淀粉老化调控对燕麦全粉挤压面条蒸煮品质的影响

燕麦粉不含面筋蛋白,使燕麦全粉面条煮熟后易浑汤、蒸煮损失率大,目前只能温水浸泡复水食用,是限制燕麦更广泛推广的难题之一。为了满足市场对燕麦全粉面条的需求,以利用二级挤压技术生产的燕麦全粉挤压面条为试材,对成型面条进行了调湿老化、蒸制老化及冷冻老化处理,比较了不同老化方式对燕麦全粉挤压面条蒸煮品质的影响。结果表明,调湿老化处理的面条蒸煮损失率最小(2.26%~3.34%),蒸制老化次之(4.19%~5.19%),冷冻老化最大(5.16%~7.97%)。不同老化处理的面条感官评分差异不显著,以调湿老化处理24h的面条感官评分最高(87.2分);调湿老化处理面条的淀粉相对结晶度(12.47%~16.10%)、热焓值(1.044 0~1.056 0J·g-1)及回生值(519.5~558.0cP)均最大,蒸制老化次之,冷冻老化最小。综合分析可知,对燕麦挤压面条进行淀粉老化处理,能够显著降低燕麦全粉挤压面条的蒸煮损失率,最优方式为调湿老化24h。     

土豆饽饽的工艺标准化研究

为响应中国马铃薯主粮化的战略,推进传统特色主食的推广,开展了对"土豆饽饽"加工工艺的标准化研究。以感官评价和质构分析为筛选依据,形成一套适合工业化生产的加工技术。结果表明,淀粉添加量对硬度的影响很大,与皮厚度相同,两者对感观评分都具有很大的影响。适宜的研磨时间、淀粉添加量、皮厚度和蒸煮时间都能改善"土豆饽饽"的品质。试验优化确定"土豆饽饽"最佳工艺参数为淀粉添加量7%,研磨时间20 s,皮厚度0.4 cm,最佳蒸煮时间25 min。最佳配方产品外观良好,颜色淡黄,表皮晶莹,口感黏糯筋道,具有蒸煮马铃薯的独特风味。     

基于响应面法的豆粕挤压系统参数优化

为了考察挤压膨化生产大豆组织蛋白过程中相关参数对系统参数的影响,以豆粕为原料,利用响应面模型,以豆粕含水率、膨化机螺杆转速和机筒温度为输入变量,以扭矩为响应变量,探索豆粕挤压膨化系统的相关参数对扭矩影响规律和挤压膨化系统最佳参数。结果表明:豆粕含水率、膨化机螺杆转速和机筒温度对扭矩具有显著的影响;膨化机转速是影响扭矩的主要因素。采用优化方法对试验参数进行了优化计算,当豆粕含水率为17.2%、膨化机转速为202.5 r.min-1、机筒温度为110℃时,膨化机工作性能指标达到最优。     

高水分蒸煮挤压小麦混合粉的研究

食品蒸煮挤压技术是多学科交叉所产生的一门高新技术,蒸煮挤压作为一种高温短时的加工方法,能够将输送、压缩、混合、蒸煮、杀菌、成型等多种操作单元同时完成。本实验优化了双螺杆机的加工工艺参数,DS56-Ⅲ型双螺杆挤压膨化机挤压腔内限流区的温度在125℃．含水率为40％、螺杆转速为215rpm,该条件下得到的最好产品膨化度为2．51,经过蒸煮挤压后的食品含水率为35％～37％。     

挤压膨化碱处理豆渣制备水溶性膳食纤维工艺的研究

以豆渣为原料,并在碱液处理后直接挤压膨化制备豆渣水溶性膳食纤维.以水溶性膳食纤维得率为指标,对物料水分、挤压温度、螺杆转速及氢氧化钠浓度进行了单因素试验.采用响应面分析方法,对挤压膨化提高碱处理豆渣水溶性膳食纤维的工艺条件进行了优化,并建立了物料水分、挤压温度、螺杆转速三因素的回归模型.确定了挤压膨化碱处理豆渣制备水溶...     

挤压膨化对绿茶茶渣中粗纤维影响

利用双螺杆挤压膨化机对绿茶茶渣进行挤压膨化加工,采用响应面设计方法建立物料含水量、喂料速度、螺杆转速以及套筒温度与绿茶茶渣中粗纤维含量之间的回归模型。结果表明,各参数对绿茶茶渣中粗纤维含量影响由大到小依次为：螺杆转速>套筒温度>喂料速度>物料含水量,获得低粗纤维含量的最佳挤压膨化参数为物料含水量70%,喂料速度90r/min,螺杆转速90r/min,套筒温度50℃。在此条件下,茶渣中粗纤维含量为15%,与膨化前原料相比,粗纤维含量下降了3%。     

干热变性紫薯淀粉成膜工艺优化

紫薯中直链淀粉含量较高,具有较好的成膜性。以干热变性紫薯淀粉为基质,探究变性淀粉添加量、甘油添加量和海藻酸钠添加量对干热变性紫薯淀粉成膜特性的影响,通过响应面分析法确定干热变性紫薯淀粉最佳成膜工艺参数。结果表明:当变性淀粉添加量为3.99%,甘油添加量为1.52%,海藻酸钠添加量为0.60%时,干热变性紫薯淀粉膜的性能最优。研究成果将为干热变性紫薯淀粉可食用膜的工业化生产提供理论指导。     

氮、硫肥配施对稻茬麦氮素利用及籽粒产量和品质的影响

为探讨稻茬小麦的氮硫肥施用技术,在水稻秸秆全量还田条件下设置0、195和270 kg·hm^-2 3个施氮水平和0、30和60 kg·hm^-23个施硫水平,研究氮、硫肥配施对小麦氮素吸收利用、籽粒产量和品质的影响。结果表明,随施氮量的增加,小麦穗数、穗粒数和产量均显著增加,面团形成时间和稳定时间延长,但施氮量达270 kg·hm^-2时氮肥农学效率和表观利用率显著下降,籽粒支链淀粉、清蛋白、醇溶蛋白和谷蛋白含量降低。增施硫肥可使籽粒产量显著增加,延长面团形成时间和稳定时间,并提高籽粒支链淀粉、谷蛋白和总蛋白含量。相比其他氮、硫肥组合处理,施氮195 kg·hm^-2配合施硫60 kg·hm^-2提高了总氮素积累量、氮肥农学效率和氮肥利用效率;该组合处理下籽粒产量比仅施氮270 kg·hm^-2处理提高了5.7%。此外,195 kg·hm^-2施氮量配施硫60 kg·hm^-2还提高了面团形成时间、稳定时间和蛋白各组分含量。这说明氮硫合理配施可提升小麦对氮素的吸收利用,起到提高籽粒产量、改善籽粒蛋白品质和粉质质量的作用;减氮条件下通过适量配施硫肥可作为小麦优质高效生产的栽培途径。     

双螺杆挤压鸡肉混合物工艺参数的优化

以大豆、大米、鸡肉、全脂乳粉为原料,按一定比例混合,采用Box-Behnken中心组合试验研究双螺杆挤压工艺参数。综合考察物料含水率、喂料速度、螺杆转速、温度对糊化度的影响,在此基础上对变量进行响应面分析,得出最佳挤压参数是:物料含水率23.32%,五区温度105℃,螺杆转速160r/min,喂料速度30r/min。     

高湿挤压技术生产组织化大豆蛋白工艺的优化研究

以感官评价为指标,通过响应面实验优化高水分组织化大豆蛋白挤压工艺条件,确定物料水分含量为55%,机筒温度为150℃,螺杆转速为208 r/min,大豆分离蛋白加入量34%条件下挤出物的感官评价最好,形成质地均匀一致,富有弹性和韧性,色泽光亮的产品,纵向撕开后可以观察到明显的纤维结构.     

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).