姬松茸富硒液体发酵条件优化及其菌丝营养成分分析

为探讨姬松茸富硒液体发酵的最佳工艺条件及其菌丝营养价值,以深入研发和应用姬松茸等食用菌富硒菌丝产品,本文通过正交试验对姬松茸富硒液体发酵条件进行优化,并对其富硒菌丝营养成分进行分析。结果表明,姬松茸富硒液体发酵的最佳条件为:装富硒液体发酵培养基装量80 m L(250 m L三角瓶),硒浓度15μg/m L,摇床转速80 r/min,培养时间10 d。在此条件下制得的菌丝干重和富硒率分别为2.05 g/100 m L和5.78%;测定分析了姬松茸富硒发酵菌丝体的蛋白质、可溶性糖、多糖及氨基酸等营养物质含量,初步确定姬松茸富硒液体发酵菌丝体具有较高的营养价值,可考虑作为一种补硒保健品。     

响应面法优化桃汁富硒红茶复合饮料的研究

采用响应面法优化富硒红茶的提取工艺,以可溶性固形物和茶多酚的提取率为指标,对提取时间、料液比和浸提温度等因素进行考查,并将提取的富硒红茶汤与桃汁进行复配,得到了桃汁富硒红茶复合饮料。结果表明,在浸提时间22 min,料液比1∶100(g∶m L),浸提温度89℃的条件下,茶汤中茶多酚的提取率为4.32%。测定茶汤的相关理化指标:p H值5.61,可溶物浸出率为38.6%,可溶性糖约占提取物0.74%,硒含量0.23μg/L,其中的营养成分含量丰富。选取桃汁进行调配,保留富硒红茶原本的茶香,茶香较浓,口感干润、醇厚。     

富硒保健酸奶的研制

通过L9(33)正交试验,确定富硒乳酸菌制作酸奶生产用发酵剂的最佳发酵条件为:发酵温度42℃,加硒量7μg·mL-1,接种量4%。测得发酵剂的活菌数为9.45×108cfu·mL-1,硒的转化率达到84.15%,活力为0.65,符合酸奶发酵剂的质量要求。用此发酵剂生产富硒酸奶的最佳工艺条件为:富硒发酵剂接种量7%,加糖量6%,培养温度42℃,发酵时间4.5h。该酸乳的硒含量达0.49μg·mL-1,转化硒为0.4815μg·mL-1,转化率为98.25%。与普通乳酸菌发酵酸乳相比,该产品硒含量提高了约480倍。     

梨果心与果皮中多酚提取工艺的研究

多酚具有抗氧化、抗衰老等生理功能。为充分开发利用梨加工产品的副产物——梨果心与果皮中富含的多酚,本试验以鸭梨果心、果皮为材料,采用正交试验方法,研究其多酚提取的最佳工艺条件。结果表明：温度和浸提时间对果心和果皮多酚的提取效果没有显著影响;果皮多酚的提取效果受料液比、提取次数和溶剂三个因素的影响较大;果心多酚的提取效果仅受料液比的影响较大。梨果心和果皮多酚的适宜提取工艺条件为：以80%乙醇为提取溶剂,料液比为1∶15（m∶V）,提取二次,其提取液中的多酚含量可分别达到530μg·g-1和488μg·g-1。     

响应面法优化酶-超声波辅助同步提取鸭骨素工艺

以新鲜鸭骨为原料,采用酶-超声波辅助同步提取鸭骨素,并以可溶性固形物和蛋白质含量为考察指标,在单因素试验的基础上采用响应面法优化鸭骨素提取工艺条件。结果表明,酶-超声波辅助同步提取鸭骨素的最佳工艺条件为:超声温度62℃,超声功率248 W,超声时间5.1 h,酶添加量1.34%。此条件下鸭骨素提取液中可溶性固形物含量和蛋白质含量分别为(25.8±0.047)°Bx和(20.9±0.018)g·100 g-1。采用酶-超声波辅助同步提取的鸭骨素提取液中可溶性固形物和蛋白质含量极显著高于单一酶解法、微波提取法和超声波提取法(P0.01)。     

富硒土壤中有效硒浸提剂和浸提条件研究

以青海东部富硒土壤为供试材料,对6种有效硒浸提剂NaHCO3、KH2PO4、K2SO4、EDTA、AB-DTPA和DTPA的最佳浸提时间和土液比进行了筛选,并结合土壤有效硒最佳浸提剂的小麦生物学校验,以找出适宜富硒土壤有效硒提取的浸提剂及其浸提条件。结果表明：6种有效硒浸提剂对富硒土壤中硒的浸提量均随着土液比的增大而减少,且均随浸提时间的逐渐增加而增加。EDTA和DTPA的最佳土液比则为1/20,振荡时间为30 min;K2SO4、AB-DTPA、NaHCO3和KH2PO4四种浸提剂最佳浸提土液比均为1/15,其中K2SO4和AB-DTPA的最佳提取时间为60 min,其余两种浸提剂NaHCO3和KH2PO4的最佳浸提时间均为90 min。6种不同浸提剂在最佳提取条件下提取的土壤有效硒含量与小麦籽粒中富集的硒含量呈极显著正相关关系,但土壤有效硒的提取量以DTPA最少,其次为K2SO4,分别只占KH2PO4、NaHCO3、AB-DTPA及EDTA提取量的16% ~ 47%和36% ~ 85%,故不适用于作为石灰性富硒土壤有效硒的浸提剂。KH2PO4、NaHCO3、AB-DTPA和EDTA 提取的硒含量不仅与小麦籽粒中硒含量呈极显著正相关,而且浸提量高,提取过程简单,重复性好,故均可作为石灰性富硒土壤的有效硒浸提剂。     

苍耳子、田基黄中黄酮类物质提取含量测定及对比研究

为考察苍耳子和田基黄中黄酮提取优化的研究和总含量的测定,及对两者黄酮总含量的对比研究。通过芦丁作为标准物测定总黄酮含量,采用L9(34)正交试验法确定乙醇浸提回流法的最佳浸提工艺条件。试验结果显示,苍耳子最佳浸提条件为乙醇浓度为60%,提取温度70℃,提取时间4 h,料液比为1:30 (g/mL),此条件下苍耳子总黄酮提取率为3.89%。田基黄最佳浸提条件为：乙醇浓度为50%,提取温度为80℃,提取时间为1 h,料液比为1:50 (g/mL)。以总黄酮浸提率作为考察指标,苍耳子最佳浸提工艺下总黄酮的提取率为3.89%;而田基黄总黄酮提取率为4.31%。结果表明田基黄中黄酮含量较于苍耳子高。本工艺简单可行,有较好的参考价值。     

南瓜果胶提取工艺的优化研究

为建立适用于从南瓜中提取果胶的超声波辅助酸解工艺,采用单因素试验确定提取南瓜果胶的各因素水平,包括提取液酸度、料液比(g/mL)、浸提温度和浸提时间。利用L9(34)正交试验优化南瓜果胶的超声辅助酸解条件。结果表明,当超声辅助酸解条件为：提取液pH 2.0,料液比(g/mL)1:30,浸提温度75℃,浸提时间60 min,南瓜果胶得率最高,达到21.9%。     

Design and Experimental Analysis of Silicon Oil Clutch

采用热水浸提、醇沉法提取红枣多糖,对红枣多糖提取工艺与一般理化性质进行了研究.选择浸提固液比、温度、时间和浸提次数作为单因素进行梯度实验,确定其条件范围,再通过正交实验L9(33)进一步确定红枣水溶性多糖最佳提取工艺条件.结果表明,最佳提取工艺条件为:固液比1:7,浸提温度80℃,浸提时间2 h,反复浸提2次.理化性质研究结果表明,提取的红枣多糖中含有多肽和AA,为蛋白质复合多糖.     

‘紫加1号’花色苷提取工艺及抗氧化活性分析

旨在优化‘紫加1号’嫩茎叶花色苷提取工艺,并探讨其体外抗氧化活性。采用溶剂浸提法提取‘紫加1号’嫩茎叶花色苷,通过单因素试验和正交试验,分析浸提时间、浸提温度、料液比、乙醇浓度和提取次数对花色苷提取率的影响,确定提取‘紫加1号’花色苷的最佳工艺。通过水杨酸法、邻苯三酚自氧化法和DPPH法对‘紫加1号’花色苷的体外抗氧化活性进行测定。结果表明,花色苷最佳提取工艺为浸提温度50℃、浸提时间2.5 h、料液比为1:100 g/mL、乙醇浓度为55%、提取2次,此条件下得率为62.34 mg/100g,接近实际值56.23 mg/100g,说明结果准确可靠。同时,‘紫加1号’花色苷对羟基自由基(·OH)、超氧基自由基(O₂^-·)和1,1-二苯基-2-三硝基苯肼自由基(DPPH)有明显的清除作用,半数抑制浓度(IC₅₀)依次为0.488 mg/mL、0.764 mg/mL和0.032 mg/mL。该法能够有效提取‘紫加1号’嫩茎叶花色苷,且获得的花色苷具有明显的体外抗氧化活性。     

冷冻干燥速溶蛋花汤的加工技术

介绍了运用冷冻干燥技术进行速溶蛋花汤的加工,研究了生产工艺、特点以及影响产品质量的主要因素。试验表明,采用冷冻干燥技术加工的速溶蛋花汤,具有营养丰富、风味独特、方便快捷等特点。     

Measuring of Quantity of Matter-mass and the Measuring of Inertia of Matter-momentclm

A new definition of inertia,i.e. the momentum is the measuring of inertia of matter, is proposed. The article through and etc., subjects, the correctness of the new notion of inertia:The monentum is the measuring of inertia has been demonstrated, and the unsolved contradictions of the traditional definition of inetia. And the mass is the measuring of inertia has been revealed.     

香蕉遗传转化方法研究进展

香蕉是热带亚热带发展中国家重要的粮食作物和碳水化合物来源。但近年来,香蕉生产受到严重的病虫危害。大多数香蕉栽培品种是三倍体,生长周期长,而且不孕。由于没有种子,给繁殖和育种带来一定的困难。遗传转化技术的发展为香蕉品种的改良提供了一种有效的手段。香蕉的遗传转化方法有电激法、基因枪法、农杆菌介导法等。农杆菌介导法的应用是香蕉品种改良的一个重大突破。香蕉遗传转化的外植体也发展到多种,有原生质体,胚性细胞悬浮系,分生组织,以及横切薄片等。近几年,随着分子生物学的发展,出现了转化效率更高,重复性更好的香蕉遗传转化技术。如农杆菌和基因枪结合法,离心辅助农杆菌介导法、真空渗透技术等。这些新技术新方法的出现,必将推动香蕉产业高速发展。     

壳聚糖对石榴果汁澄清效果的影响

利用壳聚糖的絮凝作用对壳聚糖在甜石榴汁澄清中的应用效果进行了研究,试验结果表明,壳聚糖用量为0.3g/L、澄清时间为60min、温度为35℃时,甜石榴汁透光率可达85%以上,且通过对壳聚糖处理前后可溶性固形物、总酸、VC等营养成分含量的比较,确定以上工艺参数为甜石榴汁澄清的最佳选择。     

新疆布尔津县土地利用格局特征研究

基于RS与GIS技术,利用景观生态学理论及景观格局指数对布尔津县土地利用现状进行定量分析。结果显示为：（1）布尔津县以草地、林地为主要景观类型,镶嵌着耕地、水域等景观类型。（2）四个分区（即高山区、丘陵区、平原区、荒漠区）的林地资源组成差异明显,耕地、居民、交通及工矿用地集中分布在丘陵区和平原区（3）从各项指数来看,高山区的多样性指数较低;平原区是受人文因素最多的区域,景观优势度低,各种土地利用类型比例差异不大,有利于生态可持续发展,但要合理的开发利用;荒漠区生态环境相对脆弱,要加强生态环境的保护与改善。通过该研究对布尔津县的土地利用现状作一个了解,为该县乃至整个地区的景观规划和可持续发展战略提供科学依据。     

酸枣幼根原生质体的制备

以生长6～9 d的酸枣种子幼根为试验材料,0.7 mol·L-1甘露醇作为渗透压稳定剂、pH值5.5～6.0、28℃恒温水浴条件下,以光学显微镜观察的水解总时间、初始产生原生质体的时间、原生质体产量及细胞碎片量为指标,研究通过酶水解来制备酸枣幼根原生质体的方法.结果表明,在含1％果胶酶+4％纤维素酶R-10+3％纤维素...     

影响核桃贮藏品质因素的分析

介绍了几种核桃贮藏方法,综述了影响核桃贮藏品质的几个主要因素,以及针对上述影响因素提出若干解决对策.     

Efficiency of water use of early plantings of sunflower

Rain fed crop production in Mediterranean environments depends to a large extent on strategies that avoid the intense summer drought. Early plantings of sunflower have given consistently higher yields in such environments, but the basis for such yield increases has not been explored. We conducted two field experiments at Cordoba (Spain) to investigate the effects of an early and a late planting date on the components of water-limited crop productivity; namely, water use (T), water use efficiency (TE) and harvest index (HI) of sunflower. The results were generalized by simulating rain fed sunflower yields, under early (1 January) and late (15 March) plantings, for a 25-year period with the aid of a simulation model of the Ceres type (OILCROP-SUN) which has been validated in Cordoba. Experimental seed yields of early plantings in 1989 and 1996 were 2.0 and 3.0 t ha⁻¹, while late plantings yields were 1.3 and 2.4 t ha⁻¹, for the 2 years. Average simulated yields were 2.7 ± 1.1 and 1.9 ± 0.7 t ha⁻¹ for early and late plantings, respectively. For the 2 years, T of early plantings was higher than that of late plantings, but the response of TE and HI to planting date was not the same in the two experiments. In the simulation exercise, T and TE of early plantings were consistently higher than those of late plantings, while there were no differences in the HI for the two planting dates. We conclude that early plantings of sunflower increase rain fed yields by increasing both T and TE, while the impact of planting date on HI very much depends on the crop water stress pattern, which is quite variable from year to year even in the predictable Mediterranean environment.     

Establishment of High-frequency Regeneration System of Explants of Alfalfa

The cotyledon and hypocotyl of eight varieties of alfalfa( Medicago sativa L. )are used to study the effect of different cultivation procedures and genotypes on embryogenic callus and embryoid induction,plant development and transplant of alfalfa.The varieties of alfalfa with high embryoid induction rate and high differentiation rate are screened. A high frequency regeneration system for alfalfa tissue culture is established:which is benifical to the gene transformation of alfalfa.     

Laboratorial Method of Determining Limit of Yielding of Material

Based on the relation between the incipient yield pressure and the limit of yielding in cylinder according to the elastic disabled rule, a laboratorial method of determining limit of yielding of material is designed and a set of experimental data were gained by the method. The incipient yield pressure of the cylinder is gained by analyzing the experimental data, and then the limit of yielding is gained. The laboratorial method has a good reliability as the experimental value has a little error to the theory value. It has a definite engineering signification and theory value to research the mechanical capability of material and the disabled rule of high pressure vessel.