Chemical composition,antioxidant activity and anti‐lipase activity of Origanum vulgare and Lippia turbinata essential oils

This study reported the chemical composition, phenolic content, antioxidant and anti‐lipase activity of oregano and Lippia essential oils. The major compounds found in oregano essential oil were γ‐terpinene (32.10%), α‐terpinene (15.10%), p‐cymene (8.00%) and thymol (8.00%). In Lippia essential oil, α‐limonene (76.80%) and 1,8‐cineole (4.95%) represented the major compounds. Oregano essential oil had higher phenolic content (12.47 mg gallic acid mL^?1) and DPPH scavenging activity (IC₅₀ 0.357 μg mL^?1) than Lippia essential oil (7.94 mg gallic acid mL^?1 and IC₅₀ 0.400 μg mL^?1, respectively). Both essential oils had similar antioxidant indexes (about 1.2) determined by Rancimat. Moreover, oregano essential oil had also higher anti‐lipase activity (IC₅₀ 5.09 and 7.26 μg mL^?1). Higher phenolic content in the essential oils was related with higher scavenging and anti‐lipase activities. Oregano and Lippia essential oils could be used as natural antioxidants on food products.     

Determination of phthalate esters in wine using solid-phase extraction and gas chromatography–mass spectrometry

A method for the determination of six phthalate esters in wine samples has been developed. The phthalates were extracted from wine samples with an optimised solid-phase extraction method on C18 column and quantification was achieved via gas chromatography coupled with a mass spectrometer. The method was linear between 0.015 and 5.000 μg mL⁻¹ for DMP, DEP and DEHP and between 0.018 and 5.000 μg mL⁻¹ for iBP, DBP and BBP. The LOQs of DMP, DEP and DEH were 0.024 μg mL⁻¹ while those of iBP, DBP and BBP were 0.029 μg mL⁻¹. The intra-day method repeatability was between 10% and 15% RSD, whereas the inter-day method repeatability was between 13% and 21% RSD. A survey was performed on white and red wines (n = 62) from the market, winemakers and an experimental pilot plant. All the analysed samples were phthalate contaminated. Commercial wine showed higher detection frequency and level of total phthalate, DBP and BBP than those produced in a pilot plant. iBP and DEHP concentrations were similar in all the groups of samples. iBP concentration was higher in red wines than in white ones.     

Determination of 13 Phenolic Compounds in Rice Wine by High-Performance Liquid Chromatography

Rice wines are widely consumed by the general public in Asian countries, while comprehensive studies focused on the individual phenolic compounds in rice wines are limited. A rapid method for simultaneous determination of 13 phenolic compounds in rice wines by high-performance liquid chromatography (HPLC) was developed and validated, and the phenolic compounds in commercial rice wine samples (Chinese rice wine, Japanese sake, and Korean makgeolli) were determined in this paper. The identified compounds contained gallic acid (GA), protocatechuic acid (PRCA), vanillic acid (VA), syringic acid (SRA), caffeic acid (CA), ferulic acid (FA), p-coumaric acid (pCA), sinapic acid (SA), chlorogenic acid (CHA), (+)-catechin (CAT), (?)-epicatechin (EPI), quercetin (QUE), and rutin (RUT). Phenolics were separated with a C18 reversed-phase column at 38 °C by gradient elution using 3 % acetic acid aqueous solution (solvent A) and acetonitrile (solvent B) (0 min, 5 % B; 5 min, 8 % B; 10 min, 15 % B; 20 min, 25 % B; and 25 min, 5 % B) as the mobile phase at 280 nm with flow rate of 1.0 mL min^?1. With direct injection of rice wine samples, the chromatograms of all analytes were observed within 20 min, all calibration curves were linear (R ²?>?0.995) within the range, limits of detection (LOD) ranged from 0.02 to 0.06 μg mL^?1, and good recoveries (88.07–106.80 %) and precision (relative standard deviation (RSD)?<?5.36 % ) were obtained for all compounds. This method was applied to quantify phenolic compounds in commercial rice wine samples (Chinese rice wine, Japanese sake, and Korean makgeolli), and good separation peaks were observed and catechin was the predominant phenolic in the samples. The average values of total phenolic contents of the three groups of rice wine were significantly different (p?<?0.01). In conclusion, this procedure can be used to determine the phenolic compounds in various types of rice wines, as well as to characterize and differentiate rice wine samples.     

Inhibition of the decrease of volatile esters and terpenes during storage of a white wine and a model wine medium by caffeic acid and gallic acid

Caffeic acid and gallic acid were tested as inhibitors of the decrease of volatile acetate esters, ethyl esters and terpenes during storage of a white wine and a model wine medium. Wine and model wine samples were analysed by SPME along with GC–MS. At t = 0, no effect on the concentration of any volatile was observed as a result of adding each phenolic acid in any of wine or model wine samples. Many esters, such as isoamyl acetate, ethyl hexanoate, ethyl octanoate, ethyl decanoate, and linalool decreased during storage of Debina-white wine for up to 20 months. Caffeic acid and gallic acid at 60 mg/L inhibited the decrease of these volatiles. Isoamyl acetate, ethyl hexanoate and linalool decreased during storage of the model wine medium containing 0, 20 or 40 mg/L SO₂. Caffeic acid and gallic acid inhibited the decrease of three volatiles; SO₂ inhibited the decrease of isoamyl acetate and ethyl hexanoate. In some cases, SO₂ increased the inhibitory action of two phenolic acids. The inhibitory action of caffeic acid and gallic acid was dose dependent in the range 0–60 mg/L. Caffeic acid was active at 7.5 mg/L while gallic acid at 15 mg/L.Present results indicate that caffeic acid and gallic acid may be taken into account as potent inhibitors of the disappearance of aromatic volatile esters and terpenes in wines at concentrations similar to those existing in wines.     

Does u.v. light affect the total phenolic compound,anthocyanin, antioxidant capacity,and sensory profiles in wines?

In the study, by applying ultraviolet (u.v.) lights (254 nm) for 45 min to red wines from fermented Cabernet Franc, Cabernet Sauvignon, Merlot, and Petit Verdot (Vitis vinifera L.) grapes, we examined the total phenolic compound, total anthocyanin, and antioxidant capacity by four different methods, trans-resveratrol, (+)-catechin, gallic acid content, and the change in tasting profiles of the wines after application. According to the results of the research, the u.v.-C application has caused an increase in all parameters examined. If we talk about averages without distinguishing between varieties, after the application the total phenolic compound content of 3206 increased to 3356 mg gallic acid equivalent (GAE) per L and after u.v.-C application, the total anthocyanin content increased from 411 to 780 mg L⁻¹, the ABTS [2,2′-azinobis(3-ethyl-benzothiazoline-6-sulphonic acid)] value increased from 30 to 33 μmol trolox mL⁻¹, the DPPH ((2,2-diphenyl-1-picrylhydrazyl) level increased from 13 to 16 μmol trolox mL⁻¹, the FRAP (ferric reducing antioxidant power) level increased from 15 to 16 μmol trolox mL⁻¹, and the CUPRAC (cupric reducing antioxidant capacity) level increased from 40 to 45 μmol trolox mL⁻¹. The u.v. application affected trans-resveratrol the most among the phenolic compounds and an average increase of 12.99% was obtained. The rate of increase after u.v. application was 3.33% in (+)-catechin and 5.57% in gallic acid. The highest correlation between antioxidant activity measurement methods was measured to be 0.998 between FRAP and DPPH. In addition, u.v.-C application has had a positive effect on taste-based sensory profiles. In recent years, the search for a diet with a high antioxidant content has become even more important.     

Antioxidant capacity and antioxidative compounds in barley (<Emphasis Type="Italic">Hordeum</Emphasis><Emphasis Type="Italic">vulgare</Emphasis> L.) grain optimized using response surface methodology in hot air roasting

Response surface methodology was used to predict optimum conditions for hot air roasting of barley grains (temperature, time, and amount). Antioxidant capacity in the grains was highest under optimum conditions of 250 °C, 63.5 min and 42 g (one and a half layers). A correlation of R ² = 0.74 (p < 0.05) was found between 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and total phenolic contents. Ethanol and aqueous extracts were prepared from grains roasted under optimum conditions and assessed for antioxidant capacity. Antioxidative compounds in the extracts were then identified using GC–MS. The IC₅₀ value of ethanol extract was significantly lower (11.45 μg mL^–1) than that of aqueous extract (33.54 μg mL^–1) and α-tocopherol (12.6 μg mL^–1) but higher than BHT (9.59 μg mL^–1). The same trend was observed in linoleic acid assay. In reducing power, the ethanol extract and α-tocopherol were not significantly different. Phenolic acids p-hydroxybenzaldehyde, vallinic and gallic acids were identified as the major compounds in the extracts. The results obtained from this study show that it is possible to optimize antioxidant capacity in barley grains during roasting.     

Mixed fermentation of jujube juice (Ziziphus jujuba Mill.) with L. rhamnosus GG and L. plantarum-1: effects on the quality and stability

This study was conducted aiming at improving the quality of jujube juice by mixed fermentation of lactobacilli. Selection of favourable lactobacilli and addition of nitrogen sources were explored as an efficient method to improve the viability of probiotic in jujube juice. After fermentation, the viability increased to 9.15 ± 0.10 Log CFU mL⁻¹, while the content of lactic acid increased to 5.61 ± 0.03 mg mL⁻¹. The total phenolic and total flavonoid content were 2663.03 ± 11.95 μg mL⁻¹ and 163.95 ± 0.47 μg mL⁻¹ respectively. Moreover, the stability of fermented jujube juice during refrigeration was investigated, which showed that the viability dropped to 8.84 ± 0.6 Log CFU mL⁻¹ and the concentration of lactic acid slowly increased to 6.51 ± 0.04 mg mL⁻¹; the ABTS value showed a 4.26% reduction and FRAP value did not significantly (P < 0.05) change during refrigerated storage. In addition to the existing knowledge, our data aid to the future applications of the jujube as a potential ingredient in novel probiotic foods formulation.     

Effects of physicochemical factors and in vitro gastrointestinal digestion on antioxidant activity of R‐phycoerythrin from red algae Bangia fusco‐purpurea

R‐phycoerythrin (R‐PE) was purified from the red algae Bangia fusco‐purpurea after 35–50% ammonium sulphate fractionation followed by ion‐exchange column chromatography on DEAE‐Sepharose, resulting in a purity (A₅₆₅/A₂₈₀) ratio of 5.1. The circular dichroism spectroscopy results suggested that the structure of R‐PE is predominately helical. The antioxidant activity of R‐PE was studied and revealed changes in conformation and antioxidant activity at different temperatures and pH values. After in vitro‐simulated gastrointestinal (GI) digestion of R‐PE, the scavenging activity of ABTS radical (EC₅₀, 769.9 μg mL^?1), DPPH radical (EC₅₀, 421.9 μg mL^?1), hydroxyl radical (EC₅₀, 32.4 μg mL^?1) and reducing power (A₇₀₀ = 0.5, 625.8 μg mL^?1) were measured. Gel filtration chromatography analysis showed that the molecular weight distribution of the final GI digest that still contained high antioxidant activity was <3 kDa. Our present results indicate that digestion‐resistant antioxidant peptides of R‐PE may be obtained by in vitro GI proteinases degradation.     

Changes in growth kinetics and motility characteristics of Escherichia coli in the presence of sulphoraphane isolated from broccoli seed meal

In this investigation, the purified sulphoraphane from broccoli seed meal was evaluated in a range of 5–400 μg mL⁻¹ against Escherichia coli. The results showed that levels above 200 μg mL⁻¹ can inhibit 100% growth of 10⁶ CFU mL⁻¹ up to 5 h and cause a deformation of sigmoid behaviour in the growth kinetics, and even the bacterial population is reduced. On the other hand, low sulphoraphane levels such as 5–25 μg mL⁻¹ also have effects on the bacterium, such as the decrease in the maximum specific growth rate and the loss of ability to adjust to a growth model when maintained in isothermal conditions. In addition, sulphoraphane has an effect on swimming motility and swarming motility in semi-solid medium. The interaction of natural sulphoraphane–E. coli and the effect in the short periods can draw attention in research on food science and technology.     

Phenolic compounds and antioxidative properties of selected wines from the northeast of Thailand

The phenolic contents and antioxidative properties of selected wines, produced in the northeast of Thailand, were evaluated and compared, particularly those produced at Suranaree University of Technology (SUT) Farm as a case study. Nine wine varieties were used to evaluate their total phenolic content (TPC) by Folin–Ciocalteu method, free radical scavenging efficacy by DPPH method and reducing power by ferric reducing-antioxidant power (FRAP) method. The red wines had significantly higher (p < 0.05) amounts of total phenols, flavonoids and antioxidant activities (AA) compared to white wines. Capillary electrophoresis (CE) was used as a powerful and high performing tool for analysis of principal phenolic compounds in the wines. t-Resveratrol was found in Shiraz, Zinfandel and blended wine varieties. (+)-Catechin was found in all wine varieties, except in Chasselar Dore. (+)-Catechin was present in wines at a higher level than (−)-epicatechin. In red wine, gallic acid was the dominant phenolic acid found.     

Comparative study of the essential oils of three Beilschmiedia species and their biological activities

This study was designed to examine the chemical compositions of the essential oils from three Beilschmiedia species and antioxidant, antimicrobial, antityrosinase, acetylcholinesterase and anti‐inflammatory activities. The essential oils of B. kunstleri, B. maingayi, B. penangiana gave β‐caryophyllene (10.6–12.1%), β‐eudesmol (17.5–24.1%) and δ‐cadinene (17.5–28.7%) as the most abundant components respectively. The bark oil of B. maingayi showed the highest activity in β‐carotene/linoleic acid (125.9%) and phenolic content (288.2 mg GA g^?1), while B. penangiana bark oil was found to have strong activity in DPPH (IC₅₀ 84.7 μg mL^?1) and ABTS (IC₅₀ 108.3 μg mL^?1). The essential oils of B. penangiana showed the best activity against Candida glabrata with MIC value 31.3 μg mL^?1. The bark oil of B. penangiana gave 82.5% tyrosinase inhibiton. The leaf oil of B. maingayi gave the highest inhibition in AChE (66.6%) and lipoxygenase (77.0%) assay. Our findings demonstrate that the essential oils have great potential for applications in pharmaceutical and food industries.     

Antioxidant activities of five Chinese rice wines and the involvement of phenolic compounds

Chinese rice wine has been claimed to have health-promoting effects, which may be related to the antioxidant activity in vivo. In this study, total antioxidant, reducing, free radical scavenging, and superoxide anion radical scavenging activities were determined in five Chinese rice wines (Guyuelongshan, Hongqu, Shousheng, Foshou, and Nuomi) comparing with synthetic antioxidants, such as butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT). Ten individual phenolic compounds including caffeic acid, syringic acid, and rutin, (−)-epicatechin, (+)-catechin, gallic acid, vanillic acid, p-coumaric acid, ferulic acid and quercetin, were identified and quantified by HPLC. Results indicated that rice wines exhibited high antioxidant power, and that total antioxidant activity, reducing capacity and free radical scavenging activity were highly correlated with total phenolic content. Nuomi with the highest content of phenolic compounds showed the highest antioxidant activity, while Foshou had the lowest content with lowest activity. Syringic acid and (+)-catechin contributed most to the phenolic compounds and were highly correlated with all antioxidant properties (r² > 0.75). However, vanillic acid, p-coumaric acid and quercetin showed little contribution to the antioxidant function.     

Antioxidative and anti‐inflammatory potential of phenolics from purple basil (Ocimum basilicum L.) leaves induced by jasmonic,arachidonic and β‐aminobutyric acid elicitation

The study presents changes in the phenolic levels, antioxidant and anti‐inflammatory potential of purple basil leaves caused by different chemical elicitors: arachidonic acid (AA), jasmonic acid (JA) and β‐aminobutyric acid (BABA). The application of the all tested elicitors increased the concentration of phenolic compounds, including flavonoids and phenolic acids; especially, in comparison with control (457.62 μg g^?1 FW), the rosmarinic acid level significantly increased after AA and JA treatment ‐ 705.0 and 596.5 μg g^?1 FW, respectively. Phenolics from AA‐elicited plants showed the highest anti‐inflammatory activities designated as lipoxygenase (EC₅₀ = 1.67 mg FW mL^?1) and cyclooxygenase inhibition (EC₅₀ = 0.31 mg FW mL^?1). Elicitors' treatments (especially AA and JA) may be a very useful biochemical tool for improving the production of phenolic compounds in purple basil leaves.     

Growth and fermentation kinetics of a mixed culture of Saccharomyces cerevisiae var. bayanus and Williopsis saturnus var. saturnus at different ratios in longan juice (Dimocarpus longan Lour.)

Cofermentation of longan juice by mixed cultures of Saccharomyces cerevisiae var. bayanus EC‐1118 and Williopsis saturnus var. saturnus CBS254 at two inoculation ratios (EC‐1118:CBS254 = 1:100 and 1:1000 cfu mL^?1) was performed to ascertain their impact on longan wine aroma compound formation. The results showed improved aroma compound profiles in the longan wine fermented with mixed yeasts in comparison with the longan wines fermented with single yeasts in terms of increased production of acetate esters, fatty acid ethyl esters, alcohols and carboxylic acids. The impact of cofermentation on longan wine aroma formation was affected by the ratio of S. cerevisiae EC‐1118 to W. saturnus CBS254 with 1:100 cfu mL^?1 being more effective. This research suggests that the inoculation ratio of mixed yeasts may be used as an effective means of manipulating longan wine aroma.     

Polyphenolic composition,antioxidant and antiproliferative effects of wild and cultivated blackberries (Rubus fruticosus L.) pomace

The content of total polyphenolics, antioxidative capacity and antiproliferative activity were tested in wild and cultivated blackberry pomace. Wild blackberry pomace extract Tw2 showed the highest following contents: total polyphenolics (50.16 mg GAE g⁻¹ dw), flavonoids (7.73 mg Qc g⁻¹ dw), flavonols (6.63 mg Qc g⁻¹ dw) and total monomeric anthocyanins (13.40 mg Cy g⁻¹). Tw2 extract significantly inhibited free radicals: IC₅₀^DPPH = 127.76 μg mL⁻¹, IC₅₀^ABTS = 26.53 μg mL⁻¹ and IC₅₀ ^{˙ OH} = 168.62 μg mL⁻¹, and the growth of breast adenocarcinoma IC₅₀^MCF7 = 306.68 μg mL⁻¹ and cervix epitheloid carcinoma cell lines IC₅₀^HeLa = 315.49 μg mL⁻¹. Wild blackberry varieties had higher extraction yields, higher total polyphenolic contents and possessed stronger biological effects compared to cultivated blackberries (P < 0.05). All blackberry extracts showed high biological potential that could be attributed to high total polyphenols and flavonoids content and could be utilised as value-added functional food.     

The Study of Phenolic Compounds as Natural Antioxidants in Wine

Plant phenolics present in fruit and vegetables, and that are particularly rich in red wine, have received considerable attention because of their potential antioxidant activity. Human consumption of antioxidants has many alleged health benefits, including protection against cardiovascular diseases, and, most recently, cancer. Red wines contain a variety of polyphenolic antioxidants. Five samples of commercial red wines from Spain and four phenolic compounds of red wine: gallic acid, trans-resveratrol, quercetin and rutin, have been studied. The total phenolics content and the total antioxidant activity (TAA) of wines was determined. The total phenolic content, determined according to the Folin-Ciocalteu method, varied from 1800 to 2300?mg/L, expressed as gallic acid equivalents (GAE). The antioxidative effects of wine phenolics were determined using a system based on the inhibition by antioxidants of the absorbance of the radical cation. The relationship between antioxidant activity of phenolic compounds, as hydrogen donating free radical scavengers, and their chemical structures was studied. Furthermore, the total antioxidant activity of the wines investigated was well correlated with phenol content. Thus, the results confirm that red wine polyphenols are, in vitro, significant antioxidants.     

The influence of heat treatment of chickpea seeds on antioxidant and fibroblast growth‐stimulating activity of peptide fractions obtained from proteins digested under simulated gastrointestinal conditions

This study presents the effect of heat treatment of chickpea seeds on biological activity of peptides obtained by in vitro gastrointestinal digestion. The most significant antiradical activity against ABTS^+? expressed as IC₅₀ value was observed for 3.5‐ to 7‐kDa peptide fraction from TC hydrolysate (41.01 μg mL^?1). In turn, peptide fraction of 3.5–7.0 kDa obtained from raw chickpea seeds hydrolysate showed the highest antiradical activity against DPPH^? and Fe²⁺ chelating activity with IC₅₀ value of 20.94 and 52.53 μg mL^?1, respectively. The highest Cu²⁺ chelating activity was observed for peptides obtained from TC hydrolysate (IC₅₀ = 56.60 μg mL^?1). Peptide fraction <3.5 kDa from TC hydrolysate demonstrated the most significant reducing power (0.362 A₇₀₀/μg mL^?1). The peptide fraction of 3.5–7 kDa from TC hydrolysate also showed the highest fibroblast growth‐stimulating activity. These results indicated that the heat treatment process has no significant effect on antiradical activity against DPPH^? and Fe²⁺ chelating ability of peptides.     

Comparative study of antioxidant and antibacterial properties of the edible mushrooms Pleurotus levis,P. ostreatus,P. pulmonarius and P. tuber‐regium

Comparative studies of functional properties among closely related mushroom species, supported by molecular identification, standard cultivation and extraction protocols, are not well documented. We compared antioxidant and antibacterial properties of standardised hydroalcoholic extracts of four Pleurotus species (P. levis, P. ostreatus, P. pulmonarius and P. tuber‐regium). Antioxidant properties were investigated using DPPH and ABTS radical scavenging capacity, total phenolic content, β‐carotene‐linoleic and ORAC assays. Antibacterial effect was assessed using the microplate method. The functional properties of standardised mushroom extracts were different in species studied. β‐carotene–linoleic acid and ORAC assays showed high antioxidant activity, particularly in P. ostreatus. Pleurotus tuber‐regium exhibited the lowest antioxidant activity in the ORAC assay (3316.0 μmol of trolox equivalent mL^?1), but exerted the most potent bacteriostatic and bactericidal activity. Bacillus subtilis showed a high degree of susceptibility to a very low concentration (3.33 μg mL^?1) of P. levis extract. Remarkable antioxidant and antibacterial properties were found in P. levis and P. tuber‐regium compared to the other species studied that are cultivated commercially.     

Development of a HPLC method combined with ultraviolet/diode array detection for determination of monosodium glutamate in various food samples

An effective, simple and rapid analytical method using HPLC was developed for the analysis of monosodium glutamate (MSG) in various food samples obtained from local market in Turkey. The determination of MSG was performed by its derivatisation with o-phthaldialdehyde (OPA). A high-performance liquid chromatography-ultraviolet/diode array detection method was performed by using C₁₈ (150 mm × 4.6 mm, 2.7 μm) column with the mobile phase consisting of 10 mm phosphate buffer solution (pH = 5.90) and methanol (75:25, v/v). The applied method was optimised and the validated. The method was linear from 1 to 50 μg mL⁻¹ of MSG. The correlation coefficient value of the developed method was obtained as R² = 0.9999. The limit of detection and limit of quantification limits were 0.015 and 0.050 μg mL⁻¹, respectively. MSG contents of the food samples range from 0.09 g kg⁻¹ to 120.80 g kg⁻¹. The validated method was successfully applied for the analysis of MSG in several food samples.     

Electron spin resonance (ESR) spectroscopic assessment of the contribution of quercetin and other flavonols to the antioxidant capacity of red wines

Health benefits of red wine have been ascribed in part to the antioxidant properties of quercetin and other flavonols. Red wines, however, contain many other polyphenolic compounds with antioxidant potential. The present study has assessed the antioxidant capacity of seven red wines using electron spin resonance spectrometry to measure their ability to donate hydrogen atoms to a stable Fremy's radical. Antioxidant capacity of the wines was strongly related to the total phenol content (r = 0.872, P < 0.01) but less so to total flavonol content (r = 0.651, P < 0.10). The only flavonols detected in the wines by HPLC with post‐column derivatisation were the aglycones and conjugated forms of quercetin and myricetin. These accounted for less than 2% of total phenolic content when expressed as gallic acid equivalents. Although these flavonols showed marked ability to quench Fremy's radical, they contributed less than 1.5% to the total antioxidant capacity of the wines. Consequently, quercetin is not a major antioxidant in red wine. The antioxidant activity of other polyphenols may be of greater importance in contributing to the reputed health benefits of moderate wine consumption. © 1999 Society of Chemical Industry