响应面法优化干热变性莲子淀粉膜制备工艺

以干热变性莲子淀粉为主要原料,研究变性淀粉用量、甘油用量和干燥温度对干热变性莲子淀粉膜性能的影响,并采用响应面分析及加权评价函数法对膜性能指标进行综合优化,得到干热变性莲子淀粉的最佳成膜工艺条件为:变性莲子淀粉用量为3.53%,甘油用量为1.51%,干燥温度80.61℃。本研究成果将为干热变性莲子淀粉可食膜的工业化生产提供理论指导。     

海南槟榔提取物急性毒性研究及保健饮料开发

研究海南槟榔提取物的急性毒性及保健饮料的开发。一次性灌胃给予小鼠最大容积和最大混悬浓度的槟榔提取物,观察小鼠急性毒性反应,评价槟榔提取物的安全性;正交设计法优化得出槟榔提取物、白砂糖和柠檬酸的最佳配方;用不同用量的阿拉伯胶、羧甲基纤维素钠、海藻酸钠作为稳定剂,评价最佳稳定剂。14 d内,小鼠外观、精神、行为无异常,槟榔提取物最大给药量为5.0 g/kg;槟榔饮料的最佳配方为槟榔提取物添加量0.2%,柠檬酸添加量0.05%,白砂糖添加量10%,槟榔饮料的最佳稳定剂为0.2%的阿拉伯胶。槟榔提取物安全性高,槟榔保健饮料具有槟榔的淡香味,适合大众口味。     

莲子低聚糖提取工艺优化及其组分分析

采用响应面分析法对莲子低聚糖热水浸提工艺参数进行优化,探讨浸提时间（min）、浸提温度（℃）和水料比（V/W）对热水浸提莲子低聚糖得率的影响,建立提取莲子低聚糖的二次项数学模型并验证其可靠性,得到最优提取工艺参数,并采用高效液相色谱法对莲子低聚糖组分进行初步分析。结果表明：热水浸提莲子低聚糖的最佳提取工艺条件是浸提时间为66 min,浸提温度为81 ℃,水料比为80 ∶ 1,在此工艺条件下莲子低聚糖得率为8.09％。影响低聚糖提取工艺的主次因素顺序为：水料比>浸提温度>浸提时间。高效液相色谱法测定莲子低聚糖,发现莲子低聚糖由四聚糖、三聚糖和二聚糖组成。     

茶叶水溶性膳食纤维的制备及其理化特性的研究

对酶法提物茶叶水溶性膳食纤维(SDF)的工艺及其理化性能进行研究,探讨了料液比、pH值、酶添加量、温度及时间对SDF提取率的影响。在单因素试验基础上,通过L16(45)正交试验确定最佳提取工艺。结果表明:pH值对茶叶SDF提取的影响最大,其次依次为温度、酶添加量、时间、料液比;茶叶SDF提取的最佳工艺为:温度60℃、酶添加量0.08g/g、pH值9.0、时间2.0h、料液比1∶20,提取率达53.72%,所得SDF具有较好持水力、膨胀力和持油力,对胆固醇、胆酸钠也有一定吸附作用,为一种优质膳食纤维。     

黑参调配乳饮料配方的研究

开发一款新型的具有抗疲劳、提高免疫力的功能性饮料的乳饮料,以黑参和牛奶为主要原料,加入酒曲发酵后调配,以产品发酵感官、产品感官为指标,通过正交实验优化其配方。结果表明最佳发酵工艺为:黑参添加量为1.2%,酒曲发酵,添加量为0.6%,室温浸泡2h,37℃发酵3.5h,最佳配方工艺为:白砂糖5.5%,柠檬酸0.1%,草莓香精0.09%。该实验为黑参乳饮料的开发提供了参考。     

微波法乙醇提取莲子酚类物质的工艺

以莲子干品为原料,在单因素试验的基础上,通过正交试验确定了乙醇提取莲子多酚类物质的最佳工艺条件为乙醇浓度90%、液料比1∶10、微波功率300 W、提取时间35 s、提取3次。在此条件下浸提,莲子多酚提取率为7.74 mg·g^-1。     

红香椿内酯豆腐生产工艺的研究

以红香椿和大豆为原料,以葡萄糖酸-δ-内酯为凝固剂,采用单因素及正交试验方法,研究了红香椿豆腐的加工工艺条件,讨论了香椿提取液添加量、豆浆浓度、凝固剂用量、凝固温度与时间对豆腐品质的影响.结果表明:红香椿提取液添加量为15.0%时,按豆浆浓度(豆∶ 水=1∶ 5)添加0.30%的葡萄糖酸-δ-内酯,在90℃下凝固35 min后冷却即可得到浅绿而有光泽、凝固性和保水性好、口感细腻,具有典型香椿香气和豆香的红香椿豆腐.     

麒麟藻渣制备膳食纤维工艺研究

以提取卡拉胶后的麒麟藻废渣为原料,利用木瓜蛋白酶和α-淀粉酶对粗纤维进行酶解,制备膳食纤维。正交试验优化提取工艺,得出最佳工艺条件为：料液比为1∶30,时间1.5 h,温度为65℃,蛋白酶用量为0.35%、α-淀粉酶用量为1.5%,膳食纤维得率为35.58%。按照最佳工艺条件提取的麒麟藻渣膳食纤维,膨胀力10.93 mL/g,持水力721.72%。     

茶叶籽油及茶皂素复合提取工艺研究

采用果胶酶开展水酶法提取茶叶籽油及茶皂素工艺研究,单因素实验探索酶量、作用温度、作用时间、料液比等对油得率及副产物茶皂素得率的影响;在此基础上开展中心组合试验,进行响应面分析对提取工艺进行优化。结果表明:回归方程为R=-61.384+0.719A+2.994B+4.829C+3.475D+0.015AB+0.075AD+0.045BC+0.065BD-0.122A2-0.040B2-0.913C2-0.663D2;最佳工艺条件为酶解温度45℃、酶解时间3.8 h、料液比1∶5.3(g∶mL)、果胶酶添加量7.3 mL(0.2%),验证试验茶叶籽油得率为27.0%,为茶叶籽资源开发提供了基础资料。     

含硅复混肥料不同用量对滴灌棉田土壤酶活力、养分吸收及产量的影响

通过田间试验,研究含硅复混肥料不同用量(300、450和600kg·hm-2)对滴灌棉田土壤酶活力、养分吸收及产量的影响。结果表明,施用含硅复混肥料可显著提高土壤脲酶和碱性磷酸酶活力,且碱性磷酸酶活力随肥料用量的增加而显著增加;施用含硅复混肥料对纤维素酶、蔗糖酶活力无显著影响;可显著提高土壤微生物量碳,且随肥料用量的增加而显著增加,但对微生物量氮无显著影响。含硅复混肥料中、高用量均可显著促进棉花植株对氮、磷和钾素吸收。含硅复混肥料低用量下棉花产量与对照无显著差异,中等用量和高用量下棉花子棉产量分别较对照增加了18%和20%。     

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.     

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.     

Recent Modifications of Chitosan for Adsorption Applications: A Critical and Systematic Review

Chitosan is considered to be one of the most promising and applicable materials in adsorption applications. The existence of amino and hydroxyl groups in its molecules contributes to many possible adsorption interactions between chitosan and pollutants (dyes, metals, ions, phenols, pharmaceuticals/drugs, pesticides, herbicides, etc.). These functional groups can help in establishing positions for modification. Based on the learning from previously published works in literature, researchers have achieved a modification of chitosan with a number of different functional groups. This work summarizes the published works of the last three years (2012–2014) regarding the modification reactions of chitosans (grafting, cross-linking, etc.) and their application to adsorption of different environmental pollutants (in liquid-phase).