理化因子对‘芙蓉李’花色苷稳定性的影响

‘芙蓉李’是南方种植面积大、鲜食与加工兼用的优良李品种。本研究以‘芙蓉李’为材料,研究温度、pH、光照、金属离子、氧化还原剂等理化因子对‘芙蓉李’花色苷稳定性的影响。结果表明：‘芙蓉李’花色苷在60 ℃、2 h以内比较稳定;pH对花色苷的稳定性有显著影响,并在酸性条件下较为稳定,但光照能加速花色苷的降解;金属离子中K ⁺和Fe ³⁺可增强花色苷的稳定性,而Al ³⁺会使花色苷的稳定性下降;‘芙蓉李’花色苷耐氧化性、还原性差。     

山桃稠李浆果花色苷超声提取工艺优化及稳定性考察

本文以山桃稠李为材料,对其中花色苷的超声提取工艺进行优化,并以花色苷提取液为材料,研究了光、温、pH、金属离子、抗坏血酸等9方面因素对其稳定性的影响。结果表明:山桃稠李花色苷最佳超声提取工艺条件为,提取温度60℃、料液比1:10、超声功率120 W、提取时间20 min、乙醇浓度为60%;各环境因素、常用试剂、食品添加剂均会对山桃稠李花色苷稳定性产生不同程度的影响。     

百香果果皮主要有效成分连续提取工艺

百香果是西番莲科西番莲属的芳香热带水果,其果皮约占鲜果的55%,富含膳食纤维、维生素、花色苷及果胶等多种有效成分,加强对百香果皮的产业化利用具有重要的环境价值和商业潜力。为充分利用百香果皮资源,提高百香果皮有效成分的利用率,先后采用微波辅助、超声波辅助和微生物发酵技术,从百香果皮中提取果胶、花色苷和膳食纤维等有效成分,通过单因素试验和响应面分析对提取过程的各阶段关键环节进行优化。结果表明：百香果果皮中果胶最佳提取条件为液料比65∶1(mL/g)、pH 2.5、微波功率450 W、微波时间5.0 min;从提取果胶后的滤渣中提取花色苷的最佳提取条件为乙醇浓度50%,液料比60∶1(mL/g),pH 3.5,超声功率550 W,超声时间35 min;从提取果胶和花色苷后的百香果皮渣中提取膳食纤维最佳提取条件为液料比12.5∶1(mL/g),接种量5.0%,发酵温度35℃,发酵时间20 h,在此工艺条件下,百香果皮中果胶、花色苷和膳食纤维的得率分别为12.45%±0.06%、1.21%±0.03%和55.56%±0.05%。联产工艺中,花色苷、膳食纤维的得率虽然与单产相比分别减少了15.39...     

不同提取剂对油棕果皮中花色苷稳定性的影响

研究蒸馏水、0.8%柠檬酸提取液、60%酸性乙醇3种提取剂对油棕嫩果皮中花色苷稳定性的影响。结果表明,酸性乙醇对油棕嫩果皮花色苷的提取率最高,达到542μg/g;3种提取液在272 nm处有最大吸收峰,提取液中的组分均易溶于甲醇和丙酮;3种花色苷提取液在颜色的变化上随pH值变化一致;在日光照射和室内自然光条件下,花色苷柠檬酸提取液较为稳定,酸性乙醇提取液次之,蒸馏水提取液最差;在4~100℃的温度范围内,花色苷柠檬酸提取液较为稳定;蔗糖和葡萄糖添加量为20%时,对花色苷提取液基本无影响;花色苷柠檬酸提取液受金属离子影响较大,锌离子对花色苷提取液具有增色作用。     

大黄游离蒽醌提取工艺的正交优化研究

目的：从药材大黄中提取游离蒽醌类化合物并分离其各个组分,优选大黄游离蒽醌化合物的提取工艺。方法：酸处理大黄粗粉,使蒽醌苷脱糖链水解成为游离的羟基蒽醌,有机溶剂萃取得总游离蒽醌,pH梯度萃取依次分离并得到大黄酸、大黄素、芦荟大黄素、大黄酚和大黄素甲醚组分。正交试验法考察水解时间、回流时间、提取温度和提取溶剂对大黄总游离蒽醌及各组分提取效果的影响,对其产物进行分析。结果：以总蒽醌为指标,最佳提取条件为药材粗粉用20%硫酸微沸水解3小时,氯仿在99℃下回流提取4小时。以各个组分为指标,溶剂的主导影响因素更为明显,氯仿对各成分均有较好浸提效果;苯仅对大黄酚和大黄素甲醚效果好,石油醚对所有组分都不理想。结论：优化的最佳因素组合是稳定高效的提取工艺。     

烘焙温度与时间对福建水仙乌龙茶风味品质的影响

试验以福建水仙毛净茶为材料,设温度(110、120、130、140、150℃)、时间(1、3、5、7、9、11、13 h)2因素进行烘焙处理。结果表明:不同处理游离氨基酸总量在1.52%~2.33%,茶汤pH值在5.19~5.39,均低于对照;相同时间,温度越高,游离氨基酸总量和pH值越低;还原糖在17.1%~21.7%,变化规律不明显。对茶汤pH值进一步方差分析表明,不同处理茶汤pH值均极显著低于对照;相同温度不同时间,低温(110℃、120℃)pH值差异达极显著,中温(130℃)、高温(140℃、150℃)差异不显著;相同时间不同温度间差异极显著。烘焙影响茶汤风味,烘焙后茶汤pH值在5.23~5.28间,火功为中火时,茶汤呈酸味,其呈酸物质有待进一步分析。     

莱鲍迪苷A热稳定性影响因素试验研究

研究不同加热温度条件下影响莱鲍迪苷A稳定性的因素,方法采用高效液相色谱法测定试验前后样品莱鲍迪苷A含量,试验结果表明影响莱鲍迪苷A热稳定性的主要因素包括干燥方式、水分含量和加热时间。     

高效液相色谱法测定芦荟及芦荟制品中的芦荟甙

建立测定芦荟及芦荟制品中芦荟甙含量的高效液相色谱方法.用甲醇超声提取、反相液相色谱法紫外检测器检测,根据色谱峰的保留时间定性,外标法定量.采用ODS柱,以甲醇一醋酸(体积比50:50)为流动相,紫外检测器于359nm处检测.结果表明:芦荟甙的进样量为10μL、流速1.0mL/min和柱温40℃时,进样量与色谱峰面积呈良好的线性关系(r=0.9999);样品加标回收率为96.8%～102.0%;方法的精密度好,变异系数(CV)小于4.6%(n=10);方法检测限为0.05 mg/kg.方法快速、简便、准确,所测结果稳定、重现性好,可作为芦荟及芦荟制品中质量检验的一种定量方法.     

绿茶芦荟珍珠保健胶囊产品稳定性的试验

在相对湿度75%,温度37℃的条件下,对绿茶芦荟珍珠保健胶囊进行了三个月的稳定性试验。结果表明:该产品的功效成分、理化指标、微生物指标等检测项目均末发生变化。绿茶芦荟珍珠保健胶囊产品检验结果均符合企业标准要求,产品质量稳定。     

不同有色米品种色素含量及稳定性研究

采用pH示差法研究了不同有色米色素水溶液中花色苷的含量。结果表明,P1的花色苷含量最高,为0.632 mg/g,P18的花色苷含量最低,为0.049 mg/g,其他品种的花色苷含量介于二者之间。采用比色法研究了光照及温度对黑米色素稳定性的影响。结果表明,P4、P8的色素稳定性相对较好,P16、P17相对较差。最后,利用主成分分析,筛选出的色素含量高且稳定性好的优质黑米品种为P4。     

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.     

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.     

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.     

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.