红树莓叶片中黄酮类物质提取及抗氧化性的研究

以小浆果果树红树毒叶片为实验材料，利用分光光度法测定其总黄酮含量，并采用烘箱贮存法研究了不同添加量红树毒叶片提取物粗黄酮在猪油中的抗氧化性。结果表明：鲜样中红树毒叶片总黄酮含量是278．73mg／100g，干样中是533．71mg／100g；红树毒叶片提取物粗黄酮对猪油有一定的抗氧化作用，并随添加量的增加而增强；增效剂以(柠檬酸)对红树毒叶片提取物粗黄酮无增效作用，而Vc具有一定的增效作用。抗氧化活性顺序为：0．02％槲皮素＞0．02％PG＞0．02％BHT＞0．4％粗黄酮＞0．05％粗黄酮 0．05％Vc＞0．2％粗黄酮＞0.1％粗黄酮＞0．05％粗黄酮＞0．02％粗黄酮＞0．05％粗黄酮 0．05％CA＞对照。     

玉米须黄酮抗氧化活性的研究

为了解玉米须黄酮的抗氧化活性，试验从抗脂质过氧化和还原力等方面对玉米须黄酮提取物的抗氧化活性进行了试验研究。结果表明，玉米须黄酮具有较强的还原力，对亚油酸过氧化及小鼠肝匀浆脂质过氧化产生的丙二醛均具有较好的抑制作用。在试验浓度范围内，玉米须黄酮粗提物、正丁醇萃取物及乙酸乙酯萃取物对亚油酸与小鼠肝匀浆脂质过氧化的抑制率分别达到90.1％、84.4％和66.2％及95．0％、77.7％和72.3％。试验结果表明，玉米须黄酮具有较好的抗氧化活性。     

蜂胶黄酮萃取物脂质体制备工艺的优化及体外缓释特性

本研究运用均匀设计方法，以脂质体黄酮包封率、平均粒径、冷藏稳定性为指标，对蜂胶黄酮萃取物脂质体制备工艺进行了初步优化，结合体外释放特性评价最终确定制备工艺条件为：蜂胶黄酮萃取物100mg、蛋黄卵磷脂500mg、胆固醇80mg、旋转蒸发温度45℃、0．01mol／L pH7．4磷酸盐缓冲液用量25ml、超声作用时间25min。在此最佳条件下制得脂质体的黄酮包封率为86．6％，平均粒径为104．78nm，4℃冷藏一个月的稳定率为77．0％。     

大豆异黄酮提取工艺的研究

试验采用80％的乙醇溶液萃取脱脂豆粕，将浸取液蒸发浓缩后，用正己烷萃取脂溶性物质，用盐酸除去蛋白，经分离后用大孔树脂进行纯化，最后用丙酮萃取提纯，大豆异黄酮纯度可达到70．56％，其中大豆甙元占44．66％，染料木黄酮糖甙为55．34％。     

杨梅叶黄酮类化合物最佳提取工艺研究

为确定杨梅叶中黄酮类化合物的提取工艺，用乙醇溶液浸提，结合超声波辅助方法，萃取杨梅叶中的黄酮类化合物，探讨了影响提取率的主要因素，最后用正交法确定了好的提取工艺。结果表明：在45倍于样重的40％的乙醇浸泡24h后，超声波辅助萃取45min，连续提取2次，黄酮的总浸出率可达99．30％，杨梅叶中的黄酮含量为8．16％。     

超临界CO2萃取杜仲叶总黄酮的研究

本论文采用超临界CO2萃取技术萃取杜仲叶总黄酮，对萃取温度、时间、压力和夹带剂用量四因素进行研究，并采用紫外分光光度法对萃取物中的总黄酮进行定量分析。确定了超临界CO2萃取杜仲总黄酮的最佳工艺条件为：温度为45℃、时间为2．5h、压力为30MPa、夹带剂用量为3．5ml／g。黄酮提取率为73．26％，产品纯度为19．82％。     

麦胚中黄酮的提取新工艺研究

研究了利用乙醇提取麦胚黄酮及利用微波辅助萃取的方法提高麦胚黄酮的提取率。结果表明：通过单因素试验和正交试验，确定乙醇提取麦胚黄酮的最佳条件为：以80％乙醇按照固液比1：25，于80℃条件下提取2次，共5h，麦胚黄酮提取率达到80％以上．．微波处理3min，提取时间较常规方法缩短一半，提取率有很大提高。     

超临界CO2萃取芦笋中总黄酮的工艺研究

采用超临界CO2萃取技术对芦笋中的黄酮类化合物进行了萃取研究，运用L9（3^4）正交表系统研究了萃取压力，萃取温度，萃取时间以及夹带剂用量对萃取率的影响。确定了超临界CO2萃取芦笋总黄酮的最佳工艺条件为：温度为70℃、时间为2h、压力为30MPa、夹带剂（75％乙醇）用量为2．0mL／g。此条件下得到总黄酮比率为1．35％，其黄酮得率是常规溶剂乙醇提取法总黄酮得率的2．7倍。     

松口蘑深层发酵上清液抗氧化活性研究

通过1，1-二苯基-2-苦肼基自由基（DPPH）体系来研究体外松口蘑深层发酵上清液的抗氧化活性。将松口蘑深层发酵上清液通过石油醚和乙酸乙酯分为不同种类萃取物，研究各萃取部位抗氧化活性。结果表明，松口蘑发酵上清液乙酸乙酯萃取物自由基清除率最强（52．4％），且自由基清除率随浓度增加而增强；其他萃取部分的抗氧化能力递减顺序为：发酵液（33％）〉乙酸乙酯萃余液（20．3％）〉石油醚萃余液（14．6％）〉石油醚萃取液（5．2％）。定性试验初步验证上清液乙酸乙酯萃取物中抗氧化成分可能为黄酮、酚类、有机酸等。     

覆盆子黄酮抗氧化活性研究

经分离提取后,对覆盆子黄酮提取物的体外抗氧化活性进行了研究,结果表明,覆盆子黄酮提取物对OH、H2O2、DPPH均有不同程度的清除作用,清除率强弱顺序为：纯化后的覆盆子黄酮〉覆盆子黄酮二次萃取物〉覆盆子黄酮粗提物;覆盆子黄酮提取物对花生油的自动氧化也有明显的抑制作用,0．2％覆盆子黄酮提取物在油脂中的添加量好于0．02％的BHT。     

ANTIOXIDANT PROPERTIES OF COCOA POWDER

This study was aimed to determine antioxidant properties of cocoa powder. Crude cocoa extracts were fractionated using prepacked column (25 cm  ×  2.0 cm) with Sephadex LH 20 and an increase in water–acetone (85:15, 70:30, and 40:60, v/v) as elution. The resulting fractions 1 (F1), 2 (F2) and 3 (F3) were tested for phenolic contents, antioxidant capacity, identification of bioactive compounds liquid chromatography-mass spectrometry (LC-MS) and stability test. Theobromine and caffeine were major compounds detected in F1 and F2. Monomer, dimer and trimer were identified in F3 as m/z 289, 578 and 867, respectively. Addition of F1 and F2 could reduce antioxidant capacity of F3. Catechin and epicatechin in F3 was stable when stored at 4 and −20C for 5 months. High antioxidant capacity in F3 was likely due to the monomeric, dimeric and trimeric phenolic compounds. The presence of methylxanthines could reduce antioxidant capacity of flavonoids in cocoa powder.

PRACTICAL APPLICATIONS

Numerous studies have been reported on the health benefits of cocoa powder. Polyphenol compounds present in cocoa powder could significantly contribute to their health-promoting activities. The study of bioactive compounds (polyphenols and methylxanthines) toward antioxidant capacity could reveal their actual antioxidant properties. Stability of individual polyphenol compounds under different storage condition and time could help in preserving their quality when producing products from cocoa powder.     

鱼油复合抗氧化剂的研究

探讨了几种抗氧剂的抗氧化能力，并进行了对比试验。运用正交试验法确定复合抗氧化剂配方，并与商用复合抗氧化剂进行了比较。结果表明，试验采用的复合抗氧化剂优于商用复合抗氧化剂。     

紫甘蓝色素抗氧化能力的研究

从还原能力、抗脂质过氧化和对自由基清除能力等方面对紫甘蓝色素的抗氧化能力进行了试验研究和评价，并对花色苷的含量进行了测定。结果袁明紫甘蓝色素具有一定的还原能力，对脂质过氧化、DPPH（1，1-二苯基-2-苦肼基）自由基均具有较强的抑制和清除作用，且在试验浓度范围内其最大抑制率和清除率分别为对亚油酸的抑制率为54．39％；对DPPH自由基的清除率为93．2％。表明，紫甘蓝色素作为具有抗氧化功能的天然色素，有广阔的应用前景。     

ANTIOXIDANT PROFILES OF CORBARA SMALL TOMATOES DURING RIPENING AND EFFECTS OF AQUEOUS EXTRACTS ON J774 CELL ANTIOXIDANT ENZYMES

The influence of ripening on the antioxidant profile of Corbara small tomatoes was studied in fruit at five different ripening stages. An increase in the content of both carotenoids and flavonoids was observed during ripening. At the "deep red"stage (StIV) fruit had an average carotenoid content 58% higher than that of the "ripe"stage (StIII) which is the usual harvest time for markets. Carotenoid concentrations parallel the value of lipophilic amioxidant activity while the aqueous/methanol antioxidant activity was not correlated with total flavonoid content. The effect of antioxidants extracted from stage IV tomato was assayed on an oxidative-stressed culture of macrophages by measuring the activity of the antioxidant enzymes. An aqueous extract containing the pool of hydrophilic antioxidants was prepared. The antioxidant effects of this pool were compared with the same effect produced by a mixture of standard compounds constituted by the main tomato hydrophilic antioxidants. Results demonstrate that the efficacy of Corbarino aqueous extract on this cell system is higher than that of reconstituted mixture .     

ANTIOXIDANT POTENTIAL OF 5-n-PENTADECYLRESORCINOL

The antioxidant potential of 5-n-pentadecylresorcinol was determined with five different oils. Alkylresordnol (AR) was added at 0.025%, 0.050% and 0.075%, respectively. For comparison, 0.01% butylated hydroxyanisole (BHA) was used as antioxidant. Oils were incubated at 10, 25 and 40C. Peroxide values were determined at different time intervals. Accelerated tests using a pro-oxidant were also conducted with each oil. AR was shown to slow oxidative rancidity of the oils.
The ability of AR to slow lipid oxidation in cereal products was also studied. Wheat bran, rye bran and whole grain millet meal were treated with 0.050% and 0.075% AR and BHA, respectively, and stored at 40C. Peroxide values were determined at different time intervals. AR was shown to slow lipid oxidation in cereal products.     

ANTIOXIDANT POTENTIAL OF TEMPEH AS COMPARED TO TOCOPHEROL

SUMMARY –The antioxidant potential of tempeh to preserve tocopherol-stripped corn oil was studied. Different levels of tempeh were mixed into corn oil, and incubated at 37°C for a maximum of 6 wk. Peroxide values were determined biweekly. Results showed that tempeh can prevent lipid oxidation. Corn oil containing 50% tempeh showed higher antioxidant potential than those containing 25% tempeh, 0.01%α-tocopherol, or 0.03%α-tocopherol. This study substantiates the antioxidant potential of tempeh and suggests its use with other foodstuffs to help preserve the lipids contained therein.     

生物抗氧剂α-硫辛酸的保健功能

被誉为“万能抗氧剂”的α-硫辛酸是近年来不断研究开发的一种极强体内活性功能因子。对α-硫辛酸的抗衰老、解毒、降糖、辐射保护、应激保护、皮肤保健、保肝护肝等保健功能作概要论述。     

花色苷类色素抗氧化活性研究进展

天然色素花色苷具有较强的抗氧化活性,本文对花色苷的抗氧化活性检测方法进行了总结,主要对体外方法像清除DPPH·的能力、ABTS+,ORAC等进行介绍,为进一步研究花色苷类色素的抗氧化活性提供便利.     

PHENOLIC COMPOUNDS AND ANTIOXIDANT POWER IN MINIMALLY PROCESSED SALAD

ABSTRACT

Phenolic content and antioxidant power of Lactuca sativa var. capitata (L.), Cichorium indivia var. latifolium (L.) and Eruca sativa (Mill.) were determined in fresh‐cut products during storage at 4C. In fresh‐cut leaves, storage did not affect the antioxidant power in escarole, whereas after 24 h, lettuce exhibited a transient rise in ferric‐reducing antioxidant power value (+50%), which was associated with increased phenol content. In rocket salad, the antioxidant power increased significantly just 1 h after cutting. The major phenols determined in escarole and lettuce hydroxycinnamic derivatives were chlorogenic acid, di‐caffeoylquinic and caffeoyltartaric acids, which increased significantly in fresh‐cut products of both species during storage. In rocket salad, only hydroxycinnamic and kaempferol derivates were found, and their content was not influenced by processing and storage even if it is probably related to the higher antioxidant power found for this species.

PRACTICAL APPLICATIONS

Many phenolic compounds are antioxidants that may contribute to reduce human diseases (e.g., cancer and heart diseases). The beneficial effects of a diet rich in vegetables have been partially attributed to an increased consumption of phenols with high antioxidant capacity. Processing vegetables (e.g., salad) for minimally processed products influences the antioxidant capacity of the tissues with different effects in relation to the species used.     

从天然植物中开发抗氧化剂研究进展

综述了天然植物中起抗氧化作用的活性成分及其抗氧化和清除自由基的作用机理及国内外天然植物开发天然抗氧化剂的一些研究现状和新进展，并提出了一些展望。