京尼平交联乳清蛋白和壳聚糖膜的制备

以乳清蛋白和壳聚糖为原料制备复合膜,同时利用天然无毒的京尼平作为交联剂,研究其制备工艺。通过单因素试验研究成膜材料比例、热处理温度、塑形剂、交联剂对乳清蛋白和壳聚糖复合膜性能的影响,并对复合膜进行表征和抑菌性研究。结果表明,京尼平可以作为交联剂用来制备乳清蛋白和壳聚糖复合膜,并且可以较好地改善复合膜的拉伸性能和阻隔性能,膜制备的最佳工艺条件是乳清蛋白(WPC)与壳聚糖(CS)配比为6:4,甘油添加量4%,热处理温度70℃,京尼平添加量0.4%,此时复合膜的拉伸强度(TS)1.79 MPa,断裂伸长强度(E)30.28,透光率(T)37%,水蒸气透过率(WVP)1.25,溶解性(S)34%。在此条件下制得的复合膜具有良好的阻隔性能、抗拉强度、致密性和抑菌性能,可用于食品保鲜和抗菌内外包装的使用。     

明胶-壳聚糖可食膜的制备及性能表征

以明胶和壳聚糖为成膜材料,以水蒸气透过率、抗拉强度和断裂伸长率为考察指标,研究可食膜制备的最佳工艺条件,同时采用红外光谱、X-射线衍射、扫描电镜和热稳定性分析对可食膜进行了性能表征研究。结果表明,最佳成膜工艺条件为:明胶与壳聚糖共混比例4∶6,明胶浓度1.5%,甘油浓度0.3%,吐温-80浓度0.1%,该工艺条件下制得的可食性共混膜较单一成分的膜具有较低的水蒸气透过率,且抗拉强度和断裂伸长率较高。对复合膜的性能表征研究结果表明,明胶与壳聚糖之间相容性较好,相互作用强烈。     

亚麻籽壳中提胶的工艺研究

研究探讨了从亚麻籽壳中提胶的关键因素料液比、浸提温度、浸提液pH值、浸提时间对亚麻籽胶提取率的影响。结果表明,料液比对亚麻壳提胶的提取率影响最大,其次为浸提温度和浸提液pH值,浸提时间对提胶提取率的影响最小。从亚麻籽壳中提胶的最佳工艺组合条件为料液比1∶16 (g∶m L),浸提温度75℃,浸提液pH值6.5,浸提时间90 min。在此条件下亚麻籽胶的提取率为26.7%±0.2%,所得胶的黏度为6 188±18.2 m Pa·S。用亚麻籽壳提取胶质具有高效低耗的特点,是亚麻籽综合开发利用可以选择的方向之一。     

南疆一膜三行栽培棉花根系分布对灌水频次的响应

【目的】在3 900 m³·hm^-2灌溉定额下，研究膜下滴灌灌水频次对南疆棉花根系形态与分布的影响。【方法】以中棉所96A为试验材料，采用76 cm等行距配置；设置4个灌水频次处理，分别为灌水6次(T6，单次灌水量650.0 m³·hm^-2)、灌水8次(T8，单次灌水量487.5 m³·hm^-2)、灌水10次(T10，单次灌水量390.0 m³·hm^-2)和灌水12次(T12，单次灌水量325.0 m³·hm^-2)；采用土壤根系挖掘法分层采集中间行棉花0～60 cm土层的根系，利用根系扫描仪进行扫描，然后统计分析根表面积、体积等指标。【结果】在南疆一膜三行等行距栽培模式下，0～60 cm土层中直径小于1 mm的根系的根长和根表面积分别占总根长和总根表面积的94.5%和71.9%。根总体积与根直径紧密相关，随着根直径的增加，各处理的根长、根表面积、根体积呈现先减小后增加的...     

羧甲基化马铃薯渣基可食性包装膜的制备及特性研究

以羧甲基马铃薯渣为基料,辅以增塑增强等改良助剂,研制一种新型羧甲基马铃薯渣基可食性包装膜,通过食性包装膜的机械性能、阻隔性能、速溶性能以及封合特性等进行研究,结果表明可食性包装膜优化制备工艺参数为羧甲基马铃薯薯渣添加量2.0 g,壳聚糖的添加量0.2 g,海藻酸钠1.2 g,甘油1 mL,硬脂酸0.2 g,所制备的可食性包装膜膜厚为90±3μm,抗拉强度7.88±0.03 MPa,速溶时间25±1 s,水蒸气透过系数仅0.218±0.006 g·mm /（m2·d·kPa）,氧气透过系数仅2.011±0.007 cm3·cm/（cm2·s·Pa）,透油系数0 g·mm/（m2·d）,封合强度高达7.47±0.01 N/15 mm。可食性包装膜质地光洁均一、细腻耐折,可用于食品调味料及粉剂等可食性绿色包装。     

羧甲基化马铃薯渣基可食性包装膜的制备及特性研究

以羧甲基马铃薯渣为基料,辅以增塑增强等改良助剂,研制一种新型羧甲基马铃薯渣基可食性包装膜,通过食性包装膜的机械性能、阻隔性能、速溶性能以及封合特性等进行研究,结果表明可食性包装膜优化制备工艺参数为羧甲基马铃薯薯渣添加量2.0 g,壳聚糖的添加量0.2 g,海藻酸钠1.2 g,甘油1 mL,硬脂酸0.2 g,所制备的可食性包装膜膜厚为90±3μm,抗拉强度7.88±0.03 MPa,速溶时间25±1 s,水蒸气透过系数仅0.218±0.006 g·mm/(m2·d·kPa),氧气透过系数仅2.011±0.007 cm3·cm/(cm2·s·Pa),透油系数0 g·mm/(m2·d),封合强度高达7.47±0.01 N/15 mm。可食性包装膜质地光洁均一、细腻耐折,可用于食品调味料及粉剂等可食性绿色包装。     

不同厚度聚乙烯薄膜对韭薹低温贮藏品质的影响

为建立冷藏条件下韭薹自发气调包装(MAP)保鲜方法,将新鲜预冷的韭薹(200±0.5)g密封包装于25 cm×60 cm的聚乙烯(Polyethylene,PE)薄膜包装袋内,薄膜厚度分别为10、20、25、30、45μm,于(0±0.5)℃下贮藏105 d,研究不同O₂和CO₂透过率的薄膜对韭薹贮藏过程中包装袋内O₂和CO₂体积分数及产品品质的影响。结果表明,不同O₂和CO₂透过率的聚乙烯薄膜包装处理都可以很好地抑制韭薹品质劣变;不同处理组之间袋内O₂和CO₂的体积分数均存在显著差异(P<0.05);45μm PE袋(O₂透过率(4 080±352)cm³·m^-2·d^-1·0.1 MPa^-1、CO₂透过率(16 566±1 415)cm³·m^-...     

壳聚糖-植酸复合膜的制备及其对鲈鱼片保鲜品质的影响

以壳聚糖为成膜剂,植酸为抗氧化剂,并添加丙三醇制备一种具有保鲜性能的壳聚糖-植酸复合膜。以复合膜的拉伸强度、断裂拉伸率、水蒸气透过系数、透光率为考察指标,进行单因素试验,再以拉伸强度为响应值,运用Design Expert 软件对壳聚糖添加量、植酸添加量、丙三醇添加量进行三因素三水平响应面试验设计。以感官品质、色差、电子鼻分析为指标,探究复合膜对鲈鱼保鲜风味效果的影响。结果表明,复合膜的最佳工艺配方为：壳聚糖添加量1.5 g/100 mL,植酸添加量0.06 g/100 mL,丙三醇添加量0.225%。此条件下制成的复合膜工艺最好,拉伸强度可达29.281 MPa。由该复合膜包裹的鲈鱼片可以保持较高的感官品质,有效控制L*、a*值的降低和b*值的升高。采用电子鼻进行气味检测,发现随着储藏时间的延长,PE保鲜膜包裹的鲈鱼肉响应强度大于复合膜组。按最优配方制备的壳聚糖-植酸复合膜对鲈鱼片具有一定的保鲜效果。     

花色苷稳定性及其微胶囊制备研究

采用紫外分光光度法,分析温度、光照、pH及蔗糖质量浓度4个因素对花色苷稳定性的影响;为提高花色苷的稳定性,研究以海藻酸钠为壁材,CaCl₂和壳聚糖为固化剂,制备花色苷微胶囊的工艺配方。结果表明,花色苷稳定性降低(以花色苷质量分数低于30%为限)的临界条件分别为：40℃、室内光、pH 3.0、蔗糖质量浓度100 mg/mL,其中温度对其稳定性的影响最大;花色苷微胶囊的最佳制备工艺为：使用针头孔径为0.70 mm的注射器,芯壁比1∶4(V/V),海藻酸钠质量浓度30 mg/mL,CaCl₂质量浓度20 mg/mL,壳聚糖质量浓度15 mg/mL,该工艺条件下制备的花色苷微胶囊呈球状,表面光滑,包埋率为91.54%。     

鼠尾草酸米糠蛋白复合膜的制备及性能研究

开发具有生物活性的鼠尾草酸可食性米糠蛋白复合膜,并研究其物理性能、结构及抗氧化活性。以米糠分离蛋白为成膜基质,添加鼠尾草酸制成复合膜,通过检测抗拉强度测试其机械性能,通过测定水蒸气透过率、透光率,通过扫描电镜等手段阐明其组织结构,并通过氧自由基清除能力判断其抗氧化性,研究和探讨鼠尾草酸米糠蛋白复合膜的理化性能。鼠尾草酸添加量在0~0.8%(W/V)时,随着添加量的增加,复合膜的透明度升高,颜色逐渐加深变为墨绿色,抗拉强度和断裂伸长距离均先升高后降低;0.5%鼠尾草酸添加量下米糠蛋白复合膜具有最大抗拉强度(984 g)和最长断裂距离(5.89 mm)。添加鼠尾草酸的米糠蛋白复合膜水蒸气透过率比未添加对照组有所提高,可见该膜具有较好的组织结构。添加鼠尾草酸的米糠蛋白复合膜,随着添加量的增大,该复合膜的自由基(DPPH·)清除活性提高,该复合膜的抗氧化活力(p0.05)显著提高。结果显示,所制备的鼠尾草酸米糠蛋白复合膜具有抗氧化性能,可应用于包装行业。     

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.     

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.     

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.     

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...