Total equivalent antioxidant capacities (TEAC) and phenolic contents of 32 spices extracts from 21 botanical families grown in Poland were investigated. The total antioxidant capacity was estimated by the following methods: ABTS (2,2′azinobis-(3-ethylbenzthiazoline-6-sulfonic acid)), DPPH (1,1-diphenyl-2-picrylhydrazyl radical) and ferric reducing/antioxidant power (FRAP) expressed as TEAC. The total phenolics were measured using a Folin–Ciocalteu assay. Qualitative and quantitative analyses of major phenolics by reverse-phase high-performance liquid chromatography (RP-HPLC) were also used. Major phenolic acids identified in analyzed species were caffeic, -coumaric, ferulic and neochlorogenic, while predominant flavonoids were quercetin, luteolin, apigenin, kaempferol and isorhamnetin. Myricetin was detected only in . Many investigated spices had high levels of phenolics and exhibited high antioxidant capacity. The TEAC values of the spices ranged from 1.76 to 346 μM trolox/100 g dw, from 7.34 to 2021 μM trolox/100 g dw, and 13.8 to 2133 μM trolox/100 g dw for ABTS , DPPH and FRAP, respectively. The total phenolic content, measured using a Folin–Ciocalteu assay, ranged from 0.07 to 15.2 mg of gallic acid equivalents (GAE)/100 g dw. The herbs with the highest TEAC values were , and the species belonging to the Labiatae and Compositae family. A positive relationship between TEAC (ABTS and FRAP) values and total phenolic content, measured by HPLC, was found only in family groups with many representative herbs within Labiatae and Compositae.
Epidemiological studies have shown an inverse relationship between dietary flavonoid intakes and cardiovascular diseases. fruits are the main winter fruits consumed in the Mediterranean diet, so they are the main source of dietary flavonoids. The possible beneficial effects are due, not only to the high amounts of vitamins and minerals, but also to the antioxidant properties of their flavonoids. Dietary flavonoids may help to supplement the body antioxidant defences against free radicals. These compounds’ possible beneficial effects are due to their antioxidant activity, which is related to the development of atherosclerosis and cancer, and to anti-inflammatory and antimicrobial activity. The present review summarizes the existing bibliography on biological and pharmacological studies of flavonoids, both and .
Antioxidative activity and functional properties of protein hydrolysates from yellow stripe trevally ( ) meat, hydrolyzed by Alcalase 2.4L (HA) and Flavourzyme 500L (HF) with different degrees of hydrolysis (DH) were investigated. As the DH increased, DPPH radical-scavenging activity and reducing power of HA decreased ( 0.05). Metal chelating activity of both HA and HF increased with increasing DH ( < 0.05). HF generally had a higher ( < 0.05) chelating activity than had HA at the same DH tested. At low DH (5%), HA exhibited a better DPPH radical-scavenging activity while, at high DH (25%), HF had a higher ( < 0.05) reducing power. For the functional properties, hydrolysis by both enzymes increased protein solubility to above 85% over a wide pH range (2–12). When the DH increased, the interfacial activities (emulsion activity index, emulsion stability index, foaming capacity, foam stability) of hydrolysates decreased ( < 0.05), possibly caused by the shorter peptide chain length. At the same DH, the functionalities of protein hydrolysate depended on the enzyme used. The results reveal that antioxidative activity and functionalities of protein hydrolysates from yellow stripe trevally meat were determined by the DH and by the enzyme type employed.
This study selected 13 fruits and vegetables to determine their total phenolic and flavonoid contents and their stimulatory effects on splenocyte proliferation from female BALB/c mice. The highest total phenolic content was observed in mulberry (1515.9 ± 5.7 mg gallic acid equivalents (GAE)/100 g fresh matter (FM)) among four selected fruit species. The highest total phenolic content was observed in a variety of red onions (310.8 ± 4.9 mg GAE/100 g FM) among nine selected vegetable species. The highest total flavonoid content was observed in mulberry (250.1 ± 6.3 mg quercetin equivalents (QE)/100 g FM) among the selected fruits. The highest total flavonoid content was observed in ceylon spinach (133.1 ± 26.2 mg QE/100 g FM) among the selected vegetables. The mulberry, strawberry and red onion demonstrated an immuno-modulatory potential via stimulating splenocyte proliferation. Bitter melon showed a significantly ( < 0.05) negative correlation with splenocyte proliferation. Their immuno-modulatory components are highly correlated with phenolics, including flavonoids. The total phenolic contents in all selected fruits and vegetables significantly correlated with splenocyte proliferation in vitro.
Analysis of biogenic amines (BA) in foods was reviewed. Biogenic amines are natural antinutrition factors and are important from a hygienic point of view as they have been implicated as the causative agents in a number of food poisoning episodes, and they are able to initiate various pharmacological reactions. Histamine, putrescine, cadaverine, tyramine, tryptamine, β-phenylethylamine, spermine, and spermidine are considered to be the most important biogenic amines occurring in foods. Analysis of BA is important because of their toxicity and their usage as indicators of the degree of freshness or spoilage of food. Several methods have been developed for determination of biogenic amines in food. The analytical methods used for quantification of BA are mainly based on chromatographic methods: thin layer chromatography (TLC), gas chromatography (GC), capillary electrophoresis (CE) and high-performance liquid chromatography (HPLC). HPLC is most often used for the analysis method of BAs. Due to low volatility and lack of chromophores of most BA, UV-spectrometric detectors cannot be used. The large majority of assays employs fluorimetric detection with precolumn or postcolumn derivatization techniques. This review shows that these methods allow quantitative determination of biogenic amines, individually or simultaneously in foods.
The antioxidant properties of two wild edible mushroom species from the northeast of Portugal, (L.) Gray and (Fr.) Quél., were evaluated. Methanolic extracts from the entire mushroom, the cap and the stipe, separately, were screened for their reducing power and free radical scavenging capacity by chemical assays. The total phenolic content was determined, in order to assess its effect on the extract’s antioxidant activity. Both two species showed antioxidant potential; but proved to be more active. The portion of the mushroom used had an influence on the results obtained, with the cap methanolic extracts exhibiting the greatest antioxidant effect.
Total antioxidant capacities of 133 Indian medicinal plant species sampled from 64 families were assessed by ABTS, DPPH and FRAP assays, and their total phenolic contents measured by Folin–Ciocalteu assay. These species exhibited a broad range of antioxidant activities, varying from 0.16 to 500.70 mmol TEAC/100 g DW in the ABTS assay. The antioxidant activity values similarly varied with the DPPH and FRAP assays. Significant and positive linear correlations were found between total antioxidant capacities and phenolic contents ( = 0.89–0.97), indicating that phenolics were the dominant antioxidant constituents in the tested medicinal plants. Preliminary identification of the major phenolic compounds from 83 selected medicinal plants by reversed-phase HPLC revealed phenolic acids, tannins, flavonoids, curcuminoids, coumarins, lignans, and quinines. The fruit of , pericarp of and gall of showed very high levels of hydrolysable tannins, and the gum of presented very high levels of catechin and epicatechin in addition to tannins. Major phenolics in many of the medicinal plants were identified for the first time (e.g., , , and ). This systematic investigation of a large number of Indian medicinal plants proved important for understanding their chemical constituents and functionality in Ayurvedic medicine, and contributes to the search for natural sources of potent antioxidants.
The knowledge of dietary intake of polyphenols and their bioaccessibility in the human gut are key factors in assessing their significance in human health. The aim of this work was to estimate the amount of total polyphenols consumed in a whole diet (Spanish Mediterranean diet) and their intestinal bioaccessibility. Total polyphenols were determined, as the sum of the polyphenols present in methanol:acetone:water extracts (extractable polyphenols) of plant foods and condensed tannins and hydrolysable polyphenols (non-extractable polyphenols) in the corresponding residues. The polyphenols intestinal bioaccessibility was estimated by an in vitro gastrointestinal model where food polyphenols are released by enzyme digestion and colonic fermentation. The mean daily intake of polyphenols in the Spanish diet was estimated between 2590 and 3016 mg/person/day. The amount of non-extractable polyphenols was almost double that of extractable polyphenols. It was estimated that about 48% of dietary polyphenols are bioaccessible in the small intestine, while 42% become bioaccessible in the large intestine.
The nutritional compositions of 34 edible seaweed products of the sp., , and sp. varieties were analyzed. This study determined amino acid and fatty acid (FA) distributions and contents of protein, fat, and total fibre of these seaweed varieties. In general, the marine macroalgae varieties tested demonstrated low lipid contents with 2.3 ± 1.6 g/100 g semi-dry sample weight (s.w.) and proved to be a rich source of dietary fibre (46.2 ± 8.0 g/100 g s.w). The pure protein content of seaweed products varied widely (26.6 ± 6.3 g/100 g s.w. in red algae varieties and 12.9 ± 6.2 g/100 g s.w. in brown algae varieties). All essential amino acids were detected in the seaweed species tested and red algae species featured uniquely high concentrations of taurine when compared to brown algae varieties. Interestingly, the FA distribution of seaweed products showed high levels of n-3 FA and demonstrated a nutritionally ideal n-6/n-3 FA ratio. The predominante FA in various seaweed products was eicosapentaenoic acid (C20:5, n-3) which was at concentrations as high as 50% of total FA content.
Raspberry ( ), blackberry ( ), raspberry × blackberry hybrids, red currant ( ), gooseberry ( ) and Cornelian cherry ( ) cultivars and native populations of varied pigmentation, originally from the Mediterranean area of Northern Greece, were assayed for antioxidant activity (determined as ferric reducing antioxidant power (FRAP) and deoxyribose protection), ascorbic acid, phenol, and anthocyanin contents. FRAP values ranged from 41 to 149 μmol ascorbic acid g dry weight and protection of deoxyribose ranged from 16.1% up to 98.9%. Anthocyanin content ranged from 1.3, in yellow-coloured fruit, up to 223 mg cyanidin-3-glucoside equivalents 100 g fresh weight in Cornelian cherry, whereas phenol content ranged from 657 up to 2611 mg gallic acid equivalents 100 g dry weight. Ascorbic acid content ranged from 14 up to 103 mg 100 g fresh weight. The present study outlines that the native Cornelian cherry population is an extremely rich source of antioxidants, demonstrating its potential use as a food additive.
Nine tropical fruits were analyzed for total phenol contents, ascorbic acid contents and antioxidant activities. The antioxidant activities were evaluated based on the ability of the fruit extracts to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH), reduce iron(III) to iron(II) and to bind to iron(II) ions. The results were compared to those of orange. It was found that guava, papaya and star fruit have higher primary antioxidant potential, as measured by scavenging DPPH and iron(III) reducing assays. Banana, star fruit, water apple, langsat and papaya have higher secondary antioxidant potential as measured by the iron(II) chelating experiment.
The unique and delicate flavour of olive oil is attributed to the volatile compounds that develop during and after oil extraction from the olive fruit. The formation of these volatile compounds and the fruit characteristics that affect the formation are examined in this review. The role of extraction time -temperature interactions in volatile development and other factors that impact volatile development, such as fruit storage prior to oil extraction, are also considered. The volatile compounds that develop during extraction become less dominant during oil storage with the emergence of volatile compounds from chemical oxidation. The presence or absence of particular volatile compounds partly explains quality differences in olive oils.
The antioxidant activities of three Portuguese wild edible mushroom species, and , were evaluated. Methanolic extracts were screened for their reducing power, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging capacity, inhibition of erythrocytes hemolysis and antioxidant activity using the β-carotene linoleate model system. The amounts of ascorbic acid, β-carotene and lycopene found in the mushroom extracts were very low. Otherwise, the high contents of phenolic compounds might account for the good antioxidant properties found in all species. had the highest content of phenols and proved to be the most active, presenting lower EC values in all the antioxidant activity assays.
The physicochemical, thermal, pasting and gel textural properties of corn starches from different corn varieties (African Tall, Ageti, Early Composite, Girja, Navjot, Parbhat, Partap, Pb Sathi and Vijay) were studied. Amylose content and swelling power of corn starches ranged from 16.9% to 21.3% and 13.7 to 20.7 g/g, respectively. The enthalpy of gelatinization (Δ ) and percentage of retrogradation (% ) for various corn starches ranged from 11.2 to 12.7 J/g and 37.6% to 56.5%, respectively. The range for peak viscosity among different varieties was between 804 and 1252 cP. The hardness of starch gels ranged from 21.5 to 32.3 g. African Tall and Early Composite showed higher swelling power, peak, trough, breakdown, final and setback viscosity, and lower Δ and range of gelatinization. Pearson correlations among various properties of starches were observed. Gelatinization onset temperature ( ) was negatively correlated to peak-, breakdown-, final- and setback viscosity ( = −0.809, −0.774, −0.721 and −0.686, respectively, < 0.01) and positively correlated to pasting temperature ( = 0.657, < 0.01). Δ was observed to be positively correlated with , peak gelatinization temperature and ( ) and gelatinization conclusion temperature ( = 0.900, 0.902 and 0.828, respectively, < 0.01) whereas, it was negatively correlated to peak- and breakdown- ( = −0.743 and −0.733, respectively, < 0.01), final- and setback viscosity ( = −0.623 and −0.611, respectively, < 0.05). Amylose was positively correlated to hardness ( = 0.511, < 0.05) and gumminess ( = 0.792, < 0.01) of starch gels.
Antioxidant activities (μmol Trolox equivalent (TE)/g fresh weight) of 19 sweet potato genotypes with distinctive flesh colour (white, cream, yellow, orange and purple) were measured by oxygen radical absorbance capacity (ORAC), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and 2,2′-azinobis(3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS). Total phenolics were measured using the Folin–Ciocalteau method, total anthocyanins by the pH-differential method, and β-carotene by HPLC. The total antioxidant activity (hydrophilic + lipophilic ORAC) was highest (27.2 μmol TE/g fresh weight (fw)) for NC415 (purple-fleshed) and lowest (2.72 μmol TE/g fw) for Xushu 18 (white-fleshed). The hydrophilic-ORAC values were significantly correlated with the DPPH ( = 0.859) and ABTS ( = 0.761) values. However, the lipophilic-ORAC values were poorly correlated with the β-carotene contents ( = 0.480). The total phenolic contents (0.011–0.949 mg chlorogenic acid equivalent/g fw) were highly correlated with the hydrophilic-ORAC ( = 0.937) and DPPH ( = 0.820) values. Therefore, the total phenolic content can serve as a useful indicator for the antioxidant activities of sweet potatoes.
Honey samples from the seven most common honey types in Slovenia were screened for total phenolic content by the modified Folin–Ciocalteu method, for potential antioxidant activity using the ferric reducing antioxidant power (FRAP) assay and by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method for antiradical activity. In addition the colour characteristics of honey samples were analysed. The results of the study showed that total phenolic content, antioxidant activity and colour parameters differ widely among different honey types. Phenolic content expressed as gallic acid equivalent ranged from 44.8 mg/kg in acacia honey to 241.4 mg/kg in fir honey. Antioxidant activity was the lowest in the brightest acacia and lime honeys and the highest in darker honeys, namely fir, spruce and forest. The colour of the Slovenian honeys, analysed in this study was very variable and ranged from pale yellow to dark brown. Correlations between the parameters analysed were found to be statistically significant ( < 0.05).
is widely found in the lands of Aegean and Mediterranean regions of Turkey. The goal of this work was to test the antimicrobial activity of the essential oils and methanolic extracts of collected from three different regions at four different time intervals of the year against , , , , , , , and . Essential oils were obtained from the aerial parts of the plant by using a Clevenger apparatus, for 4 h. After distillation, the distillates were filtered, air-dried and then extracted by using a Soxhlet apparatus for 9 h to obtain the methanolic extracts. The antimicrobial activities of the methanolic extracts were tested by the disc diffusion technique. The antimicrobial activities of the essential oils obtained from were determined by minimum inhibitory concentration (MIC).The results indicated that the tested bacteria were sensitive to the essential oils and partially to the methanolic extracts. The antimicrobial activities of the essential oils against the tested bacteria differed, depending on location and seasonal variations.
In this study, the chemical composition of white ( L.), red ( L.) and black ( L.) mulberry fruits grown in the East Anatolia Region of Turkey was investigated. The highest total phenolic and flavonoid contents were observed in black mulberry (1422 mg gallic acid equivalents/100 g fresh matter and 276 mg quercetin equivalents/100 g fresh matter). had the highest total fat content (1.10%), followed by (0.95%) and (0.85%), respectively. The major fatty acids in mulberry fruits were linoleic acid (54.2%), palmitic acid (19.8%) and oleic acid (8.41%), respectively. The total soluble solids content of mulberry species varied between 15.9% ( L.) and 20.4% ( L.), acidity between 0.25% ( L.) and 1.40% ( L.), pH between 3.52 ( L.) and 5.60 ( L.), ascorbic acid 19.4 mg/100 g ( L.) and 22.4 mg/100 g ( L.), respectively. Mineral compositions of the mulberry species were 0.83% N, 235 mg/100 g P, 1141 mg/100 g K, 139 mg/100 g Ca, 109 mg/100 g Mg, 60 mg/100 g Na, 4.3 mg/100 g Fe, 0.4 mg/100 g Cu, 4.0 mg/100 g Mn and 3.1 mg/100 g Zn, respectively.
Ethanolic extracts from various parts of 26 Thai indigenous plants were examined for phenolic constituents and free radical scavenging capacity, to determine their potential as a source of natural antioxidants. Total phenolic content and total flavonoid content were evaluated according to the Folin-Ciocalteu procedure, and a colorimetric method, respectively. The results showed that total phenolic compounds and flavonoid content were higher in seed extracts of berries used in wine production, while the levels in extracts obtained from herbs and vegetables were lower. Chewing plants which have an astringent taste gave a significantly higher total phenolic content and flavonoid content. Antiradical activity determined from 1/EC by the DPPH radical-scavenging method was highest in wine production seeds and chewing plants. The correlation coefficient from regression analysis showed a positive relationship between total phenolic and total flavonoid content ( = 0.9). The results suggest that ethanolic extracts of some Thai indigenous plants exhibit a potential for use as natural antioxidants.
In order to identify new sources of safe and inexpensive antioxidants, the antioxidant capacity and total phenolic content of different fractions of 23 microalgae were evaluated, using Trolox equivalent antioxidant capacity assay and the Folin–Ciocalteu method, respectively. The microalgae were extracted using hexane, ethyl acetate and water by a three-step sequential extraction procedure. Most of these microalgae were evaluated for the first time for their antioxidant activities. It was found that the microalgae sp. FACHB 283, and CCAP 1453/17 possessed the highest antioxidant capacities and thus could be potential rich sources of natural antioxidants. In addition, the correlation coefficients between the antioxidant capacities and the phenolic contents were very small in hexane ( = 0.0075), ethyl acetate ( = 0.5851) and water ( = 0.3599) fractions. Thus, phenolic compounds were not a major contributor to the antioxidant capacities of these microalgae. This was very different from many other plant species like fruits, vegetables and medicinal plants. The microalgae could contain different antioxidant compounds from other plants.