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1.
J Agric Food Chem ; 67(33): 9295-9306, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31365237

RESUMO

As a result of an innovative olive fruit processing method involving stone removal and dehydration, a new kind of olive oil and olive flour are generated. The main objective of this work was to accomplish the comprehensive characterization of the minor compounds of both products and to evaluate the effect of the dehydration temperature on their composition. To this end, olive oil and flour samples obtained through the novel processing method were analyzed and compared with "conventional" virgin olive oils (VOO). The applied LC-MS methodology allowed the determination of 57 metabolites belonging to different chemical classes (phenolic compounds, pentacyclic trirterpenes, and tocopherols). Both the new oils and flours presented considerable amounts of olive fruit metabolites that are usually absent from VOO. Quantitative differences were found among VOOs and the new oils, probably due to the inhibition of some enzymes caused by the temperature increase or the absence of water during the processing.


Assuntos
Manipulação de Alimentos/métodos , Olea/química , Extratos Vegetais/química , Resíduos/análise , Cromatografia Líquida , Farinha/análise , Frutas/química , Azeite de Oliva/análise , Fenóis/química , Fenóis/isolamento & purificação , Extratos Vegetais/isolamento & purificação , Espectrometria de Massas em Tandem , Tocoferóis/química , Tocoferóis/isolamento & purificação
2.
Anticancer Res ; 39(8): 4043-4053, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31366486

RESUMO

BACKGROUND/AIM: Triple-negative breast cancer (TNBC) is the most aggressive subtype, predominant in African American women. In this study, the antioxidant/anticancer activity of muscadine grape extracts and the role of their phenolic and flavonoid contents in exerting these properties were investigated in TNBC cells. MATERIALS AND METHODS: Berry extracts from muscadine genotypes were investigated for total phenolic content (TPC), total flavonoid content (TFC), antioxidant capacity, and anticancer effects using breast cancer cell lines, representing Caucasians and African Americans. RESULTS: The antioxidant activity was associated with high TPC content. Extracts showed cytotoxicity up to 78.6% in Caucasians and 90.7% in African American cells, with an association with high antioxidant capacity. There was a strong correlation between TPC and anticancer/antioxidant activities. CONCLUSION: The anticancer and antioxidant effects of muscadine grapes are attributed to the TPC of extracts, which showed a stronger positive correlation with growth inhibition of African American breast cancer cells compared to Caucasians.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Extratos Vegetais/farmacologia , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Vitis/química , Afro-Americanos/genética , Antineoplásicos Fitogênicos/química , Antioxidantes/química , Antioxidantes/farmacologia , Linhagem Celular Tumoral , Cromatografia Líquida de Alta Pressão , Feminino , Flavonoides/química , Flavonoides/farmacologia , Frutas/química , Humanos , Células MCF-7 , Fenóis/química , Fenóis/farmacologia , Extratos Vegetais/química , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/patologia
3.
Analyst ; 144(17): 5261-5270, 2019 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-31364612

RESUMO

In this work, an enrichment approach for the profiling of N-linked glycans was developed by utilizing a highly porous 3D graphene composite fabricated from graphene oxide nanosheets and a phenol-formaldehyde polymer via graphitization and KOH activation. In tailoring the large surface area (ca. 2213 m2 g-1) and 3D-layered mesoporous structure, the 3D graphene composite demonstrated not only high efficiency in glycan enrichment but also the size-exclusion effect against residual protein interference. For a standard protein ovalbumin digest, 26 N-linked glycans were identified with good repeatability, and the detection limit was as low as 0.25 ng µL-1 with the identification of 13 N-linked glycans (S/N > 10). When the mass ratio of the ovalbumin digest to the interfering proteins, i.e., bovine serum albumin and ovalbumin was 1 : 2000 : 2000, 18 N-linked glycans could still be detected with sufficient signal intensities. From a 60 nL minute complex human serum sample, up to 53 N-linked glycans with S/N > 10 were identified after the 3D graphene enrichment, while only 20 N-linked glycans were identified by the porous graphitized carbon material used for comparison. In addition, the application of the 3D graphene composite in profiling the up-regulated and down-regulated N-linked glycans from the real clinical serum samples of ovarian cancer patients confirmed the potential of the 3D graphene composite for analyzing minute and complicated biological samples.


Assuntos
Grafite/química , Nanoestruturas/química , Ovalbumina/química , Polissacarídeos/análise , Albumina Sérica/química , Feminino , Formaldeído/química , Humanos , Neoplasias Ovarianas/sangue , Oxirredução , Fenol/química , Fenóis/química , Polímeros/química , Polissacarídeos/isolamento & purificação , Porosidade , Soro
4.
J Agric Food Chem ; 67(35): 9840-9850, 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31424924

RESUMO

In the present study, methanolysis of poplar biomass was conducted for the selective transformation of hemicellulose and lignin, which leads to methyl glycosides (mainly C5 glycosides) and lignin fragments in the liquefied products that can be separated according to their difference in hydrophilicity. The distribution of methyl glycosides and delignification was dependent on the presence of acid catalysts and reaction temperatures. The obtained lignin fraction was separated into solid lignin fragments and liquid lignin oil according to their molecular weight distribution. Subsequently, directional conversion of methyl C5 glycosides into methyl levulinate was performed with dimethoxymethane/methanol as the cosolvent. A yield of 12-30% of methyl levulinate yield (based on the methyl glycoside) was achieved under these conditions. The remaining cellulose-rich substrate showed enhanced susceptibility to enzymatic hydrolysis, resulting in a yield of glucose of above 70%. Overall, the described strategy shows practical implications for the effective valorization of biomass.


Assuntos
Fracionamento Químico/métodos , Glucose/isolamento & purificação , Ácidos Levulínicos/isolamento & purificação , Metanol/química , Fenóis/isolamento & purificação , Extratos Vegetais/isolamento & purificação , Populus/química , Madeira/química , Catálise , Celulose/química , Celulose/isolamento & purificação , Glucose/química , Ácidos Levulínicos/química , Lignina/química , Lignina/isolamento & purificação , Fenóis/química , Extratos Vegetais/química
5.
Phytochemistry ; 166: 112077, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31374519

RESUMO

Radical scavenging activity and subsequent oxidation resulting in quinone products represent one of the important features of phenols occurring in plants and other biological systems. However, corresponding thermochemistry data can be still considered scarce. For phenol and 25 para-substituted phenols, we investigate the thermodynamics of the individual reaction steps, including three subsequent hydrogen atom transfers, as well as hydroxyl HO radical addition, leading to final ortho-quinone formation. The substituent and solvent effect of water on corresponding reactions enthalpies is elucidated. Solvent enhances substituent induced changes in the investigated reaction enthalpies. The reliability of employed computational methods for the thermodynamics of hydrogen atom donating ability of studied phenols and catechols is assessed, too. Obtained linear equations enable estimation of studied reaction enthalpies from Hammett constants of substituents.


Assuntos
Depuradores de Radicais Livres/química , Fenóis/química , Quinonas/química , Radical Hidroxila/química , Isomerismo , Relação Estrutura-Atividade , Termodinâmica
6.
J Agric Food Chem ; 67(32): 8819-8838, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31322880

RESUMO

Recent studies about hot-water extracts from sugar maple (Acer saccharum Marsh.) bark and buds demonstrated that they contain high amounts of phenolic structures that may be used as antioxidant food additives. However, the detailed chemical composition of these maple-derived extracts has yet to be determined. By performing high-performance liquid chromatography-diode array detector-high-resolution mass spectrometry (HPLC-DAD-HRMS)-based dereplication, we were able to spike and classify almost 100 metabolites in each hot-water extract. The sugar maple bark hot-water extract is rich in simple phenolic compounds and phenylpropanoid derivatives, while bud extract contains predominantly flavonoids, benzoic acids, and their complex derivatives (condensed and hydrolyzable tannins). Among those chemical structures, we tentatively identified 69 phenolic compounds potentially reported for the first time in the genus Acer. Considering the growing commercial demand in natural products, the phenolic fingerprints of sugar maple bark and bud hot-water extracts will help in promoting these two maple-derived products as new sources of bioactive compounds in the food, nutraceutical, and cosmetic industries.


Assuntos
Acer/química , Casca de Planta/química , Extratos Vegetais/química , Acer/metabolismo , Cromatografia Líquida de Alta Pressão , Flavonoides/química , Flavonoides/isolamento & purificação , Flavonoides/metabolismo , Fenóis/química , Fenóis/isolamento & purificação , Fenóis/metabolismo , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/metabolismo , Espectrometria de Massas por Ionização por Electrospray
7.
Chem Commun (Camb) ; 55(60): 8876-8879, 2019 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-31286121

RESUMO

Here we report template-free synthesis of imine-linked calix[4]arene hollow nanocapsules and their utility in the effective delivery of a poorly soluble cancer drug into tumor cells. These stimuli-responsive nanocapsules show high drug loading and release which resulted in a 40-fold higher cytotoxicity for breast cancer cell line over normal cells.


Assuntos
Antineoplásicos/farmacologia , Calixarenos/química , Camptotecina/farmacologia , Portadores de Fármacos/química , Nanocápsulas/química , Fenóis/química , Antineoplásicos/química , Calixarenos/síntese química , Calixarenos/toxicidade , Camptotecina/química , Portadores de Fármacos/síntese química , Portadores de Fármacos/toxicidade , Liberação Controlada de Fármacos , Humanos , Concentração de Íons de Hidrogênio , Células MCF-7 , Nanocápsulas/toxicidade , Fenóis/síntese química , Fenóis/toxicidade
8.
J Agric Food Chem ; 67(31): 8573-8580, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31293156

RESUMO

Glycosylation endows both natural and synthetic small molecules with modulated physicochemical and biological properties. Plant and bacterial glycosyltransferases capable of decorating various privileged scaffolds have been extensively studied, but those from kingdom Fungi still remain underexploited. Here, we use a combination of genome mining and heterologous expression techniques to identify four novel glycosyltransferase-methyltransferase (GT-MT) functional modules from Hypocreales fungi. These GT-MT modules display decent substrate promiscuity and regiospecificity, methylglucosylating a panel of natural products such as flavonoids, stilbenoids, anthraquinones, and benzenediol lactones. Native GT-MT modules can be split up and regrouped into hybrid modules with similar or even improved efficacy as compared with native pairs. Methylglucosylation of kaempferol considerably improves its insecticidal activity against the larvae of oriental armyworm Mythimna separata (Walker). Our work provides a set of efficient biocatalysts for the combinatorial biosynthesis of small molecule glycosides that may have significant importance to the pharmaceutical, agricultural, and food industries.


Assuntos
Proteínas Fúngicas/química , Glicosiltransferases/química , Hypocreales/enzimologia , Metiltransferases/química , Fenóis/química , Animais , Biocatálise , Cristalografia por Raios X , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Glicosilação , Glicosiltransferases/genética , Glicosiltransferases/metabolismo , Hypocreales/genética , Inseticidas/química , Inseticidas/farmacologia , Metilação , Metiltransferases/genética , Metiltransferases/metabolismo , Mariposas/efeitos dos fármacos , Fenóis/farmacologia , Especificidade por Substrato
9.
J Agric Food Chem ; 67(30): 8402-8410, 2019 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-31276623

RESUMO

Wines aged in oak wood barrels with various uniform tannin contents (which were classified according to their total ellagitannins contents as predicted by Near Infrared Spectroscopy on the untoasted wood) and different toasting levels (high precision toasting by radiation) were distinguished according to their overall abilities to resist against oxidation. Wine trials were carried out on two different vintages (2015, 2016) and three grape varieties (Sauvignon blanc, Sémillon, Chardonnay). Regardless of the vintage and the wine matrix, a relationship was established between wine oxidative stability (based on EPR spin trapping methodology) and oak barrel tannin potential. The extraction kinetic of ellagitannins by wines appeared linear during barrel aging and achieved its maximum at six or eight months, in a grape variety dependent manner. Oak wood barrel tannin potentials and toastings had no effect on wine glutathione and polyphenols contents. However, wines aged in new barrels with both low and medium tannin potentials, preserved at the end of aging and important number of S-N containing compounds, which was in addition to the known ellagitanins, revealed wines better antioxidant stability.


Assuntos
Antioxidantes/química , Manipulação de Alimentos/instrumentação , Quercus/química , Taninos/análise , Vinho/análise , Madeira/química , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas , Fenóis/química , Vitis/química
10.
Chem Biol Interact ; 310: 108753, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31319075

RESUMO

Multitarget ligands (MTL) based on sterically hindered phenol and containing a quaternary ammonium moiety (SHP-n-Q) were synthesized. These compounds are inhibitors of cholinesterases with antioxidant properties. The inhibitory selectivity is 10-fold potent for BChE than for AChE. IC50 of SHP-n-Q for BChE is 20 µM. SHP-n-Q and their nanosystems exhibit more pronounced antioxidant properties than the synthetic antioxidant (hindered phenol, butylated hydroxytoluene). These compounds display a low hemolytic activity against human red blood cells. The nanotechnological approach was used to increase the bioavailability of SHP-n-Q derivatives. For water soluble SHP-n-Q derivative, the self-assembled structures have a size close to 100 nm at critical association concentration (0.01 M). Mixed cationic liposomes based on l-α-phosphatidylcholine and SHP-n-Q of 100 nm diameter were prepared. The stability, encapsulation efficacy and release from liposomes of a model drug, Rhodamine B, depend on the structure of SHP-n-Q. Cationic liposomes based on l-α-phosphatidylcholine and SHP-3-Q show a good stability in time (1year) and a sustained release (>65 h). They are promising templates for the development of anti-Alzheimer MT-drug delivery systems.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Fenóis/química , Acetilcolinesterase/química , Compostos de Amônio , Antioxidantes/farmacologia , Butirilcolinesterase/química , Inibidores da Colinesterase/farmacologia , Humanos , Lipossomos/química , Nanoestruturas , Fenóis/síntese química , Relação Estrutura-Atividade
11.
Food Chem ; 298: 125098, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31276942

RESUMO

This work aimed to optimize an aqueous extract rich in phenolic compounds and potential functional properties made of Ilex paraguariensis, Melissa officinalis, and Cymbopogon citratus. The lyophilized extract was used for the development of an ice cream. Total phenolics, FRAP, DPPH, Folin-Ciocalteu's reducing capacity, and total reducing capacity of different combinations of herbal extracts were tested and modeled using response surface methodology. Simultaneous optimisation was employed to maximize the bioactive compounds in the extract and the lyophilized optimum combination was added to ice cream. The lyophilized extract contained quercetin-3-rutinoside, hesperidin, isoquercetin, caffeic acid, and 5,7-dihydroxyflavone. The optimised extract, which showed antihypertensive, antidiabetic, and antioxidant activity using in vitro protocols, increased total phenolics and antioxidant activity in comparison to the control ice cream. The ice cream presented a sensory acceptance index of 83%. After 72 days of storage (-18 °C), total phenolics and antioxidant activity significantly decreased.


Assuntos
Indústria de Processamento de Alimentos/métodos , Sorvetes , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Adolescente , Adulto , Anti-Infecciosos/farmacologia , Anti-Hipertensivos/química , Anti-Hipertensivos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Linhagem Celular , Cymbopogon/química , Feminino , Flavonoides/análise , Flavonoides/química , Armazenamento de Alimentos , Humanos , Sorvetes/análise , Ilex paraguariensis/química , Masculino , Melissa/química , Pessoa de Meia-Idade , Oligossacarídeos/química , Fenóis/química , Paladar
12.
Food Chem ; 299: 125115, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31288161

RESUMO

The nutritional and antinutritional components of minor millets were correlated with mixolab dough mixing behavior and in vitro protein and starch digestibility. Total arabinoxylan (r = -0.53, p < 0.05) and dietary fiber (r = -0.66, p < 0.05) content significantly (p < 0.05) increased protein weakening. Peak viscosity negatively correlated with phenolic (r = -0.55, p < 0.05) content. The dietary fiber and phenolics suppressed retrogradation. Protein digestibility negatively correlated with tannin (r = -0.70, p < 0.05), phytic acid (r = -0.69, p < 0.05), phenolics (r = -0.79, p < 0.05), flavonoids (r = -0.72, p < 0.05) and total dietary fiber content (r = -0.84, p < 0.05). A positive correlation of resistant starch (RS) with total dietary fiber (r = 0.85, p < 0.05), phenolics (r = 0.89, p < 0.05), flavonoids (r = 0.83, p < 0.05), phytic acid (r = 0.43, p < 0.05) and tannin content (r = 0.79, p < 0.05) was observed. Millets predicted lower glycemic index than wheat and it was found to be negatively associated with the RS (r = -0.96, p < 0.05) and total dietary fiber content (r = -0.89, p < 0.05) and positively correlated (r = 0.98, p < 0.05) with rapidly digestible starch. The millets may be diversified for personalized nutrition and development of functional food.


Assuntos
Pão , Milhetes , Proteínas de Vegetais Comestíveis/farmacocinética , Amido/farmacocinética , Fibras na Dieta/análise , Digestão , Índice Glicêmico , Milhetes/química , Panicum/química , Fenóis/análise , Fenóis/química , Reologia , Setaria (Planta)/química , Amido/química , Triticum/química , Viscosidade , Xilanos/análise
13.
Food Chem ; 299: 125114, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31326758

RESUMO

UPLC-ESI-HRMS/MS was used to identify the free, esterified and bound phenolic compounds in Kainth fruit extracts. In total, around 17, 15 and 18 free, esterified and bound phenolic compounds respectively were identified. Among these, Procyanidin B2, Epicatechin, Phloridzin, Hesperetin, etc. are being reported for the first time. The total phenolic content of free, esterified and bound fractions were 178.33 ±â€¯6.90, 151.33 ±â€¯7.73 and 707.16 ±â€¯19.77 mg GAE/100 g of fruit. The major phenolic compounds quantified were chlorogenic acid (7.97 mg/100 g), arbutin (7.05 mg/100 g) and catechin (44.56 mg/100 g) in free, esterified and bound form respectively. Various antioxidant assays (DPPH, ABTS, TAC and FRAP) were performed for all the extracts. Among different extracts, the bound phenolics exhibited the highest antioxidant activity. Systematic identification and quantitative profiling of phenolics in Kainth fruit being presented for the first time would help in utilising this fruit for designing functional food formulations.


Assuntos
Antioxidantes/análise , Frutas/química , Fenóis/análise , Pyrus/química , Antioxidantes/química , Cromatografia Líquida , Hidrólise , Fenóis/química , Extratos Vegetais/química , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em Tandem
14.
Anal Chim Acta ; 1078: 200-211, 2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31358220

RESUMO

The effect of the ionization in the RP-HPLC retention of 66 acid-base compounds, most of them drugs of pharmaceutical interest, is studied. The retention time of the compounds can be related to the pH measured in the mobile phase (pwsH) through the sigmoidal equations derived from distribution of the neutral and ionic forms of the drug into the stationary and mobile phases. Fitting of the obtained retention vs. pH profiles provides the retention times of the ionic and neutral forms and the pKa values of the drugs in the mobile phase (pwsKa). The obtained pwsKa values are linearly correlated to the pKa values in water (pwwKa) with two different correlations, one for neutral acids and another for neutral bases that reflect the different influence of the dielectric constant of the medium in ionization of acids and bases. The retention of the neutral species is well correlated to the octanol-water partition coefficient of the drugs as measure of the lipophilicity of the drug, which affects chromatographic retention. Also, the retention time of the ionized forms is related to the retention time of the neutral forms by two different linear correlations, one for anions and the other for cations. These last correlations point out the different retention behaviour of anions and cations: anions are less retained than cations of the same lipophilicity, as measured by the octanol-water partition coefficient of the neutral form. The different retention behaviour of anionic, cationic and neutral forms is confirmed by the hold-up times obtained from different approaches: pycnometry and retention times of anionic (KBr and KI) and neutral (DMSO) markers. Hold-up times obtained by pycnometric measurements agree with those obtained by retention of neutral markers (0.83-0.85 min), whereas hold-up time for anions is mobile phase pH dependent. At acidic pH it is similar to the hold-up time for neutral markers (0.83 min), but then it decreases with the increase of mobile phase pH to 0.65 min at pH 11. The decrease can be explained by the ionization of the silanols of the column and exclusion of anions by charge repulsion. Although not directly measured, the obtained retention data and correlations indicate hold-up time for cations are similar or slightly lower than hold-up time for neutral compounds (0.77-0.83 min). The model proposed and the correlations obtained can be very useful for its implementation in retention prediction algorithms for optimization of separation purposes.


Assuntos
Aminas/química , Ácidos Carboxílicos/química , Fenóis/química , Piridinas/química , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia de Fase Reversa/métodos , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Modelos Químicos
15.
Molecules ; 24(13)2019 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-31288489

RESUMO

Black mulberry is a widely acknowledged ancient traditional medicine. Its extract and constituents have been reported to exert various bioactivities including antimicrobial, hypotensive, analgesic etc. effects. While black mulberry preparations are also used as antispasmodic agents in folk medicine, no related studies are available on its isolated constituents. Through an extensive chromatographic purification, seven phenolic compounds were isolated from the methanol extract of Morus nigra root bark, including morusin (1), kuwanon U (2), kuwanon E (3), moracin P (4), moracin O (5), albanol A (6), and albanol B (7). A complete NMR signal assignment of moracin P and O was achieved, and related literature errors confusing the identity of moracin derivatives are hereby clarified. Compounds 2, 5 and 7 were identified as strong antispasmodic agents on isolated rat ileum and tracheal smooth muscles, while compound 3, a methoxy derivative of 2, was inactive. Moracin O (5) inhibited the ileal and tracheal smooth muscle contractions with Emax values of 85% and 302 mg, respectively. Those actions were superior as compared with papaverine. Our findings demonstrate that prenylated arylbenzofurans, geranylated flavonoids and Diels-Alder adducts from Morus nigra are valuable antispasmodic agents. Compounds 2, 5 and 7 are suggested as marker compounds for quality control of antispasmodic mulberry preparations. Moracin O (5) is a new lead compound for related drug development initiatives.


Assuntos
Morus/química , Parassimpatolíticos/química , Fenóis/química , Casca de Planta/química , Extratos Vegetais/química , Raízes de Plantas/química , Benzofuranos/metabolismo , Avaliação Pré-Clínica de Medicamentos , Flavanonas/metabolismo , Metanol/química , Parassimpatolíticos/farmacologia , Prenilação , Resorcinóis/metabolismo , Solventes/química , Relação Estrutura-Atividade
16.
Food Chem ; 298: 125004, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31260986

RESUMO

There is general interest in strategies to control polyphenol oxidase (PPO)-initiated enzymatic browning because it is often associated with declining food quality. Cyclodextrins are cyclic glucan oligosaccharides that form inclusion complexes with a number of PPO substrates. This study focuses on the effect of ß-cyclodextrins (ßCyD) on PPO-catalyzed reactions. Potato enzyme extracts and semi-purified potato PPO served as enzyme sources. Substrates included phenolics endogenous to potatoes. Reaction time-courses were followed spectrophotometrically; rates were compared by analysis of variance. Extents of ßCyD inhibition of PPO-catalyzed reactions are shown to be substrate specific and can be quantitatively accounted for based on degrees of ßCyD substrate sequestration. There was no evidence for direct irreversible ßCyD inactivation of potato PPO. An apparent "direct PPO inactivation" by ßCyD is shown to result from a sequence of sequestration-dependent reactions that occur in commonly employed assay systems for the quantification of PPO in fruits and vegetables.


Assuntos
Catecol Oxidase/química , Catecol Oxidase/metabolismo , Solanum tuberosum/enzimologia , beta-Ciclodextrinas/química , Catálise , Catecol Oxidase/antagonistas & inibidores , Fenóis/química , Fenóis/metabolismo , Proteínas de Plantas/antagonistas & inibidores , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Especificidade por Substrato , beta-Ciclodextrinas/metabolismo
17.
J Sci Food Agric ; 99(13): 6049-6059, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31342530

RESUMO

BACKGROUND: The scarcity of irrigation water is severely affecting global crop production. In this context, biostimulants are increasingly used as alternatives means against abiotic stress conditions. In this study, phenolic compounds composition and bioactive properties of common bean (Phaseolus vulgaris L.) plants grown under water stress conditions and biostimulants application were investigated. RESULTS: Sixteen individual phenolic compounds were detected in both pods and seeds with a notable difference in their compositional profile. A significant effect on phenolic compounds content and composition was also observed for the biostimulants tested. Regarding the antibacterial activity, pods of the second harvest and seed extracts showed significant efficacy against Bacillus cereus, especially in water-stressed plants, where all biostimulant treatments were more effective than positive controls. Moreover, all biostimulant treatments for seed extracts of water-stressed plants were more effective against Staphylococcus aureus compared with ampicillin, whereas streptomycin showed the best results. Extracts from pods of the second harvest from normally irrigated plants showed the best results against the fungi tested, except for Penicillium verrucosum var. cyclopium. Finally, no significant cytotoxic effects were detected. CONCLUSION: In conclusion, the biostimulants tested increased total phenolic compounds content compared with control treatment, especially in pods of the first harvest and seeds of water-stressed plants. Moreover, bioactive properties showed a varied response in regard to irrigation and biostimulant treatment. Therefore, biostimulants can be considered as a useful means towards increasing phenolic compounds content, and they may also affect the antimicrobial properties of pods and seeds extracts. © 2019 Society of Chemical Industry.


Assuntos
Desidratação , Phaseolus/química , Phaseolus/fisiologia , Fenóis/farmacologia , Extratos Vegetais/farmacologia , Água/metabolismo , Bacillus cereus/efeitos dos fármacos , Bacillus cereus/crescimento & desenvolvimento , Phaseolus/crescimento & desenvolvimento , Phaseolus/microbiologia , Fenóis/química , Fenóis/metabolismo , Extratos Vegetais/química , Extratos Vegetais/metabolismo , Sementes/química , Sementes/crescimento & desenvolvimento , Sementes/metabolismo , Sementes/microbiologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Estresse Fisiológico , Água/análise
18.
Food Chem ; 300: 125195, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31326676

RESUMO

Presence of pungent gingerols in ginger oleoresin makes it an ideal natural flavoring candidate for the food industry. The study reports its incorporation for synergistic enhancement of flavor and nutraceutical portfolio of candied mango. The process is systematically optimized at bench-scale for gingerols infusion and subsequent candying treatment in a range of hypo and hypertonic osmotic solutions for critical transport properties. After that, optimization of the drying process and the scale-up study was conducted with a 200 folds increase in the batch size. Collated effects of multistep optimization resulted in 85.6, 76.8, 60.2% retention in ß-carotene, total phenolics, Vitamin C, respectively, along with minor color difference and significant improvement in sensory scores over fresh mango. Mass transfer and quality parameters were comparable in both scales, implying excellent repeatability and scalability of the process. Compared with a similar commercial product, substantial improvement in quality characteristics along with 376.7% reduction in overall processing time was achieved.


Assuntos
Doces , Catecóis/química , Álcoois Graxos/química , Aromatizantes/química , Indústria de Processamento de Alimentos/métodos , Mangifera/química , Ácido Ascórbico/análise , Ácido Ascórbico/química , Cor , Dessecação/métodos , Suplementos Nutricionais/análise , Qualidade dos Alimentos , Frutas/química , Gengibre/química , Humanos , Fenóis/análise , Fenóis/química , Paladar , beta Caroteno/análise , beta Caroteno/química
19.
J Sci Food Agric ; 99(13): 5946-5952, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31206683

RESUMO

BACKGROUND: Grape berries produce significant amounts of phenolic compounds. These are an essential qualitative factor due to their nutritional value and effect on berry color and texture. Salicylic acid (SA) and its derivatives usually lead to enhancement of phenolic content in plant tissues. The present study was conducted to evaluate the effect of different levels of SA (0.0, 50.0, 100.0, and 200.0 mM) on the production of phenolic compounds and the derivatives (anthocyanin and flavonoid) in the grape berries, with emphasis on malvidin-3-O-ß glucoside as a regular anthocyanin in red grapes. RESULT: The results showed that total phenolics content were significantly enhanced in SA-treated (100.0 and 200.0 mM) berries compared to untreated ones. Salicylic acid treatment at all concentrations considerably improved the anthocyanin content in the berries and, compared with untreated berries, the accumulation of malvidin-3-O-ß glucoside was higher in SA-treated fruits. In particular, the 200.0 mM concentration caused approximately two times more malvidin-3-O-ß glucoside than the control. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging capacity of the fruits treated with SA were significantly higher than those of the untreated berries. The activity of phenylalanine ammonia-lyase (PAL) in SA treated fruits significantly increased as compared with the untreated clusters. CONCLUSION: A general evaluation of the current results leads us to the conclusion that SA is a suitable and recommendable treatment for improving and increasing the phenolic and antioxidant capacity of grape berries. Spraying grape berries at pre-véraison stage with SA could therefore be a convenient strategy to increase quality and nutritional value of grape berries considerably. © 2019 Society of Chemical Industry.


Assuntos
Antocianinas/química , Frutas/química , Extratos Vegetais/química , Ácido Salicílico/farmacologia , Vitis/química , Antioxidantes/metabolismo , Cor , Frutas/efeitos dos fármacos , Fenóis/química , Fenilalanina Amônia-Liase/genética , Fenilalanina Amônia-Liase/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Vitis/efeitos dos fármacos , Vitis/genética
20.
J Sci Food Agric ; 99(13): 5994-6000, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31215047

RESUMO

BACKGROUND: Dynamic high-pressure microfluidization (DHPM) is an emerging and promising technique for continuous production of fluid foods. This study aimed to investigate the influence of DHPM and conventional homogenization (CH) on the quality of peach juice. Processing was performed by passing peach juice through CH at 20 MPa and DHPM at 20-160 MPa for one or three passes. The effect of DHPM pressure and passing number were also assessed. RESULTS: The results indicate that DHPM could maintain the antioxidant activity of peach juice much better than CH processing. Total phenolic compounds were decreased by 11.7% and 7.9%-15.8% through CH and DHPM processing in different conditions. Moreover, particle size, non-enzymatic browning index and turbidity decreased significantly under DHPM and CH processing, and decreased more and more with the increasing of DHPM pressure and treatment times. However, vitamin C content and zeta-potential did not reveal remarkable variation before and after these two types of processing. CONCLUSION: Taken together, DHPM is able to maintain the quality and stability of peach juice, which can be a reliable technological alternative to CH to produce fresh-like peach juices. © 2019 Society of Chemical Industry.


Assuntos
Manipulação de Alimentos/métodos , Sucos de Frutas e Vegetais/análise , Preparações de Plantas/química , Prunus persica/química , Manipulação de Alimentos/instrumentação , Fenóis/química , Pressão
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