Organic Amendment Effects on the Transformation and Fractionation of Aluminum in Acidic Sandy Soil

Addition of organic amendments can alleviate the level of aluminum (Al) phytotoxicity in acid soils by affecting the nature and quantity of Al species. This study evaluated the transformation of Al in an acidic sandy Alaquod soil amended with composts (10 and 50 g kg^?1 soil of yard waste, yard + municipal waste, GreenEdge^®, and synthetic humic acid) based on soil Al fractionation by single and sequential extractions. Though the organic compost amendments increased total Al in soil, they alleviated Al potential toxicity in acidic soil by increasing soil pH and converting exchangeable Al to organically bound and other noncrystalline fractions, stressing the benefits of amending composts to improve acid soil fertility. The single‐extraction method appears to be more reliable for exchangeable Al than sequential extraction because of the use of nonbuffered pH extract solution.     

交替双频逆流超声辅助提取条斑紫菜蛋白和多糖

为了高值化利用条斑紫菜资源,该文采用交替双频逆流超声辅助提取技术生产条斑紫菜蛋白和多糖混合产品。研究了复合双频和交替双频2种超声模式对条斑紫菜蛋白和多糖提取效果的影响,采用中心组合设计响应面优化试验进行工艺优化。结果显示,交替双频超声模式显著优于复合双频超声模式。料液比、提取时间和温度均对提取效果影响显著。确定的交替双频逆流超声辅助提取的最优条件为:料液比14mg/mL、时间88min、温度41℃、pH值9.0、15和20kHz交替双频超声、超声交替工作时间3s、超声功率200W/L。在此最优条件下,条斑紫菜蛋白和多糖混合产品的生产能力最高,单位质量原料生产出的产品得率为(48.180.08)%,其中蛋白得率为(24.350.07)%,纯度为(45.610.33)%,多糖得率为(23.830.02)%,纯度为(44.640.37)%,比传统提取方法,得率提高了168%,时间缩短了64%;比单频逆流超声辅助提取方法,得率提高了50%,时间缩短了18%。从生产成本分析,交替双频逆流超声辅助提取方法具有明显技术优势和工业推广价值。     

水相酶解法提取菜籽油与菜籽蛋白工艺的优化

为提高菜籽蛋白的利用率，采用水相酶解法提取菜籽油与菜籽蛋白，以超滤法分离菜籽蛋白，重点对酶处理的工艺参数进行了研究。试验对各种酶的作用效果进行了比较，确定采用纤维素酶、果胶酶按活力比3∶1配方的复合酶处理效果较好；由优化试验得出酶处理的工艺参数为：固液比1∶5，酶用量30 U/g，酶处理时间100 min；在最佳工艺条件下获得高质量的菜籽油与菜籽蛋白，油与蛋白质得率分别为92.6%、82.3%。     

酶法有限水解含油菜籽蛋白的机理及动力学

为探索油菜籽水相酶解法萃取菜籽油的机理,以Alcalase蛋白酶在温度50℃、pH8.0条件下,对以水剂法从菜籽中提取的含油菜籽蛋白进行酶解处理.试验研究结果表明:含油菜籽蛋白乳液的固形物颗粒度对酶解反应速率有明显影响,总的趋势是颗粒度越小,酶促反应速率越大;酶催化水解速率随水解进程呈指数下降,在反应过程中过高的底物浓度会抑制酶的失活.在此基础上由试验数据推导出描述催化水解含油菜籽蛋白的动力学方程,由此通过控制酶与底物浓度之比、反应时间,可以控制水解作用的程度,从而指导和优化菜籽水相酶解法提取菜籽油的工艺.     

影响大蒜精油提取得率的工艺参数研究

研究了大蒜精油提取条件，包括反应温度、反应pH值、反应时间和蒸馏时间对大蒜精油提取得率的影响，初步确定了采用鲜蒜提取风味物质的最适工艺条件。     

菜籽蛋白的提取和纯化

为了对菜籽饼进行综合利用,以低温压榨制油的双低菜籽饼为原料,探讨了菜籽蛋白的提取和纯化工艺.通过料液pH值的先后调节对比、正交、提取次数和纯化试验,得到较佳工艺条件:采用先调pH值法,水溶液的pH值为12,提取时间为20 min,温度为室温,提取3次,通过pH5和7的两步沉淀,经干燥得到分离蛋白,蛋白纯度达84.8%,得率为38.9%,且有害物质残留较少.先调pH值法与后调法相比,总的提取率可提高20个百分点,达90%以上.     

Evaluation of available silicon content and its determining factors of agricultural soils in Japan

To evaluate the available silicon (Si) content in agricultural soils in Japan and to investigate the determining factors of this content, we collected 180 soil samples from the surface layer of paddies and upland fields in Japan and determined their available Si contents. A phosphate buffer (PB; 0.02 M, pH 6.9) or an acetate buffer (AB; 0.1 M, pH 4.0) was used to extract available Si from the soil samples, and the Si concentrations in the extracts were determined by inductively coupled plasma-atomic emissions spectroscopy (ICP-AES). The total Si content and selected physicochemical properties were also determined for the soil samples. The median values of the available Si contents by the PB and AB methods were 48.8 and 79.7 mg kg^?1 and corresponded to 0.017% and 0.027% of the total Si content, respectively. The overall data showed log-normal distributions. The available Si content of the upland soils was significantly higher than that of the paddy soils by both the PB (p < 0.01) and AB methods (p < 0.05). The available Si contents by the PB and AB methods had a significant positive correlation (p < 0.01) and they had significant negative correlation with the total Si content (p < 0.01). The values of the available Si contents by the PB and AB methods correlated positively with the pH, total carbon (C) content, and dithionite-citrate bicarbonate extractable iron (Fed) and aluminum (Ald), acid oxalate extractable iron (Feo) and aluminum (Alo), Fed-Feo and Alo+1/2Feo values (p < 0.01). A multi-regression analysis indicated that pH, amorphous minerals and crystalline iron (Fe) oxides were the dominant determining factors of available Si in the soils, and these three variables explained approximately two thirds of the variation of available Si content in agricultural soils in Japan. In terms of soil type, Terrestrial Regosols, Dark Red soils and Andosols had relatively high available Si contents, whereas Sand-dune Regosols, Red soils and Gray Lowland soils had relatively low contents. In terms of region, the soils in the Kanto and Okinawa regions had relatively high available Si contents and those in the Kinki, Shikoku and Chugoku regions had relatively low contents. In conclusion, the available Si content and its determining factors for agricultural soils in Japan were quantitatively elucidated, and this will contribute to the establishment of rational soil management?—including the application of silicate materials, taking into account the Si-supplying power of the relevant soils—for sustainable and productive agriculture in Japan.     

Determination of ammonium,amides, and soluble carboxylates in plant tissues

Methods for extraction and determination of ammonium, amides and soluble carboxylates in plant tissues are compared and discussed. The procedure recommended involves extraction of finely ground plant tissues with 0.2 M formic acid, determination of ammonium and amides in the extract by overnight alkaline hydrolysis and distillation in Conway microdiffusion dishes, measurement of extracted ammonium using Carlson's rapid diffusion‐conductivity instrument, and estimation of soluble organic acids by titration after separation and purification with ion exchange resins. The method described is reasonably rapid, and gives complete recovery and highly reproducible results. The final solution of organic acids is suitable for direct chromatographic analysis.     

土壤样品中酞酸酯含量分析的前处理研究——提取液浓缩过程与净化的影响

通过比较索氏提取和超声提取这两种提取土壤酞酸酯的方法,认为从提高回收率和降低背景干扰角度出发,超声提取法更合适作为土壤酞酸酯分析的前处理。针对超声提取过程中的一些操作步骤的细节做了比较研究,表明提取液不蒸干可减少酞酸酯的挥发损失,提取液过净化柱与否对GC-MS分析多数酞酸酯组分影响不大,不过净化柱处理可提高土壤酞酸酯的分析效率,但土壤中过多的色素干扰可能会影响某些组分(如邻苯二甲酸二(2-乙基)己酯)的分析结果。     

辐照对发酵玉米芯中裂褶菌多糖提取及流变学性质的影响

对裂褶菌发酵玉米芯进行γ射线辐照处理,研究不同处理条件下辐照对裂褶菌多糖提取率及流变学性质的影响。结果显示:在5~20kGy辐照剂量范围内,同一剂量下,多糖提取率随辐照原料水分含量的增加而上升,60%水分含量、10kGy处理下多糖提取率达到最高值7.95%。辐照处理对所提取裂褶菌多糖溶液粘度有不同程度的降低,15.0%水分含量、20kGy处理下,多糖的零剪切粘度η0降至最低值10.79 Pa.s;辐照处理对裂褶菌多糖的粘弹性亦有显著影响,G′、G″以及二者之交点Gx值的变化趋势与η0值的基本一致。本研究得到如下结论:γ射线辐照处理对发酵玉米芯中裂褶菌多糖可起到降解、增溶的作用。     

提取方式对茶树菇菌糠多糖提取效率及生物学活性的影响

为探究不同提取方式对茶树菇菌糠多糖提取的影响,本研究采用热水浸提、超声浸提、稀酸水解3种方式提取茶树菇菌糠。结果表明,提取方式对菌糠多糖的提取效率有较大影响,其中以稀酸水解提取法效率最高,当硫酸浓度为2%、浸提时间为60 min、料液比为1∶25 g·mL^-1、温度为121℃时,多糖提取率最高为29.29%,分别比热水浸提和超声浸提法提高了6.72和13.88倍。3种提取方式制备的多糖均有较好的抗氧化活性和生物学活性,其中热水浸提多糖具有较好的2,2'-联氮-双-3-乙基苯并噻唑啉-6-磺酸(ABTS)自由基和羟基自由基清除能力,而稀酸水解多糖具有较好的1,1-二苯基-2-三硝基苯肼(DPPH)自由基清除能力和还原力。不同方式制备的多糖均能有效促进水稻种子的萌发,并缓解铜离子对水稻种子萌发的抑制效果,尤其对根部的促进效果最为显著,当稀酸水解多糖浓度为1 000 mg·L^-1时,对照水稻种子根长增加37.75%,铜离子胁迫下水稻种子根长增加112.10%。研究结果表明提取方式不仅影响菌糠多糖的提取效率,同时对其生物学活性也有较大的影响,这对于菌糠多糖的开发利用具有一定的参考价值。     

茶多糖提取条件的研究

采用二次回归正交旋转组合设计方法研究温度、时间、料液比、pH值对绿茶、乌龙茶、红茶等茶多糖(TPS)提取率及活性的影响。结果表明，各因子对三类茶TPS提取率影响的大小依次为pH值、温度、时间、料液比；对TPS活性影响最大的是pH值，在酸性或碱性环境下提取的TPS活性都最低。建立的回归模型显著性检验均达极显著水平，无失拟因素存在，模型较好的拟合了TPS提取率与各因子之间的关系。结合TPS提取率及活性测定，利用期望函数途径进行模拟选优，并进行验证，得到TPS提取率的优化条件为温度0～1水平，时间0～1水平，料液比0～0.5水平，pH值-0.95水平左右。     

姜黄色素提取及防腐效果研究

研究了姜黄色素(Curcumin)的提取工艺和防腐效果。试验表明：用Na₂HPO₄－柠檬酸缓冲液,在30 g脱脂姜黄粉中加入8倍的水和酶活为800 u/mL的α-淀粉酶液5.0 mL、酶活为300 u/mL的果胶酶液0.5 mL、酶活为30 u/mL的纤维素酶液2.0 mL,用浓度为1 mol/L的盐酸调pH值至4.5,50℃下酶解120 min,再用浓度为1 mol/L的氢氧化钠调pH值至10,浸提60 min过滤。第二、第三次浸提不再加酶,直接加入6倍和5倍的水,用上述同样的方法调节pH值,分别浸提50 min和45 min。三次提取液混合,用浓度为1 mol/L的盐酸调pH值至6.0使姜黄色素沉淀,经离心分离和真空冷冻干燥,姜黄色素得率为5.47%。浓度在0.025%以上的姜黄色素碱水溶液对馒头、豆腐、熟牛肉有良好的防腐效果,浓度在0.05%以上对苹果原汁具有防腐性。姜黄色素经加热煮沸后防腐作用降低。     

从沉积物中分离重金属不同提取方法的比较

Three extraction methods, ultrasonic assisted extraction (USE), microwave assisted extraction (MSE), and conventional single extraction (CSE), in conjunction with the modified three-stage BCR sequential extraction procedure (SEP) were applied to examine the contents of Cd, Cu, Cr, Ni, Pb and Zn from lake sediment samples, to know whether these techniques can reduce extraction time and improve reproducibility. The SEP and developed alternative single extraction methods were validated by the analysis of certified reference material BCR 601. By the use of optimized sonication and microwave conditions, steps 1, 2 and 3 of the BCR sequential extraction methods (excluding the hydrogen peroxide digestion in step 3, which was not performed with sonication and microwave) could be completed in 15-30 min and 60- 150 s, respectively. The recoveries of total extractable metal contents in BCR 601, obtained by three single extractions ranged from 93.3%-102%, 88.9%-104% and 81.2%-96.2% for CSE, USE and MSE, respectively. The precision of the single extraction methods was found in the range of 3.7%-9.4% for all metals (n = 6).     

Recovery efficiencies of nitrogen,phosphorus and potassium of the garlic crop

Garlic plants demand high quantities of nutrients, and fertilizers recommendations are necessarily evaluated for the availability of attributes such as recovery efficiency. The objective of this study was to evaluate the recovery efficiencies of nitrogen (N), phosphorus (P) and potassium (K) by micropopagated and conventionally propagated garlic plants. Two experiments were conducted in a greenhouse containing a sample of a Red Yellow Latosol, arranged in randomized blocks with five replications. Treatments consisted of four combinations of nutrients (kg per hectare): complete NPK (240-1200-550), without N (0-1200-550), without P (240-0-550) and without K (240-1200-0). Micropopagated plants maintained adequate contents of N, P, and K, as well as good growth and development even without nutrients application; however, the depletion of N and K impaired the productivity of these plants. In both cultivations, recovery efficiencies of N, P and K were low and closely related to the garlic propagation.     

采用微波技术提取紫菜多糖的工艺研究

在微波浸提与热水浸提比较的基础上,进行了紫菜多糖微波提取工艺L₉(3⁴)正交优化试验和微波不同提取方式对紫菜多糖提取率的影响研究。结果表明：微波提取优于热水提取,微波冻融提取效果最佳,提取率最高达7.45%,而热水提取率为2.05%。影响微波浸提的主要因素为浸提时间,其次是微波功率和液固质量比。优选方案为微波功率200 W、提取时间8 min、水与紫菜液固质量比40∶1。真空冷冻干燥紫菜多糖质量明显优于减压热风干燥和常压热风干燥。     

Comparisons of Various Chemical Extracts as Quantity Factors to Determine Metal-Buffering Capacity of Soils

Applicability of various chemical extracts was investigated as quantity (Q) factors to determine cadmium (Cd), zinc (Zn), and copper (Cu) desorption quantity–intensity (Q/I) relationships in soils. The metal extracts were sums of sequential metal fractions (except the residual fraction) using Tessier's (TSE) and Community Bureau of Reference (BCR) procedures and various single chemical extracts: 1.0 M potassium nitrate (KNO₃), 1.0 M magnesium nitrate [Mg(NO₃)₂], 1.0 M magnesium chloride (MgCl₂), and 0.11 M acetic acid (CH₃COOH) solutions. Water-extractable metal was applied as a fixed intensity (I) factor. The TSE or BCR metal fractions were significantly correlated with diethylenetriaminepentaacetic acid (DTPA)–extractable metals, and all the metal desorption Q/I curves were linearly fitted. However, most of metal BC values estimated by using the single chemical extracts were very low and did not have consistent trends for target metals. Only 0.11 M CH₃COOH-extractable metals might be reliable. Therefore, TSE and BCR metal fractions can be applicable to replace DTPA-extractable metals, and 0.11 M CH₃COOH-extractable metals might also be useful.     

超临界CO_2萃取大蒜精油及油树脂的研究

研究了大蒜精油及油树脂的超临界 CO2 提取工艺 ,探讨了粒度 ,萃取及分离的温度、压力和时间对各萃取率的影响 ,建立了萃取温度、压力与各萃取率的数学模型。确定了超临界 CO2 同时提取大蒜精油及油树脂的优化工艺条件     

水媒法提取食用油技术研究进展

该文提出了水媒法提油技术的概念。水媒法提油技术是指以水为主要媒介的提油技术(水媒法),可辅以或不辅以与水互溶的可食用物质(例如乙醇)、食品级酶、超声波、微波等处理以破坏油料细胞壁和/或破乳的食用油提取方法。水媒法的提油过程主要分为分成破碎、提取、破乳和分离四个阶段。水媒法发展至今60余年,已全面发展了水代法、水酶法和乙醇水提法等多种制油技术。目前水媒法的产业化还存在一些问题,如油料的预处理、酶的种类与成本等。但是,水媒法绿色健康、符合可持续发展要求,随着工艺设备、分离技术等的发展,该技术将更加完善,成为未来未来取代传统工艺的新主流。该文将水媒法研究领域的成果进行归纳总结并为其未来发展提供理论参考。     

工艺条件对猪皮提取物质构和微观结构影响的初步研究

为了给猪皮提取物在肉制品加工中的应用创造条件,采用单因素试验,分别测定不同提取条件(煮沸时间、料液比、pH值、盐浓度)下凝胶质构和微观结构的变化,在此基础上,采用正交试验优化提取条件。单因素试验表明煮沸时间、料液比、提取液pH值对猪皮提取物的质构特性都有显著影响,煮沸时间为60min、料液比为1:5、提取液pH值为5时形成的凝胶最好,盐浓度对质构特性无显著影响。正交试验表明,料液比1:5,盐浓度为3%,煮沸时间60min,pH=6的提取条件下获得的提取物凝胶的质构特性及微观结构最好。