Antioxidant activities of volatile components isolated from Eucalyptus species

Extracts of three species of eucalyptus leaves (Eucalyptus polyanthemos Schauer, E globulus Labill and E perriniana) and their major volatile components were assessed for antioxidant activity in two different assays. The inhibitory effect of each extract and its components towards aldehyde/carboxylic acid conversion was measured over a period of 30 days. Their inhibitory effects towards malonaldehyde formation from lipid by oxidation with Fenton's reagent were also measured; the extract from E polyanthemos inhibited the oxidation of hexanal completely for 30 days at a level of 200 and 500 µg ml^?1. It also inhibited malonaldehyde (MA) formation in cod liver oil by 86% at the 160 µg ml^?1 level. At the 500 µg ml^?1 level, thymol, 1,8‐cineole, benzyl alcohol and terpinen‐4‐ol identified in the extract from E polyanthemos reduced the extent of hexanal oxidation over a period of 30 days by 100, 96, 82 and 75% respectively. In the lipid/MA assay, thymol, benzyl alcohol, terpinen‐4‐ol and 1,8‐cineole inhibited MA formation by 80, 63, 58 and 26% respectively at the level of 160 µg ml^?1. Thymol exhibited potent antioxidant activity comparable to that of the known natural antioxidant α‐tocopherol. © 2001 Society of Chemical Industry     

Natural volatile treatments increase free‐radical scavenging capacity of strawberries and blackberries

Free‐radical scavenging capacities of strawberries and blackberries treated with methyl jasmonate (MJ), allyl isothiocyanate (AITC), essential oil of Melaleuca alternifolia (tea‐tree oil or TTO), and ethanol (EtOH) were investigated. All of these natural volatiles tested reduced the severity of decay in both strawberries and blackberries during storage at 10 °C as compared to the control. Most of these compounds enhanced antioxidant capacity and free‐radical scavenging capacity, except the AITC treatment. The MJ treatment for strawberries and blackberries had the highest antioxidant capacity, expressed as oxygen radical absorbance capacity (ORAC) values, after 7 days of storage. Moreover, the MJ treatment promoted the antioxidant capacity in strawberries and blackberries as measured by the radical 2,2‐di (4‐tert‐octylphenyl) ‐1‐picrylhydrazyl (DPPH) and the radical cation 2,2′‐azinobis(3‐ethylbenzothiazoline‐6‐sulfonic acid) diammonium salt (ABTS^?+) scavenging activity in both 7 and 14 days after storage. The MJ treatment also increased scavenging capacities on the superoxide radical (O₂^??), hydrogen peroxide (H₂O₂), hydroxyl radical (^?OH), and singlet oxygen (¹O₂) in strawberries and blackberries. Treatment with TTO or EtOH enhanced most of these free‐radical scavenging capacities, except for H₂O₂ in strawberries, and for O₂^?? and ¹O₂ in blackberries. These results indicated that all of the natural volatile compounds tested in this study, except AITC, promoted the antioxidant capacity and scavenging capacity of most major free radicals and, thus, helped to improve the physiology of berry fruits and enhanced their resistance to decay. While AITC was also very effective in reducing decay, its effect on free‐radical scavenging capacity was inconsistent, suggesting that additional mechanisms may be involved in its inhibition of fungal growth. Copyright © 2007 Society of Chemical Industry     

来凤姜的抗氧化与抑菌活性及挥发性化合物研究

目的 探究来凤姜(Zingiber officinale)的抗氧化、抑菌活性及挥发性化合物,并与云南小姜和山东莱芜娃娃姜进行对比。方法 以绿水镇、漫水乡、百福司镇3地的来凤姜为研究对象,分析其对1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基清除率和对金黄色葡萄球菌的抑菌效果。采用气相色谱-离子迁移谱法(gas chromatography-ion mobility spectrometry, GC-IMS)对来凤姜LS3(绿水镇3号姜)、BF5(百福司镇5号姜)、MS10(漫水乡10号姜)的挥发性化合物进行分离鉴定,并与YNXJ(云南小姜)和SDLW(山东莱芜娃娃姜)进行对比,基于相似度和主成分分析其特征挥发性物质。结果 来凤姜LS21(绿水镇21号姜)的抗氧化活性最强,MS7(漫水乡7号姜)对金黄色葡萄球菌的抑菌作用最强,与我国其他地方特色生姜相比,来凤姜中的茴香醛、异戊醛、3-甲基丁醛、2-庚酮单体及二聚体相对含量较高,为其特征挥发性化合物。不同产地来凤姜相比,绿水镇LS3的β-月桂烯聚合物、β-月桂烯二聚体、α-水芹烯...     

Antioxidant activity of pomegranate rind powder extract in cooked chicken patties

The radical scavenging activity, reducing power and phenolic composition of pomegranate rind powder extract (RP) were determined and antioxidant properties of RP was evaluated in cooked chicken patties compared with vitamin C (VC) during refrigerated storage. Freshly minced chicken meat were assigned to one of the following six treatments: control (meat without any antioxidant); RP 5, RP 10, RP 15 and RP 20 (5, 10, 15 and 20 mg equivalent RP phenolics 100 g^?1 meat, respectively) and VC 50 (50 mg VC 100 g^?1 meat). The RP exhibited significantly (P < 0.05) higher reducing power and 1,1‐diphenyl‐2‐picrylhydrazyl radical scavenging activity. Incorporation of RP into chicken patties significantly (P < 0.05) reduced the HunterLab L* values compared with control and VC patties. Total phenolic content (as tannic acid equivalent) significantly (P < 0.05) increased from 308 in control to 441 μg g^?1 in RP 20 patties. Addition of RP to chicken patties did not affect any of the sensory attributes. The values of thiobarbituric acid reactive substances were significantly (P < 0.05) reduced from 1.530 in control patties to 0.135 mg malonaldehyde kg^?1 samples in RP patties. Pomegranate rind powder extract treatment (RP 10, RP 15 and RP 20) substantially inhibited (P < 0.05) lipid oxidation in cooked chicken patties to a much greater extent than VC treatment. Therefore, pomegranate rind powder can be utilized as an excellent natural antioxidant source.     

Antioxidant activity of proteins and peptides

Proteins can inhibit lipid oxidation by biologically designed mechanisms (e.g. antioxidant enzymes and iron-binding proteins) or by nonspecific mechanisms. Both of these types of antioxidative proteins contribute to the endogenous antioxidant capacity of foods. Proteins also have excellent potential as antioxidant additives in foods because they can inhibit lipid oxidation through multiple pathways including inactivation of reactive oxygen species, scavenging free radicals, chelation of prooxidative transition metals, reduction of hydroperoxides, and alteration of the physical properties of food systems. A protein's overall antioxidant activity can be increased by disruption of its tertiary structure to increase the solvent accessibility of amino acid residues that can scavenge free radicals and chelate prooxidative metals. The production of peptides through hydrolytic reactions seems to be the most promising technique to form proteinaceous antioxidants since peptides have substantially higher antioxidant activity than intact proteins. While proteins and peptides have excellent potential as food antioxidants, issues such as allergenicity and bitter off-flavors as well as their ability to alter food texture and color need to be addressed.     

Antioxidant activities of volatile and non‐volatile fractions of selected traditionally brewed Korean rice wines

Antioxidant activities of traditionally brewed Korean rice wines have recently been reported. The objective of this study was to identify the antioxidant activities of the volatile and non‐volatile fractions of three Korean rice wines, and further to identify the active ingredients responsible for the antioxidant properties. Volatile and non‐volatile components of three rice wines, Measilju, Kukwhaju and Gugijaju, were separated into seven fractions according to their polarities. Antioxidant activities were determined by an aldehyde–carboxylic acid assay for the volatile fractions and a lipid–malondialdehyde assay for the non‐volatile fractions. Volatile constituents of each fraction were identified and quantified using gas chromatography–mass spectrometry. In addition, antioxidant activities of specific authentic chemicals from the volatile fractions of the wines were measured, and the antioxidant properties of the volatile fractions were determined. Identification of volatile compounds potentially showing high antioxidant activities were conducted in each fraction of the three wines. Among the volatile compounds identified from volatile fractions of the wines, benzeneethanol, 2‐furanmethanol and 4‐ethyl‐2methoxyphenol showed the highest antioxidant activities, when added at higher concentrations (~100 µg/g). Identification of antioxidant properties, as well as the specific compounds responsible for these antioxidant properties, could aid Korean rice wine product developers, in terms of strategic planning for sales in the Korean market. Copyright © 2014 The Institute of Brewing & Distilling     

Antioxidant activity of sugar molasses, including protective effect against DNA oxidative damage

ABSTRACT:  Extracts were obtained from molasses, a byproduct of the sugar industry, via a number of chromatographic steps. Their antioxidant capacity was studied, including the inhibitory effect upon DNA oxidative damage; the phenolic compound profile thereof was ascertained as well. Two extracts exhibited significant antioxidant features, expressed by their capacity to decolorize ABTS radical cation and to scavenge hydroxyl free radicals (via deoxyribose assay). Those 2 extracts also brought about protection against induced DNA oxidative damage (via decreasing DNA scission, as assessed by electrophoresis). The phenolic compounds syringic acid, p -hydroxybenzoic acid, vanillic acid, p -hydroxybenzaldehyde, and ferulic acid were positively identified and quantified.     

芹菜籽挥发油化学成分及其降低亚硝酸钠活性分析

采用超临界二氧化碳萃取法（SFE-CO2）提取芹菜籽挥发油;用气相色谱-质谱联用技术（GC-MS）对芹菜籽挥发油化学成分进行分离鉴定,共分离出36种化学成分,鉴定的27种化合物占挥发油总含量的99.72%,含量最高的物质为柠檬烯（33.08%）,其次分别为N,N’-1,2-二苯基乙酰胺（23.04%）,γ-榄香烯（14.96%）,2-氯-1-（3,4-二甲基苯基）-2-甲基-1-丙酮（6.01%）,N,N’-二乙酰基-1,4-苯二胺（5.73%）,石竹烯（3.51%）等;利用紫外分光光度计计算芹菜籽挥发油对亚硝酸钠的清除率,实验结果显示芹菜籽挥发油可以明显的清除亚硝酸钠,当挥发油用量为40μL时,清除率最大为89.80%。      

柠檬果皮精油挥发性成分的GC-MS分析

采用水蒸气蒸馏法(SD)与有机溶剂萃取法分别提取干、鲜柠檬果皮的精油,通过气相色谱和质谱联用仪测定了柠檬果皮精油的挥发性成分。结果显示:较简单的有机溶剂萃取法更有利于果皮精油挥发性成分的保留,依据化合物的质谱特性鉴定出柠檬果皮油里含有72种挥发性成分。柠檬果皮精油的主要成分为柠檬烯,含量在50%以上。      

柠檬桉果实、叶挥发油的成分分析及对比

采用水蒸气蒸馏法分别提取柠檬桉果实和柠檬桉叶挥发油,用气相色谱-质谱（GC-MS）联用技术对两者挥发油成分进行对比分析,并对柠檬桉果实中主要组分的作用进行分析。结果表明:柠檬桉果实挥发油得率为0.76 m L/100 g（以鲜重计）,柠檬桉叶挥发油得率为1.3 m L/100 g。柠檬桉果实挥发油中有37种成分,其中单萜类9种,氧化单萜8种,倍半萜5种,氧化倍半萜7种,芳香族化合物1种,其他化合物7种,主要成分具体为:1R-α-蒎烯、γ-松油烯、石竹烯等;桉叶油的主要组分为:香茅醛、β-香茅醇、异胡薄荷醇。两者相同组分较少,有α-蒎烯、异胡薄荷醇、α-松油醇等,含量差别较大。      

水苎麻叶挥发性成分分析及其抗菌活性研究

采用GC-MS分析方法对水苎麻叶中的挥发性成分进行分析。从中鉴定出20个组分,其中油酸含量最高,占44.47%。抗菌活性实验结果显示,挥发性成分对大肠杆菌、金黄色葡萄球菌、枯草芽孢杆菌、酿酒酵母菌具有抑制和杀灭作用。     

Analysis of the volatile constituents of black chokeberry (Aronia melanocarpa Ell.)

The volatile constituents of black chokeberry were analysed by gas chromatography and mass spectrometry. Concentrations of the 48 compounds identified were in general below their individual threshold values. The main compounds were benzaldehyde cyanohydrin, hydrocyanic acid and benzaldehyde. Among other benzene derivatives identified in the press juice were benzylalcohol, 2-phenylethanol, phenylacetaldehyde, salicylaldehyde, acetophenone, 2′-hydroxyacetophenone, 4′-methoxyacetophenone, phenol, 2-methoxyphenol and methyl benzoate.     

大曲中产香兼性厌氧细菌的筛选及挥发性成分分析

从浓香型大曲中分离筛选兼性厌氧细菌,研究该类菌在制曲工艺环境中种群分布的可行性,并进一步探索该类群微生物的产香特性及其挥发性组分,为提高大曲质量奠定基础。采用二氧化碳培养法对大曲样品进行菌株的筛选及分离纯化,最终获得9株兼性厌氧细菌。其中编号为X3菌株产香性能突出,经初步鉴定属于棒状杆菌属。进一步通过顶空固相微萃取—气相色谱—质谱联用分析X3菌株固态发酵产物的挥发性物质,结果表明,其挥发性物质中的吡嗪类物质、苯乙醇、愈创木酚、苯甲醛等,与浓香型大曲产香物质相符。     

Antioxidant activity of Indian propolis and its chemical constituents

We report for the first time the antioxidant activity of the aqueous and ethanol extracts of Indian propolis (AEP and EEP, respectively). The antioxidant activity was measured by chemical and electrochemical assays. Reducing power and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity were the chemical assays, whereas, cyclic voltammetry was used as the electrochemical assay. In all these assays, AEP showed significantly greater activity over EEP; which is in contradiction with the previous reports of propolis from other countries. This may be due to its higher polyphenol content. Hence aqueous extract may well be a substitute of organic solvent extracts of propolis. Moreover, two flavonoids, pinocembrin (1) and galangin (2) were isolated from EEP; among which (2) showed high DPPH radical scavenging activity. Thus Indian propolis, being a rich source of natural antioxidants, may be used in the prevention of various free radicals related diseases.     

调味香料草果挥发油的抗氧化性能及清除自由基能力

利用水蒸气蒸馏法提取了调味香料草果的挥发油,产率为1.62%。从总体抗氧化能力、清除超氧阴离子自由基能力和清除羟基自由基能力三个方面,测定了该挥发油的抗氧化活性,并与合成抗氧化剂没食子酸丙酯(PG)做了比较。实验结果表明,在一定浓度范围内,草果挥发油清除超氧阴离子自由基的能力和清除羟基自由基的能力均强于PG。从而说明草果挥发油具有良好的抗氧化效果。     

Antioxidant activity of the phenolic compounds of hawthorn,pine and skullcap

The significance of antioxidants in preventive medicine is well known. Increasing interest has been devoted to naturally occurring compounds – polyphenols – because of their beneficial health effects. The subject of this study was to examine the antioxidative activity of polyphenolic preparations containing oligomeric procyanidin from the bark of common pine (Pinus sylvestris L.) and hawthorn (Crataegus oxyacantha L.) and flavones of skullcap (Scutellaria baicalensis Georgi) roots. Multi-constituent mixtures were fractionated, and the antioxidative activity of fractions was tested in vitro with linoleic acid oxidation by AAPH-generated radicals. All preparations at 6 and 12 ppm concentrations exhibited protective activity, from 45% to 95% in relation to the control sample. The average activity of preparations was higher than those of their fractions used at the same concentrations, and it was similar to trolox and BHT activity.     

Antioxidant activity of medicinal plant extracts in cookies

The antioxidant activity of ethanolic extracts of parsley, buckthorn, mint, caraway, and their mixture "Vitalplant" was evaluated, and the potential of "Vitalplant" mixture extract to retard the process of lipid oxidation in cookies was tested. The antioxidant activity was estimated by 2 direct (ESR) and 4 indirect (spectrophotometric) tests and correlated with the total phenolic and flavonoid content. The potential of "Vitalplant" mixture extract to retard the process of lipid oxidation in cookies was measured by thiobarbituric acid (TBA)-reactive-substances assay (TBARS) and DPPH˙ (1,1-diphenyl-2-picryl-hydrazyl) test. Significantly different (P < 0.05) amounts of total phenolics were found among extracts in the following order: mint > buckthorn > "Vitalplant" > parsley > caraway. Total flavonoid content varied from 0.510% (parsley) to 2.05% ("Vitalplant"). A statistically significant correlation was found between IC(50) values on DPPH˙ and total flavonoid content of the samples (r=- 0.94, P < 0.05) and between IC(50) values on DPPH˙ and IC(50) values on O(2) (·-) scavenging activity (r= 0.89, P < 0.05). A correlation between reducing activity and total phenolic content was found to be positive and statistically significant (r= 0.94, P < 0.05). "Vitalplant" mixture exhibited a relatively high antioxidant activity in most of the tests, which can be explained by synergistic effects of the ingredients of which it is composed. Finally, "Vitalplant" extract addition (2%, 4%, and 6%) improved antioxidant activity and oxidative stability of the cookies in dose-dependent manner. PRACTICAL APPLICATION: Supplementation of cookies with a mixture of Petroselini fructus, Frangulae cortex, Mentha piperitae folium, Carvi fructus can retard the process of lipid oxidation and elevate antioxidant activity of the final product.     

Natural Antioxidant Extract from Fenugreek (Trigonella foenumgraecum) for Ground Beef Patties

Ground beef patties (75% lean) containing synthetic antioxidants, or Fenugreek (Trigonella foenumgraecum) extracts were cooked to internal temperature 70°C, and evaluated for storage stability at 4°C. Thiobarbituric acid values of raw or cooked samples containing fenugreek extracts were lower than controls (P<0.05). Fenugreek extracts delayed the induction period of oxidative rancidity. No differences were observed in psychrotrophic bacterial counts, and samples containing fenugreek extracts had lower Hunterlab “a” and higher “b” values. Samples with Fenugreek extracts had better oxidative stability and Fenugreek may be a promising natural antioxidant source.     

Evaluation of Antioxidant Activity of Green Tea Extract and Its Effect on the Biscuits Lipid Fraction Oxidative Stability

ABSTRACT:  This article investigates the effect of green tea extract (GTE) on biscuits lipid fraction oxidative stability. The antioxidant activity of GTE was compared with commonly used synthetic antioxidant butylated hydroxyanisole (BHA). Biscuits were prepared in 3 variations. Control samples were prepared without addition of antioxidants. The other variations were prepared by adding BHA (0.02%) and GTE at 3 different levels: 0.02%, 0.1%, and 1%. Biscuits were subjected to sensory studies and instrumental and chemical analysis. Phenolic compounds of GTE characterized powerful antioxidant activities evaluated using free radical, 2,2-diphenyl-1-picrylhydrazyl method, compared with gallic acid and significantly better than BHA. Antioxidants added to the samples clearly slowed down the process of oxidation of fatty acids, inhibiting the monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) decomposition. Addition of GTE at the level of 1% gave an excellent antioxidant effect on the biscuits lipid stability, inhibiting hydroperoxides formation by about 47% to 73% compared with BHA, which showed about 16% to 60% inhibition. However, GTE did not improve significantly lipid stability, measured by anisidine value ( p -AV), and inhibited formation of secondary oxidation products only by 3.5%. After accelerated storage time, insensitivity of oxidized-like flavor was about 2 times higher for control samples compared to samples with addition of antioxidants. Moreover, after storage biscuits treated with natural antioxidant received a higher panel score of overall acceptance compared to samples with BHA. Using volatile compound formation as a marker of lipid oxidation, both GTE and BHA were effective inhibitors of the decomposition of hydroperoxides.