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Phenolic compounds, including flavonoids, are nutritionally important for their antioxidant activities and protective functions against disease risk caused by oxidative stress. These compounds are primarily found in fruits, and mangoes are an important source. This paper aims to address these issues.

In this work, the antioxidant activities of mangoes cultivated in three different ways were evaluated by their ability to capture free radicals using the DPPH radical.

The results showed that the biodynamic mangoes had highest antioxidant activity in mature‐green and ripe fruits, while for those of organic origin the antioxidant activity was highest in unripe fruits. The organic mangoes also showed highest values of phenolic compounds at all maturation stages. The mangoes from conventional crops had lower values for all parameters evaluated in this study than the organically and biodynamically cultivated fruits.

This work brings an important contribution in the field of agriculture at a time when organic and biodynamic systems of cultivation are an alternative to the conventional system and that pollutes the environment and produces food that contains quantities of chemical contaminants that can damage the health of the consumer. The comparison in phenolic compounds content, flavonoids and antioxidant activity in biodynamic, organic and conventional systems is original and of great importance, showing that the ecological cropping systems are less harmful to the environment and promote improvements to the chemical composition of foods.

The purpose of this paper is to study the effect of new heterocyclic compounds on styrene butadiene rubber (SBR) mixes.

It has been found that the starting material 1 could react with cyromazine (2) and/or 4‐aminoantipyriene (4) as amino compounds in the presence of triethylorthoformate and in the boiling dioxane to yield triazine‐3 and/or pyrazolo 5 derivatives, respectively. The chemical structures of the new products 3 and 5 have been established by their elemental analyses spectroscopic data IR, Ms and 1H, 13C NMR. These two compounds were evaluated as antioxidants in SBR, and this evaluation was confirmed by physico‐mechanical properties of vulcanizates, IR spectra and scanning electron microscope.

The difference between maximum torque MH and minimum torque ML (ΔM), tensile strength, modulus and elongation at break increases in the presence of prepared antioxidants while the equilibrium swelling decreased. The rubber vulcanizates were subjected to thermal oxidative aging at 90°C for up to seven days. It has been found that new compounds 3 and 5 can protect SBR vulcanizates against oxidative deterioration.

The solubility of the prepared compounds 3 and 5 is very poor and they are only soluble in dimethyl formamide (DMF) or dimethyl sulphoxide (DMSO) which have high boiling points. Also, new compounds 3 and 5 have melting points (above 300°C).

Triazine and antipyrine derivatives have many medical and industrial applications.

The new synthesized compounds revealed excellent antioxidant behaviour in comparison with the commercial antioxidant phenyl‐β‐naphthyl amine (PβN) which is used in industry.

This paper aims to examine the bioactive compounds and texture properties of cereal bars formulated with banana peel flour during storage.

Seven cereal bars were produced and stored during 11 months, under vacuum and protected from the light. The total phenolic compounds, the activity antioxidant by ABTS [2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)] method, the DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) method expressed as EC50 (concentration required to reduce the original amount of free radicals by 50 per cent) and texture properties were evaluated over the storage period.

In general, total phenolic compounds decreased during storage (from 4.19 to 1.11 mg GAE. g-1f.w.). Although the total antioxidant activity (ABTS method) increased during the fifth month, it reduced during storage (from 3.41 to 0.30 µmol TE.g-1f.w.); and the EC50 was not modified in many formulations, though it decreased in other formulations during storage period (from 3913 to 19221 g fruit.g-1 DPPH). The force of rupture began to increase in the fourth month (reaching 62.4 N), and hardness began to increase in the ninth month (reaching 444 N). The formulation and time factors influenced the total phenolic compounds, total antioxidant activity (ABTS method), force of rupture and hardness, while EC50 was only influenced by the formulation (p-value = 0.001). A principal component analysis showed that time had little effect on the most important characteristics considered in description of the cereal bars.

Cereal bars can be consumed up to the third month of storage, considering the texture of the products. Moreover, the presence of bioactive compounds in cereal bars depends on the addition of banana peel flour, which it contributes to the insertion of total phenolic compounds and total antioxidant activity in cereal bars, aggregating functional properties in these products.

This study aims to evaluate the effect of grape seed extract on the thermal oxidation of soybean oil.

Four treatments were used: soybean oil (SO), butylhydroxytoluene (BHT), antioxidant at concentration of 100 mg/kg in soybean oil (BHTSO), grape seed extract at a concentration of 100 mg/kg in soybean oil (Extract), and mixture at a concentration of 50 mg/kg of grape seed extract (Mixture) and 50 mg/kg of BHT in soybean oil subjected to 180°C for 20 h. The total phenolic compounds were quantified by spectrophotometry using the Folin-Ciocalteu reagent. The antioxidant activity was evaluated by the ABTS^•+, DPPH^• and FRAP acid systems. The fatty acid composition and phytosterols were determined by gas chromatography (GC) and tocopherols were determined by high-performance liquid chromatography.

Among the treatments studied, the Extract and the Mixture presented lower losses of total phenolic compounds, DPPH^• and FRAP, while BHTSO had an opposite effect. After 10 h of heating, the Mixture and the Extract were more effective in reducing the formation decomposition products, measured by the amount of total polar compounds. The Mixture resulted in higher retention of essential fatty acids at the end of heating. The Extract and Mixture showed higher retention rates of total tocopherols and the Mixture resulted in 338.71 mg/100 g (P ≤ 0.05) of total phytosterol after 20 h of heating.

Oils undergoing the heating process suffer major changes, requiring the addition of antioxidant compounds. As a result of the questioning on the use of chemical additives, research on natural antioxidants, as substitute to the synthetic ones, is increasing. Among the natural compounds with high antioxidant potential, the grape wastes such as its seeds are highlighted. Studies using grape seed extract are scarce.

This research aims to evaluate the antioxidant potential of oregano extract (OE), as well as its isolated and synergistic effect when applied to soybean oil (SO) under thermal oxidation.

In order to determine the antioxidant activity of oregano extract and its synergistic effect with tert‐butylhydroquinone (TBHQ), thermal oxidation was performed using the following treatments: SO, SO with 50 mg/kg of TBHQ, SO with 3,000 mg/kg of OE, and SO with 3,000 mg/kg of oregano extract and 50 mg/kg of TBHQ (mixture). The treatments underwent heating at 180°C for 20 hours, and analyses of oxidative stability, total polar compounds, tocopherols and fatty acids composition were performed. The results obtained were subjected to analysis of variance and Tukey test for averages at 5 percent, using the program ESTAT version 2.0.

Considering the results of antioxidant activity and total phenolic compounds, it was possible to verify that the ethanolic extract of oregano has presented antioxidant potential. Furthermore, considering the results obtained in the analyses of oxidative stability, polar compounds, tocopherols and fatty acids profile, it was possible to observe that the extract has prevented lipid oxidation when added to SO.

The study offers information on the use of natural antioxidants as an alternative to the use of synthetic antioxidants, which can be considered toxic.

This study aims to analyze the levels of vitamin C, phenolic compounds and antioxidants in baby food. Providing nutritious food to the infants is essential for their growth and development. Baby foods are foods prepared from any suitable nutritive material and intended for feeding children after six months of age. The search for foods that meet the nutritional needs of children and that also promote aspects of health has increased on the part of parents.

A total of 17 different types of baby foods (2 brands) were purchased and the vitamin C content, total phenolic compounds (TPC) and antioxidant activity were determined. The authors also assessed the adequacy of labeling in accordance with regulatory parameters. Data was submitted to analysis of variance, and the means were compared by the Tukey test at 5% probability. Principal component analysis was performed to evaluate the results (phenolic compounds, vitamin C and antioxidant activity) from the multidimensional point of view.

In general, the labeling of baby foods proved to be within the legislation, but with confusing information for the consumer. BF7-AAPO (apple pulp and juice, papaya and orange juice), BF-BAO (banana, apple juice and oatmeal) and BF-AA (apple pulp and juice) showed the highest vitamin C content (20–28 mg/100 g; p < 0.001). BF-A (apple), BF-B (banana) and BF-AA showed the highest TPC (7–8.2 mg/100 g; p < 0.001). BF-CP (cassava-parsley), BF-PCBCP (potato, carrot, beef and cassava-parsley) and BF-PCBB (potato, carrot, beef and broccoli) showed the highest antioxidant activity (44–48%; p < 0.001). High value of TPC was related to high value of antioxidant activity in baby foods. In conclusion, vitamin C content in the baby foods was different from those reported on the labels and there was a direct relationship between the content of TPC and the antioxidant capability.

The objective of this work was to evaluate bioactive compounds and antioxidant activity in baby foods. So far, few papers have reported on the subject as the authors seek to know about essential nutrients. However, this knowledge is important because these compounds can decrease and/or prevent inflammatory processes in the body.

This paper aims to evaluate effects of the fortification of polyphenolic compound mixtures of quercetin, caffeic acid, tryrosol and hydroxytyrosol in olive oil oxidation.

The authors measured olive oxidation initiated by copper using thiobarbituric acid reactive substance, as an indicator of lipid peroxidation.

Overall, most mixture combinations exhibited oxidation similar to olive oil alone. Some mixture combinations of polyphenolic compounds acted as antioxidants; however, as the concentrations were changed, they became prooxidant in nature.

In vitro studies have limitations for extrapolation to in vivo and clinical studies.

Such information will be useful in determining optimal concentrations and combinations of antioxidants for reducing rancidity and perhaps as models that could be used to modulate various chronic diseases that are associated with oxidative stress.

Olive oil, along with fruits, vegetables and fish, are important constituents of health promoting diets, such as the Mediterranean diet. Active ingredients include monounsaturated fatty acids, oleic acid and a variety of antioxidants including various polyphenolic compounds.

The purpose of this paper is to investigate the efficient exploitation of bioactive compounds present in red, green and brown seaweeds to develop hygienic products.

To analyse the antioxidant properties and identification of significant bioactive compounds of green, red and brown seaweed treated cotton fabrics, total antioxidant activity, DPPH Free radical scavenging activity and gas chromatography-mass spectrometry analysis were used.

The experimental result specifies that the maximum antioxidant activity of 126.50 µg/ml and inhibition percentage of 76 ± 0.15 percent was achieved in the seaweed treated cotton fabrics. All six seaweed treated fabrics proved slightly lesser water vapour and air permeability compared with the untreated fabric.

The seaweed treated cotton materials are suitable for making wound dressing, surgical wear, face mask, sportswear, healthcare and hygienic applications.

The purpose of this paper is to determine the antioxidant activity of natural polyphenols from larch wood by the amperometric method.

Direct measurements of antioxidant activity were carried out by the amperometric method in an oxidizing mode with glassy carbon as a working electrode, set potential +1.3V and using a flow-injection system with 2.2 mM phosphoric acid as the mobile phase with a flow rate of 1.2 ml/min.

The reported results show the following values of antioxidant activity for the tested compounds: (−)-secoisolariciresinol – 0.199 ± 0.002 mg/L (p < 0.05); isolariciresinol – 0.196 ± 0.002 mg/L (p < 0.05); lariciresinol - 0.222 ± 0.001 mg/L (p < 0.05); O-isopropylidene derivative of (−)-secoisolariciresinol - 0.143 ± 0.002 mg/L (p < 0.05); (+)-dihydroquercetin – 0.153 ± 0.002 mg/L (p < 0.05); and quercetin – 0.521 ± 0.001 mg/L (p < 0.05). The last product was tested as the reference of a widely used current antioxidant. General tendencies of determined values of antioxidant activity for studied compounds are in good correlation with published data as determined by the t-BuOOH-initiated lipid peroxidation method.

Described results show practical applicability of the amperometric method as being faster and cheaper in comparison to other methods, including oxygen radical absorbance capacity (ORAC) assay or 2,2′diphenyl-1-picrylhydrazyl (DPPH) reagent based assay.

The described results show the first-time application of the amperometric method for the evaluation of the antioxidant activity of phenolic compounds from larch wood.

Examines the antioxidant activities of a range of hydroxy‐substituted phenolic acids by estimating their relative abilities to scavenge the ABTS_+ radical cation generated in the aqueous phase, expressed as the Trolox equivalent antioxidant capacity (TEAC value). These common food components have varying reducing abilities, dependent on the positions and extent of hydroxylation of their phenol ring. Reports the research results which suggest that some simple phenolic acids are most effective antioxidants, up to two to three times as active as vitamin C. Their relative abundance in fruits, oils, etc. indicates that they may be highly significant contributors to the overall dietary antioxidant intake. Para‐coumaric acid (4‐hydroxycinnamic acid) was found to have a TEAC value of 2.2mM (more than twice the antioxidant activity of vitamin C). Ferulic acid (3‐methoxy, 4‐hydroxycinnamic acid), the active component of oryzanol (rice bran oil) was found to have a TEAC value of 1.9 mM and gallic acid (3, 4, 5‐trihydroxybenzoic acid) a TEAC of 3.0mM (i.e. three times the antioxidant activity of vitamin C). Discusses the significance of these and other related compounds as food antioxidants and as non‐nutrient antioxidants in the diet.