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1.
Abstract: The desired mix of alpha‐linolenic acid (ALA)‐enriched structured lipid (SL) and physically blended lipid (PB) was prepared from grape seed oil and perilla oil at a weight ratio of 3:1. The major triacylglycerol species (LnLnL) in PB was drastically increased after interesterification (SL), from 0.5% to 16.8%. After the reaction, the total unsaturated fatty acid at the sn‐2 position was decreased from 98.83% in PB to 91.36% in SL. The reduction of vitamin E compounds was also observed. Compared with a PB‐based emulsion, SL‐based emulsions showed oxidative instability, as assessed by lipid hydroperoxide (LOOH) and 2‐thiobarbituric acid‐reactive substances (TBARS) values, which was mainly due to the SL which contained less LA, ALA, and ΣUSFA at the sn‐2 position and less γ‐tocopherol than did PB. PB‐, and SL‐based emulsions with Ginkgo biloba extract (GBE) which showed significantly lower values of LOOH and TBARS compared to a blank control. GBE was effective in retarding the oxidation of the emulsion by quenching the free radicals in the water phase of the emulsion and inhibiting the formation of primary and secondary oxidation products. These results indicate that GBE could be used as an antioxidant additive for stabilizing ALA‐enriched emulsions. Practical Application: The results suggest the possibility to supplement Ginkgo biloba extract in alpha linolenic acid‐enriched structured lipid‐based emulsions which would increase the therapeutic value and enhance the antioxidant potential of the emulsions.  相似文献   

2.
Caffeic acid was used to synthesize 4‐vinylcatechol (4‐VC) by thermal decarboxylation and to prepare caffeic acid phenethyl ester (CAPE) by esterification reaction. The identities of synthesized products were confirmed by 1H NMR. Antioxidative activities of 4‐VC and CAPE were compared with α‐tocopherol and BHT in stripped soybean oil at 60 °C under the dark. To evaluate the degrees of oxidation at different concentrations and combinations, peroxide value (PV) and 1H NMR were performed. From the results of PV, the formation of primary oxidation products (i.e., hydroperoxides) in stripped soybean oil containing 200 ppm CAPE was the slowest. The relative oxidation degree of 200 ppm CAPE (9.5%) was lower than other samples on 9 d. Similar results were obtained by 1H NMR analysis. After 15 d of storage, levels of conjugated diene forms and aldehydes of 200 ppm CAPE sample (57.3 and 0.9 mmol/mol oil) were also lower than other treatments. In addition, 4‐VC and α‐tocopherol were found to have a synergistic antioxidant effect.  相似文献   

3.
Abstract: This study examined the effectiveness of fat and water soluble antioxidants on the oxidative stability of omega (ω)‐3 rich table spreads, produced using novel multiple emulsion technology. Table spreads were produced by dispersing an oil‐in‐water (O/W) emulsion (500 g/kg 85 camelina/15 fish oil blend) in a hardstock/rapeseed oil blend, using sodium caseinate and polyglycerol polyricinoleate as emulsifiers. The O/W and oil‐in‐water‐in‐oil (O/W/O) emulsions contained either a water soluble antioxidant (green tea extract [GTE]), an oil soluble antioxidant (α‐Tocopherol), or both. Spreads containing α‐Tocopherol had the highest lipid hydroperoxide values, whereas spreads containing GTE had the lowest (P < 0.05), during storage at 5 °C, while p‐Anisidine values did not differ significantly. Particle size was generally unaffected by antioxidant type (P < 0.05). Double emulsion (O/W/O) structures were clearly seen in confocal images of the spreads. By the end of storage, none of the spreads had significantly different G′ values. Firmness (Newtons) of all spreads generally increased during storage (P < 0.05). Practical Application: Lipid oxidation is a major problem in omega‐3 rich oils, and can cause off‐odors and off‐flavors. Double emulsion technology was used to produce omega‐3 enriched spreads (O/W/O emulsions), wherein the omega‐3 oil was incorporated into the inner oil phase, to protect it from lipid oxidation. Antioxidants were added to further protect the spreads by reducing lipid oxidation. Spreads produced had good oxidative stability and possessed functional (omega‐3 addition) properties.  相似文献   

4.
The antioxidant properties of caffeic acid and bovine serum albumin in oil-in-water and water-in-oil emulsions were studied. Caffeic acid (5 mmol/kg emulsion) showed good antioxidant properties in both 30% sunflower oil-in-water (OW) and 20% water-in-sunflower oil emulsions (WO), pH 5.4, during storage at 50 °C. Although bovine serum albumin (BSA) (0.2%) had a slight antioxidant effect, the combination of caffeic acid and BSA showed a synergistic reduction in the rate of development of rancidity, with significant reductions in concentration of total volatiles, peroxide value (PV) and p-anisidine value (PA) for both emulsion types. The synergistic increase in stability of the OW and WO emulsions containing BSA and caffeic acid was 102.9% and 50.4% respectively based on total oxidation (TOTOX) values, which are calculated as 2PV + PA, with greater synergy calculated if based on formation of headspace volatiles. The OW emulsion was more susceptible to the development of headspace volatiles by oxidation than the WO emulsion, even though the degree of oxidation assessed by the TOTOX value was similar.  相似文献   

5.
The antioxidant properties of selected amino acids were tested using in vitro assays and oil‐in‐water (O/W) emulsions under riboflavin (RF) photosensitization. Headspace oxygen content, lipid hydroperoxides, and conjugated dienes were determined for the degree of oxidation. Riboflavin photosensitization was adapted as the oxidation driving force. In vitro assays showed that cysteine had the highest antioxidant properties followed by tryptophan and tyrosine. However, in O/W emulsions under RF photosensitization, tyrosine inhibited lipid oxidation whereas tryptophan acted as a prooxidant. Tryptophan accelerated the rates of oxidation in O/W emulsion without RF. The antioxidant properties of amino acids differed depending on the antioxidant determination methods, oxidation driving forces, and food matrices.  相似文献   

6.
BACKGROUND: Little is known about the relation between haemoglobin (Hb)‐mediated lipid and protein oxidation in muscle foods and how these two reactions can be inhibited by naturally occurring antioxidants. This study was aimed at evaluating (1) lipid oxidation and protein oxidation induced by 20 µmol L?1 Hb during chilled and frozen storage of washed cod mince and (2) the efficiency of 10–1000 ppm (0.063–6.3 mmol L?1) caffeic acid in preventing these reactions. RESULTS: Addition of 20 µmol L?1 Hb increased peroxide value (PV), rancid odour, protein carbonylation, protein insolubilisation, redness loss and α‐tocopherol loss in ice‐stored washed cod mince. Since both lipid and protein oxidation developed at the same time, it was not possible to conclude which reaction initiated the other. All studied reactions were efficiently inhibited by ≥ 50 ppm caffeic acid, which could be a result of α‐tocopherol regeneration, general radical scavenging, reduced formation of oxidised Hb forms and/or conformational changes in Hb structure. During frozen storage the only clear effect of Hb was increased PV, and here caffeic acid was less efficient as an antioxidant. CONCLUSION: Hb‐induced lipid and protein oxidation occurred quickly in ice‐stored washed cod mince, and the two reactions could not be separated in time. During frozen storage, Hb caused only limited lipid oxidation. Caffeic acid (≥50 ppm) was an efficient antioxidant during ice storage. Copyright © 2010 Society of Chemical Industry  相似文献   

7.
抗坏血酸对大豆蛋白乳液抗氧化稳定性的研究   总被引:1,自引:0,他引:1  
本试验通过研究抗坏血酸对大豆蛋白乳液体系中油脂的抗氧化作用,明确抗坏血酸作为天然抗氧化剂在乳化体系中的抗氧化机理。本研究采用溶解氧(DO)和顶空氧气消耗法测定大豆蛋白乳液体系在pH 3.0的环境下抗坏血酸对乳液体系氧消耗的影响;验证不同过渡金属Fe~(2+)、Cu~+对抗坏血酸在乳液中清除自由基能力、降解速率、乳液粒径变化和对大豆蛋白乳液氧化稳定性影响。研究表明:通过激光粒度仪分析乳液在储存期间的粒径变化趋势相同,含有抗坏血酸的乳液与对照组没有明显区别,加入金属离子的乳液粒径偏大;15 mmol/L抗坏血酸能够几乎完全消耗乳液体系中溶氧量;抗坏血酸能够在过渡金属Fe~(2+)和Cu~+发生促氧化时通过转移电子和清除体系中的自由基起到抗氧化作用;与对照组相比,Fe~(2+)和Cu~+可加速抗坏血酸降解和氧的消耗,但并没有引起乳液氢过氧化物和己醛含量的快速增加。说明抗坏血酸在大豆蛋白乳液体系中可通过清除自由基和加速乳液体系中氧消耗的多种机制稳定乳液。  相似文献   

8.
Hempseed oil was used to form oil‐in‐water emulsions, and the effect of heating, storage and light on the oxidative stability of the dispersed phase was investigated. Lipid oxidation rate increased following thermal processing and light exposure, whereas oxidation markers remained relatively unaffected during emulsions storage at 4 °C for 10 days. Induction times of the emulsions were reduced up to 26% and the concentration of thiobarbituric acid reactive substances increased up to 4.5‐fold, depending on the processing conditions. Selected berries as potential sources of natural antioxidants were screened for polyphenol and anthocyanin content in order to investigate their ability to retard lipid oxidation in comparison with a commercially available synthetic counterpart. Raspberry powder extract significantly improved the oxidative stability of hemp‐based emulsion compared with the control and was even more effective compared to a synthetic antioxidant when samples were subjected to heat treatment.  相似文献   

9.
The extracts (0.5% [w/w]) from Caesalpinia spinosa or tara (CS) and Caesalpinia decapetala (CD) leaves were evaluated for their ability to inhibit lipid oxidation using oil‐in‐water (O/W) emulsions as the model system. Liquid chromatography (LC) combined with mass spectrometry (MS), using a hybrid quadrupole time‐of‐flight (QTOF) mass spectrometer, was employed for (1) the identification of potential antioxidant species in the extracts and (2) to follow their evolution through aging of the emulsions. CS extracts, containing esters and conjugated forms of gallic acid (GA), turned out to be more effective than CD, rich in flavonoid species, in stabilizing the O/W emulsions. After 3 wk at 33 °C, peroxide values of emulsions stabilized with CS and CD extracts were 6.7 and 18.2 meq hydroperoxides/kg, respectively. Responses measured for the oligomers and esterified forms of GA in CS containing emulsions decreased with time; however, the response for the free form of GA kept increasing.  相似文献   

10.
The antioxidant activity of dichloromethane extract from ginger was evaluated during 6 months of storage of refined sunflower oil at 25 and 45 °C. Free fatty acid (FFA) content, peroxide value (POV) and iodine value (IV) were used as criteria to assess ginger extract as an antioxidant. After 6 months of storage at 45 °C, sunflower oil containing 1600 and 2400 ppm ginger extract showed lower FFA contents (0.083 and 0.080%) and POVs (24.5 and 24.0 meq kg?1) than the control sample (FFA contents 0.380%, POV 198.0 meq kg?1). Sunflower oil containing 200 ppm butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) showed FFA contents of 0.089 and 0.072% and POVs of 26.5 and 24.7 meq kg?1 respectively after 6 months of storage at 45 °C. Similarly, after 6 months of storage at 45 °C, IVs of sunflower oil containing 1600 and 2400 ppm ginger extract were 80 and 92 respectively, higher than that of the control sample (53). However, IVs of sunflower oil treated with 200 ppm BHA and BHT were 94 and 96 respectively after 6 months of storage at 45 °C. These results illustrate that ginger extract at various concentrations exhibited very strong antioxidant activity, almost equal to that of synthetic antioxidants (BHA and BHT). Ginger extract also showed good thermal stability and exhibited 85.2% inhibition of peroxidation of linoleic acid when heated at 185 °C for 120 min. Therefore the use of ginger extract in foods is recommended as a natural antioxidant to suppress lipid oxidation. © 2003 Society of Chemical Industry  相似文献   

11.
Decarboxylation of ferulic acid would increase the solubility in oils. Rice bran extract (RBE) containing 29 mg ferulic acid/g RBE was decarboxylated to obtain decarboxylated rice bran extract (DRBE), and its antioxidant capacity in oil system was studied. After addition of DRBE (500 ppm), oxidation was monitored for 20 days at 60 °C under the dark. To compare the oxidation degree, 500 ppm of ferulic acid and well-known lipid soluble antioxidant, α-tocopherol, were used. Contents of conjugated dienes and aldehydes were measured using 1H NMR as well as peroxide value (POV). On 7 days of oxidation, DRBE (539.0 meq/kg oil) showed lower POV than the control (819.7 meq/kg oil). Also, contents of total conjugated form and aldehydes were 194.60, and 5.94 mmol/L oil, which were lower than those of control (323.63 and 15.94 mmol/L oil). However, after 10 days of oxidation, antioxidant capacity of DRBE was not observed.  相似文献   

12.
The effect of soybean lecithin addition on the iron‐catalyzed or chlorophyll‐photosensitized oxidation of emulsions consisting of purified canola oil and water (1:1, w/w) was studied based on headspace oxygen consumption using gas chromatography and hydroperoxide production using the ferric thiocyanate method. Addition levels of iron sulfate, chlorophyll, and soybean lecithin were 5, 4, and 350 mg/kg, respectively. Phospholipids (PLs) during oxidation of the emulsions were monitored by high performance liquid chromatography. Addition of soybean lecithin to the emulsions significantly reduced and decelerated iron‐catalyzed oil oxidation by lowering headspace oxygen consumption and hydroperoxide production. However, soybean lecithin had no significant antioxidant effect on chlorophyll‐photosensitized oxidation of the emulsions. PLs in soybean lecithin added to the emulsions were degraded during both oxidation processes, although there was little change in PL composition. Among PLs in soybean lecithin, phosphatidylethanolamine and phosphatidylinositol were degraded the fastest in the iron‐catalyzed and the chlorophyll‐photosensitized oxidation, respectively. The results suggest that addition of soybean lecithin as an emulsifier can also improve the oxidative stability of oil in an emulsion.  相似文献   

13.
Flavonoids have attracted attention due to pharmacological and antioxidative activities. The effects of flavonoids on the physical and oxidative stabilities of lecithin emulsified soybean oil-in-water (O/W) emulsions were investigated at 25°C during 29 days of storage. Addition of 100 ppm hesperidin, hesperitin, rutin, or quercetin improved the physical stability of O/W emulsions but did not change particle size values, compared to a control with no flavonoids during storage. Quercetin showed the highest antioxidant activity for inhibition of lipid oxidation based on lowered lipid hydroperoxide formation and 2-thiobarbituric acid reactive substances values in emulsions, followed by rutin, hesperitin, and hesperidin. Hesperidin and hesperitin did not affect antioxidative activities in O/W emulsions under metal ion-catalyzed conditions. Addition of hesperidin, hesperitin, rutin, and quercetin to soybean oil O/W emulsions improved the physical and oxidative stability of emulsions lacking added metal ions.  相似文献   

14.
为提高牡丹籽油乳液的氧化稳定性,将叔丁基对苯二酚(TBHQ)与天然抗氧化剂(生育酚、抗坏血酸)进行复配,测定不同抗氧化剂对牡丹籽油乳液的抗氧化作用,并分析了不同复配抗氧化剂的相互作用机制。结果表明:在贮藏30 d时,添加和未添加抗氧化剂牡丹籽油乳液的粒径相较于0 d 均略有增加,200 mg/kg TBHQ与800 mg/kg抗坏血酸复配时乳液的Zeta电位绝对值最大,且抗氧化作用最强;TBHQ与抗坏血酸表现出较好的协同抗氧化作用,与生育酚表现出拮抗作用;TBHQ与生育酚之间拮抗作用的原因主要是TBHQ减少了生育酚在牡丹籽油乳液中油水界面的含量,而TBHQ与抗坏血酸之间协同作用主要是由于抗坏血酸增加了TBHQ在牡丹籽油乳液中油水界面的含量。综上,TBHQ与抗坏血酸复配能提高牡丹籽油乳液的氧化稳定性。  相似文献   

15.
Grape (Kyoho) skin, used to retard lipid oxidation in edible oil foods, was investigated to reduce lipid oxidation in an oil-in-water (O/W) emulsion during 20 day of storage. The antioxidant efficacy of Kyoho skin extracts in O/W emulsions was determined by the measurement of secondary oxidation products. Moreover, principal component analysis (PCA) was conducted to determine similarities between emulsions treated with or without Kyoho skin extracts and standards. The data revealed that Kyoho skin extracts exhibited >93% inhibition and reported a similar p-anisidine (4.30–20.71) and TBARS (6.08–11.15 mg MDA L−1) values over the standards during 20 day of storage. PCA (PCs 1 (51.83%) and 2 (18.85%)) demonstrated a similarity in the contribution of Kyoho skin extracts over the synthetic antioxidants in O/W emulsion. Overall, these findings highlighted the possibility of using Kyoho skin extracts as natural antioxidants to decrease oxidative rancidity in foods.  相似文献   

16.
Alpha-linolenic acid (ALA) enriched structured lipid (SL) was produced by lipase-catalyzed interesterification from perilla oil (PO) and corn oil (CO). The effects of different reaction conditions (substrate molar ratio [PO/CO 1:1 to 1:3], reaction time [0 to 24 h], and reaction temperature [55 to 65 °C]) were studied. Lipozyme RM IM from Rhizomucor miehei was used as biocatalyst. We obtained 32.39% of ALA in SL obtained under the optimized conditions (molar ratio-1:1 [PO:CO], temperature-60 °C, reaction time-15 h). In SL, the major triacylglycerol (TAG) species (linolenoyl-linolenoyl-linolenoyl glycerol [LnLnLn], linolenoyl-linolenoyl-linoleoyl glycerol [LnLnL]) mainly from PO and linoleoyl-linoleoyl-oleoyl glycerol (LLO), linoleoyl-oleoyl-oleoyl glycerol (LOO), palmitoyl-linoleoyl-oleoyl glycerol (PLO) from CO decreased while linolenoyl-linolenoyl-oleoyl glycerol (LnLnO) (18.41%), trilinolein (LLL) (9.06%), LLO (16.66%), palmitoyl-linoleoyl-linoleoyl glycerol (PLL) (9.69%) were increased compared to that of physical blend. Total tocopherol content (28.01 mg/100 g), saponification value (SV) (192.2), and iodine value (IV) (161.9) were obtained. Furthermore, oxidative stability of the SL was also investigated by addition of 3 different antioxidants (each 200 ppm of rosemary extract [SL-ROS], BHT [SL-BHT], catechin [SL-CAT]) was added into SL and stored in 60 °C oven for 30 d. 2-Thiobabituric acid-reactive substances (TBARS) value was 0.16 mg/kg in SL-CAT and 0.18 mg/kg in SL-ROS as compared with 0.22 mg/kg in control (SL) after oxidation. The lowest peroxide value (POV, 200.9 meq/kg) and longest induction time (29.88 h) was also observed in SL-CAT.  相似文献   

17.
Antioxidant Activity of Whey in a Salmon Oil Emulsion   总被引:2,自引:0,他引:2  
The antioxidant capabilities of whey in a Tween 20TM‐stabilized salmon emulsion were investigated. Whey fractions inhibited formation of thiobarbituric acid reactive substances (TBARS) and lipid peroxides in a 10 % salmon oil emulsion in the order of whey > high‐molecular‐weight (HMW) fraction > low‐molecular‐weight fraction. Heating the HMW fraction exposed sulfhydryls, with optimum exposure at 80 °C. Heating the HMW fraction above 80 °C increased antioxidant activity. The HMW fraction of whey (80 °C) alone, α‐tocopherol (40 ppm) alone, and their combination inhibited TBARS 59,19 and 86%, respectively, at 21 d of storage. Sulfhydryls oxidized before a‐tocopherol, suggesting that sulfhydryls are the primary antioxidant. Results indicate that whey proteins could be useful antioxidants in food emulsions.  相似文献   

18.
Abstract: Chlorophyll photosensitized oxidation of W/O emulsion consisting of oils with different fatty acid composition was studied and β‐carotene effects on the singlet oxygen oxidation affected by phosphatidylcholine were evaluated by determining peroxide value (PV) and conjugated dienoic acid (CDA) contents. An emulsion was composed of purified oil (sunflower, soybean, canola, or olive oil), water, and xanthan gum (50:50:0.35, w/w/w) with addition of phosphatidylcholine (0 or 250 ppm) and β‐carotene (0, 1, 5, or 10 ppm). PV and CDA content of oil in the emulsion were increased with time under chlorophyll photosensitized oxidation, and the oxidation rate was higher in the emulsion consisting of sunflower or soybean oil whose polyunsaturated fatty acids content was high compared to canola or olive oil. Addition of β‐carotene to the emulsion significantly decreased the oil oxidation under chlorophyll photosensitization, however, co‐addition of phosphatidylcholine decreased the antioxidant activity of β‐carotene, suggesting an antagonistic antioxidation between them. Practical Application: The results of this study can be applied to the area of emulsion foods such as salad dressing to have improved texture and stability by decreasing the oil oxidation and providing desirable color by use of β‐carotene with phosphatidylcholine as emulsifier.  相似文献   

19.
Bulk oils and oil-in-water emulsions were subjected to high hydrostatic pressure (HHP) (200, 650 MPa) treatment so as to estimate the effect of applied pressures on lipid oxidation. HHP-treated and non-treated samples were left to autoxidise under accelerated conditions (2 weeks, 70 °C) and their oxidative status was periodically estimated by measurement of conjugated dienes and peroxide value. Total changes of thiobarbituric acid-reactive substances were recorded as additional oxidative markers for emulsions. Results showed an increase in oxidation as pressure was increased especially at 650 MPa. Lipid oxidation rates that were more pronounced for HHP-treated samples can be correlated to measured dissolved oxygen that was also higher. HHP did not seem to have an effect on emulsion droplet size. The addition of Majorana syriaca (200 ppm) ethyl acetate extract led to protection against lipid oxidation under HHP and atmospheric conditions, 20.9–38.7% and 28.9–43.2%, respectively. It was observed that the antioxidant effect of M. syriaca extract under HHP was weaker.  相似文献   

20.
The effect of 75% ethanol extract of daraesoon and samnamul (200 mg/kg) on the lipid oxidation of soybean oil-in-water (4:6, w/w) emulsion containing iron (5 mg/kg) in dark conditions at 25°C was studied by determining headspace oxygen and hydroperoxide contents. Polyphenol, carotenoid, and chlorophyll contents were also evaluated using spectrophotometry. The headspace oxygen contents were higher and hydroperoxide contents were lower (p<0.05) in the emulsions with added daraesoon and samnamul extracts compared with the control emulsion without the extract. The antioxidant activity of the daraesoon and samnamul extracts in the lipid oxidation of the emulsions was comparable to that of dibutylhydroxytoluene at 200mg/kg. Polyphenols, carotenoids, and chlorophylls were degraded during oxidation of the emulsions, possibly due to a role of the antioxidants. The results suggest that contribution to the improved lipid oxidative stability of the emulsion with added samnamul and daraesoon would be due to polyphenols and pigments, respectively.  相似文献   

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