6-Ni(II) potentiates cytotoxic effects of InsP6 on Jurkat cells and may be a potential adjuvant in the treatment of cancer., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Unlabelled: Folin-Ciocalteu colorimetric assay (FC) is the most widely used assay to estimate the total phenolic content in foods, beverages, herbs and other plant extracts, but many chemical compounds may act as interfering agents, producing inaccurate estimations of the real concentration of phenolic compounds in the matrix. Based on this limitation, the objective of this study was to compare, quantitatively, the Folin-Ciocalteu and Prussian Blue (PB) assays in estimating the total phenolic content in purple grape juices (n = 20; Vitis labrusca L.) and teas (n = 25) from different botanical origins using 96-well microplates. PB assay presented a low limit of detection (PB = 0.27 mg/L; FC = 0.25 mg/L) and quantification (PB = 0.92 mg/L; FC = 0.82 mg/L), showing its suitability in screening the total phenolic content in grape juices and teas. FC and PB assays presented a high association (P < 0.0001) for teas (r = 0.887) and grape juices (r = 0.923). The advantages of PB over FC assay are its simplicity, low time consumption (15 min reaction as compared to 60 min reaction for the FC assay), lower usage of reagents (solutions are prepared in a mM base), and higher selectivity. Additionally, PB assay was proven to be reproducible and repeatable and, therefore, may be used as an alternative to FC assay., Practical Application: Prussian Blue assay (PB) has been used as an alternative to Folin-Ciocalteu assay (FC) to estimate the total content of phenolic compounds in herbs and some natural products. In our study we showed that the advantages of PB assay over FC are its simplicity, low time consumption (15 min reaction as compared to 60 min reaction for the FC assay), lower usage of reagents (solutions are prepared in a mM base) and higher selectivity as compared to FC assay. Additionally, PB assay was proven to be reproducible and repeatable and, therefore, may be used as an alternative to FC assay., (© 2015 Institute of Food Technologists®)