The effects of temperature and pH on the extraction of oxalate and pectin from green kiwifruit (Actinidia deliciosa L.), golden kiwifruit (Actinidia chinensis L.), kiwiberry (Actinidia arguta) and persimmon (Diospyros kaki)

Oxalates and pectin were extracted from four locally grown fruits at three different pH levels, 6.9, 0.6 and ?0.3, at two different temperatures, 21 and 80 °C. Green kiwifruit (Actinidia deliciosa L. Hayward), golden kiwifruit (Actinidia chinensis L. Hort 16A Zespri), kiwiberry (Actinidia arguta, CV. Takaka Green) and persimmon (Diospyros kaki) contained moderate levels of oxalates. Total and soluble oxalates were more efficiently extracted at 21 °C using 2 m HCL, while the highest amounts of pectin were extracted from the fruits at 80 °C using 0.2 m HCL. Extraction using 0.2 and 2 m HCL gave the highest yields of total oxalates, which ranged from 47.1 to 220.4 mg total oxalates per 100 g dry matter (DM) for persimmon and kiwiberry, respectively. Extraction using water at 21 °C gave soluble oxalate contents ranging from 21.2 mg 100 g^?1 DM, for persimmon, to 105.0 mg 100^?1 DM, for kiwiberry fruits. Extraction of pectin was not achieved efficiently using water at either temperature, while extraction using 2 m HCL gave lower values; optimal extractions of pectin were achieved at 80 °C using 0.2 m HCL.     

提取方法对天麻多糖提取率及其抗氧化活性的影响

分别采用热水浸提、超声辅助提取和酶法提取对四川平武乌天麻多糖进行提取,并对天麻多糖提取率及其抗氧化化活性进行比较,为筛选适合天麻多糖提取的方法提供参考。结果表明:3种提取方法对天麻多糖提取率及其抗氧化活性影响较大,其中酶法提取天麻多糖提取率最高(为50.315%),与其他2种提取方法间差异达到极显著水平(P0.01);在DPPH和FRAP法抗氧化评价体系中,多糖抗氧化活性表现为超声辅助提取酶法提取热水浸提法,而在ABTS抗氧化评价体系中,其活性顺序是酶法提取超声辅助提取热水浸提。综合分析,超声辅助提取和酶法提取有利于天麻多糖提取,且能保持其高效的抗氧化活性。     

荷叶离褶伞可溶性多糖提取工艺研究

对荷叶离褶伞(Lyophyllum decastes Sing)可溶性多糖的提取工艺进行了研究,通过正交设计和方差分析确定了多糖的最佳提取条件。结果表明:时间和温度对荷叶离褶伞多糖的提取影响较大,其最佳工艺为温度85℃、pH9.0、料液比1∶15、提取时间1.5h,用苯酚-硫酸法测定最佳提取工艺条件下固形物中多糖含量为65.52%。     

超声波酶法提取豆渣中水溶性多糖条件的优化

以水酶法提油后的副产物豆渣为原料,采用超声波协同纤维素酶法提取水溶性大豆多糖。在相同的超声波条件下(超声功率150W、超声温度88℃、超声时间17min、液固比28∶1、六偏磷酸钠溶液浓度2%)对水酶法提油后的豆渣进行预处理,在此基础上考察ViscozymeL复合纤维素酶对水溶性大豆多糖提取率的影响,首先对提取工艺进行单因素的选择,然后设计三因素三水平的正交实验,确定超声波协同纤维素酶法提取水溶性大豆多糖的最佳工艺条件为:液固比28∶1,酶解时间1.5h,酶解温度45℃,纤维素酶用量0.4%,pH4.0。在此条件下,超声波酶法的提取率为25.92%,与超声波法的水溶性大豆多糖的提取率(11.51%)相比,提高了14.41%。      

水浴法和微波法提取金针菇下脚料多糖的优化及比较研究

采用水浴法和微波辅助法对金针菇下脚料多糖的提取工艺进行了研究。实验结果表明,水浴料液比、提取温度和提取时间对金针菇下脚料多糖提取率有显著影响,优化的水浴提取工艺条件为料液比1:20,提取温度为80℃,提取时间2.0h,提取率达13.68%;微波提取料液比、微波功率和微波时间对金针菇下脚料多糖提取率有显著影响,优化的微波提取工艺为料液比为1:25,微波功率320W,微波提取时间80s,提取率达13.80%。与传统的水浴法相比,微波提取法效率高、节约能源,应用前景广阔。     

北沙参多糖的提取工艺、理化性质和生物活性研究进展

北沙参是伞形科植物珊瑚菜的干燥根,为常用药食两用资源。北沙参多糖作为北沙参主要成分之一,具有良好的生物活性。北沙参多糖的提取分为溶剂提取和辅助提取两大类,然而不同的提取方法的多糖得率、结构及生物活性不尽相同,本文介绍了其总糖含量、分子量、单糖组成、糖苷键构型等理化性质。目前对北沙参多糖的生物活性研究主要集中在免疫调节、抗氧化、抗肿瘤、抗炎及降血糖等方面,在医药、保健功能食品等领域有着良好的前景。本文就国内外学者对北沙参多糖的提取工艺、分离纯化、结构特征及生物活性研究进行了系统性的总结和归纳,同时也指出了北沙参多糖的高级结构、作用机制及构效关系尚不明确的问题,为其深入研究及有效开发利用提供科学参考。     

豆渣中水溶性大豆多糖提取工艺的研究

采用正交实验法对豆渣中水溶性大豆多糖的提取过程进行研究,实验结果表明,第一次提取过程的优化工艺条件为:固液比为1∶8,提取时间4.5h,温度90℃,提取率为13.74%;整个提取过程的优化工艺条件为:固液比为1∶8,提取时间4.5h×3,温度80℃,提取率为53.96%。     

响应面法优化热水浸提灰树花多糖的工艺研究

以灰树花子实体为原料,采用响应面法对热水浸提灰树花多糖的工艺进行了优化。通过单因素实验确定了最佳提取次数为2次。利用Plackett-Burman设计确定了影响多糖得率的主要因素为浸提温度、料液比、浸提时间。再用最陡爬坡实验逼近最优响应区域。最后通过Box-Behnken设计建立了多糖得率的二次多项式模型,并获得了最优提取条件为:浸提温度85℃、浸提时间2.51h、料液比1∶25,经验证实验得到多糖得率为24.423%。      

Acid‐soluble and pepsin‐soluble collagens from grass carp (Ctenopharyngodon idella) skin: a comparative study on physicochemical properties

In this study, acid‐soluble (ASC) and pepsin‐soluble (PSC) collagens with triple helical structures were successfully extracted from the skin of grass carp (Ctenopharyngodon idella) by two different extraction approaches. SDS‐PAGE pattern revealed that ASC and PSC are type I collagens with typical α1, α2 and β‐chains. In addition, the intensity of χ‐chain (trimer) in ASC was higher than that of PSC, representing the presence of the high proportion of intra‐ and intermolecular cross‐links of extracted collagens with large molecular weight using the acid method. Differential scanning calorimetry (DSC) results demonstrate that T_d (69.04 °C) of ASC was higher than T_d (62.20 °C) of PSC. Both ASC and PSC had the highest solubility at acidic pHs or at a low concentration of NaCl (<2%, w/v). The results of FTIR suggested the ASC and PSC maintained in the helical secondary structure at high degree.     

响应曲面法优化热水浸提红托竹荪多糖的工艺研究

以红托竹荪为原料,用热水浸提法提取其多糖。在单因素实验基础上,采用响应曲面法对提取工艺进行优化,最后通过Box-Behnken设计建立了热水浸提红托竹荪多糖的二次多项式模型,并得到了优化提取工艺条件为:浸提时间3.5h,浸提温度75℃,料液比1∶31,提取次数2次,经验证实验红托竹荪多糖的提取得率为12.05%。      

不同提取方法对松茸多糖理化性质及抗氧化活性的影响

目的研究不同提取方法对松茸多糖(polysaccharide of Tricholoma matsutake,TMP)的理化性质及抗氧化活性的影响,并以提取得率和抗氧化活性为依据,筛选出最优方法。方法采用热水浸提、超声提取、酶提取和微波提取等4种提取方法,获得4种相应的多糖。利用高效阴离子交换色谱和傅里叶红外光谱对4种多糖的化学特性进行了结构表征。结果 4种多糖的提取得率顺序为热水浸提多糖超声提取多糖酶提取多糖微波提取多糖。在4种多糖中,超声辅助多糖含量最高(48.98%),蛋白含量最低(0.2%)。抗氧化试验结果表明,超声辅助多糖的还原力和·OH的清除力均高于其他3种多糖;从清除DPPH活性来看,超声辅助多糖和热水浸提多糖的EC_(50)分别为1.06和0.98 mg/mL,二者活性相当,均远高于其他2种多糖。结论综合考虑提取得率、多糖含量和抗氧化活性,超声提取为最优方法。4种多糖的单糖组分基本相同,但它们的摩尔比有明显不同。     

滑子菇水溶性多糖提取工艺的研究

探讨了以滑子菇为原料提取水溶性多糖的最佳工艺条件,实验结果表明:料液比为1∶60、温度为80℃、浸提时间为5h,为提取滑子菇多糖的最佳工艺条件,产率达1.685%。     

不同来源水溶性大豆多糖功能特性及基本结构的比较研究

目的提取3种常见大豆加工副产物豆腐渣、大豆蛋白渣和大豆皮中的水溶性大豆多糖(soluble soybean polysaccharides,SSPS),比较分析不同来源水溶性大豆多糖进行功能特性和基本结构。方法通过抗氧化性、乳化性和起泡性评价3种水溶性大豆多糖的功能特性,通过高效液相色谱和傅里叶变换红外光谱对3种水溶性大豆多糖的基本结构进行分析。结果豆腐渣中的水溶性大豆多糖(SSPSⅠ)具有最高的抗氧化性、乳化性和起泡性,大豆皮中的水溶性大豆多糖(SSPSⅢ)次之,大豆蛋白渣中水溶性大豆多糖(SSPSⅡ)的抗氧化性、乳化性和起泡性最差。傅里叶变换红外光谱和高效液相色谱的图谱表明,3种来源水溶性大豆糖在基本结构方面无显著性差异。结论不同来源的水溶性大豆多糖功能特性存在一定差异,而基本结构无显著性差异。     

石耳多糖的提取工艺研究

采用单因素试验和正交试验设计,探讨提取时间、料液比和提取温度对石耳多糖提取率的影响,筛选出了最佳提取工艺。结果表明,影响石耳多糖提取率的主次因素为料液比、提取温度及提取时间;石耳多糖最佳提取工艺条件为:提取温度80℃,提取时间4h,料液比1∶10。在此工艺条件下,水溶性石耳多糖的提取率为4.63%。     

An investigation of ripening and handling strategies for early season kiwifruit (Actinidia deliciosa cv Hayward)

The proportion of the world's population that cannot get enough food to eat is increasing. Research has led to methods of increasing yields in ‘good’ soils with heavy inputs of fertilisers and other agrochemicals. But millions of people have to rely on food grown with few inputs on soils that are difficult to manage and present severe nutritional problems. There is a pressing need to devise sustainable systems of production that increase yields for these people. The problems that need to be overcome and the opportunities for advance are examined. Innovative agronomic practices are being developed that show promise of success. Quantitative models for soil and plant processes have also been developed and should be applied, to a greater extent than at present, in assessing possible practices in a given area, and in adapting practices to suit conditions. In addition there are a range of new techniques for measuring soil conditions and plant characteristics which should greatly facilitate progress. New methods of supplying crops with nutrients and water have led to spectacular improvements in the production of many horticultural crops in the Western world. Improvements in quality and the introduction of new products have been especially notable. They have enriched the lives of the consumer and created wealth for the producer. Pollution of the environment occurs almost everywhere. It has contributed to the economic decline of some of the earliest industrial areas of the world. Methods of overcoming the chemical constraints to plant growth on polluted and disturbed soils have been devised and have played a major part in improving the appearance of some of these former industrial areas and enabling them to attract modern industries and to enjoy new prosperity. Forest decline brought about by atmospheric pollution is becoming very serious in Western Europe and the USA. So far the only practical remedy involves the application of selected nutrients chosen on the basis of site characteristics.     

平菇多糖的提取条件及其沉淀特性研究

研究不同的提取温度、时间、粉碎粒径等对平菇多糖提取得率的影响,采用方差分析得到平菇多糖最佳提取条件为粉末粒径0.125mm,料水比1:15,浸提温度80℃,浸提时间3h,用优化后的提取工艺对平菇多糖进行提取,最终的多糖得率可以达到9.03%。同时比较了乙醇质量分数和温度等对平菇多糖沉淀特性的影响,将提取得到的平菇多糖经过脱色、脱蛋白后用紫外和红外扫描证明其与蛋白质以复合物形式存在。     

黑小麦麸皮可溶性膳食纤维的提取及其功能性质研究

以黑小麦麸皮为原料,采用超声辅助酶解提取可溶性膳食纤维,优化工艺并对其性质展开研究。结果表明:在液料比为35∶1(m L/g)、水浴时间60 min、酶底比200 U/g、超声功率350 W的条件下SDF得率最高为19.308%,与模型预测值相符。黑小麦麸皮可溶性膳食纤维对羟自由基的清除率为81.43%,还原力为1.688;良好的物化特性,预防各种肠道疾病:持水力、膨胀力分别为8.02、5(m L/g);吸附胆固醇降血脂的功能特性:pH=2和pH=7时对胆固醇吸附量分别为3.96、5.02/g/g,对胆酸钠的吸附率为29.36%。     

王不留行多糖提取工艺研究及其含量测定

采用水提醇沉提取工艺,运用单因素实验和正交实验,以多糖提取率为评价指标,确定王不留行多糖的最佳提取工艺条件。多糖含量测定方法采用酶解-苯酚-硫酸法。结果表明,王不留行多糖最佳工艺条件为提取温度100℃,提取时间2h,水料比10∶1（mL/g）,提取次数为3次。在此优化条件下的多糖提取率为29.32%。王不留行经清炒炮制后,多糖提取率降为22.15%。      

马蹄多糖微波辅助提取工艺优化及其抗氧化活性研究

以马蹄为原料,利用正交试验优化其多糖的微波辅助提取工艺,并对马蹄多糖的抗氧化性进行检测。结果表明:以蒸馏水为提取溶剂,马蹄多糖最佳提取工艺为微波功率600 W,料液比115(g/mL),提取时间3 min,该条件下马蹄多糖提取率可达8.12%,纯度达83.2%。马蹄多糖有较强的还原力,在0.01~0.10 mg/mL质量浓度范围内与抗坏血酸相当;对羟自由基有较强的清除能力,在0.10 mg/mL时,马蹄多糖对羟自由基的清除率达到46.18%。     

水-酶连续提取百合非淀粉多糖工艺研究

研究了热水和果胶酶连续提取百合鳞茎中非淀粉多糖的工艺条件。首先利用Box-Behnken实验设计及响应面分析确定热水提取百合非淀粉多糖的条件;再经单因素实验与正交实验优化果胶酶提取水提百合渣中非淀粉多糖的工艺参数。结果表明,水-果胶酶连续提取百合非淀粉多糖的最佳工艺条件为:温度62℃、液料比19∶1,水提4h后,剩余残渣中加入果胶酶（酶添加量1800U/g）于温度30℃、pH5.5的条件下酶解20min。在此条件下,百合非淀粉多糖的得率为8.63%。