Bio-antioxidants activity: their mechanisms and measurement methods

Bioactive food components [such as phenolic compounds, carotenoids, anthocyanins, tochopherols, ascorbic acid, flavonoids, minerals, enzymes and pectin] are active ingredients in food or dietary supplements, which proven to have an important role in health, and are safe for human consumption. These compounds exert their antioxidant effects by different mechanisms such as single electron transfer or hydrogen atom transfer, and their efficiencies can be evaluated by several methods such as ferric reducing ability of plasma, oxygen radical absorbance capacity assay, total radical trapping antioxidant parameter, total oxidant scavenging capacity, conjugated dienes, lipoxygenase activity inhibition assay, chemiluminescence, deoxyribose, tocopheroxyl radical attenuating ability, and nitric oxide radicals trapping. In this review, these mechanisms and methods will be discussed in details

[Effects of various factors on the oxidative stability of omega -3 fatty acid-enriched Doogh [Iranian yoghurt drink]]

Milk and dairy products are generally recognized as healthful foodstuffs. Their negligible content of polyunsaturated fatty acids [PUFAs] has prompted investigators to consider fortifying them with long chain PUFAs, but the main challenge is the high susceptibility of PUFAs to oxidation and rancidity. Therefore, in the present study the possibility of using long chain PUFAs to fortify Doogh [a traditional Iranian yoghurt-based beverage], as a functional dairy product, as well as the effect of different factors on the physical stability and peroxide value of the fortified Doogh during storage, were determined. omega -3-Fatty acid-fortified Doogh was prepared using yogurt, water, salt, the soluble phase of gum tragacanth, and crude rapeseed, soy bean, and fish oil. The fortified Dooghs [a mixture of oil and yoghurt or of Doogh and oil] were homogenised using ultrasound at different amplitudes and durations in order to find the optimum processing conditions [amplitudes and duration]. Moreover, effects of several factors [heat treatment, storage temperature, intensity and duration of sonication, and oil content] on the physical stability and peroxide value of the fortified Dooghs during storage [35 days] at 2 temperatures [5 and 22 Degree°C] were determined. The findings showed that the preparation method of fortified Doogh had significant effects on its homogenization extent and physical stability. Furthermore, during storage the peroxide value of the samples increased, particularly at the higher temperatures, while they were quite stable physically. It may be concluded that ultrasound treatment can homogenize and stabilize omega -3-fatty acidfortified Doogh, with no undesirable effect on peroxide value during storage at refrigeration temperatures

[Effect of gamma irradiation on the antioxidant and antimicrobial activities of cinnamon powder]

Spices and herbs have been added to foodstuffs since old times due to their medicinal, preservative and flavouring effects. They are, however, often contaminated with microorganisms. Gamma irradiation is currently used widely to eliminate microbial contaminations in foods. The aim of the study was to determine the effects of gamma irradiation on the antioxidant and antimicrobial activities of cinnamon [Cinnamomum zeylanicum]. Samples of cinnamon were exposed to gamma irradiation at doses of 10, 15, 20 and 25 kGy, followed by preparing hydroalcoholic [50% ethanol] extracts from them for sequence analysis. The antioxidant activity of the irradiated and control samples was measured by DPPH radical scavenging, ferric reducing power, and bleaching of beta-caroten, and the total phenolic content was also determined. The broth diluting method was applied for the determination of minimal inhibitory concentration [MIC] of E. coli and S. aureus. All tests were performed in triplicates, and the least significant difference [LSD] statistical test at alpha = 0.01 was used to compare differences among the means. Gamma irradiation had no adverse effects on antioxidant activities and total phenolic content of the samples. Only at doses more than 10 kGy did the radical scavenging activity of the cinnamon extract increase [DPPH test]. With regard to the effect of gamma irradiation on antimicrobial activity, as compared to the control value, there was no statistically significant difference in the activity of irradiated samples up to a dose of 25 kGy. Gamma irradiation treatment of cinnamon had no adverse effect on its antioxidant and antimicrobial activities. Gamma irradiation at doses up to 25 kGy seems to be appropriate for cinnamon

Evaluation antioxidant and antimicrobial effects of cinnamon essential oil and echinacea extract in Kolompe

Applications of natural ingredients not only increase the shelf life of food but also omit the problems of synthetic preservatives compounds. Cinnamon verum essential oil [CVEO; 0.05, 0.1, 0.15%] and Echinacea purpurea extract [EPE; 0.25, 0.5, 0.75%] were added to Kolompe [a traditional cookie in Kerman-Iran] and their antioxidant and antimicrobial effects were compared with the samples of BHA [100 and 200 ppm] and control [without any antioxidant]. Peroxide and tiobarbituric acid values [PV and TBA] and total count, mold, yeast, Escherichia coli, Enterobacteriaceae, Bacillus cereus, positive Staphylococci -coagulase were measured for antioxidant and antimicrobial assessment, respectively. PV and TBA values of control were more than others and antioxidant effect of CVEO-0.05 was similar to BHA-0.01 [p<0.01]. The least PV and TBA values were for CVEO-0.1. Application of EPE-0.25 was too led more antioxidant effect [increased by increasing%] than BHA-0.01. All samples lacked aerobic microorganism, yeast and mold except EPE-0.25 [that was the same with control] in 30[th] day. The number of these microorganisms in EPE-0.5 was lower than control, BHA-0.01 and BHA-0.02. No microorganism was in EPE-0.75 that expressed strong antimicrobial effect of this level extract. Antioxidant effects for CVEO-0.1, CVEO-0.25, EPE-0.1 and EPE-0.25 were more than BHA. With increasing of concentration, PV and TBA values for pro-oxidant effect increased. Application of CVEO and EPE in Kolompe was strong effect in microbial properties and increase the shelf life of Kolompe

Antioxidant activity of satureja hortensis L. essential oil and its application in safflower oil

It has been considered by researchers to study the possibility of replacing chemical food additives [synthetic antioxidants] by natural products [medicinal plants]. This study investigated the antioxidant properties of Satureja hortensis L. essential oil [SHEO] on safflower oil oxidation. Different assays have been used to evaluate the antioxidant activity of SHEO: total phenol content [TPC], DPPH, ABTS+, ferric thiocyanate [FTC], beta - carotene bleaching. For evaluation of SHEO effect on safflower oil oxidation, peroxide value [PV], conjugated dienes [CD], and tiobarbituric acid [TBA] indices were compared with BHT [a synthetic antioxidant]. TPC of SHEO was determined to be 293.7 mg gallic acid equivalent in 1 ml of sample and IC[50] was 0.71 mg/ml in DPPH. 0.4 and 0.1 mg/ml of SHEO at all time [1, 5, 10, 15 min] showed the highest and lowest antiradical ABTS+ activity [118.2 and 26.6 microg/ml AscAE =Ascorbic acid equivalent] in 15 min. In FTC and FTC-TBA, 8 mg/ml SHEO showed the highest activity. In beta-carotene bleaching of 0.1-2 mg/ml SHEO, 0.1 has the minimum [%9.02], and 1 and 2 has the maximum inhibitory effects [%34.33 and%36.86 inhibitions]. 4 mg/ml of SHEO had the highest inhibitory effect in the safflower oil test and that peroxide does not have significant difference with 0.1 mg/ml BHT. Antioxidant activities of SHEO concentrations increased in all indices [pandamp; lt; 0.05] and various concentrations were able to slow down the oxidation process

Zataria multiflora and bunium persicum essential oils as two natural antioxidants

Autoxidation is considered to be the main route of edible oil deterioration, which produces undesirable odors and flavors [attributed to primary and secondary products of unsaturated fatty acids] during storage and heating. Antioxidant activities of Zataria multiflora [ZMEO] and Bunium persicum [BPEO] essential oils [EOs] in linseed oil [containing higher omega-3 in vegetable sources] were studied with 4 indexes. Total phenol content, electropositive potential [by bleaching using violet ethanol solution of DPPH], antioxidant capacity [by radical cation of ABTS], scavenging activity of hydrogen peroxide and Fe-reducing power of the EOs were measured. Then ZMEO and BPEO [0.6, 1, 1.4, 1.8 mg/ml] were added to linseed oils; peroxide and tiobarbituric acid in 0[th]- 15[th] days [at 60°C] were compared with TBHQ [0.01, 0.02] and BHT [0.1, 0.2]. IC50 of ZMEO and BPEO in mentioned assays were 0.78 and 1.52; 0.11 and 7.50; 0.31 and 0.72 mg/ml and RP0.5 for reducing power assay was 0.76 and 2.12 mg/ml. Total phenolic compound of ZMEO and BPEO were 322 and 50.6 mg/ml. The best antioxidant levels of reductive oxidation were 600 for ZMEO and BPEO and 20 for TBHQ. PV and TBA values demonstrated that both of EOs in linseed oil had the same antioxidant activity in 600 ppm [ZMEO>BPEO] in 4 tests, and EOs will be used as natural antioxidants as a good replacement in 600 ppm with BHT [100] and TBHQ [10] as synthetic

[Evaluation of antioxidant activity of Lavandula angustifolia essential oil in crude soybean oil system]

It has been considered by researchers to study the possibility of replacing chemical food additives such as synthetic antioxidants by natural products especially medicinal plants. The aims of this study were as follow: [i] to determine the major components of the essential oil of Lavandula angustifolia. [ii] to evaluate the antiradical activities of this essential oil by DPPH°, ABTS°+ and beta-carotene bleaching assays and [iii] to evaluate the antioxidant activity of this essential oil in crude soybean oil. The main chemical components of essential oil were identified by GC/MS. Antiradical activities of mentioned essential oil was measured by different methods and finally, its antioxidant activity was determined in crude soybean oil system by Oven method. Six main compounds were identified: linalool [27.89%], camphore [10.82%], 1, 8 cineol [9.05%], inalol acetate [8.86%], borneol [7.29%] and alpha-terpineol [5.04%]. EC50 of essential oil was 35.54 +/- 1.58 mg/ml. In ABTS°+ assay, maximum antioxidant activity was related to 40 mg/ml concentration of essential oil. In beta-carotene bleaching assay, maximum antioxidant activity of essential oil was related to the 10 mg/ml concentration of it [54.4 percent radical scavenging activity]. In oven test, essential oil could inhibit of primary and secondary oxidation products of crude soybean oil at 0.8 mg/ml that was almost equal to BHA at 0.2 mg/ml. Antiradical activity of essential oil of Lavandula angustifolia was proved and it seems that after complementary examination, it can be used as natural antioxidant in food, especially those containing edible oils

Evaluation of antioxidant and antimicrobial effects of chamomile [matricaria chamomilla L.] essential oil on cake shelf life

Essential oils of medicinal plants such as chamomile are very complex natural mixtures which can contain compounds at quite different concentrations and some of their components have antioxidant and antimicrobial activities in foodstuff. The antioxidant and antimicrobial effects of chamomile essential oil in cake preparation were evaluated during 75 days of storage. Cake were produced: cakes were treated with chamomile essential oil in three levels [0.05%, 0.1%, 0.15%], cakes were not treated with synthetic and natural antioxidant and antimicrobial agents, and a commercial cake containing synthetic antioxidant [tert butyl hydro quinine= TBHQ] and antimicrobial [potassium sorbate] agents. In all samples peroxide value, thiobarbitoric value, acidity, microbial test [yeast and mould] and sensory test [color, flavor, texture, taste and overall quality] were determined at time intervals 1, 7, 15, 30, 40, 60 and 75 days. Statistical results showed that, the sample containing chamomile at 0.15%, had good antioxidant and antimicrobial activity in comparison with the control samples [without any synthetic and natural antioxidant and antimicrobial agents] [p<0.01]. But its activity was less than that of synthetic ones [TBHQ and potassium sorbate as antioxidant and antimicrobial agent] [p<0.01]. In sensory evaluation, the sample containing chamomile at 0.05% had higher score in flavor, taste and overall acceptability than the samples at 0.15 and 0.1% [p<0.05]. Chamomile essential oil as a natural antioxidant and antimicrobial agent can increase shelf-life of food products and due to absence of synthetic agents are safe with no side effect on human health

Antioxidant and antimicrobial potential of echinacea purpurea extract and its effect on extension of cake shelf life

Oxidation of lipids causes reduction of different properties of products that contains lipids. Nowadays, there is a growing demand for the natural antioxidants due to the harmful effects of synthetic antioxidants such as BHA, BHT and TBHQ. In this study, extract of aerial parts of Echinacea purpurea L. was used instead of synthetic antioxidants in cake then, antioxidant and antifungal activity of Echinacea purpurea L. extract [EPE] were evaluated in cake. The antioxidant activity of EPE and synthetic antioxidant was compared by measuring peroxide and thiobarbituric acid values during 60 days storage at 25 [degree sign]C. Antimicrobial properties of EPE were evaluated by counting of molds in Dicholoran Glycerol agar [DG18%] medium and free fatty acid analyses were assessed by IUPAC method. The effect of the extract on the color, texture, taste and total acceptability of the cake samples was carried out by a group of 20 trained panelists using Hedonic test. Different levels of EPE were able to retard the oxidation rate of cake, the 1000 ppm of it showed the lowest PV and the antioxidant activity of EPE was higher than BHA 200 ppm [p<0.01]. EPE at 1500 and 2000 ppm showed the best antimicrobial activity [p<0.01]. Cakes which containing the extract were well acceptable in terms of sensory parameters. Results showed that EPE was more effective in controlling growing molds and lipid oxidation during 60 days storage at 25 [degree sign]C and it can be used instead of synthetic antioxidant and preservatives

Application of zataria multiflora boiss. and satureja hortensis L. essential oils as two natural antioxidants in mayonnaise formulated with linseed oil

Mayonnaise is one of the food emulsions [O/W] that is used as a condiment in various foods. Linseed oil [containing omega-3 fatty acids] was used at the replacement levels of 10, 15 and 20% of soybean oil in mayonnaise formulation and the sensory properties of samples were evaluated. In the second part of this research, the Zataria multiflora Boiss. [ZMEO] and Satureja hortensis L. [SHEO] [500, 1000 and 1500] were added to oil of mayonnaise and their antioxidant effects, peroxide [PV] and conjucated diene [CD] values were compared with BHA syntethic antioxidant [100 and 200 ppm]. 15% of linseed oil used as replacer for soybean oil, showed no significant differences in the color, texture, taste, smell, mouth feel and overal acceptability compared with control samples, and this same ratio of 15 percent was used in subsequent tests. Statistical results of PV and CD indexes revealed that ZMEO [500] and the SHEO [1000 and 1500] had better antioxidant effect than BHA [100 and 200]. In determination of secondary oxidation products, TBA value showed that ZMEO [500] was not significantly different than BHA [200] and that SHEO [1000] had better antioxidant activity than BHA [100 ppm]. The results of antioxidative effect and sensory properties [showed no significant difference in taste and smell score compared with control sample] of formulated mayonnaise showed that these natural antioxidants in mayonnaise formulation can ameliorate the quality of product as functional food due to advancing the public health

[Possibility of the functional oil production from flax [omega-3] and safflower [omega-6] seeds and evaluation of its physico-chemical properties during 4 months storage]

Although the importance of omega -3 and omega-6 essential fatty acid has been known but functional and physiological properties of omega-3 and omega-6 fatty acid are different. The balance use of omega-3 and omega-6 fatty acid is more important because in vivo can't make them. Possibility production of the functional oil from vegetable sources such as flaxseed [containing omega-3] and safflower [containing omega-6] oils including extraction, formulation and preservation. After extraction of the oils from flaxseed and safflower, physicochemical properties of the oils were examined and the product underwent the fractionation process in order to increase the omega-3 ratio. Then, functional oil was formulated using a 1:1 mixture of omega-3 and omega-6. Storage conditions and stability of the oil were also investigated for four months [0, 1, 2, 3 and 4 months] by studying peroxide, thiobarbituric acid and Rancimat indexes. Results: Results showed that the omega-3 ratio may be increased from 50.19 to 52.59% [p<0.05] through fractionation. During the storage of the functional oil in the four months, the peroxide index increased from zero to 100.43 and 4.99 [meq O[2] /k oil], the thiobarbituric acid index also increased from zero to 4.99 and 0.026 [malondialdehyde mg /k oil], and the Rancimat index decreased from 2.10 to 0.33 and from 2.10 to 1.35 [p<0.05] in the refrigerator and freezer, respectively. With the fractionation process can increase the amount of omega-3 fatty acid about 4/78 percent [p<0.05]. Diagnostic examination showed that during the storage of the functional oil peroxide value of oil were under standard, so recommended using refrigerator in order to preserve functional oils

investigation on the antioxidant activities of hyssopus officinalis L. and Echinacea purpurea L. plant extracts in oil model system

Nowadays, there a growing demand for the natural antioxidants due to the harmful effects of synthetic antioxidants. Therefore, introduction of new natural antioxidants [especially those with plant origin] is very important. The present study explores the chemical constitution and antioxidant activity of leaf extract of Hyssopus officinalis L. and extract of aerial parts of Echinacea purpurea L., as two valuable natural antioxidants in soybean oil. Total phenolic content of the water extract of Hyssopus officinalis L. and Echinacea purpurea L. were determined by Folin-Ciocalteu method. The antioxidant activity [AOA] of these two extracts were evaluated with DPPH[*], ABTS[*+] and beta carotene bleaching [BCB] methods. Furthur, the oven tests including peroxide and thiobarbituric acid values were done at 70°C in soybean oil system. Total phenolic content of Hyssopus officinalis L. and Echinacea purpurea L. were 200 and 60 mg/g phenolic components [galic acid equivalent], respectively. In DPPH* test, EC[50] value of Hyssopus officinalis L. and Echinacea purpurea L. were 35.6 +/- 4.7 and 123.0 +/- 10.9 ppm, respectively. In the oven test [in soybean oil], AOA of all concentrations of HOE was comparable to BHT and BHA at the concentration of 100 ppm. AOA of EPE was comparable to BHT at concentrations of 100 and 200 ppm, but lower than that of BHA. In all three DPPH[*], ABTS[*+] and beta carotene bleaching tests, the antioxidant activity of Hyssopus officinalis extract [HOE] was greater than that of Echinacea purpurea extract [EPE]. The antioxidant activity of both extracts improved with increase of the concentration. Further, HOE and EPE were able to reduce the oxidation rate of soybean oil under conditions of the oven test at 70°C. Thus, these two extracts could be appropriate natural alternatives to synthetic antioxidants

Application of satureja hortensis l. and zataria multiflora boiss. Essential oils as two natural antioxidants in soybean oil during microwave heating

Autoxidation is considered to be the main route of edible oil deterioration, which produces undesirable odors and flavors during storage and heating. The unpleasant flavor of oxidized oil has been attributed to primary and secondary products of unsaturated fatty acids. The microwave heating is a rapid method when compared with other methods of heating. In this research, the effect of microwave heating on the oxidative stability of soybean oil amended with either of Satureja hortensis L. [SHEO] and Zataria multiflora Boiss [ZMEO] essential oils was evaluated and compared with synthetic antioxidant [butylated hydroxyl toluene= BHT; 200 ppm]. Soybean oil containing with SHEO [200 and 1000 ppm], ZMEO [200 and 1000 ppm] and BHT [200 ppm] were heated using microwave oven [600 W] for 25 min and spectrophotometer was used to determine UV absorption. Peroxide value [PV], conjugated dienes [CD] and conjugated trienes [CT] indices were measured. Statistical results showed that PV after 25 min were increased in all treatments and the stability of soybean oil treated with synthetic antioxidant [BHT, 200 ppm] was higher than oil treated with the studied essential oils [SHEO and ZMEO, 200 and 1000 ppm]. Diene and triene indices increased during the heating. There was a positive correlation between PV, diene and triene indices during the process of microwave heating. The two essential oils [SHEO and ZMEO, in concentrations of 200 and 1000 ppm] showed fairly good antioxidant activities as compared with BHT [200 ppm] in soybean oil control sample [refined- bleached- deodorized soybean oil without any additives]

[Physicochemical properties of Iranian varieties/lines of safflower oil and seed as a rich source of omega-6]

High in take of saturated fatty acids and animal fats, increases cardiovascular disease, cancer and obesity whereas omega -3 and omega -6 poly unsaturated fatty acids as necessary fatty acids have preventive effect on aforementioned disease. Necessity of omega -3 and omega-6 acids and limitation of their sources with increasing of population, make scientists to find other sources. For optimal usage of internal oil resources such as safflower, increasing of its cultivation and existence of Saffola as a mutative variety [high amount of oleic acid], this research for investigation the physicochemical characteristics of seed and oil of six variety/line of safflower farmed in Iran and the comparison of type and amount of oil and classification of them to oleic or linoleic acid group was done. Varieties/lines of Iranian safflower including Goldasht [as a spring variety], Mahali Esfehan, Esfehan 14, Esfehan 28 [as spring lines], Padide [as a fall variety] and Sina [as a day land farming variety] were provided [Provision Institute and Improvement of Plant and Seed located in Karaj], and characteristics of safflower seeds [oil, protein, ash, moisture and fiber contents] and its extracted oil [acid, iodine and saponification values, fatty acids profile and color] were investigated. Results indicated that the studied varieties/lines were only linoleic safflower [no any oleic safflower]. Iranian safflower varieties/lines have the highest amount of omega -6 [72.6 - 75078] in comparison with other oil sources which are valuable and necessary fatty acids

[Antioxidant effect of dill [anethum graveolens boiss.] oil in crude soybean oil and comparison with chemical antioxidants]

Today, the growing interest has been focused on the use of medicinal plants and their active components as natural sources, due to their well-known abilities to scavenge free radical. Antioxidant effectively and to different ways can prevent from reaction free radical with biomolecules [e.g., protein, amino acids, lipid and DNA] and cause reducing cell injury and death, chronic diseases and cancers. To determine the chemical composition and antioxidant properties of the essential oil of Anethum graveolens Boiss. in crude soybean oil. In this study, essential oil was obtained from the seeds and it was analyzed by GC/MS. The chemical compositions were identified. The antioxidant activity was investigated with two methods, DPPH free radical scavenging and beta-carotene/linoleic acid. Also, antioxidant activity of essential oil was determined by measuring peroxide and thiobarbituric acid values in crude soy bean oil and results were compared with synthetic antioxidant BHT and BHA. Results showed that six major components in the essential oil were: D-carvone [36.09%], limonene [19.89%], dill apiole [16.83%], E-dihydrocarvone [7.36%], Z-dihydrocarvone [6.59%] and thymol [6.5%]. In DPPH system, the EC50 value of Anethum graveolens essential oil was determined as 2.57 +/- 1.52 mg/ml. This parameter for BHT was 0.016 +/- 0.001. By the beta-carotene bleaching system, antioxidant activity of essential oil at 7 mg/ml [77.29%] that was almost equal to BHT at 0.1 mg/ml. In oven test, essential oil could inhibit of primary and secondary oxidation products of crude soy bean oil at 0.6 mg/ml that was almost equal to BHA at 0.1 mg/ml. Results showed that the essential oil of Anethum graveolens could be used as a natural antioxidant in foodstuffs after complementary tests and it causes functionality in them

[ investigation on the antioxidant activity of essential oil of Zataria multiflora Boiss. In soy bean oil]

Great interest has recently been focused on the addition of herbs and their derivatives to foods and biological system, due to their well-known abilities to scavenge free radicals. The aims of this study were to evaluate the antioxidant activity of the essential oil of Zataria multiflora Boiss. and [ii] to use this essential oil as natural antioxidant in crude soy bean oil. In this study, essential oil was: [i] analyzed by GC/MS and its chemical components were identified. The antioxidant activity of essential oil was investigated with DPPH? free radical scavenging and beta-carotene bleaching methods and was compared with synthetic antioxidant [BHT]. Also, the antioxidant activity of essential oil was determined by measuring peroxide and thiobarbituric acid values in crude soy bean oil [oven test]. Results showed that carvacrol [26.08%] and thymol [17.23%] were main phenolic components in the essential oil. The EC50 value of Zataria multiflora essential oil was determined as 2.22 +/- 0.04 mg/ml. This parameter for BHT was 0.58 +/- 0.02. By the beta-carotene bleaching system, antioxidant activity of essential oil at 0.45% was equal to 72% and for BHT at 0.1% was determined 81%. In oven test, the antioxidant activity of Zataria multiflora essential oil at 0.1% was almost equal to BHA at 0.02% in crude soy bean oil. The essential oil showed good antioxidant activity and therefore, it can be used as a natural antioxidant in some foods after complementary tests