番木瓜籽蛋白提取工艺及其性质研究

为开发利用番木瓜籽中的蛋白质,以番木瓜籽蛋白提取率为指标,通过单因素实验比较超声辅助提取(UAE)与超声-微波协同辅助提取(UMAE)对番木瓜籽蛋白提取的影响,并确定辅助提取方法及条件,后采用Box-Behnken试验设计优化提取工艺,并对番木瓜籽蛋白等电点、溶解性、起泡性、乳化性、持水性等性质进行研究。结果显示:UMAE较UAE提取番木瓜籽蛋白具有更快速、高效、节能的特点;响应面优化UMAE提取工艺条件为料液比1∶90,提取2 min,功率50 W,提取率约为52.31%,与理论值无显著差异;番木瓜籽蛋白的等电点p I4.56,p H4.5时起泡性最好,乳化性、溶解度最低;该蛋白持水能力较低,为(1.58±0.3)g/g。     

pH、离子强度等因素对椰子分离蛋白溶解性和乳化性的影响

分析椰子分离蛋白(CPI)溶解性、乳化性、乳化稳定性及pH、离子强度和温度对这些功能特性的影响。结果表明,与大豆分离蛋白和棉籽分离蛋白相比,椰子分离蛋白具有较好的溶解性、乳化性、吸油性和吸水性;而pH、离子强度和温度等因素对椰子分离蛋白的溶解性、乳化性和乳化稳定性有显著影响。在等电点附近,椰子分离蛋白表现出最低的溶解性与乳化性;低离子强度可提高椰子分离蛋白的溶解性和乳化性,而高离子强度降低了其溶解性和乳化性;CPI在60℃时有较好的溶解性和乳化性。     

椰子分离蛋白起泡性、黏度及其影响因素的研究

分析了椰子分离蛋白(CPI)起泡性、泡沫稳定性、黏度及pH、离子强度、温度和蛋白质浓度对这些功能特性的影响。结果表明,椰子分离蛋白的起泡性和黏度与大豆分离蛋白(SPI)相近;而pH、离子强度、温度等因素对椰子分离蛋白的起泡性和黏度有显著的影响。在等电点(pH4.5)附近,CPI的起泡性和黏度最小,但却表现出最高的泡沫稳定性(91.25%);低离子强度可以提高椰子分离蛋白的起泡性,但高离子强度使CPI的起泡性、泡沫稳定性和黏度都变小;在70℃时CPI的黏度最大;蛋白质浓度变大时,CPI的黏度也显著增大。     

提取方法对脱脂松仁粕蛋白性质的影响

以脱脂松仁粕为原料,比较提取方法对蛋白性质的影响。采用Osboren分级提取各组分蛋白,并与碱法提取的蛋白进行理化性质与功能性质的比较。研究不同蛋白的等电点、热变性温度、氨基酸组成、十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(sodium dodecyl sulfate-polyacrylamide gelelectrophoresis,SDS-PAGE)及不同蛋白的溶解性、起泡性和起泡稳定性、乳化性和乳化稳定性。结果表明:Osboren提取的清蛋白、球蛋白、谷蛋白的蛋白质含量分别为77.87%、68.23%、79.05%,碱法提取的蛋白含量为83.50%;四种蛋白的等电点为3.4、3.8、3.6、4.0,热变性温度为94℃、81℃、95℃、112℃;四种蛋白的必需氨基酸组成基本合理,主要含有谷氨酸与精氨酸;SDS-PAGE分析得出四种蛋白的条带有差别但主要集中在9.31~41.32ku;除乳化性和乳化稳定性以碱法提取的蛋白最好外,其余加工性质清蛋白均为最好。由此可见不同的提取方法对SDS-PAGE、热变性温度及加工性质均有不同的影响。     

美藤果蛋白质功能性质的研究

使用三亚市美藤果种植基地种植的美藤果种仁的脱脂粉,分别采用酶法除杂浓缩法和碱溶酸沉淀法进一步提取蛋白质,分别得到美藤果浓缩法蛋白(PPC)和碱提取的蛋白(PPI)。实验数据表明：其等电点近似为pH 4.5;2种方法提取蛋白粉的溶解性都是随pH的升高呈先降低后升高的趋势;在吸水性、吸油性和起泡性方面,PPC比PPI略好;在溶解性和粘度方面,PPI优于PPC;在50℃左右PPC和PPI吸油性最大时,分别达到293%和165%。     

马铃薯浓缩蛋白制品的功能性质评价

实验主要比较了马铃薯全蛋白粉、HCL沉淀蛋白 ,FeCl3沉淀蛋白、大豆分离蛋白以及酪蛋白的溶解度、乳化力和起泡力。结果得出上述各种蛋白制品中蛋白质在pH 8 0时的溶解度分别为 70 %、 2 7%、 6 5%、 97%和 90 % ;马铃薯全蛋白粉的乳化力和起泡力与大豆分离蛋白相当     

大豆乳清蛋白的热促凝聚及其对分离蛋白功能性的影响

分别在pH8.0和pH4.5对"碱提酸沉"法制备大豆分离蛋白过程中所得提取液进行热处理,研究了大豆乳清蛋白的热促凝聚效果及其对所制备分离蛋白功能性的影响。结果表明:加热处理可降低大豆乳清中乳清蛋白的含量,在pH8.0和pH4.5时提取液经70℃加热10 min分别使25.7%和40%乳清蛋白转移到分离蛋白产品中。以普通分离蛋白为对照,对3种分离蛋白产品进行功能性分析,发现3种产品均在pH4.5~4.8的范围内溶解度最小,70℃加热10 min所制备分离蛋白的持水性明显高于普通分离蛋白,但其持油性、起泡性、泡沫稳定性和乳化性均低于普通分离蛋白,而乳化稳定性无显著差异。     

微生物蛋白酶改性大豆分离蛋白的研究进展

本文主要综述了近十年来国内外微生物蛋白酶改性大豆分离蛋白的研究进展,分析了酶法改性蛋白质的特点和方式,简要介绍了几种微生物蛋白酶改性大豆分离蛋白的效果。包括Alcalase蛋白酶,枯草杆菌蛋白酶,米曲蛋白酶等,一般可改善大豆分离蛋白的溶解性、吸水性、乳化性、起泡性等。     

花生多肽的理化性质及抗氧化性质研究

本文研究了pH、温度、蛋白浓度等因素对花生多肽活性的影响,与花生分离蛋白相比,在温度30-80℃和pH值2～12时花生多肽具有较高的溶解性,更好乳化性、起泡性和泡沫稳定性,但有较低的吸水性和吸油性。此外,花生多肽体外抗氧化能力较强,具有较强的还原力、羟自由基清除力、2,2-二苯基苦味苯肼（DPPH）自由基清除力。表明花生多肽具有良好的理化特性和抗氧化性能,可作为功能食品或保健食品主要成分或添加剂。     

椰麸组分蛋白的氨基酸组成、结构与乳化性分析

为提高椰子加工副产物的利用,本研究从椰麸中依次提取4种组分蛋白,包括清蛋白、球蛋白、谷蛋白-1和谷蛋白-2.分析这4种组分蛋白的氨基酸组成,并利用SDS-PAGE技术分析其亚基组成和分子量.同时分析其表面疏水性,并研究不同离子强度对椰麸各组分蛋白的乳化性和乳化稳定性的影响.结果表明,椰麸蛋白质中清单白、球蛋白、谷蛋白-...     

Comparative Assessment of the Efficacy of Various Nitrogen Fertilizers

Summary

The efficiency of N fertilizers is usually poor; often less than 50% of the applied N is taken up by the crop. This review focuses on various N fertilizers with respect to the significance of different N loss pathways, namely (i) ammonia volatilization, (ii) dinitrogen and nitrogen oxide emissions, and (iii) nitrate leaching. Further, the significance of biological N immobilization, ammonium fixation and, finally, the impact of nitrate vs. ammonium uptake on crop yield are also discussed. The reviewed literature shows that N fertilizers may differ markedly in their susceptibility to losses. There is, however, considerable scope to improve N efficiency of each N source by proper N management practices.     

Studies on natural repellents against potato tuber moth (Phthorimaea operculella Zeller) in country stores

Summary The effects of the leaves of five plant species, one from each of the generaAmbrosia, Anemone, Eupatorium, Eucalyptus andLantana, on potato tuber moth were investigated under indigenous storage conditions at the Central Potato Research Station, Shillong (1800 m above sea level). Their action was compared with that of a biological insecticide (spores ofBacillus thuringiensis), a chemical insecticide (carbaryl), and an untreated control. The data collected after six months storage on tuber damage, sprout damage and the rotting indicated that the leaves ofLantana aculeata provided most protection to the tubers, reducing damage from over 70% in the check to below 5%, and sprout damage from over 45% to below 3%. Next best wasEucalyptus globulus followed byB. thuringiensis. They may be used on tubers stored for table use or for seed as they had no adverse effect on germination or on the yield of a subsequent crop.     

Mineral composition of some traditional Mexican teas

Teas of plant origin traditionally consumed by the Mountain Pima of Chihuahua, Mexico, were analyzed for mineral nutritional content. Fe, Cu, Zn, Ca, and Mg composition was determined for native teas made from shoots ofTagetes lucida, T. filifolia, Elytraria imbricata, andHolodiscus dumosus, and from root xylem ofCeanothus depressus andPhaseolus ritensis. Native uses of these teas are also described.     

Novel food and non-food uses for sorghum and millets

Sorghum and millets have considerable potential in foods and beverages. As they are gluten-free they are suitable for coeliacs. Sorghum is also a potentially important source of nutraceuticals such antioxidant phenolics and cholesterol-lowering waxes. Cakes, cookies, pasta, a parboiled rice-like product and snack foods have been successfully produced from sorghum and, in some cases, millets. Wheat-free sorghum or millet bread remains the main challenge. Additives such as native and pre-gelatinised starches, hydrocolloids, fat, egg and rye pentosans improve bread quality. However, specific volumes are lower than those for wheat bread or gluten-free breads based on pure starches, and in many cases, breads tend to stale faster. Lager and stout beers with sorghum are brewed commercially. Sorghum's high-starch gelatinisation temperature and low beta-amylase activity remain problems with regard to complete substitution of barley malt with sorghum malt . The role of the sorghum endosperm matrix protein and cell wall components in limiting extract is a research focus. Brewing with millets is still at an experimental stage. Sorghum could be important for bioethanol and other bio-industrial products. Bioethanol research has focused on improving the economics of the process through cultivar selection, method development for low-quality grain and pre-processing to recover valuable by-products. Potential by-products such as the kafirin prolamin proteins and the pericarp wax have potential as bioplastic films and coatings for foods, primarily due to their hydrophobicity.     

In vitro antimicrobial activity of different accessions ofSolanum commersonii Dun. from Uruguay

Summary The in vitro antimicrobial activity of extracts from accessions ofSolanum commersonii Dun. collected in the south of Uruguay was investigated against five microorganisms including the pathogenRalstonia solanacearum. A total of 30 extracts corresponding to organic and aqueous extracts were studied. Interestingly, most of the positive results for growth inhibition were againstR. solanacearum. The extracts were also analyzed for the presence of glycoalkaloids and lectins. Six of the ten aqueous extracts showed lectin presence and a wide variation in the type and amounts of glycoalkaloids, was found. Results indicate that there is no clear relationship between the antimicrobial activity against the five microorganisms screened and the presence or amounts of lectins and glycoalkaloids, traditionally regarded as possible antimicrobial metabolites in theSolanum genus, which indicates the presence of as yet unidentified antimicrobial compounds.     

Extreme resistance to infection by potato virus X in genotypes of wild tuber-bearingSolanum species

Summary Clones derived from thirty-one different accessions (nineteen of Argentine origin) belonging to eightSolanum species were screened for resistance to infection by potato virus X strain cp (PVX cp) by mechanical inoculation of plantlets that had been micropropagated in vitro. Estimates of PVX multiplication obtained by enzyme linked immunosorbent assay and slot blot nucleic acid hybridization allowed the identification of resistant clones derived from five accessions belonging toS. commersonii S. oplocense, S. sparsipilum andS. tuberosum andigena. Resistant genotypes supported PVX concentrations 5 to 15 times smaller than did the susceptible control cultivar Spunta. Graft inoculation test confirmed the presence of extreme resistance similar to that conferred by the ‘immunity’ gene X¹ (also called RX_act).     

Cyanobacteria Secondary Metabolites as Biotechnological Ingredients in Natural Anti-Aging Cosmetics: Potential to Overcome Hyperpigmentation,Loss of Skin Density and UV Radiation-Deleterious Effects

The loss of density and elasticity, the appearance of wrinkles and hyperpigmentation are among the first noticeable signs of skin aging. Beyond UV radiation and oxidative stress, matrix metalloproteinases (MMPs) assume a preponderant role in the process, since their deregulation results in the degradation of most extracellular matrix components. In this survey, four cyanobacteria strains were explored for their capacity to produce secondary metabolites with biotechnological potential for use in anti-aging formulations. Leptolyngbya boryana LEGE 15486 and Cephalothrix lacustris LEGE 15493 from freshwater ecosystems, and Leptolyngbya cf. ectocarpi LEGE 11479 and Nodosilinea nodulosa LEGE 06104 from marine habitats were sequentially extracted with acetone and water, and extracts were analyzed for their toxicity in cell lines with key roles in the skin context (HaCAT, 3T3L1, and hCMEC). The non-toxic extracts were chemically characterized in terms of proteins, carotenoids, phenols, and chlorophyll a, and their anti-aging potential was explored through their ability to scavenge the physiological free radical superoxide anion radical (O₂^•−), to reduce the activity of the MMPs elastase and hyaluronidase, to inhibit tyrosinase and thus avoid melanin production, and to block UV-B radiation (sun protection factor, SPF). Leptolyngbya species stood out for anti-aging purposes: L. boryana LEGE 15486 presented a remarkable SPF of 19 (at 200 µg/mL), being among the best species regarding O₂^•− scavenging, (IC₅₀ = 99.50 µg/mL) and also being able to inhibit tyrosinase (IC₂₅ = 784 µg/mL), proving to be promising against UV-induced skin-aging; L. ectocarpi LEGE 11479 was more efficient in inhibiting MMPs (hyaluronidase, IC₅₀ = 863 µg/mL; elastase, IC₅₀ = 391 µg/mL), thus being the choice to retard dermal density loss. Principal component analysis (PCA) of the data allowed the grouping of extracts into three groups, according to their chemical composition; the correlation of carotenoids and chlorophyll a with MMPs activity (p < 0.01), O₂^•− scavenging with phenolic compounds (p < 0.01), and phycocyanin and allophycocyanin with SPF, pointing to these compounds in particular as responsible for UV-B blockage. This original survey explores, for the first time, the biotechnological potential of these cyanobacteria strains in the field of skin aging, demonstrating the promising, innovative, and multifactorial nature of these microorganisms.     

Marine Pharmacology in 2009–2011: Marine Compounds with Antibacterial,Antidiabetic, Antifungal,Anti-Inflammatory,Antiprotozoal, Antituberculosis,and Antiviral Activities; Affecting the Immune and Nervous Systems,and other Miscellaneous Mechanisms of Action ?

The peer-reviewed marine pharmacology literature from 2009 to 2011 is presented in this review, following the format used in the 1998–2008 reviews of this series. The pharmacology of structurally-characterized compounds isolated from marine animals, algae, fungi and bacteria is discussed in a comprehensive manner. Antibacterial, antifungal, antiprotozoal, antituberculosis, and antiviral pharmacological activities were reported for 102 marine natural products. Additionally, 60 marine compounds were observed to affect the immune and nervous system as well as possess antidiabetic and anti-inflammatory effects. Finally, 68 marine metabolites were shown to interact with a variety of receptors and molecular targets, and thus will probably contribute to multiple pharmacological classes upon further mechanism of action studies. Marine pharmacology during 2009–2011 remained a global enterprise, with researchers from 35 countries, and the United States, contributing to the preclinical pharmacology of 262 marine compounds which are part of the preclinical pharmaceutical pipeline. Continued pharmacological research with marine natural products will contribute to enhance the marine pharmaceutical clinical pipeline, which in 2013 consisted of 17 marine natural products, analogs or derivatives targeting a limited number of disease categories.