抗氧化大豆多肽纯化的研究

利用超滤技术分离大豆多肽酶解物,得到分子量在5 KDa～10 KDa与小于5 KDa的多肽,利用高速逆流色谱技术(HSCCC)对分子量小于5 KDa的多肽进行分离,并利用反相高效液相色谱技术(RP-HLPC)进一步纯化,得到纯度为73.68%的大豆多肽.与未纯化的大豆蛋白酶解物相比,纯化后的大豆多肽清除超氧阴离子自由基和过氧化氢的能力分别提高了43.72%和71.64%.因此,该系列纯化方法所得产物的纯度高,抗氧化能力强,适合于抗氧化大豆多肽的制备.     

乳酸菌固态发酵制备花生蛋白肽及抗氧化活性研究

研究乳酸菌固态发酵制备花生蛋白肽,为进一步研究花生粕专用蛋白基料产品提供理论基础.本研究运用单因素和正交试验方法对固态发酵制备花生蛋白肽工艺条件进行优化,其最佳制备工艺条件为：营养盐溶液添加量25mL,乳酸菌液添加量5mL,25℃下发酵72h.此工艺下制备的花生蛋白肽的可溶性氮浓度达到70.92mg/mL,发酵液对1,1-二苯基苦基苯肼（DPPH）自由基清除率为95.00％,羟自由基清除率为86.28％.花生蛋白肽的抗氧化活性结果显示,对超氧阴离子自由基的清除率是74.19％,对铁离子和铜离子螯合率分别为17.71％和93.28％,对腊质过氧化的抑制率为36.03％,铁还原力和钼还原力吸光值分别为1.103和0.983.     

花生秆水溶性膳食纤维的超声波提取及抗氧化活性研究

研究以花生秆为原料,用超声波法提取花生秆水溶性膳食纤维(SDF),并对SDF的抗氧化活性进行了研究.单因素和正交试验结果显示超声波提取SDF的最佳工艺条件为:超声波频率28kHz、反应温度80℃、反应时间120min、超声波功率240W.在此条件下,SDF的得率为5.35%,SDF中非淀粉多糖(NSP)含量为65.49...     

硒对花生抗氧化作用的初步研究

通过对花生叶面喷施不同浓度的亚硒酸钠，初步研究了硒对花生抗氧化作用的影响，结果表明，10～60mg/LSe使叶绿素的含量和POD活性高于对照，且随着硒浓度的增加，它们的含量也相应增加;而MDA低于对照，随着硒用量的增加而下降。在Se浓度达到90 mg/L时，叶绿素含量、POD活性呈下降趋势而MDA含量则升高。10～90mg/LSe使CAT和SOD低于对照，先随硒浓度的增加而下降，在高浓度硒时又上升。     

响应面法优化磷酸化改性花生分离蛋白－多肽膜的制备工艺

    为了优化磷酸化改性花生分离蛋白-多肽膜制备工艺条件,在单因素基础上,通过响应面Box-Benhnken进行实验设计。结果表明,最优工艺参数：蛋白浓度8%、pH值8.2、甘油百分含量（占蛋白）13.4%、黄原胶百分含量（占蛋白）1%、时间60min、温度69℃、超声波功率270W、超声波频率28kHz、多肽溶液的浓度61mg/mL;此工艺条件下,膜厚度、吸水率和透光率理论预测值分别为86μm、41.9%和53.6%,验证实验值分别为88±2μm、43.1±1.2%和52.4±1.5%,两者的差值分别为2.33%、2.86%和2.24%,说明响应面二次模型的拟合良好;磷酸化改性花生分离蛋白-多肽膜的抗拉强度9.62MPa、断裂延伸率101.68%、溶解性47.69%、水蒸气透过率6.95 g•m-2· h-1等功能性质和DPPH自由基清除活性IC50值7.70 mg·mL-1、羟自由基清除活性IC50值5.98 mg·mL-1、超氧阴离子自由基清除活性IC50值4.20 mg·mL-1、铁离子螯合力活性IC50值3.79 mg·mL-1、铜离子螯合力活性IC50值13.61 mg·mL-1、脂质过氧化抑制活性IC50值8.62 mg·mL-1、铁还原力IC50值13.93mg·mL-1、钼还原力IC50值5.49mg·mL-1等抗氧化活性较磷酸化改性花生分离蛋白膜有所改善。本研究结果为磷酸化改性花生分离蛋白在蛋白膜方面的应用提供一种新途径。     

超滤法分离花生肽及其抗氧化活性的研究

用碱性蛋白酶解法制备花生多肽,将得到的花生肽酶解液通过超滤的方法进行分离得到不同分子量段的多肽,对其进行抗氧化活性的研究得到抗氧化活性最强的分子量段的多肽。将花生短肽酶解液稀释并分别通过5KD、3KD的卷式纤维膜进行超滤得到三个分子量段的花生短肽。比较各分子量段的多肽对二苯代苦味酰基（DPPH）自由基的清除率、抗亚油酸氧化能力、羟自由基的清除率及还原力。结果表明：花生肽具有一定的抗氧化能力,且3KD以下的多肽抗氧化能力最强,3-5KD分子量段的多肽次之,大于5KD分子量的多肽表现出较弱的抗氧化能力。     

鹿角蛋白提取及鹿角多肽制备和活性研究

以梅花鹿角为原料,采用碱溶酸沉法对其蛋白进行提取,利用胰蛋白酶对提取的鹿角蛋白进行酶解,得到鹿角多肽,利用FRAP法对不同酶解时间得到鹿角多肽抗氧化能力进行检测,并测定了不同浓度鹿角多肽对酪氨酸酶的抑制作用.结果表明,用1.5mol/L NaOH在pH8.5可沉淀较多蛋白,FRAP测定结果表明,胰蛋白酶水解4h时抗氧化...     

花生种子SOD活性及热稳定性研究

８个花生品种ＳＯＤ活性及热稳定性研究的结果表明：花生种子ＳＯＤ活性高,每克鲜重含９００～１６００单位之间。在几个品种中,普通型（沭阳大站秧和沛县大拖秧）ＳＯＤ活性最高,平均为１５７６．８Ｕ／ｇＦＷ;珍珠豆型（赣榆小站秧和太仓拨藤）ＳＯＤ活性较低,平均为９５４．５Ｕ／ｇＦＷ。８个花生品种ＳＯＤ同工酶谱相同,均为６条Ｃｕ·Ｚｎ－ＳＯＤ带和１条Ｍｎ－ＳＯＤ带。其中Ｍｎ－ＳＯＤ以徐州６８—４活性最高,为２１９．７Ｕ／ｇＦＷ,其它几个品种Ｍｎ－ＳＯＤ活性在５６～１００Ｕ／ｇＦＷ。８个花生品种的ＳＯＤ都具有较高的热稳定性,在９０℃保温１０ｍｉｎ仍保留了２２％～４１％的活性,其中Ｍｎ－ＳＯＤ热稳定性高于Ｃｕ·Ｚｎ－ＳＯＤ。     

全生物降解地膜对南疆花生产量及土壤理化性质的影响

为研究全生物降解地膜覆盖对南疆花生产量及土壤理化性质的影响,采用PBAT(聚己二酸/对苯二甲酸丁二酯)型聚酯全生物降解地膜(简称:降解膜)覆盖为处理、普通聚乙烯PE地膜覆盖为对照(CK),分析降解膜覆盖对花生试验区土壤温度、水分、养分及产量等相关指标的影响.结果 显示:①降解膜的破损率随花生生育进程表现为6-8月较小(3%~14%),到10月收获期显著增大(29%).②降解膜处理的花生产量与CK无显著差异.③花生生育期内,降解膜覆盖0~30 cm平均土壤温度较CK高0.35℃,其中,膜下5cm、15cm和25cm分别较CK高0.38℃、0.39℃和0.27℃,但两处理间的平均土壤温度差异均不显著.降解膜覆盖0~30 cm平均土壤含水率较CK高2.08%,其中,膜下5 cm和25 cm分别较CK高3.39%和4.74%(p<0.05),而膜下15 cm的较CK低1.89%(p<0.05).④降解膜覆盖对花生不同生育时期(6月和10月)、不同土层(0~20 cm和20~40cm)的土壤速效氮磷钾养分、盐分、土壤容重以及土壤pH均无显著影响.因此,本研究认为,全生物降解地膜替代普通PE地膜应用于南疆花生栽培生产是可行的.     

Antioxidant Activities of Peanut Protein Separated by Ultrafiitration

用碱性蛋白酶解法制备花生多肽,将得到的花生肽酶解液通过超滤的方法进行分离得到不同分子量段的多肽,对其进行抗氧化活性的研究得到抗氧化活性最强的分子量段的多肽。将花生短肽酶解液稀释并分别通过5KD、3KD的卷式纤维膜进行超滤得到三个分子量段的花生短肽。比较各分子量段的多肽对二苯代苦味酰基（DPPH）自由基的清除率、抗亚油酸氧化能力、羟自由基的清除率及还原力。结果表明：花生肽具有一定的抗氧化能力,且3KD以下的多肽抗氧化能力最强,3-5KD分子量段的多肽次之,大于5KD分子量的多肽表现出较弱的抗氧化能力。     

镁肥不同用量对花生叶片抗氧化代谢的影响

利用盆栽试验,以花育33号为供试品种,研究不同施镁量对花生叶片膜脂过氧化程度及抗氧化酶活性的影响。结果表明,在缺镁胁迫下,花生叶片内脯氨酸(Pro)含量升高,丙二醛(MDA)含量积累,膜脂过氧化程度加重,产生的活性氧物质诱导超氧化物歧化酶(SOD)和过氧化氢酶(CAT)的活性暂时升高;适量施镁可以降低花生叶片中的MDA含量,提高SOD、过氧化物酶(POD)、CAT的活性,有利于提高花生抵抗膜脂过氧化的能力,提高花生叶片生理活性,延缓衰老;不同施镁量对于花生叶片中POD的活性影响不大,镁胁迫下,出苗后70d清除花生植株体内活性氧的关键酶是SOD和CAT。     

干燥方式对槟榔理化特性和抗氧化能力的影响

本研究以槟榔为对象,采用色差、气质、液相、紫外等分析手段,研究不同干燥方法对槟榔外观形态、活性成分和抗氧化能力的影响.结果表明:槟榔的干燥速率与温度呈正相关,最快到达干燥终点的是微波干燥;干燥后槟榔外皮亮度增加,绿色度下降,黄色度提高;槟榔干制品的厚度与干燥温度呈负相关,低温的冻干可基本保持槟榔的厚度;干燥过程中槟榔的...     

Influences of Molecular Weights on Physicochemical and Biological Properties of Collagen-Alginate Scaffolds

For tissue engineering applications, biodegradable scaffolds containing high molecular weights (MW) of collagen and sodium alginate have been developed and characterized. However, the properties of low MW collagen-based scaffolds have not been studied in previous research. This work examined the distinctive properties of low MW collagen-based scaffolds with alginate unmodified and modified by subcritical water. Besides, we developed a facile method to cross-link water-soluble scaffolds using glutaraldehyde in an aqueous ethanol solution. The prepared cross-linked scaffolds showed good structural properties with high porosity (~93%) and high cross-linking degree (50–60%). Compared with collagen (6000 Da)-based scaffolds, collagen (25,000 Da)-based scaffolds exhibited higher stability against collagenase degradation and lower weight loss in phosphate buffer pH 7.4. Collagen (25,000 Da)-based scaffolds with modified alginate tended to improve antioxidant capacity compared with scaffolds containing unmodified alginate. Interestingly, in vitro coagulant activity assay demonstrated that collagen (25,000 Da)-based scaffolds with modified alginate (C25-A63 and C25-A21) significantly reduced the clotting time of human plasma compared with scaffolds consisting of unmodified alginate. Although some further investigations need to be done, collagen (25,000 Da)-based scaffolds with modified alginate should be considered as a potential candidate for tissue engineering applications.     

Foaming and Emulsifying Properties of Fractions of Gluten Peptides Obtained by Limited Enzymatic Hydrolysis and Ultrafiltration

Gluten hydrolysates were prepared by limited enzymatic hydrolysis with a protease having a chymotryptic activity in the presence or in the absence of cysteine during the dispersion phase of the process. The hydrolysates were fractionated by ultrafiltration, using two inorganic membranes with different molecular weight cut-off (MWCO), 50 kg/mol and 150 kg/mol. The retentates were enriched in hydrophobic peptides and the permeates were enriched in hydrophilic peptides. The foaming and emulsifying properties of hydrolysates, retentates and permeates were analysed at two pHs (4 and 6·5) and two salt concentrations (0·2 and 2% NaCl). Hydrolysates displayed a foaming capacity, but the foams were not stable. Permeates generated foams at pH 6·5 only, and these foams had a very short life-time. Permeates displayed no emulsifying properties. Retentates yielded foams with a good stability and were more efficient than whole hydrolysates to stabilise emulsions. They provided a strong resistance to coalescence. The functional properties of retentates were only sightly influenced by pH and ionic strength. Neither cysteine addition, which helps gluten dispersion and increases the yield of soluble hydrolysate, nor the MWCO of the ultrafiltration membranes influenced the functionality of the hydrolysate fractions.     

六堡茶多糖理化性质、体外抗氧化及其对人脐静脉血管内皮细胞的保护作用

以六堡茶为原料,利用水提醇沉法制得茶多糖粗品,经脱蛋白纯化后用30%、50%、70%的乙醇溶液进行分段,得到3种六堡茶多糖LTPS-30、LTPS-50和LTPS-70,并分析了其化学组成、分子量分布等理化性质;以自由基清除法(ABTS)和铁离子还原法(FRAP)评价其抗氧化活性;并以Na2S2O3损伤的人脐静脉血管内皮细胞(HUVEC)为模型,探讨了它们对HUVEC氧化损伤的保护作用。结果表明,3种六堡茶多糖样品均为主要含有2个组分的非均一酸性多糖,平均分子量和总糖含量均为LTPS-70LTPS-50LTPS-30;而在蛋白质和总酚含量及两种抗氧化体系下的抗氧化活力均为LTPS-70LTPS-50LTPS-30,且LTPS-70表现出最强的细胞保护作用。说明茶多糖粗品经70%乙醇纯化后具有较强的生物活性,具有良好的应用前景。     

抗氧化酶和植物螯合肽对苎麻重金属Cd胁迫的应答

为了探究抗氧化酶和植物螯合肽在苎麻耐镉生理机制中的作用,本研究以苎麻耐性品种‘川苎8号'为实验材料,对其进行5、25、50 mg/L的镉处理,7 d后分别测定其生物量、镉含量、抗氧化酶活性、植物螯合肽含量以及相关基因表达量。结果表明5 mg/L镉处理‘川苎8号'的株高、根长与生物量受到促进,25、50 mg/L镉处理下‘川苎8号'的株高、根长与生物量受到抑制,‘川苎8号'主要将镉积累在根部,不同镉处理下转运系数均小于1,25 mg/L镉处理时镉积累量与转运系数均显著高于其他处理;镉胁迫后‘川苎8号'地上部和地下部超氧化物歧化酶（SOD）活性显著升高,丙二醛（MAD）活性显著降低,过氧化氢（H₂O₂）含量显著上升;5、25 mg/L镉处理时地下部植物螯合肽（PCs）与谷胱甘肽（GSH）含量显著低于对照,50 mg/L镉处理时高于对照但未达到显著差异;PCs和GSH在地上部和地下部承担着不同的解毒作用;各浓度处理的地上部BnPCS1相对表达量均与镉含量呈极显著正相关（P<0.01）,高浓度（25、50 mg/L）处理的地上部BnGCL1相对表达量与镉含量呈正相关（P<0.01）;低浓度（5 mg/L）处理下SOD活性显著高于对照,与各部位镉含量均呈极显著正相关（P<0.01）,高浓度镉处理时地下部SOD活性与镉含量呈极显著负相关（P<0.01）,地下部PCs含量与镉含量呈极显著正相关（P<0.01）。综合分析说明,‘川苎8号'在低浓度镉胁迫时主要通过激活抗氧化酶活性消除细胞中自由基的毒害,高浓度镉胁迫时通过调节抗氧化酶活性和PCs与GSH合成解除镉的毒害。     

Bioactive Properties of Peptides and Polysaccharides Derived from Peanut Worms: A Review

Peanut worms (Sipunculids) are unsegmented marine worms that usually inhabit shallow waters. Peanut worms are good source of bioactive compounds including peptides and polysaccharides. Many recent studies have investigated the bioactive properties of peptides and polysaccharides derived from peanut worms in order to enhance their applications in food and pharmaceutical industries. The peptides and polysaccharides isolated from peanut worms have been reported to possess anti-hypertensive, anti-oxidant, immunomodulatory, anti-inflammatory, anti-cancer, anti-hypoxia and wound healing activities through the modulation of various molecular mechanisms. Most researchers used in vitro, cell culture and animal models for the determination of bioactivities of peanut worm derived compounds. However, studies in humans have not been performed considerably. Therefore, it is important to conduct more human studies for better utilization of marine bioactive compounds (peptides and polysaccharides) derived from peanut worms. This review mainly focuses on the bioactive properties of peptides and polysaccharides of peanut worms and their molecular mechanisms.