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.     

Antioxidant function of tea dregs protein hydrolysates in liposome–meat system and its possible action mechanism

Tea dregs possess abundant proteins, and the objective of this study was to investigate the antioxidant activity of tea dregs protein hydrolysate with limited hydrolysis by protamex and its possible action mechanism. Tea dregs protein was hydrolysed by alcalase, protamex or neutrase. The hydrolysis condition was optimised, and the hydrolysate was characterised for 1,1‐diphenyl‐2‐picryl hydrazyl (DPPH) radical‐scavenging activity, hydroxyl radical‐scavenging activity and antioxidant activity in linoleic acid (LA) system and in chicken products. Tea dregs protein hydrolysate (TDPH) was formulated (0.1%, 0.5%, 1.0%, w/w) into chicken products to determine in situ antioxidant efficacy. Thiobarbituric acid‐reactive substances (TBARS) and peroxide value (POV) formed in chicken products during storage (4 °C, 0–7 days) were analysed. Results showed that the optimum hydrolysis condition was at 50 °C, pH 7.0 for 20 min, and the concentration of tea dregs protein was 1.5%; ratio of protamex to substrate was 6000 U g^?1. The radical‐scavenging ratio of TDPH to 1,1‐diphenyl‐2‐picryl hydrazyl (DPPH) was 90.30% at the concentration of 0.1 mg mL^?1 and that to hydroxyl radical was 65.18% at the concentration of 1.0 mg mL^?1. Moreover, it also showed strong antioxidant activity both in linoleic acid (LA) system and in chicken products. The molecular weight distribution of tea dregs hydrolysates was determined by nanofiltration tubular membrane, and the protein hydrolysates with molecular weight above 8000 Da had more effective antioxidant activity. The radical‐scavenging activities to DPPH and hydroxyl radical were 85.72% at 0.1 mg mL^?1 and 71.52% at 1.0 mg mL^?1, respectively. These findings suggest that the enzymatic hydrolysate of tea dregs protein probably possesses the specific peptides/amino acids which could stabilise or terminate the radicals through donating hydrogen. In addition, the hydrolysate could form a physical barrier around the fat droplets.     

Antioxidant activity of blueberry anthocyanin extracts and their protective effects against acrylamide‐induced toxicity in HepG2 cells

In this study, the antioxidant activities of blueberry anthocyanin extracts from ten blueberry varieties were evaluated based on the methods of scavenging activities for DPPH radicals, ABTS radicals, hydroxyl radicals and ferric reducing antioxidant power (FRAP) assay. Among the ten blueberry varieties, Polaris had the highest antioxidant abilities and the largest amounts of anthocyanins identified by HPLC‐MS. The protective effects of anthocyanin extracts from Polaris (AEP) against acrylamide (AA)‐induced toxicity in HepG2 cell models were also evaluated due to the neurotoxic, genotoxic and potentially carcinogenic effects of AA. The protective effects of AEP on the damage of HepG2 cells were explored from the aspects of cell viability, T‐SOD and CAT activity and MDA level. The AEP (5, 10, 20 μg mL^?1) could significantly increase cell viability (P < 0.01) and inhibit AA‐induced cytotoxicity. Polaris also markedly promoted the activity of SOD, CAT and inhibited MDA level. The results showed that AEP had strong antioxidant activities, presenting high protective effects against AA‐induced cell damage in HepG2 cell models.     

Characterization of cosmetic cream with Mesembryanthemum crystallinum plant extract: influence of formulation composition on physical stability and anti‐oxidant activity

Cosmetic or pharmaceutical composition containing superoxide dismutase (SOD) was usually used in topical administration, particularly, in fighting against skin ageing and in the protection of the skin against radiation exposure. Mesembryanthemum crystallinum is a halophyte plant widely used in the traditional medicine, characterized by the presence of anti‐oxidants enzymes in responses to abiotic stresses. In the present study, we prepared a formulation with M. crystallinum extract characterized by naturally occurring SOD and catalase in association with other anti‐oxidants molecules. The SOD activity was measured by 3‐(4,5‐dimethyldiazol‐2‐yl)‐2,5‐diphenyl‐tetrazolium bromide/riboflavin method, catalase by colorimetric method and the total anti‐radical activity was measured by 1,1‐diphenyl‐2‐picrylhydrazyl radical (DPPH) method. Formulations contain a significant SOD activity (8.33 U mg^?1), a catalase activity (0.5 × 10⁷ UC) and an anti‐radical activity (30% of DPPH inhibition). The formulation storage (15 days at 4°C) showed a marked loss of total anti‐oxidant capacity. The addition of the M. crystallinum extract induced also a reduction in formulation viscosity and pH.     

High-performance liquid chromatographic determination of triclosan and triclocarban in cosmetic products

A high–performance liquid chromatographic (HPLC) method for the determination of triclosan and triclocarban in cosmetic products was developed. Triclosan and triclocarban quantities in 168 of cosmetics were investigated and statistical analyzed with this method. The optimal condition are as follows: An Agilent SB‐C8 analytical column (250 × 4.6 mm, 5μm) was utilized, and mixed buffer solution of methanol and 0.01 mol L^?1 phosphate (pH 3.0) (72 : 28, V/V) were used for isocratic elution at a total flow rate of 1.0 mL min^?1. It is found the calibration curves had a good linear regression with UV detection (280 nm) within test range of 0–110 μg mL^?1 with the correlation coefficients of 0.999 in all cases. This method is simple, selective, convenient, and reproducible for the determination of triclosan and triclocarban in commercial cosmetic products.     

The development of a suitable manufacturing process for ‘Benifuuki’ green tea beverage with anti‐allergic effects

Epigallocatechin‐3‐O‐(3‐O‐methyl) gallate (EGCG3″Me) has been reported to inhibit type I allergy better than epigallocatechin gallate (EGCG), a major catechin in tea leaves (Camellia sinensis L). We examined the effects of extraction and sterilization on the catechin content and histamine release from mast cells, as a representative reaction of early phase allergy, in the manufacture of ‘Benifuuki’ green tea beverage. Among various varieties of tea, the cultivar ‘Benifuuki’ contains approximately 2% of EGCG3″Me. Ester‐type catechins and their epimers increased with the increased extraction temperature of the tea. A tea infusion, extracted at 90 °C, strongly inhibited histamine release from mast cells. Furthermore, sterilization affected the catechin content in the manufactured green tea beverage. Sterilization at high temperature promoted the isomerization of catechins and the sterilized green tea beverage had a strong inhibitory effect. When EGCG3″Me, EGCG, epicatechin‐3‐O‐gallate (ECG) and their epimers, GCG3″Me (gallocatechin‐3‐O‐(3‐O‐methyl) gallate), GCG (gallocatechin‐3‐O‐gallate) and CG (catechin‐3‐O‐gallate) were compared, the anti‐allergic effect of GCG3″Me was strongest, and the order of activity was GCG3″Me > EGCG3″Me > GCG > EGCG. We consequently suggest that it was necessary to extract components from tea at the highest temperature possible, and to pasteurize under retort conditions (118.1 °C, 20 min), to manufacture functional green tea beverage with an anti‐allergic action. Copyright © 2005 Society of Chemical Industry     

Allometric and biochemical responses of grapevines subjected to drought and enhanced ultraviolet‐B radiation

Background and Aims: The aim of this study was to evaluate differences in adaptive responses in grapevines (Vitis vinifera L. cv Soultanina) exposed to either drought, enhanced ultraviolet‐B (UV‐B) radiation or the combination of the two environmental stresses. Methods and Results: Results indicated pronounced effects on allometric parameters in plants exposed to the enhanced UV‐B radiation. The combined application of drought and enhanced UV‐B radiation considerably affected shoot growth rate and leaf dry weight. Guaiacol peroxidase (GPX, EC 1.11.1.7), ascorbate peroxidase (APX, EC 1.11.1.11), superoxide dismutase (SOD, 1.15.1.1) and catalase (CAT, 1.11.1.6) activities increased significantly in the enhanced UV‐B radiation treatment. Drought resulted in a significant increase in proline concentration, while the exposure of plants to enhanced UV‐B radiation resulted in the production of UV‐B absorbing compounds (UV_abs). Conclusions: Under drought conditions proline accumulation seemed to be the main mechanism of adaptation contributing to plant's antioxidant defence. On the other hand, under enhanced UV‐B radiation, the accumulation of the UV‐B absorbing compounds and the increase in antioxidant enzymes activities constitute the main mechanisms of grapevine adaptation. Significance of the Study: The data obtained indicate the occurrence of two different mechanisms of adaptation in response to the stressor applied. Furthermore, the patterns of proline and UV_abs concentration changes under stress conditions suggest that the biosynthesis of these two compounds might follow competing metabolic pathways.     

Layer‐by‐Layer Thin Film of Iron Phthalocyanine as a Simple and Fast Sensor for Polyphenol Determination in Tea Samples

Polyphenols have attracted attention due to their antioxidant capacity and beneficial effects to health. Therefore, fast, inexpensive, and efficient methods to discriminate and to quantify polyphenols are of interest for food industry. In this paper, Layer‐by‐Layer films of poly(allylamine hydrochloride) and iron tetrasulfonated phthalocyanine were employed as sensor for determination of polyphenols in green tea (camellia sinensis), and green and roasted mate teas (ilex paraguariensis). The polyphenol sensor was tested in catechol standard solution by differential pulse voltammetry (DPV), reaching a limit of detection of 1.76 × 10^?7 mol/L. The determination of polyphenols in the tea samples was obtained by analytical curve and catechol standard addition using electrochemical techniques. Projection techniques (information visualization) were applied to the DPV results of the tea samples and a pattern of separation following the phenolic content was obtained. The results support the application of the sensor in fast classification of beverages according to their polyphenol content.     

Polyphenolic composition and in vitro antioxidant activities of native‐ and tannase‐treated green tea extracts

The antioxidant activities of native‐ and tannase‐treated green tea extracts along with their major polyphenol components were investigated. The polyphenolic content and composition of the tea before and after tannase treatment were determined by liquid chromatography coupled with mass spectrometry (LC‐MS). Approximately 99% of the (?)‐epigallocatechin gallate (EGCG) and (?)‐epicatechin gallate (ECG) in green tea extract were converted by tannase to (?)‐epigallocatechin (EGC) and (?)‐epicatechin (EC), respectively, after 30 min. Biotransformed green tea exhibited a significantly higher DPPH˙ radical scavenging activities than native green tea (EC₅₀ value of 0.024 ± 0.001 and 0.044 ± 0.001 mg mL^?1, respectively). Kinetic parameters such as scavenging rate and stoichiometry were calculated. The rate of DPPH˙ radical scavenging activities for tannase‐treated green tea extract was shown to be higher than native green tea extract.     

Antioxidant activity of prebiotic ginseng polysaccharides combined with potential probiotic Lactobacillus plantarum C88

The potential prebiotic properties of Panax ginseng polysaccharides were studied using ten strains of Lactobacillus plantarum isolated from traditional Chinese fermented foods. These probiotics showed different growth characteristics depending on the extract and strain specificity. L. plantarum C88 showed higher cell densities and growth rate when cultured on P. ginseng polysaccharides. In the in vitro antioxidant assay, P. ginseng polysaccharides combined with L. plantarum C88 were found to possess significant DPPH, ABTS and superoxide anion radicals scavenging activities, and acidic polysaccharides showed better antioxidant activity than neutral polysaccharides. Furthermore, we evaluated the antioxidant effect of acidic P. ginseng polysaccharide combined with L. plantarum C88 strain in natural ageing mice in vivo. Acidic P. ginseng polysaccharide and L. plantarum C88 together inhibited the formation of malondialdehyde (MDA) and increased the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH‐Px), catalase (CAT) and total antioxidant capacities (T‐AOC) in a dose‐dependent manner.     

Micellar liquid chromatographic determination of arbutin and hydroquinone in medicinal plant extracts and commercial cosmetic products

A simple micellar liquid chromatographic (MLC) procedure for simultaneous determination of arbutin and hydroquinone in medicinal plant extracts and commercial cosmetic products was proposed. This method was developed and validated. The chromatographic conditions were also optimized. All analyses were performed at room temperature in an isocratic mode, using a mixture of 1% (v/v) acetonitrile and 0.006 mol L^?1 Brij 35 (pH 6.0) as a mobile phase. The flow rate was set at 1.0 mL min^?1. The analytical column was a 150 × 3.9 mm Nova‐Pak C‐18 column. The effluent from the analytical column was monitored by UV detection at 280 nm. Under the optimum conditions, arbutin and hydroquinone could be determined within a concentration range of 2–50 μg mL^?1 of arbutin, and hydroquinone was obtained with the regression equations; y = 0.045x + 0.042 (r² = 0.9923) and y = 0.091x + 0.050 (r² = 0.9930) respectively. The limits of detection were found to be 0.51 μg mL^?1 and 0.37 μg mL^?1 for arbutin and hydroquinone respectively. The proposed MLC method was applied for the determination of arbutin and hydroquinone contents in medicinal plant extracts and commercial cosmetic products. This proposed MLC method is thus suitable for routine analysis of arbutin and hydroquinone in the pharmaceutical formulations, cosmetic products and raw medicinal plant extracts.     

Isolation and identification of spermidine derivatives in tea (Camellia sinensis) flowers and their distribution in floral organs

BACKGROUND: Recently, tea (Camellia sinensis) flowers have attracted increasing interest because of their content of bioactive compounds such as catechins. The aim of this study was to investigate the occurrence of some characteristic compounds in tea flowers. RESULTS: A principal component analysis of metabolites using ultra‐performance liquid chromatography/time‐of‐flight mass spectrometry showed differences in metabolite profile between flowers and leaves of C. sinensis var. Yabukita. Four spermidine derivatives were isolated from tea flowers. One of them was determined as N¹,N⁵,N¹⁰‐tricoumaroyl spermidine based on NMR, MS and UV data. The other three were identified as feruoyl dicoumaroyl spermidine, coumaroyl diferuoyl spermidine and triferuoyl spermidine based on MSⁿ data. Tricoumaroyl spermidine as the major spermidine conjugate was not detected in tea leaves. Furthermore, it decreased during floral development and mainly occurred in anthers. CONCLUSION: This study has provided the first evidence that spermidine‐phenolic acid conjugates occur in tea flowers in considerable amounts. Their presence should prompt a reconsideration of the ecological role of tea flowers. From an economic point of view, tea flowers might be suitable as a raw material in the healthcare food and pharmaceutical industries. Copyright © 2012 Society of Chemical Industry     

Efficacy of Acorus calamus L. essential oil as a safe plant‐based antioxidant,Aflatoxin B1 suppressor and broad spectrum antimicrobial against food‐infesting fungi

The study explores the efficacy of Acorus calamus L. essential oil (EO) as a safe plant‐based broad spectrum antifungal, antiaflatoxin, antioxidant food additive. The oil completely inhibited the growth and toxin production of the toxigenic strain of Aspergillus flavus at 0.4 and 0.25 μL mL^?1, respectively. EO exhibited pronounced antifungal activity against sixteen food‐infesting fungal species at 0.5 μL mL^?1. The EO showed strong antioxidant efficacy (IC₅₀ 1.06 μL mL^?1) and nonphytotoxic nature on germination of chickpea seeds. The EO was found nonmammalian toxic showing high LD₅₀ (4877.4 μL kg^?1) for mice (oral, acute). The chemical profile of EO was determined through GC and GC–MS analysis. The findings strengthen the possibility of A. calamus EO as a plant‐based food additive in view of its favourable safety profile, antioxidant and antiaflatoxigenic efficacy and broad spectrum antimicrobial activity against food‐infesting fungi.     

Analysis of isopropyl para‐toluenesulphonate in palm‐based esters by gas chromatography with flame ionization detection and confirmed with mass spectrometry

A simple and rapid gas chromatography (GC) method with flame ionization detector was developed for detection of isopropyl para‐toluenesulphonate (IPTS) in palm‐based isopropyl palmitate (IPP) and isopropyl myristate (IPM). The method involved spiking the IPP/IPM samples with IPTS and directly injecting the spiked samples into GC without undergoing clean‐up steps. The calibration curves for IPTS showed good linearity with coefficient correlation of 0.9999 for six‐point calibration from 0.5 to 50 μg mL^?1 and 0.9996 for six‐point calibration from 0.5 to 200 μg mL^?1. IPTS recoveries from IPP were 98.6–103.5% with relative standard deviation (RSD) of 0.40–2.80%, whereas recoveries from IPM were 97.0–107.2% with RSD of 0.42–4.21%. The identity of IPTS recovered from the isopropyl esters was confirmed by a GC‐mass spectrometer detector. The method was successfully applied to the analyses of IPTS in commercial samples. It was found that there were IPTS in the range of 34.8–1303.0 μg g^?1 in the palm‐based esters for some of the samples analysed.     

Tannase from Aspergillus melleus improves the antioxidant activity of green tea: purification and biochemical characterisation

Tannase is an inducible enzyme used extensively in food, feed, pharmaceutical and chemical industries. In this study, tannase production and its biochemical properties were evaluated. From 42 Aspergillus strains analysed for potential tannase selection, Aspergillus melleus yielded the best results. Production was analysed using a complete factorial planning of 2³. Maximum activity (452.55 U mL^?1) was obtained in the optimal conditions of substrate (5.0 g), initial moisture (60%), tannic acid (2%) and 48 h of fermentation. The molecular weight of the purified enzyme was estimated as 69.52 kDa; its optimum temperature and pH were 40 °C and 5.5, respectively. Regarding the chemical effectors used, tannase was inhibited by ZnCl₂, ZnSO₄, Triton X‐100 and SDS. The addition of tannase to green tea improved its antioxidant potential by approximately 85% when compared to the control. The present results suggest that tannase may be used as an adjuvant to increase the antioxidant potential of green tea.     

Structural characterization and antioxidant activities of 2 water-soluble polysaccharide fractions purified from tea (Camellia sinensis) flower

Abstract: The water‐soluble crude polysaccharide tea flower polysaccharide (TFP), obtained from tea (Camellia sinensis) flower by boiling‐water extraction and ethanol precipitation, was fractionated by Sephadex G‐100 column chromatography, giving 2 polysaccharide fractions termed TFP‐1 and TFP‐2. The structural features of TFP‐1 and TFP‐2 were investigated by high‐performance liquid chromatography (HPLC), gel‐permeation chromatography (GPC), rheometer, infrared (IR) spectra, nuclear magnetic resonance (NMR) spectroscopy, atomic force microscope (AFM), and scanning electron microscope (SEM). Results indicated that TFP‐1 was composed of glucose: xylose: rhamnose: galactose = 1.0:1.2:0.81:0.98 with a molecular weight of 167.5 KDa, while TFP‐2 comprised glucose: xylose: rhamnose: arabinose = 1.0:0.76:2.3:2.3 with a molecular weight of 10.1 KDa. The ¹H NMR revealed that TFP‐1 contained α‐L‐Rhap, α‐D‐Galp, α‐D‐GalpNAc, α‐D‐Xylp, α‐D‐Glcp, and β‐D‐Glcp residues, while TFP‐2 was illustrated to have α‐L‐Rhap, α‐L‐Arap, α‐D‐Xylp, α‐D‐Glcp, and α‐D‐GlcpNAc residues. Antioxidant activities of these fractions were investigated using various in vitro assay systems compared with ascorbic acid. In conclusion, TFP‐2 exhibited the higher antioxidant activities and could be explored as a novel potential antioxidant. Practical Application: At present, commonly low‐grade tea is preferred to extract the tea polysaccharide, to take full advantage of tea flower resource to extract polysaccharides can greatly reduce the cost of tea products. Thus, the search for plant‐derived biomaterials from this study could generate natural value‐added products from underutilized tea plant waste and used as a medicinal agent against chronic health problems, such as cancers, aging, and atherosclerosis caused by reactive free radicals that produced from oxidation.     

Antioxidant and antimicrobial activity of pomegranate peel extract improves the shelf life of chicken products

The antioxidant and antimicrobial potential of pomegranate peel and seed extract was investigated. Pomegranate peel extract (PE) showed excellent antioxidant activity while the seed extract (PS) did not have any significant activity. The IC₅₀ value of PE for 2,2‐diphenyl‐1‐picrylhydrazyl radical scavenging was 4.9 μg mL^–1 while that of Butylated hydroxy toluene was 21.2 μg mL^–1, indicating that it was a stronger antioxidant. The efficacy of PE in scavenging hydroxyl and superoxide anion radical was also very high. It also had good reducing power and iron chelation capacity. PE showed good antimicrobial activity against Staphylococcus aureus and Bacillus cereus having minimum inhibitory concentration of 0.01%. Pseudomonas could be inhibited at a higher concentration of 0.1% while it was ineffective against Escherichia coli and S. typhimurium. Addition of PE to popular chicken meat products enhanced its shelf life by 2–3 weeks during chilled storage. PE was also effective in controlling oxidative rancidity in these chicken products.     

Increasing the antioxidant power of tea extracts by biotransformation of polyphenols

Green tea (Camellia sinensis) and yerba mate (Ilex paraguariensis) are rich in polyphenolic compounds, which are thought to contribute to the health benefits of tea. The aim of this study was to evaluate the potential antioxidant properties of green tea and yerba mate extracts before and after the enzymatic biotransformation reaction catalysed by the Paecilomyces variotii tannase. The antiradical properties of the tea extracts, as well as the standards of chlorogenic acid and EGCG, were assessed using the ORAC and DPPH assays before and after the tannase biotransformation. The antioxidant power of enzyme-treated green tea and yerba mate increased by 55% and 43%, respectively, compared with that of untreated teas. The antioxidant power of the standards was also highly increased by enzyme treatment. These results provide relevant data about the potential of the tannase application on various polyphenol sources and to increase the antioxidant power of two widely consumed beverages.     

Characteristics and upregulation of antioxidant enzymes of kitchen mint and oolong tea kombucha beverages

Kombucha is a healthy traditional beverage which is made by fermenting products with a symbiotic culture of acetic acid bacteria and yeasts. In present study, leaves of kitchen mint (Mentha cordifolia Opiz. Ex Fresen) and leaves of oolong tea (Camellia sinensis) were fermented in kombucha formula. After fermentation, titratable acidity contents and ethanol of kitchen mint, oolong tea, and mixtures of oolong tea and kitchen mint kombucha samples gradually increased with a period of fermentation time. At day 14 of fermentation, phenolic compounds and flavonoids were increased in all kombucha samples. The numbers of acetic acid bacteria and yeast in kombucha had gradually raised during 7–14 days of fermentation. DPPH and ABTS scavenging activities of these kombucha increased over a period of fermentation time and shown the highest antioxidant capacity on day 14 of fermentation. In addition, all kombucha samples exhibited the antioxidant effects by attenuating H₂O₂-induced ROS production, increasing mRNA expression of catalase, glutathione reductase (GRe), and Mn-SOD, and inducing GRe enzymatic activity in HEK-293 cells. Kombucha beverage can be used as the healthy beverages for attenuation of oxidative stress in many diseases.