魔芋贮藏保鲜与加工技术研究进展

魔芋在我国种植量巨大,资源丰富,它含有大量葡甘聚糖,营养物质多元,可食用、入药、生产日用,综合利用价值高,是一种新型保健材料。魔芋生产用量大,选择经济又适用的贮藏方式可降低贮藏过程中的魔芋腐烂坏种率,减少经济损失。魔芋经过不同程度的加工处理后,被大量用于食品、化工、生物医药、印染等各行业,既增加了魔芋附加值,又带动了魔芋产业的可持续发展。综述魔芋贮藏技术和魔芋粉、魔芋精粉、葡甘聚糖、低聚糖等魔芋精深加工技术研究现状,主要对不同规模魔芋种植量适合的贮藏技术及魔芋在不同加工阶段所采用的生产加工技术进行阐述,以期为魔芋贮藏加工研究产业化发展提供理论参考。     

魔芋葡甘露聚糖的性质与魔芋精粉品质研究

使用乌氏粘度计测定了从魔芋中分离而得的魔芋葡甘露聚糖的分子物性:分子量、分子旋转半径与分子膨胀系数。使用Haake RV12转筒式粘度计测定了魔芋溶胶的流变性质,研究表明可以使用魔芋葡甘霉聚糖的分子物性和魔芋溶胶的流变参数(稠度指数与流动指数)来评定魔芋精粉的品质。本文从红外光谱分析推测了魔芋葡甘露聚糖加碱胶凝的主要机理是脱乙酰化作用后通过氢键连接形成网状结构。     

我国魔芋食品加工现状

本文阐述了进一步开发利用我国魔芋资源的必要性，分析了国内外魔芋食品的加工技术现状，展望了魔芋食品的开发前景，并介绍几种新颖的魔芋食品加工工艺。     

国内外魔芋的开发和利用

本文从魔芋主要成份葡萄甘聚糖的众多特性出发，论述了魔芋在现代食品以及农业中的应用情况。此外，为进一步提高魔芋的经济价值，提出了魔芋精深加工的研究方向。     

魔芋中总生物碱提取试验

提取了陕西花魔芋不同部位及其加工副产物飞粉中的总生物碱,并用重量法测定了总生物碱含量。结果表明,魔芋皮中总生物碱为0.28%;魔芋块茎中总生物碱为0.134%;魔芋叶中总生物碱为0.232%;魔芋飞粉中总生物碱为0.501%。     

魔芋产品的加工现状及其发展前景

介绍了魔芋的生长特性及分布,阐明了魔芋的成分及国内外研究应用情况,展望了魔芋产品的发展前景。魔芋的重要成分是具有奇特性质的葡萄糖甘露聚糖,以此为原料或食品添加剂可研制出一系列保健食品。     

我国富硒魔芋营养评价研究现状及展望

富硒魔芋兼具魔芋和硒的独特生理药理特性。随着全民补硒工程的启动,富硒魔芋市场前景广阔。本文综述了富硒魔芋的分布及营养评价研究现状,并提出研究展望,以期为富硒魔芋产业的健康持续发展提供参考。     

风味魔芋豆腐产品研制

探讨风味魔芋豆腐制作工艺,实验结果表明,当魔芋精粉与水的比例为1：40,加碱后pH值为10左右时魔芋豆腐的口感、硬度和色泽等品质最佳。同时通过增加各种配料,采用不同配方试制出了几种风味各异的魔芋豆腐,为综合开发魔芋产品,提高魔芋的经济价值提供了一定的启示。     

魔芋飞粉的研究进展

魔芋飞粉(简称飞粉)是魔芋主要加工产品魔芋精粉(简称精粉)的下脚料,占精粉质量的30%~40%。魔芋飞粉因其独特的化学组成,具有多种功能,因此是一种值得进一步开发利用的物质。介绍了魔芋飞粉的化学成分及研究进展,并对其在环保、医药、保健品及农业等领域的应用进行了综述,以期为魔芋的研究开发和综合利用提供理论依据。     

魔芋胶的理化性、功能性、流变性及其在食品中的应用

简要介绍了魔芋、魔芋精粉，魔芋胶的理化性，功能性，流变性及其在食品工业中的应用。     

磷酸淀粉对速冻水饺冻裂率与食用品质的影响

以金苑饺子粉为原料,韭菜和猪肉作为饺子馅主料,以磷酸淀粉为面皮改良剂,考察了不同取代度和添加量的磷酸淀粉对速冻水饺冻裂率与食用品质的影响.研究结果表明,加入磷酸淀粉后速冻水饺的冻裂率较未加时明显降低(从8.7%降低至0%-4.2%).随着磷酸淀粉含量的增加,速冻水饺的食用品质也有相应的提高.     

磷酸氢二钠沉淀碎米荠醇沉多糖共沉淀物的特性

为探索磷酸氢二钠沉淀碎米荠醇沉多糖中共沉淀物的特性,选择磷酸氢二钠为沉淀剂,以磷酸氢二钠用量和pH值为试验因素,进行单因素和二次正交旋转组合试验,试验结果经方差和回归分析,结果表明,影响共沉淀物沉淀的因素是碱性的溶液体系和共存的金属离子。     

三聚磷酸钠制备小麦淀粉磷酸酯的研究

依据磷酸化试剂能将小麦淀粉酯化成淀粉磷酸单酯和双酯的原理，采用化学实验方法研究不同反应因素对淀粉磷酸单酯和双酯交联度的影响，并通过正交实验结果分析选取最佳反应备件：     

藏香猪松茸肉丸加工研究

藏猪松茸肉丸以西藏林芝主要特产藏香猪和松茸为原料,通过单因素试验研究淀粉和松茸的添加量,通过正交试验研究白砂糖、味精、五香粉和食盐、小苏打、复合磷酸盐的最佳添加量。结果表明藏香猪松茸肉丸的最佳配方为食盐2.0%、白砂糖1.5%、味精0.8%、五香粉0.2%、小苏打0.8%、复合磷酸盐0.2%、淀粉15%、松茸20%。     

磷酸单酯淀粉在蒸饺中的应用研究

利用正交试验设计方法,研究了磷酸单酯淀粉对蒸饺皮品质的影响。结果表明：磷酸单酯淀粉是对汤圆品质影响最大的因素,其次是加水量、水温。其优化工艺参数为磷酸单酯淀粉用量为7％（以小麦面粉计）,水温为95℃,水的添加量为65％（以小麦面粉计）。     

Biotic and abiotic pathways of phosphorus cycling in minerals and sediments: insights from oxygen isotope ratios in phosphate

A key question to address in the development of oxygen isotope ratios in phosphate (δ(18)O(p)) as a tracer of biogeochemical cycling of phosphorus in ancient and modern environments is the nature of isotopic signatures associated with uptake and cycling of mineral-bound phosphate by microorganisms. Here, we present experimental results aimed at understanding the biotic and abiotic pathways of P cycling during biological uptake of phosphate sorbed to ferrihydrite and the selective uptake of sedimentary phosphate phases by Escherichia coli and Marinobacter aquaeolei. Results indicate that a significant fraction of ferrihydrite-bound phosphate is biologically available. The fraction of phosphate taken up by E. coli attained an equilibrium isotopic composition in a short time (<50 h) due to efficient O-isotope exchange (between O in PO(4) and O in water; that is, actual breaking and reforming of P-O bonds) (biotic pathway). The difference in isotopic composition between newly equilibrated aqueous and residual sorbed phosphate groups promoted the ion exchange (analogous to isotopic mixing) of intact phosphate ions (abiotic pathway) so that this difference gradually became negligible. In sediment containing different P phases, E. coli extracted loosely sorbed phosphate first, whereas M. aquaeolei preferred Fe-oxide-bound phosphate. The presence of bacteria always imprinted a biotic isotopic signature on the P phase that was taken up and cycled. For example, the δ(18)O(p) value of loosely sorbed phosphate shifted gradually toward equilibrium isotopic composition. The δ(18)O(p) value of Fe-oxide-bound phosphate, however, showed only slight changes initially but, when new Fe-oxides were formed, coprecipitated/occluded phosphate retained δ(18)O values of the aqueous phosphate at the time of formation of new Fe oxides. Concentrations and isotopic compositions of authigenic and detrital phosphates did not change, suggesting that these phosphate phases were not utilized by bacteria. These findings support burgeoning applications of δ(18)O(p) as a tracer of phosphorus cycling in sediments, soils, and aquatic environments and as an indicator of paleo- environmental conditions.     

Soil phosphate stable oxygen isotopes across rainfall and bedrock gradients

The stable oxygen isotope compositions of soil phosphate (δ(18)O(p)) were suggested recently to be a tracer of phosphorus cycling in soils and plants. Here we present a survey of bioavailable (resin-extractable or resin-P) inorganic phosphate δ(18)O(p) across natural and experimental rainfall gradients, and across soil formed on sedimentary and igneous bedrock. In addition, we analyzed the soil HCl-extractable inorganic δ(18)O(p), which mainly represents calcium-bound inorganic phosphate. The resin-P values were in the range 14.5-21.2‰. A similar range, 15.6-21.3‰, was found for the HCl-extractable inorganic δ(18)O(p), with the exception of samples from a soil of igneous origin that show lower values, 8.2-10.9‰, which indicate that a large fraction of the inorganic phosphate in this soil is still in the form of a primary mineral. The available-P δ(18)O(p) values are considerably higher than the values we calculated for extracellular hydrolysis of organic phosphate, based on the known fractionation from lab experiments. However, these values are close to the values expected for enzymatic-mediated phosphate equilibration with soil-water. The possible processes that can explain this observation are (1) extracellular equilibration of the inorganic phosphate in the soil; (2) fractionations in the soil are different than the ones measured at the lab; (3) effect of fractionation during uptake; and (4) a flux of intercellular-equilibrated inorganic phosphate from the soil microbiota, which is considerably larger than the flux of hydrolyzed organic-P.     

磷酸酯加脂剂的合成与性能研究

本文以蓖麻油为主要原料，研制了兼有非离子和离子的多功能结合型磷酸酯皮革加脂剂。用正交表优化甲酯化、醚化反应的试验方案；探索了反应温度、时间、加料方式等对磷酸化反应的影响；对合成的甲酯油、醚化甲酯油、磷酸酯用红外光谱作了结构鉴定。测试了磷酸酯的水溶性、乳化力、表面张力、临界胶束浓度等性能。复配的加脂乳液耐电解质，经初步应用，取得良好效果。     

一种用于枯草杆菌发酵生产四甲基吡嗪的补料策略

考察了铵盐对Bacillus subtilis CCTCC M 208157发酵产TTMP的影响,发现磷酸铵盐(DAP)对发酵体系中TTMP的合成有显著促进作用。进一步考察了TTMP合成对DAP的需求,结果表明,高浓度的DAP有利于TTMP的合成,但高浓度的铵根离子对细胞的生长和前体(3-羟基丁酮,乙偶姻)有抑制作用。基于以上结果,建立了一种铵盐A策略,并应用于摇瓶发酵和7.5-l发酵罐培养,TTMP浓度达7.46 g/L和7.34 g/L,与分批发酵相比分别提高了55.1%和29.0%。     

Analysis of the kinetic patterns of horseradish peroxidase thermal inactivation in sodium phosphate buffer solutions of different ionic strength

The thermal inactivation of horseradish peroxidase was studied in sodium phosphate buffer solutions and in pure water at pH 7 in the temperature range of 70–95°C. The sodium phosphate ions concentration affected both the thermostability and the kinetic patterns and had a stabilizing effect. The gradual change observed at low concentrations made a series-type mechanism theoretically more coherent with the experimental observations than the conventionally applied two-fraction model. In water the kinetics is apparently First order at high temperatures, while the results obtained at 25°C support the occurrence of a series-type inactivation mechanism. The pH and enzyme concentration also affect the inactivation proFile, supporting the conclusion that the thermal inactivation is not a monomolecular process with respect to protein concentration.