This study purpose was to investigate the effect of radiofrequency low pressure cold plasma (LPCP) process by using dried peppermint (Mentha piperita) on the reduction in microbial load, antioxidant ...activity, total phenolic content, and color. The microbial load of the sample was investigated by infecting it with 106 CFU/g of Escherichia coli O157:H7, and after treatment with LPCP at 20, 50, and 60 W for 20 min. It was found that LPCP process had a significant effect on the removal of E. coli O157:H7 at 50 and 60 W, but at 20 W revealed no significant effect on this bacterium removal (p > 0.05). The LPCP significantly increased the total phenolic content (p < 0.05); consequently, antioxidant activity increased after studying the antioxidant properties by two methods of FRAP and DPPH in all 3 powers. The results also indicated that the LPCP darkened the treated sample's color.
•Dry peppermint was treated by RF low pressure cold plasma.•Escherichia coli O157:H7 removed after treatment for 20 min at 50 and 60 W.•50 W significantly increased total phenolic content and antioxidant activity.•Low pressure cold plasma significantly darkened the treated sample's color.
Propolis is considered to contain a variety of polyphenols (flavonoids, phenolic acids and their esters), waxes, steroids and terpenoids and its contents may be influenced by the vegetation at the ...site of collection as well as the species of stingless bees. The purpose of this study is to investigate the total phenolic and flavonoid content and the correlation that may exist between the mentioned class of compounds and the antioxidant properties. The ethanolic extract of propolis samples were prepared from three different stingless bee species namely Tetrigona apicalis, Heterotrigona itama and Geniotrigona thoracica, collected from one of the bee farms located in Perak, Malaysia. Antioxidant activity of the propolis samples was examined by three different methods which were DPPH, ABTS and FRAP assay. Total phenolic and total flavonoid content were determined by using Folin-Ciocalteu and aluminium chloride colorimetric method, respectively. The result shows that all propolis samples exhibited positive antioxidant activity. Propolis of G. thoracica was found to be the most potent sample in all antioxidant tests. The analysis between total phenolic and flavonoid content of propolis and its antioxidant properties were found to have a strong correlation. These results signify that the potency of propolis derived from different species is variable, depending on the phytochemical contents, thus further study on the specific bioactive compounds would be the area of interest in the near future.
The objectives of this study were to determine best conditions for the extraction of phenolic compounds from fresh, frozen and lyophilized basil leaves. The acetone mixtures with the highest addition ...of acetic acid extracted most of the phenolic compounds when fresh and freeze-dried material have been used. The three times procedure was more effective than once shaking procedure in most of the extracts obtained from fresh basil leaves – unlike the extracts derived from frozen material. Surprisingly, there were not any significant differences in the content of phenolics between the two used procedures in the case of lyophilized basil leaves used for extraction. Additionally, the positive correlation between the phenolic compounds content and antioxidant activity of the studied extracts has been noted. It is concluded that the acetone mixtures were more effective than the methanol ones for polyphenol extraction. The number of extraction steps in most of the cases was also a statistically significant factor affecting the yield of phenolic extraction as well as antioxidant potential of basil leaf extracts.
Ammi visnaga L. is an enriched medicinal plant with medicinally important compounds. Two types of nanoparticles (NPs) including silica (SiO2) and graphene oxide bound with SiO2 (GO-SiO2) NPs at ...different concentrations (0, 15, 25 mg L−1) were used as elicitors to investigate their effects on callus morphology, H2O2 content, total phenolic content (TPC), total flavonoids content (TFC), ferric reducing/antioxidant power (FRAP), and few antioxidant enzymes such as catalase (CAT), guaiacol peroxidase (GPX), superoxide dismutase (SOD), ascorbate peroxidase (APX), and polyphenol oxidase (PPO) in the callus cultures of A. visnaga. The effects of elicitation of both NPs on calli were observed using a scanning electron microscope (SEM). The 15 mg L−1 concentration of GO-SiO2 NPs produced the highest TPC (193.3 mg GAE g−1 FW), CAT (13.1 U mg−1 Protein), GPX (0.0089 U mg−1 Protein), and APX (0.079 U mg−1 Protein). Whereas, the maximum content of H2O2 (0.68 μmol g−1 FW), FRAP (0.0092 μmol mg−1), and TFC (62.27 mg QE g−1 FW) was observed at 25 mg L−1 and 15 mg L−1 of SiO2 NPs, respectively. Conclusively, in the callus culture of A. visnaga, the 15 mg L−1 concentration of GO-SiO2 NPs was the most suitable dosage for enhancing the enzymatic antioxidant activities (CAT, GPX, APX) and TPC, rather than SiO2 NPs.
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•Both nanomaterials increased biochemical and phytochemical traits in A. visnaga.•The highest antioxidant activity was observed under 25 mg L−1 SiO2 NPs.•The highest enzymatic activities observed under 15 mg L−1 GO-SiO2.
Objective: To evaluate the total phenolic content and compare the antioxidant activity of various solvent extracts and fractions from the aerial parts of Coronopus didymus through various assays. ...Methods: Total phenolic content was determined using the Folin-Ciocalteu assay and the in vitro antioxidant activity of a number of different extracts was investigated in a dose-dependent manner with three different methods: the 2,2-diphenyl-1-picrylhydrazyl（DPPH）, 2,2’-azinobis（3-ethylbenzothiazoline-6-sulfonic acid） diammonium salt（ABTS） and ferric reducing antioxidant power（FRAP） assays. A flavone was isolated from the most active ethanolic extract with high antioxidant activity using size exclusion chromatography. IC50 values were calculated for the DPPH and ABTS methods. The FRAP activity was assessed in terms of μM Fe（II） equivalent. Results: The phenolic content was found to be highest in the ethanol extract（CDA Et; 47.8 mM GAE） and the lowest in the dichloromethane extract（CDA DCM; 3.13 mM GAE）. The ethanol extract showed high radical scavenging activity towards DPPH and ABTS radicals with IC50 values of（7.80 × 102） and（4.32 × 102） μg/m L, respectively. The most active ethanol extract had a FRAP value of 1 921.7 μM Fe（Ⅱ） equivalent. The isolated flavone F10C（5,7,4’-trihydroxy-3’-methoxy flavone） was far more effective for scavenging free radicals in the DPPH and ABTS assays with IC50 of 43.8 and 0.08 μg/m L, than the standard trolox, with IC50 values of 97.5 and 21.1 μg/m L, respectively. In addition, the flavone F10C and the standard ascorbic acid had FRAP values of 1 621.7 and 16 038.0 μM Fe（Ⅱ） equivalents, respectively. Conclusions: The total phenolic content of extracts in decreasing order is ethanol extract（CDA Et）> acetone extract（CDA ACE）> phenolic extract（CDA MW）> n-hexane extract（CDA nHX）> chloroform extract（CDA CHL）> dichloromethane extract（CDA DCM）. The ordering of extracts in terms of antioxidant activity from highest to lowest is CDA Et> CDA MW> CDA DCM> CDA CHL> CDA ACE> CDA nHX in DPPH, ABTS and FRAP assays. A significant relationship is found between antioxidant potential and total phenolic content, suggesting that phenolic compounds are the major contributors to the antioxidant activity of Coronopus didymus.
Cooking by boiling dry pasta could have varying degrees of influence on nutritional and functional components. In the present study, its effect on total phenolic content and antioxidant capacity, as ...well as on the comprehensive profile of free and bound phenolics, was investigated in six commercial gluten-free (GF) pasta products. Overall, the heat treatment caused a significant reduction (P<0.01) of the total phenolic content as well as FRAP reducing power and ORAC radical scavenging, with significant differences among the pasta samples considered. The highest values were recorded in free phenolic fraction remaining in black rice (41mggallic acid equivalents100g−1 and 25mmolTrolox Equivalents100g−1) and quinoa (24mggallic acid equivalents100g−1 and 14mmolTrolox Equivalents100g−1) cooked GF pasta. Significant correlations (P<0.01) could be found between total phenolics and both the antioxidant capacity assays performed. UHPLC-ESI/QTOF-MS mass profiling allowed confirming the spectrophotometric results, while identifying the amount of free and bound fractions. Among phenolic classes, lignans exhibited the highest decrease during the cooking process, followed by stilbenes and flavonoids. However, phenolic acids and other phenolics showed the highest stability. Furthermore, cooking by boiling strongly lowered the bound-to-free ratio of phenolic compounds, by an averaged factor ranging from 14-folds for flavonoids to 5-folds for other classes of phenolics.
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•Gluten-free pasta from alternative non-wheat flours are rich in phenolics.•Boiling caused a significant reduction in total phenolic content.•Cooking by boiling lowered the bound-to-free ratio of phenolics.•The antioxidant potential of GF pasta samples increased after cooking.•Lignans underwent the highest decrease, followed by stilbenes and flavonoids.
Chocolate is a food product highly popular worldwide, and it has been proposed as a carrier for probiotic delivery. This work evaluated the viability of probiotic strains, Bifidobacterium animalis ...subsp. lactis BB-12® and Akkermansia muciniphila DSM 22959, in chocolate matrices with different cocoa percentages (33.6; 54.5 and 70.5%) throughout 28-days of aerobic storage. The pH, total phenolic content and antioxidant, antidiabetic, and antihypertensive activities were also determined at timepoints of 0 and 28-days. During storage, all chocolates showed high pH stability (variations lower than 1 unit) and it was observed a growing trend in total phenolic content and in bioactivities with the increase of cocoa content in the matrix. Regarding probiotic viability, a higher level for B. animalis subsp. lactis BB-12® was achieved in chocolate containing 70.5% cocoa (estimated in 108 CFU/g after storage). In opposite, A muciniphila DSM 22959 exhibited greater viability in chocolate with 33.6% and 54.5% cocoa (around 106 CFU/g after storage, meeting the minimum required amounts for probiotic products). Conjugating the data from physicochemical properties, bioactivities and probiotic viability, dark chocolate matrices with 54.5% and 70.5% cocoa, may be considered a promising food vector for A. muciniphila DSM 22959 and B. animalis subsp. lactis BB-12®, respectively.
•Effect of chocolate matrices on probiotic viability and bioactivities was assayed.•A. muciniphila showed greater viability in chocolate with 33.6% and 54.5% cocoa.•For BB-12®, the most suitable matrix (higher viability) contained 70.5% cocoa.•Phenolic content and bioactivities increased with cocoa augmentation in the matrix.•Dark chocolate (54.5 and 70.5% cocoa) could be a promising probiotic food vector.
Kombucha is a beverage obtained by fermenting tea containing sugar as a result of the symbiotic relationship between yeast and acetic acid bacteria. In this study, milk and various herbal teas (sage, ...blackberry, and green tea) were mixed in the ratio of 60:40 (v/v) and fermented with kombucha culture. 2.2-Diphenyl-1-picrilhydrazyl (DPPH) radical scavenging activity, total phenolic content, total reducing sugar content, and the microbiological and sensory properties of the fermented dairy beverage were examined. The highest DPPH radical scavenging activity was observed on the 1st day of storage of the blackberry tea-blended fermented beverage (98.48%), and the highest total phenolic content was observed on the 30th day of the green tea-blended fermented beverage (81.51 mg/mL). The maximum amount of glucuronic acid (0.42 g/100 mL) was observed on the 20th day of storage in the sage-blended fermented dairy beverage. The most favorite product was the blackberry blend, whereas the least favorite was the dairy beverage (control sample) fermented with kombucha based on sensory scores. This study demonstrates that milk and herbal teas could be successfully fermented with kombucha culture, thereby improving its functional properties.
•Milk and herbal teas were successfully fermented with kombucha culture.•The maximum glucuronic acid was detected in sage-blended fermented dairy beverage.•The sucrose and lactose content of all samples were higher than d-glucose content.•The most favored beverage was blackberry-milk blended product.
The Folin-Ciocalteu assay is a reference method for the quantification of total (poly)phenols in food. This review explains the fundamental mechanism of the redox reaction on which the method is ...based and looks at some of the practical considerations concerning its application. To accurately estimate the antioxidant capacity of (poly)phenolic compounds, a thorough knowledge of their structural characteristics is essential, as the two are closely associated. Therefore, to help researchers interpret the results of the Folin-Ciocalteu method, this review also summarizes some of the main phenolic structural features. Finally, we have used the Folin-Ciocalteu method to estimate the total phenolic intake associated with high adherence to a Mediterranean diet, ranked as one of the healthiest dietary patterns, which is characterized by a high consumption of (poly)phenol-rich food such as wine, virgin olive oil, fruits, vegetables, whole grains, nuts, and legumes.
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.
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