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1.
The antioxidant activities of the fermented wheat gluten hydrolysates with different fermentation times were investigated to elucidate the impact of lactic acid bacteria (LAB) fermentation on the wheat gluten hydrolysates. Prior to LAB fermentation, wheat gluten was deamidated by hydrochloric acid and then hydrolysed by pancreatin to 12 and 24 h, respectively. Results showed that LAB fermentation had significant impacts on the enzymatic efficiency and antioxidant activities of wheat gluten. The degree of hydrolysis and protein recovery of hydrolysates gradually increased and then reached maximum values, respectively, when fermenting with LAB for 36 h. The hydrolysis degree and protein recovery of fermented pancreatin 24‐h hydrolysates were larger than that of the fermented pancreatin 12‐h hydrolysates during the whole fermentation. The antioxidant activity analysis revealed a marked increase and improvement in the scavenging activities of 1,1‐Diphenyl‐2‐picrylhydrazyl·radicals, hydroxyl radicals and oxygen radical absorbance capacity, while the scavenging activities of ABTS+ radical decreased as the fermentation time extended. The antioxidant activities of pancreatin 24‐h hydrolysates were higher than that of the pancreatin 12‐h hydrolysates during the whole LAB fermentation.  相似文献   

2.
Antioxidant Activities of Rapeseed Protein Hydrolysates   总被引:2,自引:0,他引:2  
Rapeseed protein hydrolysates (RPH) were obtained by enzymatic hydrolysis of rapeseed protein using Alcalase 2.4 L FG. The degree of hydrolysis (DH) of RPH was about 25% using pH-stat method. The antioxidant activities of RPH were investigated by employing several in vitro assay, including the 1,1-diphenyl-2-picrylhydrazyl (DPPH)/superoxide/hydroxyl radical scavenging assays, and reducing power assay. RPH showed scavenging activity against free radicals such as DPPH, superoxide, and hydroxyl radicals. The radical scavenging effect was in a dose-dependent manner, and the EC50 values for DPPH, superoxide, and hydroxyl radicals were found to be 0.71, 1.05, and 4.92 mg/mL, respectively. In addition, the RPH also exhibited notable reducing power, which was 0.51 at 2.00 mg/mL. The data obtained by in vitro systems obviously established the antioxidant potency of RPH. Combined with the results of the amino acid profiles, RPH were believed to have high nutritive value in addition to antioxidant activities.  相似文献   

3.
In this study, sweet potato protein (SPP) hydrolysates were prepared by six enzymes (alcalase, proleather FG‐F, AS1.398, neutrase, papain and pepsin). The antioxidant activities and protective effect against oxidative DNA damage of SPP hydrolysates were investigated. Alcalase hydrolysates exhibited the highest hydroxyl radical‐scavenging activity (IC50 1.74 mg mL?1) and Fe2+‐chelating ability (IC50 1.54 mg mL?1) (< 0.05). Compared with other five hydrolysates, the hydrolysates obtained by alcalase had the most abundant <3‐kDa fractions. In addition, below 3‐kDa fractions of alcalase hydrolysates showed the highest antioxidant activities and protective effects against DNA damage through both scavenging hydroxyl radicals and chelating Fe2+, which was probably because of the increase in several antioxidant amino acids, such as His, Met, Cys, Tyr and Phe, as well as the hydrophobic amino acids. The results suggested that enzymatic hydrolysis could be used as an effective technique to produce high value‐added peptides products from SPP.  相似文献   

4.
目的 研究发酵巴戟天中多糖、寡糖与蒽醌单独及复配后的抗氧化活性。 方法 通过DPPH、羟自由基、超氧自由基的清除率和线虫模型对三种有效组分的抗氧化活性进行测定。 结果 多糖、寡糖与蒽醌单独作用及复配均对活性氧自由基具有清除作用,复配组在中低浓度下清除DPPH自由基和超氧自由基具有协同抗氧化作用;以羟自由基为清除对象时,在高浓度只有蒽醌+寡糖和多糖+寡糖+蒽醌组才存在协同作用。此外,复配组分对线虫的寿命延长和运动行为能力增强作用效果普遍优于单独作用。结论 发酵巴戟天中多糖、寡糖与蒽醌的含量较为丰富,复配后具有良好的抗氧化效果,可为发酵巴戟天的开发提供基础数据。  相似文献   

5.
Compositions and antioxidant properties of protein hydrolysates prepared from four carp skins: black carp, grass carp, silver carp and bighead carp, using pepsin, with a degree of hydrolysis (DH) of 6–15%, were investigated. The yield of freeze‐dried hydrolysates was in the range of 54–62 g/100 g (dry skin). The content of protein and ash in four freeze‐dried hydrolysates was 72–81% and 8–17%, respectively. All hydrolysates contained high amount of hydrophobic amino acid residues (389–480 residues/1000 residues). Meanwhile, their antioxidant properties were evaluated by in vitro assays. The results revealed that all hydrolysates possessed potent antioxidant activities and showed dose dependency as the activity increased with sample concentration, capable of scavenging 72–88% of DPPH and 61–69% of hydroxyl radicals, respectively, at the highest tested concentration. The hydrolysates exhibited high reducing power and β‐carotene–linoleic acid oxidation inhibition. Among the four hydrolysates, the hydrolysate derived from bighead carp skin was superior to others in terms of yield, DH and antioxidant activities.  相似文献   

6.
Three polysaccharides (SPP-30, SPP-60 and SPP-90) were fractionated from Sargassum pallidum by 30%, 60% and 90% (v/v) ethanol, successively. Their physicochemical properties, antioxidant and antibacterial activities of SPP-30, SPP-60 and SPP-90 were comparatively investigated. The results showed that three polysaccharide fractions contained different neutral sugar, protein, uronic acid and sulphate contents. SPP-30 had the highest molecular weight (3.77–206.73 kDa), followed by SPP-60 (5.55–189.44 kDa) and SPP-90 (4.92 kDa). SPP-30, SPP-60 and SPP-90 were composed of fucose, arabinose, galactose, glucose, xylose and mannose but with different molar ratios. Scanning electron microscopy analysis suggested that they had different surface morphology and sizes of fragmentation. In vitro antioxidant assays suggested that SPP-30 and SPP-90 exhibited stronger scavenging activities against DPPH, ABTS and hydroxyl radicals than SPP-60. Moreover, SPP-30 and SPP-60 exhibited antibacterial activities against Staphylococcus aureus, while SPP-90 exhibited moderate antibacterial activity against both Staphylococcus aureus and Escherichia coli.  相似文献   

7.
贾庆超 《食品与机械》2023,39(2):198-206
目的:制作一款新型百香果、苹果发酵乳饮料。方法:以百香果、苹果和纯牛奶为原料,以感官评价、蛋白质含量为指标,利用模糊数学评价法,考察苹果汁添加量、百香果汁添加量、蔗糖添加量、发酵时间、菌种接种量对百香果—苹果风味发酵乳感官品质的影响,并对发酵乳的抗氧化性及各项指标进行检测。结果:百香果—苹果风味发酵乳的最佳配方为纯牛奶82.59%,百香果汁2.35%,苹果汁8.00%,蔗糖7.00%,增稠剂0.06%,菌种0.002 06%,发酵时间6.50 h。此条件下,发酵乳的感官评分为8.99,蛋白质含量为3.12 g/100 g,其理化指标和卫生指标均符合相关国标要求。抗氧化性结果表明,百香果—苹果乳饮料发酵后对DPPH自由基和羟自由基的清除率均比发酵前有所提升,分别为77.7%,45.7%。结论:最佳配方下得到的发酵乳呈淡黄色,具有良好的组织状态,无乳清析出,不分层,具有百香果和苹果的清香和发酵乳特有风味,酸甜比例合适。  相似文献   

8.
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 (< 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.  相似文献   

9.
Black rice bran was fermented with Bacillus subtilis KU3 isolated from Korean traditional food, Kimchi. Antioxidant and cytotoxic activities of the fermented black rice bran were investigated. Total phenolic and anthocyanin contents decreased from 171.54 mg GAE g?1 and 2.31 mg g?1 to 139.13 mg GAE g?1 and 2.12 mg g?1, respectively, after fermentation. Antioxidant activities determined by 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical scavenging, β‐carotene bleaching and ferric thiocyanate assay were correlated with total phenolic and anthocyanin contents. Non‐fermented black rice bran extract (NFBE) showed greater antioxidant activities than fermented black rice bran extract (FBE). Cytotoxic activities measured by MTT assay showed that both NFBE and FBE had over 50% activities. The cytotoxic activities of FBE against MCF‐7 and HeLa cells were 71.65% and 68.07%, respectively, at 8.0 mg mL?1, but those of NFBE were lower than 50%. These results suggested that the cytotoxic activity of black rice bran improved through fermentation, while antioxidant activity reduced.  相似文献   

10.
Inadequate postharvest handling and storage under high temperature and relative humidity conditions produce the hard‐to‐cook (HTC) defect in beans. However, these can be raw material to produce hydrolysates with functional activities. Angiotensin I‐converting enzyme (ACE) inhibitory and antioxidant capacities were determined for extensively hydrolysed proteins of HTC bean produced with sequential systems Alcalase‐Flavourzyme (AF) and pepsin–pancreatin (Pep‐Pan) at 90 min ACE inhibition expressed as IC50 values were 4.5 and 6.5 mg protein per mL with AF and Pep‐Pan, respectively. Antioxidant activity as Trolox equivalent antioxidant capacity (TEAC) was 8.1 mm  mg?1 sample with AF and 6.4 mm  mg?1 sample with Pep‐Pan. The peptides released from the protein during hydrolysis were responsible for the observed ACE inhibition and antioxidant activities. Nitrogen solubility, emulsifying capacity, emulsion stability, foaming capacity and foam stability were measured for limited hydrolysis produced with Flavourzyme and pancreatin at 15 min. The hydrolysates exhibited better functional properties than the protein concentrate.  相似文献   

11.
Antioxidant properties of fungal chitosan from shiitake stipes   总被引:1,自引:0,他引:1  
Ming-Tsung Yen  Ruei-Chian Li 《LWT》2007,40(2):255-261
Fungal chitosan B or C was prepared by alkaline N-deacetylation of crude chitin B or C for 60, 90 and 120 min, which was obtained from air-dried shiitake stipes and its antioxidant properties studied. Chitosan showed antioxidant activities of 61.6-82.4% at 1 mg/ml and showed reducing powers of 0.42-0.57 at 10 mg/ml. At 10 mg/ml, scavenging abilities of chitosan B60 and C60 on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals were 28.4-31.3% whereas those of chitosan B90, B120, C90 and C120 were 44.5-53.5%. With regard to the scavenging ability on hydroxyl radicals at 0.1 mg/ml, chitosan B60 and C60 were 61.9% and 63.6%, chitosan B90 and C90 were 68.3% and 69.9% and chitosan B120 and C120 were 77.7% and 77.2%, respectively. At 1.0 mg/ml, chelating abilities of chitosan B60 and C60 on ferrous ions were 88.7-90.3% whereas those of the rest chitosan were 97.8-103%. EC50 values of antioxidant activity were below 1 mg/ml whereas those of reducing powers and scavenging abilities on DPPH radicals were 7.69-16.3 mg/ml. EC50 values of scavenging abilities on hydroxyl radicals were below 0.1 mg/ml whereas those of chelating abilities on ferrous ions were 0.58-0.69 mg/ml.  相似文献   

12.
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.  相似文献   

13.
As food ingredient, Anser cygnoides is farmed in large scale; however, its blood is underused. The characteristics, stability and antioxidant activities of P owder of farmed C ygnoides S erum (FACSP) were investigated. Results showed that FACSP was protein‐rich and displayed satisfactory antioxidant activities. In vitro analysis indicated that the IC50 values of 2, 2′‐azinobis‐(3‐ethylbenz‐thiazoline‐6‐sulphonate), 1,1‐diphenyl‐2‐picrylhydrazyl and hydroxyl radicals were 1.56, 2.76 and 39.55 mg mL?1, respectively. In vivo experiment showed that the activity of total superoxide dismutase and content of glutathione of the FACSP‐treated groups were enhanced, and the contents of malondialdehyde and protein carbonyl were decreased. The parameters of 400 and 800 mg kg?1 bw day?1 dose groups were equally or approximately to vitamin C. The FACSP shows potential as an antioxidant functional food at a dose of 400 mg kg?1 bw day?1.  相似文献   

14.
《Food chemistry》2005,93(4):641-649
Ganoderma tsugae Murrill was available in the form of mature and baby Ling chih, mycelia and fermentation filtrate. From these four forms, methanolic extracts were prepared and their antioxidant properties were studied. Methanolic extracts from mature and baby Ling chih showed high antioxidant activities (96.8% and 93.6%) at 20 mg ml−1, and had EC50 values of 0.53 and 1.11 mg ml−1, respectively. EC50 values in reducing power were 5.00, 2.28, 0.93 and 2.15 mg ml−1 for Ling chih, baby Ling chih, mycelia and filtrate, respectively. Methanolic extracts from mature and baby Ling chih scavenged 1,1-diphenyl-2-picrylhydrazyl radicals by 88.4% and 93.8% at 5 mg ml−1, whereas those from mycelia and filtrate scavenged by 85.7% and 79.3% at 10 mg ml−1, respectively. EC50 values in chelating ability on ferrous ions were 4.82, 3.05, 1.10 and 3.41 mg ml−1 for Ling chih, baby Ling chih, mycelia and filtrate, respectively. Total phenols were the major naturally occurring antioxidant components found in all methanolic extracts and in the range of 24.0–35.6 mg g−1. Based on EC50 values, G. tsugae was good in antioxidant properties except for the scavenging ability on hydroxyl radicals.  相似文献   

15.
《Food chemistry》2002,77(2):229-235
Winter (strains white and yellow), shiitake (strains 271 and Tainung 1) and oyster mushrooms (abalone and tree oyster mushrooms) were obtained commercially and methanolic extracts were prepared from these mushrooms and their antioxidant properties were studied. The antioxidant activities by the 1,3-diethyl-2-thiobarbituric acid method were moderate to high at 1.2 mg ml−1. Reducing powers were excellent (and higher than 1.28 absorbance) at 40 mg ml−1. Scavenging effects on 1,1-diphenyl-2-picrylhydrazyl radicals were moderate to high (42.9–81.8%) at 6.4 mg ml−1. With regards to the scavenging effect on hydroxyl free radicals, tree oyster mushrooms were the highest (54.3%) at 40 mg ml−1 whereas other commercial mushrooms were low. Chelating effects on ferrous ions were 45.6–81.6% at 1.6 mg ml−1. Total phenols were the major naturally occurring antioxidant components found. Overall, tree oyster mushrooms were better in antioxidant activity, reducing power and scavenging abilities and higher in total phenol content.  相似文献   

16.
Large amounts of fresh seed epicarp of Nelumbo nucifera Gaertn. (FSENN) are discarded in China without any utilization. The aim of this study was to identify the flavonols found in a fraction of an extract of FSENN, and to measure their levels and investigate antioxidant properties. Glycosylated flavonols in fraction 2 (Fr2) from the extract of FSENN and their aglycones were identified by HPLC-ESI–MS2 (negative mode), and six glycosylated and one aglycone flavonols in Fr2 were found. We also quantified flavonol aglycones (myricetin, quercetin, kaempferol and isorhamnetin) using HPLC method. The result showed that the quercetin content (10.2 mg/g of dry fraction) was higher than that of other aglycones. Antioxidant properties of Fr2 were evaluated in vitro by a number of methods including 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, the β-carotene bleaching method, and hydroxyl radical and hydrogen peroxide scavenging ability using the chemiluminescence method. This antioxidant potential in terms of IC50 values was 5.48, 40 ± 0.14 and 0.62 ± 0.05 μg (dry Fr2)/mL on DPPH radicals, hydroxyl radicals and hydrogen peroxide, respectively. The Fr2 also exhibited antioxidant property in the β-carotene bleaching assay. In total, it possesses high levels of flavonol compounds with high antioxidant potential, and it is beneficial for the treatment or prevention of a variety of diseases and has nutraceutical potential.  相似文献   

17.
以苦瓜汁与苹果菠萝混合果汁为原料,选用酿酒酵母(Saccharomyces cerevisiae)及植物乳杆菌(Lactobacillus plantarum)作为发酵菌种定向发酵苦瓜保健酒。以酒精度、感官评价及苦瓜皂苷产率为评价指标,采用Box-Behnken中心组合试验优化发酵条件,同时以维生素C作为阳性对照,采用清除羟自由基和Fe3+还原能力分析苦瓜保健酒的抗氧化活性。结果表明,苦瓜保健酒的最佳发酵工艺条件为苹果菠萝混合果汁∶苦瓜汁=1.5∶1、发酵时间10 d、酵母添加量为1 mL/L、乳酸菌添加量6 mL/L、发酵温度26 ℃的条件下可生产出质量最佳的苦瓜保健酒。此条件下成品果酒的品质最佳,皂苷含量达到2.78%,酒精度为11.2%vol。抗氧化试验结果表明,苦瓜保健酒有一定的抗氧化活性,0.1 mg/mL的苦瓜保健酒对羟自由基的清除率达到25%以上,对Fe3+也有一定还原能力,且其抗氧化化性与皂苷质量浓度呈正相关。  相似文献   

18.
In this study, polyphenol oxidase (PPO) and vitamin C were used as the indicators of enzymes and nutrients to evaluate the apple quality during high humidity air impingement blanching (HHAIB) process. The PPO can be completely inactivated within 7 min at 90–120 °C and can retain relatively more vitamin C in the case of PPO fully inactivation. PPO inactivation followed zero‐order kinetics model at 90 and 100 °C, and followed first‐order fraction model at 110 and 120 °C. Activation energy (Ea) of PPO inactivation was between 11.61 and 13.66 kJ mol?1 by Arrhenius equation. Vitamin C degradation under all processing temperatures was well described by first‐order model and its Ea value was 26.69 kJ mol?1. Therefore, the HHAIB process was proved to be an effective pretreatment for Fuji apple quarters to inactivate PPO fast and meanwhile to maintain produce quality.  相似文献   

19.
This study was conducted to investigate the changes in the total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activities of 80% methanol and water extracts from mustard leaf kimchi during different fermentation periods. The methanol extract exhibited higher TPC and TFC than the water extract. Both extracts from kimchi fermented for two months showed the highest antioxidant effects against the scavenging activities of 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radicals and 2,2-azino-bis diammonium salt (ABTS) radicals. Moreover, the methanol extract from kimchi fermented for two months showed the highest nitrite scavenging activity. The highest metal (Fe2+) chelating effect of the methanol extract and water extract was observed after three months and one month, respectively. Caffeic acid showed the highest increase with fermentation. These findings suggest that the antioxidant activities of kimchi depend on the fermentation period. Accordingly, this study provides basic data for improving the antioxidant activity of mustard leaf kimchi through the establishment of their fermentation period.  相似文献   

20.
The water-soluble sulphated polysaccharide conjugates were obtained from abalone viscera (Haliotis discus hannai Ino) by alkaline protease extraction followed by ethanol precipitation. Their antioxidant activities were evaluated in vitro by hydroxyl radicals scavenging activity, reducing power and metal chelating activity. Those various antioxidant activities were compared to standard antioxidants ascorbic acid and EDTA. The experimental results indicated that the crude extract having notable hydroxyl free radicals scavenging activity and moderate reducing power and chelating potency. The crude sulphated polysaccharide conjugates was enzymatically hydrolyzed by five commercially available proteases (trypsin, vernase, neutrase, pepsin and papain), and the resultant digests were tested for their antioxidant activities. Those proteolytic hydrolysates, although improving the hydroxyl radical scavenging activity in all cases except one, had lower reducing power and 3–15 times lower chelating ability than the native extract. Product derived from pepsin hydrolysate was fractionated by gel-filtration chromatography with sephadex G-100, giving two fractions containing sulphated polysaccharide conjugates termed ACP I and ACP II. The neutral monosaccharide composition of ACP I is rhamnose, fucose, xylose, mannose, galactose and glucose in a molar ratio of 1.00:45.14:4.00:5.36:33.18:2.15, with an average molecular weight of about 271 kDa. The neutral monosaccharide composition of ACP II is rhamnose, fucose, xylose, mannose, galactose and glucose in a molar ratio of 1.00:12.51:1.33:4.98:16.08:1.46, with an average molecular weight of about 6 kDa.  相似文献   

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