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1.
Food Chem ; 321: 126603, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32244142

RESUMO

The formation of 4-hydroxy-2-hexenal (HHE) and 4-hydroxy-2-nonenal (HNE) in vegetable oils and model oil systems were quantitatively assessed by RP-HPLC. Regardless of heating temperature, HHE was only detected in rapeseed and linseed oil, while HNE was detected in all tested oils. Intrinsic tocopherols suppressed HHE/HNE formation, but with similar inhibition rates (10.49-16.04%). Linear correlations were observed between HHE/HNE contents and corresponding n-3/6 fatty acid content in oils (R2 = 0.989/0.971). Model oil system revealed that HHE/HNE formation was closely related to methyl linolenate (MLN) and methyl linoleate (ML) contents. Low levels of ML (<0.5%) and MLN (<1.0%) did not lead to HHE/HNE formation. Therefore, HHE/HNE was classified as the characteristic aldehydes of n-3 and n-6 type oils, respectively. Heat map evaluation and regression analysis indicated HHE could predict the n-3 type oils oxidation, while HNE was a good indicator to estimate the oxidative deterioration of n-6 and n-9 type oils.


Assuntos
Aldeídos/química , Gorduras Insaturadas/química , Óleos Vegetais/química , Cromatografia Líquida de Alta Pressão , Ácidos Graxos/química , Temperatura Alta , Oxirredução , Tocoferóis/química
2.
Food Chem ; 318: 126484, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32151923

RESUMO

The phytochemical contents, peroxyl radical scavenging capacities (PSCs) and cellular antioxidant activities (CAAs) of free and bound fractions of rice were reported. Black rice had the highest total phenolic content and total flavonoid content in free and bound fractions, followed by red rice, brown rice, and polished rice. Black rice contained much more free phenolic compounds than other rice samples, such as cyanidin-3-O-glucoside, protocatechuic acid, and vanillic acid. Tocopherols and tocotrienols contents were highest in red rice, then in black rice, brown rice, and polished rice. PSCs and CAAs of free and bound fractions were in the order: black rice > red rice > brown rice > polished rice, except that bound CAA of red rice was higher than that of black rice. The cellular uptake rate of free phenolics was highest in red rice, while cellular uptake rates of bound phenolics were highest in brown rice and polished rice.


Assuntos
Antioxidantes/análise , Carcinoma Hepatocelular/tratamento farmacológico , Flavonoides/análise , Neoplasias Hepáticas/tratamento farmacológico , Oryza/química , Fenóis/análise , Compostos Fitoquímicos/análise , Amidinas/efeitos adversos , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Depuradores de Radicais Livres/metabolismo , Células Hep G2 , Humanos , Estresse Oxidativo/efeitos dos fármacos , Peróxidos/metabolismo , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Especificidade da Espécie , Tocoferóis/análise , Tocotrienóis/análise
3.
J Food Sci ; 85(4): 1160-1166, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32125697

RESUMO

The effect of chemical refining process on the bioactive composition, in vitro antioxidant capacity, and their correlation of perilla seed oil (PSO) were investigated. In this paper, seven samples corresponding to each step of the refining process (degumming, neutralization, bleaching, deodorization, winterization, crude, and refined oils) were studied. The results showed that phenolic compounds and tocopherols were removed from PSO to a degree of 19.4% and 5.4%, respectively. In addition, the carotenoid content of PSO decreased during the refining process. The main carotenoid of PSO was found to be lutein, and the compound was lost completely during the bleaching step of the refining process. In this paper, we analyzed the variation of carotenoid content in PSO during the refining process for the first time. Neutralization affected the contents of phytosterols the most, followed by the effects of degumming and bleaching. The demonstrated results of Pearson product-moment correlation indicated that total tocopherols were significantly correlated with the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and oxygen radical absorption capacity (ORAC) values, whereas carotenoids were significantly correlated with the DPPH value. However, phenolic compounds and phytosterols have no significant difference with DPPH, 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt, ORAC, and ferric reducing antioxidant power values. The collected information can be applied to seeking out optimum factors needed to suffice the fundamental requirements for PSO production and minimize micronutrient losses to enhance its market value. PRACTICAL APPLICATION: The present study aimed to determine influence of chemical refining in the bioactive composition of perilla seed oil (PSO) as well as its antioxidant capacity in vitro. Moreover, we also intend to find the correlation between them. Results indicated that this study supplies a good reference for the industrial parameters of the refining process to minimize micronutrient losses and further obtain high-quality PSO products for consumers.


Assuntos
Antioxidantes/química , Manipulação de Alimentos/métodos , Perilla/química , Ácido alfa-Linoleico/química , Carotenoides/química , Micronutrientes/química , Fenóis/análise , Fitosteróis/química , Óleos Vegetais/química , Sementes/química , Tocoferóis/química
4.
Chemosphere ; 249: 126087, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32062555

RESUMO

Levoglucosan, a product from thermal decomposition of cellulose, is widely known as an organic tracer of biomass burning, but has also been reported from coal smoke particulate matter (PM) including lignites. This study provides direct evidence that levoglucosan is generated not only during low-temperature burning/smoldering of xylite, but also from other lignite types including detritic and detroxylitic brown coals from Poland. Moreover, only trace amounts of mannosan and galactosan have been detected in PM of lignite smoke. The hopanes in lignite smoke PM comprise the thermodynamically unstable ßß-hopanes and hopenes, with values of the homohopane index 22S/(22S + 22R) ranging from 0.02 to 0.12. This is characteristic for immature organic matter, and combined with the presence of anhydrosaccharides can be used as tracers for lignite combustion in ambient air. Furthermore, almost all Miocene lignite smoke PM samples contain α-, ß-, γ-, and δ-tocopherols, and prist-1-ene. This is the first report of the occurrence of all four tocopherol isomers in the geological record (in lignite extracts) and in lignite smoke PM samples. Lower α-tocopherol is observed for the lignite burn-test samples than in the corresponding lignite extracts, probably due to partial chain degradation to prist-1-ene during combustion.


Assuntos
Carvão Mineral , Temperatura Baixa , Monitoramento Ambiental/métodos , Compostos Orgânicos/análise , Fumaça/análise , Poluentes Atmosféricos/análise , Galactose/análogos & derivados , Galactose/análise , Manose/análogos & derivados , Manose/análise , Material Particulado/análise , Tocoferóis/análise
5.
Ecotoxicol Environ Saf ; 191: 110241, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-32007925

RESUMO

One of the major mechanisms of heavy metal toxicity is the induction of oxidative stress. Redox-active heavy metals, like chromium, can induce it directly, whereas redox-inactive metals, like cadmium, play an indirect role in the generation of reactive oxygen species (ROS). Living organisms defend themselves against oxidative stress taking advantage of low-molecular-weight antioxidants and ROS-detoxifying enzymes. Tocopherols and plastoquinol are important plastid prenyllipid antioxidants, playing a role during acclimation of Chlamydomonas reinhardtii to heavy metal-induced stress. However, partial inhibition of synthesis of these prenyllipids by pyrazolate did not decrease the tolerance of C. reinhardtii to Cr- and Cd-induced stress, suggesting redundancy between antioxidant mechanisms. To verify this hypothesis we have performed comparative analyses of growth, photosynthetic pigments, low-molecular-weight antioxidants (tocopherols, plastoquinol, plastochromanol, ascorbate, soluble thiols, proline), activities of the ascorbate peroxidase (APX), catalase and superoxide dismutase (SOD) and cumulative superoxide production in C. reinhardtii exposed to Cd2+ and Cr2O72- ions in the presence or absence of pyrazolate. The decreased α-tocopherol and plastoquinol content resulted in the increase in superoxide generation and APX activity in pyrazolate-treated algae. The application of heavy metal ions and pyrazolate had a pronounced impact on Asc and total thiol content, as well as SOD and APX activities (the latter only in Cd-exposed cultures), when compared with algae grown in the presence of heavy metal ions or pyrazolate alone. The superoxide production in cultures exposed to heavy metal ions and pyrazolate decreased when compared to the cultures exposed to either heavy metal ions or an inhibitor alone.


Assuntos
Antioxidantes/metabolismo , Cloreto de Cádmio/toxicidade , Cromatos/toxicidade , Plastoquinona/análogos & derivados , Compostos de Potássio/toxicidade , Tocoferóis/metabolismo , Chlamydomonas reinhardtii/metabolismo , Relação Dose-Resposta a Droga , Íons , Estresse Oxidativo/efeitos dos fármacos , Fotossíntese/efeitos dos fármacos , Plastoquinona/metabolismo , Espécies Reativas de Oxigênio/metabolismo
6.
Mol Carcinog ; 59(4): 365-389, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32017273

RESUMO

α-Tocopherol (α-T) is the major form of vitamin E (VE) in animals and has the highest activity in carrying out the essential antioxidant functions of VE. Because of the involvement of oxidative stress in carcinogenesis, the cancer prevention activity of α-T has been studied extensively. Lower VE intake or nutritional status has been shown to be associated with increased cancer risk, and supplementation of α-T to populations with VE insufficiency has shown beneficial effects in lowering the cancer risk in some intervention studies. However, several large intervention studies with α-T conducted in North America have not demonstrated a cancer prevention effect. More recent studies have centered on the γ- and δ-forms of tocopherols and tocotrienols (T3). In comparison with α-T, these forms have much lower systemic bioavailability but have shown stronger cancer-preventive activities in many studies in animal models and cell lines. γ-T3 and δ-T3 generally have even higher activities than γ-T and δ-T. In this article, we review recent results from human and laboratory studies on the cancer-preventive activities of different forms of tocopherols and tocotrienols, at nutritional and pharmacological levels. We aim to elucidate the possible mechanisms of the preventive actions and discuss the possible application of the available information for human cancer prevention by different VE forms.


Assuntos
Antioxidantes/farmacologia , Suplementos Nutricionais , Neoplasias/prevenção & controle , Vitamina E/farmacologia , Animais , Antioxidantes/administração & dosagem , Carcinogênese/efeitos dos fármacos , Humanos , Neoplasias/metabolismo , Neoplasias/patologia , Oxirredução/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Tocoferóis/administração & dosagem , Tocoferóis/classificação , Tocoferóis/farmacologia , Vitamina E/administração & dosagem
7.
Ecotoxicol Environ Saf ; 193: 110345, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32092578

RESUMO

Many areas of the world are affected simultaneously by salinity and heavy metal pollution. Halophytes are considered as useful candidates in remediation of such soils due to their ability to withstand both osmotic stress and ion toxicity deriving from high salt concentrations. Quinoa (Chenopodium quinoa Willd) is a halophyte with a high resistance to abiotic stresses (drought, salinity, frost), but its capacity to cope with heavy metals has not yet been fully investigated. In this pot experiment, we investigated phytoextraction capacity, effects on nutrient levels (P and Fe), and changes in gene expression in response to application of Cr(III) in quinoa plants grown on saline or non-saline soil. Plants were exposed for three weeks to 500 mg kg-1 soil of Cr(NO3)3·9H2O either in the presence or absence of 150 mM NaCl. Results show that plants were able tolerate this soil concentration of Cr(III); the metal was mainly accumulated in roots where it reached the highest concentration (ca. 2.6 mg g-1 DW) in the presence of NaCl. On saline soil, foliar Na concentration was significantly reduced by Cr(III). Phosphorus translocation to leaves was reduced in the presence of Cr(III), while Fe accumulation was enhanced by treatment with NaCl alone. A real-time RT-qPCR analysis was conducted on genes encoding for sulfate, iron, and phosphate transporters, a phytochelatin, a metallothionein, glutathione synthetase, a dehydrin, Hsp70, and enzymes responsible for the biosynthesis of proline (P5CS), glycine betaine (BADH), tocopherols (TAT), and phenolic compounds (PAL). Cr(III), and especially Cr(III)+NaCl, affected transcript levels of most of the investigated genes, indicating that tolerance to Cr is associated with changes in phosphorus and sulfur allocation, and activation of stress-protective molecules. Moderately saline conditions, in most cases, enhanced this response, suggesting that the halophytism of quinoa could contribute to prime the plants to respond to chromium stress.


Assuntos
Chenopodium quinoa/efeitos dos fármacos , Chenopodium quinoa/metabolismo , Cromo/toxicidade , Salinidade , Poluentes do Solo/toxicidade , Biodegradação Ambiental , Transporte Biológico/efeitos dos fármacos , Chenopodium quinoa/genética , Cromo/farmacocinética , Expressão Gênica/efeitos dos fármacos , Íons/metabolismo , Ferro/metabolismo , Chumbo/metabolismo , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Prolina/biossíntese , Plantas Tolerantes a Sal/efeitos dos fármacos , Plantas Tolerantes a Sal/genética , Plantas Tolerantes a Sal/metabolismo , Sódio/metabolismo , Cloreto de Sódio/farmacologia , Poluentes do Solo/farmacocinética , Estresse Fisiológico , Enxofre/metabolismo , Tocoferóis/metabolismo
8.
Food Chem ; 315: 126235, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32006865

RESUMO

The commercialization of declared blends of olive oil and seed oil is something long approved by the European Union. There, the olive oil percentage must be at least 50% if the producer aims to advertise its presence on the front label, i.e., somewhere other than in the ingredients list. However, the Regulation did not propose any method to verify such proportion. For this purpose, we recommend the use of decisional trees, being the parameters under study those in which the greatest differences between olive and seed oils are shown: triacylglycerols, acyclic saturated hydrocarbons, free sterols, and tocopherols. In this way, to guarantee the presence of olive oil at 50%: i) palmitodiolein must be above 11-15%; ii) the ß/γ-tocopherol ratio must be below 2.4; iii) the alkane sum C21-C25 should be higher than 3.5-6%; and iv) the total sterol content cannot surpass 2400 mg/kg.


Assuntos
Análise de Alimentos/métodos , Azeite de Oliva/análise , Azeite de Oliva/química , Ácidos Graxos/análise , Análise de Alimentos/normas , Olea , Fitosteróis/análise , Sementes/química , Óleo de Girassol/análise , Óleo de Girassol/química , Tocoferóis/análise , Triglicerídeos/análise
9.
Nat Prod Res ; 34(5): 706-709, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30445845

RESUMO

Phyllanthus phillyreifolius (Euphorbiaceae), poorly studied plant species, was fractionated using conventional and high pressure extraction techniques such as supercritical fluid and pressurized liquid extractions. Lipophilic substances were extracted with n-hexane and supercritical CO2 with or without co-solvent ethanol, meanwhile higher polarity fractions were recovered with acetone and 70% ethanol. Antioxidant potential was assessed by various chemical assays, which revealed that 70% ethanol was the most effective solvent for recovery of antioxidants. UPLC-MS phytochemical analysis of hydrophilic extracts confirmed geraniin as the main constituent of P. phillyreifolius. Other quantitatively important compounds were phyllanthusiin D and elaeocarpusin. Three isomers of tocopherol (α, ß and γ) were quantified by HPLC in lipofhilic extracts. Generally, the results from this study revealed high antioxidant potential of P. phillyreifolius; consequently the plant may be considered as a promising source of antioxidants for functional foods, nutraceuticals and pharmaceutical formulations.


Assuntos
Antioxidantes/isolamento & purificação , Phyllanthus/química , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/química , Solventes/química , Antioxidantes/química , Cromatografia Líquida de Alta Pressão , Glucosídeos/análise , Taninos Hidrolisáveis/análise , Compostos Fitoquímicos/análise , Compostos Fitoquímicos/isolamento & purificação , Espectrometria de Massas em Tandem , Tocoferóis/isolamento & purificação , Tocoferóis/farmacologia
10.
Crit Rev Food Sci Nutr ; 60(3): 461-478, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-30596262

RESUMO

Unravelling the relationship between food and health requires a more in-depth knowledge of the various changes occurring in the gastrointestinal tract during digestion and which may ultimately affect the nutritional quality and safety of ingested food lipids before absorption into the bloodstream. In this context, this review deals with the oxidation process of food lipids under digestive conditions and the studies carried out on this topic using different digestion models: in vitro, in vivo or ex vivo, static or dynamic, and including one, two and/or three digestive phases (oral, gastric and duodenal). These studies have contributed to clarifying the occurrence and extent of lipid degradation under such a particular environment, many of them also highlighting the factors affecting the advance or delay of the oxidation of dietary lipids during digestion, like: food lipid content, unsaturation degree and initial oxidative status; the presence in the food bolus of compounds showing antioxidant activity (polyphenols, tocopherols…) either added or naturally present; the presence in the food bolus of proteins (including iron or not); food technological or culinary processings (salting, smoking, cooking…), among others. Likewise, the methodologies employed to study lipid oxidation under digestive conditions are also summarized and future research perspectives are discussed.


Assuntos
Digestão , Trato Gastrointestinal/metabolismo , Lipídeos/química , Lipólise , Antioxidantes/química , Humanos , Oxirredução , Polifenóis/química , Tocoferóis/química
11.
Nat Prod Res ; 34(2): 296-299, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30406669

RESUMO

Tephrosia apollinea is a legume species, native to southwest Asia and northeast Africa, rich in bioactive flavonoids (hydrophilic compounds). T. apollinea seeds were not considered previously as a potential source of lipophilic compounds such as: essential fatty acids, tocopherols, sterols, and squalene, hence, the present study were performed. The oil yield in T. apollinea seeds amounted to 11.8% dw. The T. apollinea seed oil was predominated by the polyunsaturated fatty acids - linoleic (26.8%) and α-linolenic (22.7%). High levels were recorded also for oleic (27.6%) and palmitic (14.9%) acids. Four tocopherols and one tocotrienol, with the domination of γ-tocopherol (98%) were identified in T. apollinea seed oil. The ß-sitosterol (59%), Δ5-stigmasterol (21%) and campesterol (9%) were detected as main sterols in T. apollinea seed oil. The total content of tocochromanols, sterols, carotenoids and squalene in the T. apollinea seed oil was 256.7, 338.1, 12.5 and 1103.8 mg/100 g oil, respectively. T. apollinea seeds oil, due to the high concentration of lipophilic bioactive compounds can find a potential application in the food, cosmetic and pharmaceutical industry.


Assuntos
Ácidos Graxos Insaturados/análise , Sementes/química , Esqualeno/isolamento & purificação , Esteróis/isolamento & purificação , Tephrosia/química , Tocoferóis/isolamento & purificação , Carotenoides/análise , Colesterol/análogos & derivados , Fitosteróis , Óleos Vegetais/química , Sitosteroides , Esqualeno/análise , Esteróis/análise , Tocoferóis/análise , Tocotrienóis
12.
Nat Prod Res ; 34(1): 26-33, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30663361

RESUMO

Portulaca oleracea is an annual succulent herb in the family Portulacaceae. It is a nutritious vegetable with high antioxidant properties and, it is among the richest plant source of ω-3 fatty acids, as well as a rich source of ω-6 fatty acids, ascorbic acid, tocopherols and beta-carotene. In the present study, three purslane populations under different Mediterranean environmental conditions for two years, for future valorization as novel food sources of omega-3 fatty acids, were evaluated. In particular, biomorphological characteristics, total phenols and fatty acids content were determined. The antioxidant activities were evaluated using 2,2-diphenyl-1-picrylhydrazyl assay. The population "Cas" appears to have higher antioxidant activity than the other two populations ("Cal" and "S. Ven").The saturated fatty acid content is influenced only by the year of collection, while the polyunsaturated fatty acid by the populations. The most abundant unsatured fatty acids are linoleic and linolenic acids and "Cas" attained the highest contents.


Assuntos
Antioxidantes/análise , Ácidos Graxos Ômega-3/análise , Ácidos Graxos/análise , Portulaca/química , Antioxidantes/isolamento & purificação , Ácido Ascórbico/análise , Ácidos Graxos/isolamento & purificação , Ácidos Graxos Insaturados/análise , Ácidos Linolênicos/análise , Fenóis/análise , Sicília , Tocoferóis/análise , beta Caroteno/análise
13.
Food Chem Toxicol ; 136: 111036, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31862287

RESUMO

Maqui-berry (Aristotelia chilensis) is the emerging Chilean superfruit with high nutraceutical value. Until now, the research on this commodity was focused on the formulations enriched with polyphenols from the pulp. Herein, contents of tocols were compared in the seed oil of Maqui-berry obtained through three different extraction methods followed by determining their antioxidative and enzyme inhibitions in-vitro. Firstly, oilseed was extracted with n-hexane (Soxhlet method), chloroform/methanol/water (Bligh and Dyer method) and pressing (industrial). These samples were used to access their effects against DPPH, HORAC, ORAC, FRAP, Lipid-peroxidation (TBARS), α-amylase, α-glucosidase, and pancreatic lipase. All the isomers of tocopherol and tocotrienol were identified, and ß-sitosterol was the only sterol found in higher amounts than other vegetable oils. The Bligh and Dyer method could lead to the highest antioxidative capacity compared to Soxhlet and press methods likely because the latter have a higher amount of tocopherols. Further, seed oil from Maqui berry and their tocols (α, ß, γ, δ-tocopherols, tocotrienols, and ß-sitosterol) warrant clinical investigation for their antioxidative and antiobesity potential. Taken together, these findings provide relevant and suitable conditions for the industrial processing of Maqui-berry.


Assuntos
Fármacos Antiobesidade/farmacologia , Antioxidantes/farmacologia , Inibidores Enzimáticos/farmacologia , Sitosteroides/farmacologia , Tocoferóis/farmacologia , Tocotrienóis/farmacologia , Animais , Fármacos Antiobesidade/análise , Antioxidantes/análise , Inibidores Enzimáticos/análise , Lipase/antagonistas & inibidores , Magnoliopsida/química , Masculino , Ratos Wistar , Sementes/química , Sitosteroides/análise , Tocoferóis/análise , Tocotrienóis/análise
14.
J Sci Food Agric ; 100(1): 354-361, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31588554

RESUMO

BACKGROUND: Postharvest processing, including drying, has a significant effect on the processability of oil crop seeds. High drying air temperature may significantly affect the levels of bioactive compounds in plant raw materials. We decided to investigate the subject given the lack of data on the drying of mustard seeds. The aim was to determine the effect of drying temperature on free fatty acid, phytosterol and tocopherol levels in the oil obtained from white mustard seeds. Seeds were dried in a thin layer at 40, 60, 80, 100, 120 and 140 °C. Changes in phytosterol levels were assessed using gas chromatography-mass spectrometry and changes in tocopherol levels by high-performance liquid chromatography. RESULTS: The analysis showed that, upon completion of air drying at 40-100 °C, losses of sterols did not exceed 5%, while upon completion of drying at 120 °C and 140 °C these losses amounted to 17-50%. Our investigation also showed that during drying of white mustard seed the total tocopherol levels increased, and the higher the drying temperature, the greater the increment. In seeds air-dried at 120 °C and 140 °C, the increase in tocopherol amounted to 7-9%. CONCLUSION: We also showed that the temperature of the drying agent significantly affects the tocopherol and phytosterol levels. It was found that a maximum temperature of 100 °C provides optimal drying conditions for mustard seeds. Principal component analysis identified two subgroups of oils obtained from seeds dried at 120 °C and 140 °C, which differed considerably from the other samples in terms of their bioactive component contents. © 2019 Society of Chemical Industry.


Assuntos
Dessecação/métodos , Fitosteróis/análise , Extratos Vegetais/análise , Sementes/química , Sinapis/química , Tocoferóis/análise , Cromatografia Gasosa-Espectrometria de Massas , Temperatura , Vitamina E/análise
15.
Food Chem ; 302: 125306, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31416004

RESUMO

Plasma, the fourth stage of matter, is a partially or wholly ionized state of gas. Degree of lipid oxidation and effects of antioxidants were evaluated in bulk oils at plasma treatment. Significant changes in the conjugated dienoic acid were induced after 10 min of plasma treatment, which corresponded to treatment for 2.5 h at 100 °C and 48 h at 60 °C. Tocopherol stability in the stripped corn oil was significantly higher than that in medium-chain triacylglycerol after the plasma treatment. The antioxidant capacities of 10 µM of α-tocopherol and sesamol were higher than that of ß-carotene, and synergistic effects among α-tocopherol, sesamol, and ß-carotene were not observed. Added α-tocopherol and sesamol decreased CDA formation by 33 and 30% compared to control samples after plasma treatment. Moisture content in oils decreased significantly about 20% moisture after 6 min plasma treatment. Lipid oxidation could be an important issue in plasma-treated lipid-rich products.


Assuntos
Antioxidantes/química , Óleo de Milho/química , Indústria de Processamento de Alimentos/métodos , Benzodioxóis/química , Temperatura Alta , Lipídeos/química , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Fenóis/química , Tocoferóis/química , Triglicerídeos/química , alfa-Tocoferol/química , beta Caroteno/química
16.
Food Chem ; 309: 125688, 2020 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-31732249

RESUMO

The antiradical power, at equal concentrations of active principles, of the following antioxidants were studied using the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) assay: butylated-hydroxyanisole, butylated-hydroxytoluene, tert-butylhydroquinone, ascorbyl palmitate, tocopherol, grape seed extract, olive extract and five rosemary extracts with different concentrations of carnosic acid (CA) and carnosol (COL). The reaction kinetics of DPPH scavenging activity in each studied substance identified significant variations in the time needed to reach the steady state. Rosemary extracts were seen to be more effective than the other compounds. CA had higher antioxidant activity than COL, although COL seemed to react faster with DPPH. The relevance of the CA/COL ratio for the antioxidant activity of rosemary extracts was also analysed. The presence of COL in rosemary extracts increased the antioxidant activity with an optimal CA/COL ratio of 2.5-3.0. Olive extract and grape seed extract seem to be very promising additives for use as technological antioxidants.


Assuntos
Antioxidantes/farmacologia , Extratos Vegetais/farmacologia , Rosmarinus/química , Abietanos/análise , Abietanos/farmacologia , Antioxidantes/análise , Antioxidantes/química , Ácido Ascórbico/análogos & derivados , Ácido Ascórbico/análise , Ácido Ascórbico/farmacologia , Hidroxianisol Butilado/análise , Hidroxianisol Butilado/farmacologia , Hidroxitolueno Butilado/análise , Hidroxitolueno Butilado/farmacologia , Aditivos Alimentares/análise , Extratos Vegetais/análise , Tocoferóis/análise , Tocoferóis/farmacologia
17.
Food Chem ; 309: 125735, 2020 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-31704077

RESUMO

Jabuticaba (Myrciaria jaboticaba (Vell.) Berg) is a Brazilian berry, very appreciated for in natura consumption. However, its epicarp is not normally consumed due to its stiffness and astringent taste, and in manufacture of products from jabuticaba fruit, it is responsible for the generation of large amounts of residues. The exploration of by-products is becoming important for the obtainment of valuable bioactive compounds for food and pharmaceutical industries. In this context, jabuticaba epicarp was studied regarding its chemical composition, namely in terms of phenolic compounds, tocopherols, and organic acids, and its bioactive properties, such as antioxidant, anti-proliferate, anti-inflammatory, and antimicrobial activities. A total of sixteen phenolic compounds, four tocopherols and six organic acids were identified in jabuticaba epicarp. Regarding bioactive properties, it showed high antioxidant activity, also presenting moderate anti-inflammatory, anti-proliferative, and antimicrobial activities. The extract did not present hepatotoxicity, confirming the possibility of its applications without toxicity issues.


Assuntos
Myrtaceae/química , Extratos Vegetais/química , Animais , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Antioxidantes/química , Bactérias/efeitos dos fármacos , Brasil , Frutas/química , Frutas/metabolismo , Taninos Hidrolisáveis/química , Taninos Hidrolisáveis/isolamento & purificação , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Myrtaceae/metabolismo , Óxido Nítrico/metabolismo , Fenóis/química , Fenóis/isolamento & purificação , Células RAW 264.7 , Tocoferóis/química , Tocoferóis/isolamento & purificação
18.
Molecules ; 24(24)2019 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-31842452

RESUMO

The aim of the study was to analyze the influence of the surface area to volume ratio of pressed and refined rapeseed oils on the changes in tocopherol content and polymerization of triacylglycerols during heating. In the study the pressed and refined rapeseed oil was heated at 170 °C, during 6, 12, and 18 h with three different surface area to volume (s/v) ratios (0.378, 0.189, and 0.126 cm-1). During heating, a decrease in tocopherols and increases in dimers, trimers, and oligomers of triacylglycerols were observed. However, the changes were dependent on the surface area to volume ratio used, type of oil and time of heating. The biggest changes were observed in oil with the biggest s/v ratio (0.378 cm-1), and the lowest when the s/v ratio was 0.126 cm-1. The pressed oil was characterized by faster degradation of tocopherols and slower increase of triacylglycerol polymer levels compared to refined oil.


Assuntos
Temperatura Alta , Polimerização , Óleo de Brassica napus/química , Tocoferóis/química , Triglicerídeos/química
19.
Molecules ; 25(1)2019 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-31877675

RESUMO

The aim of the study was to evaluate the influence of variety and the date of harvest of hazelnut seeds on their antioxidant potential and the profile and content of polyphenols and tocopherols. The research material included the hazelnut seeds of six varieties, harvested from July to September at equal 30-day intervals. Hazelnuts were analyzed for total fat content and antioxidant properties, whereby UPLC-PDA-ESI-MS analysis was used to determine the profile and content of polyphenols, and the HPLC method to determine the content of tocopherols. It was found that the content of fat and tocopherols in nuts increased with the ripening of the nuts. The highest fat content was found in walnut seeds of the Katalonski variety (September) and tocopherols in walnut seeds of the Olbrzym z Halle variety (177.67 mg/kg d.m.). In turn, antioxidant properties and total polyphenols content decreased with the later harvest date. The strongest antioxidant potential was found in the case of Cosford nuts harvested in July (66.93 mmol TE/100 g d.m.). These nuts were also characterized by the highest total polyphenol content (1704.9 mg/100 g d.m.). UPLC-MS analysis allowed the identification of 15 polyphenolic compounds such as phenolic acids, catechins and ellagic acid hexoside in nut seeds.


Assuntos
Antioxidantes/análise , Catequina/análise , Corylus/química , Polifenóis/análise , Sementes/química , Tocoferóis/análise , Corylus/crescimento & desenvolvimento , Ácido Elágico/análise , Polifenóis/metabolismo , Sementes/crescimento & desenvolvimento , Tocoferóis/metabolismo
20.
J Food Sci ; 84(12): 3614-3623, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31769515

RESUMO

Some amino acids have strong antioxidant activity in frying oil. This study aimed to obtain further information including antioxidant activity at different concentrations and interactions with rosemary extract, green tea extract, and ascorbic acid. Antioxidant activity of arginine, cysteine, lysine, methionine, and tryptophan was examined by increasing the concentration in soybean oil (SBO) at 180 °C within the concentration range of 0 to 15 mM. These amino acids showed increased activity with increasing concentration without showing prooxidant activity at the given concentration range. Addition of 15 mM methionine did not inhibit the prooxidant activity of α-tocopherol at high concentrations in SBO while it significantly increased the activity at each concentration of α-tocopherol. Methionine showed an additive effect with a commercial rosemary extract while lysine had an antagonistic interaction in SBO at the total concentration of 5.5 mM. Mixtures of green tea extract and methionine did not show better activity than methionine alone in SBO and stripped SBO. (-)-Epigallocatechin gallate, the major active component in green tea, showed a synergistic effect with methionine in stripped SBO but there was no significant interaction effect in SBO. Although ascorbic acid had a synergistic effect with methionine in stripped SBO, it showed a significant antagonistic effect in SBO. Methionine had strong antioxidant activity in six other vegetable oils showing a moderate correlation (R2 = 0.45 to 0.52) with the ratio of unsaturated fatty acids to saturated fatty acids indicating the effectiveness may be related to the fatty acid composition of oil. PRACTICAL APPLICATION: Some amino acid such as methionine and lysine showed stronger antioxidant activity than the leading commercial natural antioxidant, rosemary extract. These amino acids showed great potential as a natural antioxidant in frying. The price of food-grade L-methionine is generally lower than rosemary extract and green tea extract. This paper provides information on the concentration effect and interactions with currently used antioxidants such as tocopherols, rosemary extract, green tea extract, and ascorbic acid.


Assuntos
Aminoácidos/química , Antioxidantes/química , Extratos Vegetais/química , Rosmarinus/química , Chá/química , Ácido Ascórbico/química , Catequina/análogos & derivados , Catequina/química , Culinária , Temperatura Alta , Óleo de Soja/química , Tocoferóis/química , alfa-Tocoferol/química
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