Synthetic Antioxidant BHT Research Articles

The Effectiveness of Extracts of Spent Grape Pomaces in Improving the Oxidative Stability of Grapeseed Oil

Spent grape pomace is a by-product of Grappa production that is usually considered waste. Therefore, in this study, in order to promote the sustainable use of by-products from the food industry, we aimed to optimize the extraction of antioxidants from spent grape pomace and their use to improve the oxidative stability of grapeseed oil. Ultrasound-assisted extraction maximized the total phenolic content and antioxidant activity, with the latter measured according to the ferric reducing antioxidant power. The best extraction conditions identified for spent grape pomace from red and white grapes were an amplitude of 40%, a duration of 22 min and a ratio of 1:37 and an amplitude of 40%, a duration of 25 min and a ratio of 1:45, respectively. Grapeseed oil, which is rich in polyunsaturated fatty acids and susceptible to rancidity, fortified with 10%, 20% and 30% of these extracts was evaluated in terms of its oxidative stability using the Rancimat method and compared with a control oil and an oil fortified with the synthetic antioxidant BHT at the highest legal level (200 ppm). For oil fortified with 30% of the extracts obtained from red and white pomace under the best conditions, increases in the induction time of 39% and 25% compared to the control and 23.01% and 10.62% compared to the BHT-fortified oil, respectively, were reported. This study highlights the potential of using grape pomace extracts as eco-friendly antioxidants to stabilize oil and contribute to the sustainability of the food industry at the same time.

Effect of combinations of 3,4‐dihydroxyphenylacetic acid and its esters on the oxidative stability of fish oil–containing trace water

AbstractThe current study aims to comprehend the effect of the various combinations of 3,4‐dihydroxyphenylacetic acid (3,4‐DHPA) and its esters in varying molar ratios on retarding oxidation in bulk refined fish oil in the presence of 0.3% w/w water. All the esters and 3,4‐DHPA exhibited better performance than the synthetic antioxidant butylated hydroxytoluene. In the presence of trace water, the parent compound was found to have a synergistic effect with hexyl ester when used at a molar ratio of 2:1, respectively, exhibiting a higher percent reduction among all the esters and their combinations. The study also showed that the presence of extraneous water can significantly accelerate the oxidation (twofold) in a bulk fish oil system. This suggests that the microenvironment of the oil is altered when water is present and that association colloids play a key role in enhancing the rate of oxidation. Thus, while designing a competent mixture of antioxidants, the specific site of oxidation involved and the surface‐active components should be taken into consideration to efficiently retard oxidation.Practical Applications: Analyzing the impact of trace amounts of water on the efficiency of natural antioxidants, including 3,4‐DHPA and its lipophilic esters, helps to comprehend the required optimal antioxidant concentrations for such a dynamic bulk oil system. The study finds application in controlling oxidation in PUFA‐rich oils containing surface‐active minor components that can accelerate oxidation. The results of the study show that 3,4‐DHPA and its esters could be a potential replacement for the synthetic antioxidant BHT in all aspects.

Shelf Life Enhancement of Structured Lipids Rich in Omega-3 Fatty Acids Using Rosemary Extract: A Sustainable Approach.

This study investigates the efficacy of rosemary extract (RE) in stabilizing structured lipids (SL) developed using perilla seed oil (PSO) and palmolein (PO) under accelerated storage conditions. The oil samples, comprising PSO, Blend, and SL formulations with and without RE (1500 ppm) and BHT (200 ppm), were studied for their storage stability during a 30 day storage period at 65 °C, with the analysis carried out at 6 day intervals. Oxidative properties were comprehensively assessed, including both physical attributes (color, viscosity, and refractive index) and chemical parameters (peroxide value, free fatty acid (FFA), p-anisidine value, TOTOX value, conjugated dienes, and trienes). The results demonstrated that RE-enriched oil samples exhibited significantly higher oxidative stability (p < 0.05) compared to the control group. SL added with 1500 ppm of RE exhibited notable enhancements in quality parameters, showcasing reductions in FFA, TOTOX value, conjugated diene, and triene value by 44.01%, 35.42, 39.03, and 47.36, respectively, when compared to SL without any antioxidant. The RE at 1500 ppm concentration showed a similar effect as the synthetic antioxidant BHT at 200 ppm. Also, the RE demonstrated potent inhibition of the oxidation of polyunsaturated fatty acids, thereby contributing to the improved oxidative stability of the SLs. Furthermore, SL with RE also exhibited reduced degradation of the tocopherol content and total phenolic content during the storage period. Principal component analysis demonstrated that SL and blend followed similar oxidative characteristics as they fell within the same quadrant. These findings underscore RE as a potent source of antioxidants capable of scavenging free radicals and enhancing the oxidative stability of omega-3 fatty acid-rich SLs.

New Garden Rose (Rosa × hybrida) Genotypes with Intensely Colored Flowers as Rich Sources of Bioactive Compounds

Garden roses, known as Rosa × hybrida, hold a prominent position as one of the most important and economically valuable plants in horticulture. Additionally, their products—essential oil, rose water, concrete, and concentrate—find extensive use in the cosmetic, pharmaceutical, and food industries, due to their specific fragrances and potential health benefits. Rose flowers are rich in biologically active compounds, such as phenolics, flavonoids, anthocyanins, and carotenoids. This study aims to investigate the potential of five new garden rose genotypes with intensely colored flowers to serve as sources of biologically active compounds. Phenolic profile was evaluated by determination of total phenolic (TPC), flavonoid (TFC), and monomeric anthocyanins (TAC) contents and LC-MS/MS analysis of selected compounds. Antioxidant activity was evaluated via DPPH and FRAP assays, neuroprotective potential via acethylcholinesterase inhibition assay, and antidiabetic activity viaα-amylase and α-glucosidase inhibition assays. The flowers of investigated genotypes were rich in phenolics (TPC varied from 148 to 260 mg galic acid eq/g de, TFC from 19.9 to 59.7 mg quercetin eq/g de, and TAC from 2.21 to 13.1 mg cyanidin 3-O-glucoside eq/g de). Four out of five genotypes had higher TPC than extract of R. damascene, the most famous rose cultivar. The dominant flavonoids in all investigated genotypes were glycosides of quercetin and kaempferol. The extracts showed high antioxidant activity comparable to synthetic antioxidant BHT, very high α-glucosidase inhibitory potential, moderate neuroprotective activity, and low potential to inhibit α-amylase.

Antioxidant Potential of Spray- and Freeze-Dried Extract from Oregano Processing Wastes, Using an Optimized Ultrasound-Assisted Method.

Origanum vulgare is recognized worldwide for its numerous applications, in the food industry and beyond. However, the extraction of its essential oils generates a significant amount of waste. The aim of this research was to achieve the valorization of solid waste from oregano hydro-distillation, by (i) optimizing the ultrasound extraction of antioxidants, (ii) evaluating the effect of spray and freeze drying on the extract's physicochemical properties, and (iii) characterizing the obtained powder by its antioxidant capacity. A central composite design of experiments was used to optimize the sample/solvent ratio, ethanol/water ratio, and extraction time. The extract was analyzed for its antioxidant potential by determining the percentage of DPPH inhibition, FRAP, and total phenolic content (TPC). The GAB model best fit the data for the moisture sorption isotherm of the resulting powder. The antioxidant activity of the powders was tested in a ground-beef food system. The TPC was maximized at times longer than 58 min, a sample/solvent ratio between 0.058 and 0.078, and a ratio of ethanol/water around 1. Neither drying method significantly affected the antioxidant properties of the extract, even though the resulting powders from each showed a different morphology (determined using SEM). Encapsulation with maltodextrin protected the spray-dried extract during a 6-month storage period. Powders from both drying methods equally retarded lipid oxidation, and were comparable to the synthetic antioxidant BHT. It is concluded that oregano processing waste is a potent source of antioxidants, and that its dried extract, via an ultrasound-assisted process, can potentially be used as a natural alternative to synthetic antioxidants.

Pistacia lentiscus extracts as a valuable source of antioxidant compounds

Medicinal plants produced many secondary metabolites which constituted an important source of bioactive molecules. This study aims to determine organic extracts (EOs) antioxidant activity extracted from terminal branches of Pistacia lentiscus (P. lentiscus) collected at three different phenological stages (vegetative, flowering and fructification). For this, different extracts were prepared by maceration in various solvents with increasing polarity notably diethyl ether, ethyl acetate, dichloromethane, methanol and water. Antioxidant activity was reported by DPPH free radical scavenging, iron reducing capacity and total antioxidant capacity tests. Results showed that phenological stages and solvent polarities affected significantly P. lentiscus antioxidant activity. Furthermore, aqueous and methanolic extracts from vegetative stage present the highest total polyphenols, total flavonoids and condensed tannins contents. Methanolic extract from vegetative stage exhibited the greatest antioxidant activity and even exceeded that of synthetic antioxidants BHT and ascorbic acid. In this study, P. lentiscus represents an important source of antioxidant molecules. As a result, extracts of this plant could replace synthetic antioxidants in e food, pharmaceutical and cosmetic fields.

Assessment of Antioxidant Capacity, Heavy Metal, Mineral and Protein Contents of Some Medicinal Plants Selected in Van

Objective: Rosa canina L., Malus domestica L., Prunus persica L Siebold &amp;amp; Zucc., Cydonia oblonga Mill., Armenica vulgaris Lam., and Pyracantha coccinea M.Roem. are important fruits of the Rosaceae family, used in a wide variety of industries such as food, perfume, cosmetics, paint, beverage, and for economic and medical purposes. Although medicinal plants act with their natural components against diseases, they can cause toxic and unde-sirable side effects. It is important in terms of human health and food safety to examine plants for their heavy metal, mineral, protein and antioxidant capacities before they are used for treatment, food or cosmetic purposes. The heavy metals (Al, Cr, Cu, Co, Zn), minerals (Fe, Mg, Na, Ca, K), protein and antioxidant capacities of some medicinal plants grown in Van-Turkey were determined and their safety in terms of food and in medical uses were evaluated. Material and Method: After the lyophilized plants were solubilized with a wet burning (microwave) device, Al, Cr, Cu, Co, Zn, Fe, Mg, Na, Ca, K elements were analyzed in the ICPOES device. Protein analyzes were per-formed by the Gerthardt Dumatherm method. Cuprac method was used for antioxidant capacity analysis. Results: The measured values were ranged between (in mg kg−1) Al 10.753-20.407, Co 0.007-9.664, Cr 0.119-0.411, Cu 2.409-6.554, Zn 23.426-33.891, Ca 743.0-2501.7, Fe 31.7-117.6, K 3555.2-4202.9, Mg 498.7-1982.9, Na 839.8-1616.0 and Protein (%) 1.45-5.53. Detected heavy metal amounts are in general within acceptable limits determined by WHO (World Health Organization). While the Cuprac values of the plants ranged between 1.13 and 3.62, the Cuprac values for the standard synthetic antioxidants α-tocopherol and BHT were determined as 2.14 and 3.21 µmol TE g−1DW, respectively. In particular, it was determined that Rosa canina extracts showed high activity (3.62 µmol TE g−1DW) comparable to α-tocopherol and BHT. Conclusion: : For centuries, human beings have benefited from plants in the treatment of diseases. Due to the severe side effects of synthetic drugs, people in the modern world also turn to medicinal plants for the treatment of many diseases. However, conscious consumption of medicinal plants by examining them especially in terms of heavy metal amounts will prevent serious health problems in the long run. The study showed that the heavy metal amounts of some plants belonging to the Rosaceae family, which are cultured, used for therapeutic pur-poses and consumed as fruit by the people of Van, are safe for human consumption and medical uses, and their micronutrient, protein and antioxidant capacities are at the desired level for healthy nutrition and therapeutic uses.

Flavonoid profile and antioxidant properties of Algerian common yew (Taxus baccata L.)

BackgroundIn humans, various diseases are associated with the accumulation of free radicals. The antioxidants can scavenge free radicals and reduce their impact; thus, the search for effective natural antioxidants of plant origin is indispensable. The present study aims to determine, for the first time, the flavonoid compounds profile and to investigate the free radical scavenging and antioxidant properties of the methanolic extract of Taxus baccata L. from Algeria.MethodsThe determination of the flavonoid compound profile of the methanolic extract of Taxus baccata L. was established using high-performance liquid chromatography with diode-array detection coupled to electrospray ionization tandem mass spectrometry (HPLC–DAD–ESI–MS/MS). The total flavonoid content (TFC) was performed according to the aluminum chloride colorimetric method, while the free radical scavenging and antioxidant activities were carried out using three methods, namely 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical assay, 2,2'-azino-bis3-ethylbenzothiazoline-6-sulphonic acid (ABTS) radical assay and ferric reducing antioxidant power (FRAP) Assay.ResultsA total of 26 compounds including flavon-3-ols, flavanonols, flavones, flavonols and bioflavonoids were characterized and identifiedusing HPLC–DAD–ESI–MS/MS analysis, five were reported for the first time such as taxifolin, apigenin, apigenin 7-O-glucoside, isorhamnetin 3-O-rutinoside and robustaflavone. The plant extract exhibited high total flavonoid content (TFC = 204.26 ± 6.02 mg RE/g dry extract) which corresponded to its strong radical scavenging activities [(DPPH IC50 = 35.31 ± 0.29 µg/ml and ABTS IC50 = 8.27 ± 0.52 µg/ml)] as compared to the synthetic antioxidant BHT [(DPPH IC50 = 78.96 ± 5.70 µg/ml and ABTS IC50 = 13.56 ± 0.06 µg/ml)]. However, the methanolic extract of T. baccata showed the lowest ferric reducing ability as compared to the positive controls (BHT, BHA, ascorbic acid, trolox and quercetin).ConclusionOur results imply that the Taxus Baccata L. might be a potential source for the isolation of natural antioxidant compounds.

Improving oxidative stability of edible oils with nanoencapsulated orange peel extract powder during accelerated shelf life storage

Nanoemulsion systems were employed to encapsulate the orange peel extract obtained from conventional maceration and novel ultrasound assisted extraction technology. Different wall materials maltodextrin (MD), whey protein isolate (WPI) and complex maltodextrin and whey protein isolate (MD/WPI) (1:1) were used in order to enhance the nanoemulsion stability, protect the bioactive core from degradation and control the release of bioactive compounds. The freeze drying technology was then used to obtain powder encapsulates with encapsulation efficiency and loading capacity of MD, WPI and MD/WPI as 89.3,91.2,95.6% and 95.3,94.4 and 93.1% respectively which depicts that encapsulation has taken place properly. All emulsions obtained were in nanoscale range with average hydrodynamic diameter as 105.0, 201.82, 215.12 and 298.82 for primary W/O emulsion, MD, WPI and MD/WPI stabilised emulsions respectively. These encapsulates were then incorporated in soyabean and mustard oil at different concentration 100, 200 and 300 ppm and compared with free extract and synthetic antioxidant BHT to enhance storage life by controlling the oxidative changes during accelerated shelf life storage at 60o C for 24 days. The results obtained concluded that nanoencapsulated extracts performed better in prevention of oxidative indices than the free extract. However, nanocapsules encapsulated by MD/WPI exhibited higher protection of oils during storage than the maltodextrin and whey protein isolate.

Physical characteristic and antioxidant activities of liquid bath soap with substitution of β-carotene crude extract from Gracilaria sp.

Synthetic antioxidant BHT is widely used in bath soap products as an antioxidant and prevents rancidity in bath soaps, but BHT is harmful to the skin if the addition is excessive. So we need natural antioxidants that can replace the role of BHT as an antioxidant. The purpose of this study was to determine the effect of substitution of BHT with β-carotene Gracilaria sp. on the physical properties of liquid bath soap and determine the best concentration of BHT substitution with β-carotene Gracilaria sp. added to liquid bath soap formulations. This study used a completely randomized design (CRD) consisting of 3 substitution treatments for BHT with β-carotene, namely (1g BHT : 0g β-carotene), (0,5g BHT : 0,5g β-carotene), and (0g BHT : 1g β-carotene) in 100 ml of liquid soap, with 6 repetitions each. Parameters observed were pH, foam stability, viscosity, hedonic, physical stability, and antioxidant activity. The results of this study the substitution of β-carotene Gracilaria sp. the liquid bath soap had a significant effect (p<0.05) on the pH parameter and no significant effect (p<0.05) on the foam stability test and viscosity test parameters. Based on the hedonic test value, soap with the addition of 0,5 g BHT: 0,5g β-carotene has the highest test value to produce the best quality soap.

Sea buckthorn leaf extract on the stability and antioxidant activity of microencapsulated sea buckthorn oil

Sea buckthorn oil (SBO) is rich in unsaturated fatty acids and various bioactive substances, and sea buckthorn leaf extract (SBLE) presents excellent antioxidant properties. In this study, SBO microcapsules containing SBLE were prepared by spray drying. Encapsulation and the addition of SBLE significantly improved the stability of SBO by measuring the oxidative induction time (OIT) and thermogravimetric analysis. The samples with 2% SBLE addition has the OIT value of 3.95 h, which was 2.8-fold of free oil. Encapsulation and SBLE addition both showed positive effects on keeping the oxidative stability under accelerated oxidation condition by comparing the color, peroxide vale, and MDA contents. In addition, SBLE significantly increased the antioxidant activity of encapsulated SBO. The effect of 2.0% SBLE was significantly better than 0.5% and 1.0%. Comparatively, SBLE was more effective than synthetic antioxidants BHA and BHT in increasing SBO stability and antioxidant properties. Overall, as a byproduct, SBLE has the potential as a natural additive to reduce the SBO degradation and play a synergistic role on human health.

RED ONION (Allium ascalonicum) PEEL EXTRACT AS A NATURAL SOURCE OF ANTIOXIDANTS TO ENHANCE THE OXIDATION STABILITY OF REFINED BLEACHED DEODORIZED PALM OIL (RBDPO)

The repeated use of cooking oil can trigger chemical reactions that cause the cooking oil to be unstable to heat. Red onion peel may be an antioxidant because it contains flavonoid compounds, polyphenols, saponins, and alkaloids that scavenge free radicals. This study aims to prove the use of natural antioxidant concentrations of onion peel. This study used a completely randomized design (CRD) consisting of 5 treatments of onion peel extract, namely 3% (P1), 6% (P2), 9% (P3) 12% (P4), without treatment (P-), and the addition of 0,1% BHT (P+) with consecutive times. The ability of antioxidant of onion peel extract is known to be able to maintain the stability of cooking oil compared to an antioxidant synthetic BHT. Peroxide in extract oil 9% (6.65 meq/kg), Total Oxidation in extract oil 9% (15.92 meq/kg), P-anisidine in extract oil 3% and 9% (3.54 meq/kg) /kg and 3.92 meq/kg) and the iodine value of the extract oil 3%, and 9% (21.41 mg iodine/g and 20.81 mg iodine/g). It was found that natural antioxidants of onion peel extract showed better primary oxidation inhibition ability than synthetic antioxidants BHT and among the five types of antioxidant concentrations, antioxidants from onion peel extract 9% showed the best oxidation inhibition ability. So that it can be obtained that the addition of onion peel extract is used as a natural antioxidant to maintain the stability of the oil against heat

Oxidative stability of soybean and corn oils enriched with Pluchea quitoc hydroalcoholic extract

Soybean and corn oils are among the most popular vegetable oils, and are ingredients which are widely used in cooking and in the food industry. These oils contain many unsaturated fatty acids such as oleic, linoleic and linolenic acids, which makes them easily oxidized by oxygen. Extensive efforts are being made to prevent or minimize vegetable oil oxidation through the development of antioxidants. Phenolic antioxidants which are present in some extracts can be used as food additives to prevent lipid oxidation. In this study chromatographic analyses (HPLC and GC) of the Pluchea quitoc hydroalcoholic extract were performed. The content of phenolic compounds by the Folin-Ciocalteau method and the antioxidant properties against radicals 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) were also evaluated. The effect of samples prepared with soybean and corn oils enriched with Pluchea quitoc hydroalcoholic extract was determined and compared with samples of these oils which were free of antioxidants and with samples containing the synthetic antioxidant BHT. The results showed potential for application of the extract. A high content of phenolic compounds (314 milligrams of gallic acid equivalents (GAE)/g of extract) and good IC50 values were detected for the inhibition of the radicals DPPH and ABTS (13.2 µg·mL-1 and 5.6 µg·mL-1). In the evaluation of the oxidative stability of the oils enriched with this extract, it was found that at 1% concentration it was possible to obtain values of induction period (IP) close to the samples with added BHT.

Effects of natural antioxidants on the oxidative stability of Eucommia ulmoides seed oil: Experimental and molecular simulation investigations

Eucommia ulmoides seed oil with high health potential is prone to oxidative rancidity due to its rich unsaturated fatty acids. In this work, three natural antioxidants were selected for exploring the oxidation resistance of the oil compared with the common synthetic antioxidant BHT. Antioxidant activity and its dispersion and migration as well as oxygen barrier performance were predicted via the bond dissociation enthalpy (BDE), mean square displacement (MSD), binding energy (Ebinding) and permeability coefficient (S). The predicted comprehensive performance is as follows: myricetin > epicatechin > caffeic acid > BHT. Free radical scavenging assay and Rancimat assay confirmed the antioxidant activity and protective effect on oil. That is the protective effect of three natural antioxidants on Eucommia ulmoides seed oil is better than BHT and myricetin shows the optimal comprehensive performance. The induction period of myricetin/lipid system increased 164.5% compared with the control. The experimental results are in good consistent with the simulation predictions.

Ultrasound assisted extraction of bioactive compounds from pomegranate peel, their nanoencapsulation and application for improvement in shelf life extension of edible oils

In this study pomegranate peel extract was evaluated as source of antioxidant encapsulated by nano-emulsions in soybean oil. Encapsulating agents maltodextrin (MD), whey proteins isolate (WPI) and complex of maltodextrin and whey protein isolate (MD/WPI) (1:1) were used as wall material. Average droplet size of primary W/O and double W/O/W nanoemulsions stabilised by MD, WPI and MD/WPI were 108 nm, 157.82,189.94 nm and 191.12 nm respectively. Lyophilised nanoemulsion powders were added at 100, 200 and 300 ppm concentration to soyabean and mustard oil and observed for change in various oxidative stability indices during storage and were compared to non-encapsulated extract and synthetic antioxidant BHT. From the results, it can be suggested that nanoencapsulated extract at 300 ppm concentration performed better in controlling oxidative changes in both oils than unencapsulated and synthetic one, however, extract encapsulated by MD/WPI exhibited higher antioxidant effects due to controlled release of bioactive compounds.

Pomegranate (Punica granatum) peel fractions obtained by supercritical CO2 increase oxidative and colour stability of bluefish (Pomatomus saltatrix) patties treated by UV-C irradiation

The sequential fractionation by supercritical-CO2 (SC-CO2) was applied to obtain fractions enriched in bioactive compounds of pomegranate peel, and we investigated if pomegranate peel extract and fractions would be effective to inhibit lipid and protein oxidation, and discolouration of bluefish patties stored at 4 °C for 9 days, after UV-C irradiation. The non-fractionated SC-CO2 extract from pomegranate peel was rich in phenolic compounds, mainly ellagitannins, besides, it possessed lipophilic compounds such as tocopherols and β-carotene. These compounds were successfully separated by the fractionation protocols, in a lipid fraction concentrated in lipophilic compounds, and one or two fractions enriched with phenolic compounds, especially ellagitannins. The lipid fraction and the high phenolics fraction from pomegranate peel were then as effective as the synthetic antioxidant BHT in avoiding bluefish patties oxidation during refrigerated storage. Our data indicates that pomegranate peel fractions could be used to replace a synthetic antioxidant in fish meat.

Avaliação da Atividade Antioxidante e Características Físico-Químicas de Polpa de Romã ( Punica Granatum, L.)

Diversos vegetais têm sido estudados como fonte de antioxidantes naturais em substituição aos sintéticos. Embora muito conhecida e com muitas propriedades benéficas para a saúde, tais como antiteratogênica, antiproliferativa e ação anti-inflamatória, a romã ainda é pouco consumida no Brasil. Estudos têm relacionado a romã (Punica granatum, L) como fonte de substâncias que apresentam propriedades antioxidantes. As substâncias antioxidantes atuam retardando o envelhecimento e previnindo doenças crônicas. Também impedem os efeitos danosos dos radicais livres e a oxidação das moléculas que constituem as membranas das células. Os antioxidantes sintéticos são potencialmente carcinogênicos quando consumidos em doses elevadas e por tempo prolongado. O presente trabalho teve como objetivo avaliar a atividade antioxidante, em extratos etanólico e metanólico de polpa de romã Punica granatum, L, pelo método DPPH, utilizando o BHT como padrão de antioxidante sintético e, adicionalmente as características físico-químicas da polpa. Os resultados indicaram que o extrato metanólico nas concentrações de 1mg/mL e 0,1mg/mL, obtiveram um porcentual de inibição de 49,02% e 21,57 % respectivamente, o que indica um resultado muito favorável por se tratar de um extrato e não de substância isolada. Ambos os extratos apresentaram porcentagem de inibição menor que o antioxidante sinético BHT. Dos parâmetros físico-químicos encontrados para Polpa de Romã neste estudo, apenas o valor de pH, se encontra abaixo do padrão mínimo, descrito no Decreto nº 50.040/1961 os demais parâmetros estão de acordo.

Accelerated storage conditions effect on ginger- and turmeric-enriched soybean oils with comparing a synthetic antioxidant BHT

Commercial and freeze-dried powders of ginger and turmeric rhizomes were incorporated in the soybean oil at the concentration of 10% (w/w) to develop a food seasoning containing natural antioxidants to improve lipid stability. The phenolic composition, antioxidant activity, and oxidative stability of ginger- and turmeric-enriched soybean oils were evaluated during storage at 62 °C for 28 days. The phenolic characterization was performed by detecting total polyphenols through Folin-Ciocalteu assay and HPLC analyzing 6-gingerol and curcumin, respectively. The antioxidant activity was spectrophotometrically measured through 2,2-di(4-tertoctylphenyl)-1-picrylhydrazyl (DPPH) radical scavenging capacity and ferric ion reducing antioxidant power (FRAP) assays. The peroxide value (PV) and induction period (IP) have been determined through spectrophotometric and Rancimat methods thus monitoring the primary and secondary phases of lipid oxidation, respectively. The addition of freeze-dried powders derived especially from turmeric rhizome contributed to enhanced antioxidant activity and oxidative stability of soybean oil under accelerated storage conditions thanks to its enrichment in bioactive compounds highly resistant to thermal degradation. Hence, ginger and turmeric powders can be valorized as functional ingredients to be incorporated in vegetable oils for preventing their lipid structure against to oxidation, and simultaneously providing health benefits to consumers.

Ultrasound-promoted Green Synthesis of pyrido[2,1-a]isoquinoline Derivatives and Studies on their Antioxidant Activity.

To a stirred mixture of phthalaldehyde 1 (2 mmol) and methylamine 2 (2 mmol) in water (3 mL) under ultrasonic irradiation was added to activated acetylenic compounds 4 after 20 min. Alkyl bromide 3 and triphenylphosphine 5 react in another pot in water (3 mL) under ultrasonic irradiation for 15 min. After this time, this mixture was added to the first pot. After completion of the reaction, the solid residue was separated by filtration and washed with Et2O to afforded pure title compound 6. In this work, generation of pyrido[2,1-a]isoquinoline derivatives 6 are performed using phthalaldehyde 1, methylamine 2, α-halo substituted carbonyls 3, activated acetylenic compounds 4 and triphenylphosphine 5 in water under ultrasonic irradiation condition at room temperature in excellent yield at short time. In summary, multicomponent reaction of phthaladehyde, methylamine, activated acetylenic compounds, alkyl bromides and triphenylphosphine in water under ultrasonic irradiation at room temperature produced pyrido[2,1-a]isoquinoline derivatives in excellent yields. Also, Diels-Alder reaction of pyrido[2,1-a]isoquinoline derivatives with activated acetylenic compounds and triphenylphosphine under ultrasonic irradiation is investigated in two procedures. Also, the antioxidant activities of 6a, 6c, 6g and 6i were evaluated by DPPH radical scavenging and ferric reducing power analyzes. The compounds 6a exhibit excellent DPPH radical scavenging activity and FRAP compared to synthetic antioxidants BHT and TBHQ. The chief benefits of our method are high atom economy, green reaction conditions, higher yield, shorter reaction times, and easy work-up, which agree with some principles of green chemistry.

Enhancing oxidative stability of sunflower oil with sesame (Sesamum Indicum) coat ultrasonic extract rich in polyphenols

Addition of antioxidants to oils is essential to retard its oxidation. Nowadays, due to safety concerns, there is a significant demand for replacing synthetic antioxidants with natural ones. Sesame seed coat is a waste product of sesame processing. Ultrasound-assisted extraction of polyphenols from sesame coat was investigated. The highest yield of polyphenols was 7.23 mg gallic acid equivalent (GAE)/g dry nonroasted sesame coat. It was obtained with aqueous ethanol (80%) at a material:solvent ratio of 1:20 (wt/vol) using an ultrasound intensity of 30% of the maximal output power (300 W) for 40 min. High-performance liquid chromatography (HPLC) of the dried extract revealed the presence of sesamin and sesamolin at 65.967 and 38.737 mg/g, respectively. Catechin, p-coumaric acid, and chlorogenic acid were the most abundant polyphenols in the extract. The addition of sesame coat extract enhanced the oxidative stability of sunflower oil (423% increase). Practical applications Oxidative rancidity is a quality problem of refined vegetable oils. The extraction of polyphenols as a natural source of antioxidants from dried sesame coat using ultrasound was studied. Findings indicate that sesame coat extract improved oxidative stability of sunflower oil. Antioxidant efficacy of the extract was greater than that of synthetic antioxidant BHT.