Thirteen apple cultivars were analyzed for their total phenolic content, total flavonoids, anthocyanins, ascorbic acid in methanolic extracts of both peel and cortex fractions. Three in vitro assays ...(FRAP, DPPH, and CUPRAC) were used to determine the antioxidant activity. Concentration of the phytochemicals studied varied greatly between the apple peel and the cortex region. Peels showed ~ 2.8 times higher total phenolic content and ~ 2.68% higher flavonoid content than the cortex. Principal component analysis could successfully explain 76.86% and 84.27% variability in the antioxidant determinants (antioxidants/assays) in the peel and cortex region of apple cultivars, respectively. Major contributor for antioxidant activity in both apple peel and cortex was total flavonoid content. Cultivars ‘Well Spur’ and ‘Oregon Spur II’ were found to be substantially rich in these two antioxidants. The antioxidant activity was best expressed by the in vitro FRAP assay in both the fractions. Non-hierarchical K-medoids clustering reflected the presence of an antioxidant/ assay protocol apart from the antioxidant/assay we considered in this study that needs further exploration to get full spectra of antioxidant profile across apple genotypes. Based on multivariate analysis and the concept of RACI, the FRAP antioxidant assay is recommended for determining antioxidant activity in apples.
Antioxidant capacities of 51 edible and wild flowers from China were systemically evaluated using ferric-reducing antioxidant power (FRAP) and trolox equivalent antioxidant capacity (TEAC) assays, ...and their total phenolic contents were measured by Folin–Ciocalteu method. The lipophilic components of flowers were extracted with tetrahydrofuran, and the hydrophilic ones were extracted with a methanol–acetic acid–water (50:3.7:46.3, v/v/v) mixture. The results showed that different flowers had diverse antioxidant capacities and phenolic compounds were a major contributor to their antioxidant activities. Rosa rugosa, Limonium sinuatum, Pelargonium hortorum, Jatropha integerrima and Osmanthus fragrans were found to have the highest antioxidant capacities. Homogentisic acid, cyanidin-3-glucoside, protocatechuic acid, catechin, gallic acid and epicatechin were quantified in these flowers using HPLC analysis. These flowers should save as potential rich resources of natural antioxidants for use as functional food ingredients or pharmaceuticals for control of diseases caused by oxidative stress.
•A kinetic study of oleuropein extraction from olive leaves by ultrasound is suggested.•The temperature affects the extraction kinetic and the extracts composition.•Ultrasound had significant effects ...on the extraction kinetics of polyphenols.•Ultrasound power reduces the initial extraction rate of bioactive compounds.
In this study, the effect of temperature and ultrasonic application on extraction kinetics of polyphenols from dried olive leaf was investigated. Conventional (CVE) and ultrasonic-assisted extraction (UAE) were performed at 10, 20, 30, 50 and 70°C using water as solvent. Extracts were characterized by measuring the total phenolic content, the antioxidant capacity and the oleuropein content (HPLC–DAD/MS–MS). Moreover, Naik’s model was used to mathematically describe the extraction kinetics. The experimental results showed that phenolic extraction was faster in UAE (ultrasonic-assisted extraction) than in CVE (conventional extraction), being extraction kinetics satisfactorily described using Naik model (include VAR>98%). Besides, the total phenolic content, the antioxidant capacity and the oleuropein content were significantly (p<0.05) improved by increasing the temperature in both CVE and UAE. Oleuropein content reached 6.57±0.18 being extracted approximately 88% in the first minute for UAE experiments.
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•Microwave-assisted extraction is used to extract polyphenols from white button mushrooms.•RSM was combined with different parameters at which extraction was carried out.•The study ...investigated optimal conditions for the extraction of bioactive compounds.•White button mushroom is a good source of polyphenols and antioxidants.
Response surface methodology (RSM) was used to optimize the microwave-assisted extraction (MAE) of phenols from white button mushrooms (Agaricus bisporus). The total phenolic content (TPC), total flavonoid content (TFC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, and ferric reducing antioxidant power (FRAP) assays of white button mushrooms were optimized using three extraction parameters: ethanol concentration (10–90 %), extraction time (1–30 min), and solvent-to-solid ratio (5–20 mL of ethanol/water (80:20, v/v) solvent added to fixed amount of 0.2 g of sample for extraction). The ideal conditions for TPC were 58 % ethanol concentration, 16 min of extraction duration, and a solvent-to-solids ratio of 12.9 mL/0.2 g. 56 % ethanol concentration, an extraction period of 18 min, and a solvent-to-solid ratio of 12 mL/0.2 g were the ideal TFC conditions. Furthermore, the optimal conditions for maximum antioxidant activity also revealed the significant effect of independent variables. The experimental values of the responses were correlated with the predicted response values, which suggested the efficiency of MAE for extracting polyphenols from white button mushrooms. White button mushroom is an excellent antioxidant source, and conditions to extract phytochemicals have been optimized using RSM.
•S. striata is a suitable candidate for lands that are subject to drought stress.•The response to secondary metabolite was specific to the Ilam ecotype.•ROS is a regulatory mediator in the signaling ...process of biosynthetic pathways.•Salicylic acid and silicon were recognized as two modifiers of drought stress.
Foliar spraying of salicylic acid (SA) and silicon (Si) was carried out as a moderator of drought stress on growth and antioxidant system in two different ecotypes of scrophularia striata as a medicinal plant. A factorial experiment was conducted based on a completely randomized design in three replications. The statistical analysis of the studied traits showed that drought stress decreased the length and weight (dry and fresh) traits of shoot, root and stem-to-root length ratio in Ilam ecotype, while the root length and root-to-stem length ratio increased in Abdanan ecotype. The interaction between salicylic acid (SA), silicon (Si) and drought stress caused an increase in root length and the root-to-stem length ratio in Abadanan ecotype, this interaction on root fresh weight was not significant. The application of drought stress led to a reduction in the content of total phenol, flavonoid, anthocyanin and ascorbic acid in both ecotypes, but the activity of ascorbate peroxidase (APX) enzyme increased in both ecotypes and polyphenol oxidase (PPO) in Ilam ecotype. The interaction between salicylic acid (SA), silicon (Si) and drought stress increased the enzyme antioxidant activity, catalase (CAT), guaiacol peroxide (GPX), as well as the content of flavonoid, ascorbic acid and phenol in Ilam ecotype (50% field capacity +drought stress) and Abdanan ecotype (50% field capacity). However, this interaction had no significant effect on the activity of ascorbate peroxidase (APX) enzyme. The general results showed that the simultaneous use of SA and Si improves the antioxidant defense in Scrophularia striata under drought stress.
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•The drying were evaluated in different slice thicknesses, air velocity, and infrared power.•The total phenol content of dried eggplants were increased by 17–326%.•The potassium content of dried ...eggplants were increased by 709.1–1236.3%.•The optimal conditions were determined by response surface methodology.
The aim of this work was to study the effect of thickness of samples, air velocity and infrared power on the drying kinetics and quality attributes of blanched eggplant slices during infrared drying. The drying experiments were made by Response Surface Methodology (RSM) based on a Box–Behnken design (BBD). Experiments were conducted at a thickness of 3, 5, and 7 mm, air velocity of 0.5, 1.25, and 2 m/s, as well as at infrared power 1000, 1500, and 2000 W. The drying time was affected by operating parameters. The drying processes increased total phenolic content and potassium content, significantly. The total color difference (ΔE) was in the range of 10.22–25.14. In the end, this process was optimized for reaching the best experimental condition.
► The safety of synthetic antioxidants as food additives has received increasing attention. ► There is need components to act as antioxidants and to make food products safer. ► Detection of natural ...antioxidant sources for food use would be beneficial for healthy life. ► Antioxidant capacity of thyme, sage and marjoram extract was screened using DPPH assay. ► Thyme sage and marjoram exhibited stronger antioxidant activity than BHT and BHA.
The antioxidant properties and total phenolic of different extracting solvents of thyme, sage, and marjoram were examined using the stable 2,2-diphenyl-1-picrylhydrazyl-hydrate (DPPH) free radical scavenging method and Folin–Ciocalteu method, respectively. Methanol exhibited the highest extraction ability for such phenolic compound, where the total phenols were 8.10, 5.95, and 5.20 (mg gallic acid equivalent/g dry weight) for thyme, sage, and marjoram, respectively and also exhibited the strongest antioxidant capacity. On the basis of the results obtained, thyme, sage, and marjoram have a potential use as natural antioxidants due to their significant antioxidant activity. HPLC analysis of methanolic extract showed the presence of: rosmarenic acid, methyl rosmarenate, caffeic acid, cinnamic acid, chlorogenic acid and quinic acid as phenolic acids, besides some flavonoids such as ferulic acid, apigenin, luteolin and quercetin. The results demonstrated that thyme methanol extract possessed the best antioxidative activity, which were better than those of other plants, α-tocopherol and BHA.
The concept of “Integrated Multi-Trophic Aquaculture” (IMTA) is considered one of several strategies to increase biomass production from the sea by combined culture of different organisms, such as ...low-level trophic macroalgae, profiting from and reducing the environmental impact of fish farming. However, due to lack of data and scientific evidence, appropriate food regulations are lacking for IMTA to guide the production of macroalgae and their application as food products. Macroalgae are reported to be nutritious and to have valuable bioactivities including antioxidative activity. Besides valuable compounds, macroalgae can also contain elements with unwanted effects such as allergens. Thus, there is a growing concern from the food industry and food safety authorities regarding the potential occurrence of contaminating marine allergens in seaweed food products. As seaweed is produced in the ocean, allergens of marine species, such as crustaceans, molluscs or even fish might find their way into the production line and these hazards must be monitored to evaluate the risk for allergenic incidents and the need for appropriate labelling for future food products. To date, there is little data in this aspect on seaweed production in IMTA systems, where especially the occurrence of contaminating allergens could be increased due to close contact with cohabitant species. Hence, the occurrence of marine food allergens (fish parvalbumin, mollusc and crustacean tropomyosins), as well as total phenolic compounds and antioxidant activity have here been assessed in S. latissima produced in three different locations in 2020 in the vicinity of salmonids farms in Norway. We confirm the presence of phenolic compounds and antioxidative activity in S. latissima, produced in IMTA systems, in a similar range for all assessed locations and comparable to previous studies. Of the tested allergens, only crustacean tropomyosin could be detected in all locations of this study up to 1 mg/kg dry weight, however not representing a critical level for consumption.
•IMTA-produced macroalgae S. latissima for food needs to be well characterized.•Antioxidative activity of up to 1665 μmol TE/g dry weight was detected.•Crustacean allergens (0.5–1 mg/kg) were detected at all tested IMTA locations.•Cod parvalbumin, corresponding to 44.2 mg/kg cod, was detected at one location.•None of the tested marine allergens established a risk for consumption.
•Green tea yogurt showed the highest phenolic content followed by white tea yogurt and black tea yogurt.•Green tea extract showed the highest antioxidant activity followed by white tea extract and ...black tea extracts.•All the three types of tea yogurts had higher antioxidant potentials than control.•Black tea yogurt showed the lowest antioxidant activity during 21 days of storage.
The present study investigated the effect of green, white or black tea (Camellia sinensis) on the fermentation of milk and antioxidant potential of yogurt during 21 days of storage at 4°C. All yogurts were analyzed for total phenolic content (TPC), identification of phenolic compounds and antioxidant potential using diphenyl picrylhydrazyl radical scavenging (DPPH), ferric reducing antioxidant power (FRAP) and ferrous ion chelating (FIC) assays. Green tea yogurt showed the highest phenolic content (p<0.05) followed by white tea yogurt and black tea yogurt. LCMS/MS analysis revealed the absence of several phenolic compounds in tea yogurts, despite their presence in tea water extracts, as well as the presence of new phenolic compounds. All tea yogurts showed higher (p<0.05) FRAP and FIC values than respective control during 21 days of storage. However, BTY showed the lowest values of DPPH scavenging activity and FRAP during storage period. In addition, the antioxidant activity for all tea yogurts remained almost constant over storage period. In conclusion, green, white and black tea can be successfully employed to improve the antioxidant properties of yogurt and provide sustained antioxidants during storage.
The Rubiaceae family, comprising 550 species in the Philippines, is a significant source of bioactive components with ethnopharmacological uses. This study assessed the total phenolic content (TPC), ...total flavonoid content (TFC), and antioxidant activity of six Rubiaceae species, collected in Ilocos Norte, Philippines: Guettardella microphylla (Bartl. ex DC.) Merr., Timonius ternifolius (Bartl. ex DC.) Fern.-Vill., Kanapia monstrosa (A. Rich.) Arriola & Alejandro, Pyrostria triflora Arriola, Calaramo & Alejandro, Pyrostria subsessilifolia (Merr.) Arriola & Alejandro, and Psychotria luzoniensis (Cham. & Schltdl.) Fern.-Vill. Identification of the plant species was done using morphological characterization. The TFC results ranged between 1.86-3.81 mg quercetin equivalent/g dry weight (GAE/g DW), while TPC indicated 5.47-17.17 mg gallic acid equivalent/g dry weight (QE/g DW). G. microphylla showed the highest TFC (3.81±0.20 mg QE/g DW) while P. triflora exhibited the highest TPC (17.17±0.83 mg GAE/g DW). Antioxidant profiling showed P. luzoniensis exhibiting the highest activity in the NOS, ABTS, DPPH, and FRAP assays. G. microphylla showed the highest hydrogen peroxide scavenging activity, while T. ternifolius demonstrated the highest hydroxyl radical scavenging activity. Findings suggest that the crude methanolic extracts of the Rubiaceae species have relatively high TPC and TFC values and exhibit promising antioxidant capacities.
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