响应面法优化牡丹花真空冷冻干燥工艺

为优化牡丹花真空冷冻干燥工艺参数,以干燥压强、预冻温度、起始加热板温为自变量,综合评分为因变量,通过单因素试验和Box-Behnken二次旋转正交试验,并利用Design Expert 7.0软件进行了回归方程的预测模型和响应面分析,最终确定最佳工艺条件为:干燥压强49.39 Pa,预冻温度-49.68℃,起始加热板温度43.12℃,预测结果94.89分,验证试验结果得到的试验值为93.29分,达到了预测值的98.31%。其中升华干燥阶段以15℃/h降温到35℃至干燥结束,最终产品色彩均匀,收缩率为3.0%,含水率5.6%,可长期观赏、保存。     

番木瓜片真空冷冻干燥工艺研究

为了确定番木瓜片真空冷冻干燥的工艺参数,对番木瓜片真空冷冻干燥加工工艺进行试验研究。通过正交试验,研究了物料厚度、升华温度及预冻温度对冻干品复水比、色泽的影响;并采用多指标综合加权评分法对复水比、色泽进行综合评定,以优化其工艺参数。结果表明,升华温度对干燥综合效果有显著影响,物料厚度及预冻温度对干燥综合效果影响不显著;影响的主次顺序为升华温度预冻温度物料厚度;最佳工艺参数为物料厚度3 mm,升华温度35℃,预冻温度-40℃时,复水比为5.36,总色差值为9.03。该研究结果可为番木瓜片的实际生产提供一定的参考。     

栀子苷减压提取工艺优化

以栀子(Gardenia jasminoides Ellis)为原料,对栀子苷减压提取工艺条件进行优化。在单因素试验基础上,通过四因素三水平正交试验优化,以栀子苷得率为指标,研究不同提取条件对栀子苷得率的影响,确定了栀子减压提取的最佳工艺参数为提取压力0.07 MPa,提取温度60℃,料液比1∶12 (g∶mL),提取次数2次,此条件下获得的栀子苷得率为2.59%。     

微波真空干燥处理对铁棍山药多糖得率和干燥特性影响

研究微波真空干燥处理操作参数(微波功率、真空度和切片厚度)对铁棍山药多糖得率及其干燥特性的影响。以多糖得率为试验指标,采用3因素3水平正交试验,对铁棍山药的微波真空干燥工艺参数进行优化。试验结果表明,铁棍山药微波真空干燥过程中干燥阶段特征明显。所获取的铁棍山药多糖的最佳微波真空干燥操作参数为:微波功率1 200 W,真空度0.04 MPa,切片厚度8 mm。此工艺条件下铁棍山药多糖实测得率为10.01%。     

石榴渣多酚类物质提取工艺研究

以石榴渣为原料,研究了提取溶剂及其浓度、浸提温度、浸提时间和料液比对多酚提取效果的影响,并通过正交试验对4因素影响下的提取工艺进行了优化,确定了石榴渣多酚乙醇提取的最优工艺为:乙醇体积分数50%,浸提温度60℃,料液比1:20,浸提时间4h,以此优化工艺进行试验,一次提取得率为0.51%,二次提取得率为0.69%。超声波辅助提取的最佳处理时间为30min,提取2次,多酚得率为0.79%。原料干燥方式采用烘箱干燥较好。该工艺具有一定的实用性和可行性。     

超声波辅助提取多穗石柯根皮苷研究

旨在优选超声波辅助提取多穗石柯根皮苷工艺。采用控制单一变量法,分别确定超声波辅助提取多穗石柯根皮苷的料液比、乙醇浓度、浸提温度、浸提时间较优范围,然后采用L₉(3⁴)正交实验及最优组合验证实验方案优化筛选最佳提取工艺。影响多穗石柯根皮苷提取得率的因素影响大小依次为：提取时间>乙醇浓度>提取温度>料液比,最佳提取工艺条件为提取温度45℃、料液比1:30、70%乙醇浓度、提取时间35 min,在此提取工艺条件下,多穗石柯根皮苷提取得率1.421%,提取物中根皮苷纯度为3.797%,验证性实验的相对偏差RSD=0.881%,说明该最佳提取工艺重复性和稳定性较好。     

不同保存方法对蜡梅总DNA提取效果的影响及ISSR-PCR验证

本文以蜡梅新鲜成熟叶片为对照,比较了真空冷冻干燥、硅胶干燥、压标本干燥、45℃烘干、75℃烘干5种叶片干燥方法和4℃保鲜、-20℃冻存、-70℃冻存法对蜡梅总DNA提取效果的影响.结果表明硅胶干燥的样品提取的DNA完整无降解,纯度高,DNA得率为鲜叶的1/3多,压标本干燥的样品可以提到完整的DNA,DNA得率与硅胶干燥的样品相近,提取的DNA含多酚,纯度低.真空冷冻干燥样品的DNA在冷冻干燥过程中小部分受到损伤,DNA得率较鲜叶稍有下降.45℃烘干的样品可以提取到完整的DNA,纯度高,DNA得率约为鲜叶的1/2,75℃烘干的样品的DNA全部降解.ISSR扩增结果表明75℃烘干的样品提取的DNA没有获得扩增产物,其他4种干燥方法提取的DNA的扩增结果与鲜叶相同.鲜叶可在4℃冰箱保鲜存放6 d,在-20℃冰箱中冷藏半月,可在-70℃超低温冰箱中长期放置而不影响总DNA的提取质量和ISSR扩增结果.     

响应面法优化分子蒸馏纯化废次烟末中香味成分的研究

以废次烟末为原料,采用分子蒸馏技术对其超临界CO2提取物的香味成分进行分离纯化研究,以纯化物得率和感官品质为评价指标,分别考查了蒸馏压力、蒸馏温度、进料速率对其影响,采用Box-Behnken响应面法对纯化工艺的关键参数进行优化。结果表明,蒸馏温度、蒸馏压力对得率和感官品质的影响显著,得到的最优纯化工艺条件为蒸馏温度61℃,蒸馏压力111 Pa,进料速率11 m L/min,得率为1.54%,感官品质最佳。     

超声波提取芦笋中多糖的工艺研究

探索微波辅助法提取芦笋总多糖的最佳工艺,为深入研究芦笋多糖提供技术支持。采用单因素实验和3因素3水平正交试验,采用微波辅助下的水提醇沉法提取水溶性粗多糖,经真空干燥后测定粗多糖得率,以评定多糖的提取工艺。结果显示,提取芦笋粗多糖的最佳工艺条件是:料液比为1∶40,温度为80℃,时间为30min。该条件下的粗多糖得率为3.012%。     

南瓜水溶性粗多糖提取工艺的优化

报导了南瓜水溶性多糖的水提醇沉优化工艺。在单因素试验的基础上,选取南瓜水溶性多糖提取时间、提取温度和水料比3个因素进行Box-Benhnken中心组合设计,利用响应面分析法对其提取工艺参数进行优化研究。利用Design-Expert软件对南瓜水溶性多糖得率的二次多项数学模型解逆矩阵分析表明,在提取温度为72.41℃,提取时间为3.02h,水料比为33.48∶1时,南瓜水溶性多糖得率最高,最大得率预测值为2.463%,与实测值2.447%相符。利用优化工艺参数提取南瓜水溶性多糖时,具有最大的提取效果。     

Biological Activity and Quantification of Suspected Allelochemicals from Alfalfa Plant Parts

Autotoxicity restricts reseeding of alfalfa (Medicago sativa L.) after alfalfa until autotoxic chemical(s) breaks down or is dispersed into external environments. A series of aqueous extracts from leaves, stems, roots and seeds of alfalfa ‘Vernal’ were bioassayed against alfalfa seedlings of the same cultivar to determine their autotoxicity. The highest inhibition was found in the extracts from the leaves. Extracts at 40 g dry tissue l^?1 from alfalfa leaves were 15.4, 17.5 and 28.7 times more toxic to alfalfa root growth than were those from roots, stems and seeds, respectively. A high‐performance liquid chromatography (HPLC) analysis with nine standard compounds showed that the concentrations and compositions of allelopathic compounds depended on the plant parts. In leaf extracts that showed the most inhibitory effect on root growth, the highest amounts of allelochemicals were detected. Among nine phenolic compounds assayed for their phytotoxicity on root growth of alfalfa, coumarin, trans‐cinnamic acid and o‐coumaric acid at 10^?3 m were most inhibitory. The type and amount of causative allelochemicals found in alfalfa plant parts were highly correlated with the results of the bioassay, indicating that the autotoxic effects of alfalfa plant parts significantly differed.     

Changes in Seed Yield and Quality with Maturity in Onion (Allium cepa L., cv. 'Early Cream Gold')

Development of onion (Allium cepa L., cv. ‘Early Cream Gold’) seed under cool climate conditions in Tasmania, Australia occurred over a longer duration than previously reported, but similar patterns of change in yield components were recorded. In contrast to previous studies, umbel moisture content declined from 85 to 67 % over 57 days while seed moisture content decreased from 85 to 31 %. Seed yield continued to increase over the duration of crop development, with increasing seed weight compensating for seed loss resulting from capsule dehiscence in the later stages of maturation. Germination percentage was high and did not vary significantly from 53 to 77 days after full bloom (DAF), but mean germination time declined and uniformity of germination increased significantly over the same time period. The percentage abnormal seedlings declined with later harvest date, resulting in highest seed quality at 77 DAF. The results of this study suggest that the decision to harvest cool climate onion seed crops before capsule dehiscence will result in a loss of potential seed yield and quality.     

A note on the origin of Kalanchoë x vadensis Boom & Zeilinga (Crassulaceae)

Summary K x vadensis is a hybrid of K. blossfeldiana and K. marmorata obtained after doubling the number of chromosomes.     

Location of a high-lysine gene and the DDT-resistance gene on barley chromosome 7

Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans.     

Simultaneous Determination of Four Phenolic Acids in Radix Salviae Miltiorrhizae Formula Granules by QAMS

[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol...     

Avoidance of leaf rust fungi in wild relatives of cultivated cereals

Summary Avoidance of rust fungi that was based on poor appressorium induction was previously found in Hordeum chilense. In the present study 95 accessions of Triticeae were screened for avoidance of Puccinia hordei. The percentage of appressorium formation per germinated spore ranged from 6 to 90%. On none of the 41 accessions of Aegilops, Agropyron, Elymus, Secale, Thinopyrum or Triticum studied was the rate of appressorium formation lower than 25%. Lower rates of appressorium formation were, however, found on accessions of wild barley species Hordeum brachyantherum, H. marinum, H. parodii and H. secalinum. Its implications in cereal breeding are discussed.     

Variation in forage grasses as hosts of the root-knot nematode Meloidogyne naasi (Franklin) and selection for resistance in ryegrass

Summary Reactions of 13 grasses to Meloidogyne naasi varied with species; ryegrasses, fescues and their hybrids were generally susceptible and cocksfoot and timothy resistant. Marked variation in host resistance levels occurred between genotypes within cultivars.Selection of single plants, followed by tests on replicate tillers, identified resistant and susceptible genotypes in both Italian and perennial ryegrass cultivars. Resistant plants had few nematode-induced galls and fewer females and eggs than susceptibles. There was more or less continuous variation, with many genotypes intermediate between extremes of resistance and susceptibility. Selected resistant and susceptible genotypes are of use in assessing variation in nematode populations and as controls for breeding and selection programmes.     

Current and future strategies in breeding lentil for resistance to biotic and abiotic stresses

Lentil production is limited by lack of moisture and unfavorable temperatures throughout its distribution. Waterlogging and salinity are only locally important. Progress has been made in breeding for tolerance to drought through selection for an appropriate phenology and increased water use efficiency and in breeding for winter hardiness through selection for cold tolerance.The diseases rust, vascular wilt, and Ascochyta blight, caused by Uromyces viciae-fabae, Fusarium oxysporum f. sp. lentis, and Ascochyta fabae f. sp. lentis, respectively, are the key fungal pathogens of lentil. Cultivars with resistance to rust and Ascochyta blight have been released in several countries and resistant sources to vascular wilt are being exploited. Sources of resistance to several other fungal and viral diseases of regional importance are known. In contrast, although the pea leaf weevil (Sitona spp.) and the parasitic weed broomrape (Orobanche spp.), and to a lesser extent the cyst nematode (Heterodera ciceri), are significant yield reducers of lentil, no sources of resistance to these biotic stresses have been found. Directions for future research in lentil on both biotic and abiotic stresses are discussed.     

Present status and future strategy in breeding faba beans (Vicia Faba L.) for resistance to biotic and abiotic stresses

Progress is being made, mainly by ICARDA but also elsewhere, in breeding for resistance to Botrytis, AScochyta, Uromyces, and Orobanche; and some lines have resistance to more than one pathogen. The strategy is to extend multiple resistance but also to seek new and durable forms of resistance. Internationally coordinated programs are needed to maintain the momentum of this work.Tolerance of abiotic stresses leads to types suited to dry or cold environments rather than broad adaptability, but in this cross-pollinated species, the more hybrid vigor expressed by a cultivar, the more it is likely to tolerate various stresses.     

Water Extraction Process of Chinese Herbal Compound Man Gan Ning

[Objectives]To optimize the water extraction process of Chinese Herbal Compound Man Gan Ning and establish a method for its extraction and content determination...