青金桔皮中多酚的提取及其抗氧化性研究

以青金桔皮为原料,选取乙醇作为提取溶剂,采用Folin-Ciocalteu法测定其多酚含量,探讨了乙醇浓度、提取温度、料液比和提取时间对多酚得率的影响。在单因素实验的基础之上,通过正交实验优化提取工艺。采用DPPH自由基法、ABTS自由基法和铁氰化钾还原力法测定青金桔皮中多酚提取物的抗氧化活性。结果表明,青金桔皮多酚的提取工艺为乙醇浓度60%（v/v）,温度55℃,料液比1∶30（g/m L）,提取时间3h,提取1次,在此条件下多酚的得率为3.68%（以干重计,w/w）。抗氧化性实验表明,青金桔皮多酚提取物具有较强的清除DPPH自由基和ABTS自由基能力,其IC50值分别为1.38mg/m L和0.49mg/m L,还原力测定实验也得出相似的结果。      

超声波与蜗牛酶分别提取橘皮总黄酮及其抗氧化性的研究

利用超声波及蜗牛酶辅助乙醇提取橘皮总黄酮,并进行抗氧化能力测定。通过单因素与正交试验,确定了超声波提取橘皮总黄酮的影响因素顺序是：超声波温度>超声波时间>乙醇浓度〉料液比。最佳工艺为：超声波时间为80min,超声波温度为60℃,80％乙醇,料液比为1:25。在此工艺条件下,橘皮总黄酮得率（以芦丁计）为3.92％。当蜗牛酶用量为0.80％时,橘籽总黄酮提取率（以芦丁计）最高可达4.34％,较超声波提取法略高。超声波与蜗牛酶提取的橘皮总黄酮均能有效地清除DPPH自由基,且明显高于大蒜提取的总黄酮清除DPPH的效果。在抗猪油氧化时,橘皮总黄酮单独使用时不如抗坏血酸、柠檬酸来得好,但与抗坏血酸、柠檬酸具有良好的协同抗氧化作用,其增效强弱为：抗坏血酸〉柠檬酸。     

Enhancement of soluble dietary fibre, polyphenols and antioxidant properties of chapatis prepared from whole wheat flour dough treated with amylases and xylanase

BACKGROUND: Chapati preparation involves various processing steps such as mixing the flour into dough, sheeting and baking. During these processing steps, flour components are likely to undergo changes in their nutrient and polyphenol composition and their antioxidant properties due to phenol‐mediated crosslinking of proteins and carbohydrates. Therefore, in the present study, changes in nutritional, nutraceutical and antioxidant properties of chapatis prepared from doughs treated with amylases and xylanase were determined. RESULTS: An increase in insoluble dietary fibre content and a decrease in soluble polyphenol content were observed during preparation of control chapatis from whole wheat flours. However, significant increases in soluble dietary fibre and soluble polyphenol contents were observed in chapatis prepared from amylase‐treated doughs compared with control chapatis. Extracts of chapatis prepared from amylase‐ and xylanase‐treated doughs showed better antioxidant properties than extracts of control chapatis. Among these enzyme treatments, chapatis prepared from amylase‐treated doughs showed better antioxidant properties than chapatis prepared from xylanase‐treated doughs. High‐performance liquid chromatography analysis of extracts of chapatis prepared from doughs treated with amylases showed the presence of potential antioxidant phenolic acids such as caffeic, gentisic and syringic acids in addition to the phenolic acids present in control chapatis. CONCLUSION: Treatment of doughs with amylases increased the contents of soluble dietary fibre and soluble polyphenols as well as improving the antioxidant properties of chapatis. Copyright © 2011 Society of Chemical Industry     

不同产地甜橙果皮提取物抗氧化活性成分及能力研究

以8种不同产地甜橙皮为研究对象,比较其抗氧化活性成分及抗氧化能力。研究结果表明,麻阳冰糖橙皮中多酚、黄酮、单宁和VC含量最高,其含量分别为7.60mg GAE/g·样品干重、4.57mg RE/g·样品干重、17.90mg TAE/g·样品干重、17.86 mg/g·样品干重。同时,麻阳冰糖橙皮也展现了最高的铁离子还原能力[(81.50±0.93)μmol TE/g·样品干重]、很高的DPPH·清除能力[(15.77±0.64)μmol TE/g·样品干重]和ABTS·清除能力[(77.70±0.75)μmol TE/g·样品干重]。Spearman相关分析表明,这4类成分含量与抗氧化活性具有显著相关性。高效液相色谱鉴定甜橙皮中的5种主要黄酮类化合物为橙皮苷、柚皮苷、橙皮素、川陈皮素和桔红素,其中以橙皮苷含量最高[(2.63±0.21)～(4.65±0.33)mg/g·样品干重]。主成分分析和层次聚类分析将8种甜橙分为三类,第Ⅰ类:永兴冰糖橙、洪江冰糖橙、麻阳冰糖橙和浏阳脐橙;第Ⅱ类:石门冰糖橙和石门脐橙;第Ⅲ类:麻阳脐橙和邵阳脐橙。尤其以第Ⅰ类的多酚、黄酮、单宁和VC含量高,铁离子还原能力和ABTS·清除能力较强。甜橙皮中抗氧化活性物质的含量及其抗氧化活性可以作为区分不同产地甜橙的重要指标。     

山竹壳膳食纤维结合酚提取工艺的优化及抗氧化活性分析

摘 要: 目的 对比酸法、碱法和酶法水解对山竹壳膳食纤维中的结合酚(bound polyphenols in Mangosteen peel, MDF-PP)的提取效果及抗氧化性, 在这三种提取方法得到的结合酚中选择得率最高和抗氧化性最强的方法进行工艺优化。方法 首先依次采用α-高温淀粉酶、木瓜蛋白酶和糖化酶对山竹壳进行酶解, 得到膳食纤维(mangosteen peel dietary fibre, MDF)。随后分别采用酸法水解、碱法水解和酶法对MDF-PP的提取, 并分别测定了所得MDF-PP的DPPH自由基清除率, 最后选择得率最高, 抗氧化性最强的方法进行MDF-PP提取的单因素实验及响应面优化。结果 碱法水解提取MDF-PP效果最好且抗氧化性最强。由响应面法得到最佳碱法水解提取工艺条件为氢氧化钠浓度为24 moL/L, 碱水解时间为4 h, 液固比为30:1 (mL/g)。在该条件下MDF-PP的得率为(88.44±1.10) (mg GAE/10 g DW),与预测值相接近。结论 本次实验建立的响应面模型良好, 可用于预测碱法提取山竹壳时MDF-PP的得率。MDF-PP具有较好的抗氧化性, 为MDF-PP的提取和进一步的活性研究提供了参考价值。     

澳洲坚果青皮多酚提取工艺优化及其抗氧化活性

以新鲜澳洲坚果青皮为原料,研究了澳洲坚果青皮多酚的提取工艺及抗氧化活性。在单因素实验的基础上,通过4因素3水平的正交实验优化澳洲坚果青皮多酚提取工艺,并以Trolox为对照,研究其对DPPH自由基和ABTS+自由基的清除能力以及总抗氧化能力。正交实验结果表明:提取时间为90 min、料液比为1∶50（g/m L）、提取温度为50℃、乙醇体积分数为40%为最佳提取工艺条件,在此条件下澳洲坚果青皮多酚提取量达到（1027.47±10.76）mg/100 g。抗氧化实验结果表明:澳洲坚果青皮多酚对DPPH自由基和ABTS+自由基的半数清除率IC50分别为4.13、112.94 mg/L,且其总抗氧化能力约为Trolox的1.7倍。由此可知,澳洲坚果青皮多酚具有很强的抗氧化能力,可用于制备天然抗氧化剂。      

Acerola and cashew apple as sources of antioxidants and dietary fibre

Several tropical fruits have been described as natural sources of dietary fibre (DF) and phenolic compounds, associated with different health effects. The aim of this work was to ascertain the DF, phenolic compounds content (including non‐extractable polyphenols, mostly associated with DF) and antioxidant capacity in acerola fruits and cashew apples from selected clones. ‘BRS 236’ acerola fruits presented a high antioxidant capacity because of the combination of both extractable polyphenols and l ‐ascorbic acid (providing together a Folin value of 170 kg^?1 g d.m.). ‘CCP 76’ cashew apples contained 28 g kg^?1 d.m. of extractable polyphenols and 13 g kg^?1 d.m. of ascorbic acid as well as a high amount of non‐extractable condensed tannins (52 g kg^?1 d.m.). DF content was of 260 g kg^?1 d.m. in acerola fruit and of 209 g kg^?1 d.m. in cashew apple. Acerola fruits and cashew apple should therefore be considered as new natural sources of DF and phenolic compounds.     

橘皮残渣中水不溶性膳食纤维提取工艺研究

提取果胶和橙皮苷后残余的橘皮渣是一种极好的水不溶性膳食纤维来源。为了进一步实现对橘皮渣的二次利用,研究了采用化学方法从残余的橘皮渣中提取水不溶性膳食纤维(IDF)的提取工艺,同时对IDF的脱色工艺也进行了研究。结果表明,水不溶性膳食纤维最佳提取工艺条件是:NaOH浓度0.25mol/L、碱浸泡温度50℃、碱浸泡时间1.0h、固液比1∶15。膳食纤维脱色最优参数为:H2O2浓度为4%、脱色温度60℃、脱色时间3h、pH为9。在该条件下,不溶性膳食纤维产率为65.98%,提取率高达92.86%,产品颜色为乳白色。      

橘皮粗多糖的提取工艺优化及抗氧化活性评价

为了优化橘皮粗多糖的微波提取工艺,评价橘皮粗多糖的抗氧化活性;通过Box-Behnken的中心组合设计及响应面法(RSM)建立了微波提取时间(min)、料液比(g/mL)、微波功率(W)的二次回归模型,对橘皮多糖的最佳微波提取工艺条件进行优化;并通过Fenton反应和有机自由基(DPPH.)法对其进行体外抗氧化活性测试。实验表明,最佳提取条件为微波提取时间18min、料液比1:25(g/mL)、微波功率250W,在该条件下橘皮粗多糖的提取得率为33.71%,高于传统回流方法(15.75%)。橘皮粗多糖对.OH和DPPH.有显著的清除作用,可以探索作为食品工业和制药行业的天然抗氧化剂。     

桔皮膳食纤维的提取及脱色工艺研究

对碱液浸提法提取桔皮膳食纤维的工艺进行了研究。结果表明,提取膳食纤维的最佳工艺条件是：NaOH浓度0．25mol／L、碱提温度50℃、料液比1：15、碱提时间30min。桔皮膳食纤维脱色工艺的最优参数为：双氧水浓度4％、脱色温度30℃、脱色时间5min、pH值为6。     

菠萝蜜果皮多酚超声微波协同提取工艺优化及抗氧化活性研究

采用超声-微波协同提取技术（UMAE）对菠萝蜜果皮中多酚的提取工艺进行优化,并对抗氧化活性进行了评价。以单因素实验为基础,根据Box-Behnken中心组合设计原理,选取乙醇体积分数、料液比、微波功率和微波时间4因素3水平进行响应曲面分析,建立多酚得率的二次多项数学模型,分析各因素的显著性和交互作用,得到多酚提取工艺的最佳条件为:乙醇体积分数70%、料液比1∶40、微波功率75 W、微波时间12 min,多酚得率为7.19 mg/g。在该条件下,超声-微波协同提取方法提取效率优于传统水浴回流法（1.04 mg/g）、微波辅助法（5.23 mg/g）和超声辅助法（5.89 mg/g）。抗氧化活性研究表明,菠萝蜜果皮多酚提取物对DPPH自由基和ABTS自由基均有较强的清除能力,呈量效关系,其EC50值分别为101.39μg/m L和106.60μg/m L,表明多酚是菠萝蜜果皮抗氧化活性的物质基础。      

桔子皮渣水溶性膳食纤维提取工艺的优化

以超临界萃取精油等化合物以后的桔子皮渣为材料,在单因素的基础上,运用响应面分析法研究水溶性膳食纤维的提取条件。结果表明,pH值、提取时间和提取温度影响显著,并建立水溶性膳食纤维提取的二次回归方程,模型高度显著且有效,回归系数R为0.984 6,水溶性膳食纤维的最佳提取条件:提取温度92.2℃,pH值1.50,均质压力29.7MPa,提取时间2.28h,该条件下,水溶性膳食纤维的得率为25.92%。     

Effect of grape antioxidant dietary fibre on the prevention of lipid oxidation in minced fish: Evaluation by different methodologies

The effect of grape antioxidant dietary fibre (GADF) addition to minced fish muscle (MFM) on lipid stability during frozen storage (6 months) was studied. Concentrations of 0%, 2%, and 4% GADF were added to MFM samples. Analyses were carried out immediately after preparation of samples and during and after storage at −20 °C. GADF was characterized in terms of dietary fibre, total polyphenols and antioxidant capacity, and multifunctional antioxidant assays were carried out on all the MFM samples. The addition of red grape fibre considerably delayed lipid oxidation in minced horse mackerel muscle during the first 3 months of frozen storage.     

Antioxidant and functional properties of a high dietary fibre powder from carambola (Averrhoa carambola L.) pomace

The use of carambola pomace as a raw material for the production of a high dietary fibre powder (HDFP) was investigated. A face‐centred design was used to study the effects of extraction conditions, namely water‐to‐pomace ratio, time and temperature, on both reducing sugars (RS) and total extractable polyphenols (EPP) contents of fibre concentrate. RS content decreased by increasing extraction times and water‐to‐pomace ratios, while EPP tend to diminish by increasing temperature and contact time (P < 0.01). Selected HDFPs showed an EPP content in the range of 5.0–6.1 g GAE 100 g^?1 dry basis (db), with antioxidant activities between 386.2–443.9 and 204.7–228.6 μmol Trolox equivalents g^?1 db according to FRAP and ABTS assays, respectively. HDFP obtained at 55 °C, 5 min and 2:1 water‐to‐pomace ratio exhibited the highest EPP content, total dietary fibre (84.0% db) and dietary indigestible fraction (61.3% db). This product can be considered as a potential valuable food ingredient considering their oil retention and swelling capacities.     

Characteristics of fibre‐rich powder and antioxidant activity of pitaya (Hylocereus undatus) peels

The contents of total dietary fibre (TDF), soluble dietary fibre (SDF), insoluble dietary fibre (IDF) and functional properties of fibre‐rich powders (FRP) from pitaya peels with different particle size (FRP80, FRP140 and FRP250) were determined. Results showed that FRP140 had higher TDF (79.37%) and SDF (33.07%) with a balanced ratio of SDF/IDF (1:1.32) and higher water‐holding capacity (54.20 g g^?1), swelling capacity (50.63 mL g^?1), oil‐holding capacity (2.65 g g^?1) and glucose dialysis retardation index (62.83% at 60 min), compared with FRP80 and FRP250. Therefore, physiochemical properties of FRP140 were further investigated. SDF of FRP140 mainly contained rhamnose (4.95%) and galactose (1.98%), with 9.45% galacturonic acid, while IDF dominantly contained xylose (4.76%) and galactose (3.42%), with 18.54% klason lignin. Total phenolic content was 7.75 mg g^?1 and mainly composed of salicylic acid (0.98 mg g^?1) and protocatechuic acid (0.45 mg g^?1). Furthermore, FRP140 showed significant reducing power, DPPH‐scavenging activity and nitrite‐scavenging ability.     

龙须菜多酚提取工艺优化及其体外抗氧化活性

以龙须菜为原料,研究超声波辅助提取龙须菜多酚的工艺条件及其抗氧化活性。单因素考察液料比、提取温度、超声时间对龙须菜多酚含量的影响,在此基础上,利用响应面分析法优化提取工艺。结果表明,液料比40:1(mL/g)、提取温度60℃、超声时间40min为龙须菜多酚提取最佳工艺条件(龙须菜多酚提取量为1.62 mg GAE/g)。体外抗氧化活性研究表明,龙须菜多酚具有一定清除DPPH自由基和羟自由基的能力,其IC_(50)值分别为56.67,18.78μg/mL,分别相当于15.89,536.4μg/mL的抗坏血酸。     

超声辅助提取菠萝蜜果皮黄酮工艺优化及体外抗氧化活性研究

采用超声波辅助溶剂法提取菠萝蜜果皮中的黄酮,研究了不同的提取溶剂、提取方式和提取工艺因素(溶剂浓度、料液比、提取时间)对黄酮提取率的影响,采用响应面实验设计和多元二次回归分析优化提取工艺。结果表明,超声辅助溶剂法提取菠萝蜜果皮黄酮的最佳工艺为丙酮浓度61%,料液比1∶25,提取时间24 min,提取温度45℃,超声功率300 W。在此条件下进行验证实验,黄酮提取率为6.92%。且该提取条件下得到的黄酮具有良好的抗氧化能力,与VC溶液和BHT溶液相比,其DPPH、羟自由基清除率IC50值分别为:粗提液>VC溶液,粗提液>BHT溶液,还原能力大小为:粗提液>VC溶液。      

荞麦蜜抗氧化成分的挖掘和活性评价

目的确定荞麦蜜中具有抗氧化活性的主要成分。方法分别采用细胞抗氧化方法 (cellular antioxidant activity,CAA)、清除DPPH·自由基和氧自由基吸收能力法(oxygen radical absorbance capacity,ORAC法)测定荞麦蜜多酚粗提物及通过凝胶色谱柱分离的8个级份的抗氧化活性,并采用液相色谱-质谱法(liquid chromatography-mass spectrometry,LC-MS)对活性较高的级份进行鉴定。结果荞麦蜜多酚粗提物和级份8对DPPH·自由基清除能力明显强于其他级份强(P0.05),IC_(50)值分别为139.3μg/mL和180.1μg/mL;而ORAC评价发现级份5、8的ORAC值比其他组份高(P0.05),抗氧化活性高,且级份5、8的ORAC值差异不显著(P0.05),IC_(50)值分别为84.54、84.24 mmol/mg,细胞抗氧化方法评价结果显示级份3、4、8的抗氧化活性好于其他级份和多酚粗提物(P0.05),其EC_(50)值分别为0.369、0.305、0.126 mg/mL,且3者之间没有显著性差异(P0.05)。由此可见级份8可能含有荞麦蜜中特征性抗氧化成分。结论实验表明4-羟基苯甲酸、香草酸、对香豆酸和柠檬酸是荞麦蜜多酚具有抗氧化活性的主要成分,为提高荞麦蜜产品的商品价值提供理论依据。