New insight into the genetic structure of the Allolobophora chlorotica aggregate in Europe using microsatellite and mitochondrial data

The taxonomic status of Allolobophora chlorotica is still the subject of considerable discussion. After the recent experimental demonstration that the two regularly observed colour morphs (pink and green) were not fully interfertile and likely represent two distinct species, molecular analyses revealed a more complex picture with the occurrence of five mitochondrial lineages (named L1 to L5) in A. chlorotica, two within the green morph and three within the pink morph. Although nuclear markers (AFLPs) confirmed that the pink morph might consist of three different taxa, AFLPs data suggested that the green morph may be a single taxon. In order to further characterize the population genetic structure within A. chlorotica in addition to test for reproductive isolation between lineages, eight polymorphic microsatellite loci were developed using a microsatellite-enriched genomic library from an individual belonging to lineage L2. The number of alleles per locus varied from 9 to 29 in a set of individuals belonging to L2. Considerable sub-structure was observed within L2 populations suggesting a low dispersal capability in this species and a distribution of the individuals in patches that could function as panmictic units. These markers were transferable to the other lineages but only five loci could be amplified consistently in four of the lineages (L1, L2, L3 and L4). Microsatellite data confirmed that the green morph represents a single taxon. Although the integrity of the three previously documented lineages within the pink morph was also generally supported by the data, microsatellites provided evidence for hybridization between lineages and between morphs in the field. Moreover, mitochondrial data revealed the existence of two additional mitochondrial lineages within the pink morph. The taxonomic status of the pink morph remains thus unclear, requiring a thorough and comprehensive study.     

长白猪NEAT1基因C1149G多态性位点与血液和免疫性状的关联(英文)

NEAT1是一个长的非编码RNA,参与了免疫反应、paraspeckle形成以及mRNA的输出等生物学过程。本研究利用PCR-RFLP方法检测了猪(Susscrofa)NEAT1一处C1149G单核苷酸位点的多态性,在检测的猪品种中等位基因频率变异较大。关联分析结果表明,在长白猪群体中CC基因型个体,0日龄和17日龄猪瘟病毒(CSFV)抗体水平,0日龄平均红细胞体积和32日龄红细胞平均血红蛋白浓度显著高于GG或CG基因型;而32日龄的血小板分布宽度、血小板平均容积和大血小板比率则显著低于GG或CG基因型。实验结果可以为猪的分子标记和辅助育种提供参考。     

复合干型富硒苹果酒酿造的响应面工艺优化研究

为提升干型苹果酒的品质及酿制技术,对发酵工艺进行优化研究。以单一苹果作为原料生产的果酒缺乏独特风味,而为了改善苹果酒的香味和口感,研究以苹果为主料,并优选含糖量高、香气较浓郁的红富士、金冠和偏酸的澳洲青苹3个品种的苹果汁与四种富硒水果汁按一定比例进行了双重混合发酵。发酵中先通过单因素试验,后进行响应面设计中心组实验优化发酵参数,以酒精度和硒含量为响应指标,得到其最适发酵条件:酵母添加量0.3%,发酵温度为25.0℃,SO₂用量100 mg·L^-1;最佳配比4.5∶1.5∶2。制得的复合干型富硒苹果酒无论从口感、外观、香气还是营养价值上均得到了提升。     

不同淀粉对小麦面团流变学特性及馒头品质的影响

向小麦粉中添加马铃薯淀粉、绿豆淀粉和玉米淀粉,研究淀粉种类及添加比例对面团流变学特性及馒头品质的影响。结果表明:添加马铃薯淀粉和绿豆淀粉,面团吸水率随添加量增大呈下降趋势,添加玉米淀粉则吸水率呈上升趋势;面团拉伸能量随淀粉添加量增大而减弱,延伸度先增大后减小。综合来看,添加淀粉使得面团面筋网络结构不同程度弱化,小麦粉中淀粉添加量不宜超过20%。     

玉米胚芽粕在面包制作中的应用

利用榨取油脂后的玉米胚芽粕开发面包新品种,以提高玉米加工附加值为目的,采用面团特性测定和面包质量评价的方法,对6个添加不同含量玉米胚芽粕的样品面团流变学特性和面包品质特性进行分析。结果表明,随着每1 kg面粉中玉米胚芽粕添加量由0 g增加到90 g,面团吸水率由65.1%上升到78.1%,弱化度由78 BU上升到120 BU;而稳定时间则由16.5 min下降到4.9 min,形成时间由14.2 min下降到8.2 min,最大拉伸阻力由533BU下降到330 BU,面团评价值由104.7 cm2下降到43.9 cm2;面包样品的体积由6 750 mL/kg迅速下降到4 500mL/kg,面包的色泽、质地、口感等其他品质指标均有下降趋势。据此认为,在面包制作中,添加玉米胚芽粕是可行的,但为了使面包品质不受较大影响,面粉中玉米胚芽粕的添加量应不超过50 g/kg。     

Einfluss differenzierter Stickstoffdüngung auf Kornertrag und Backqualität von Winterweizen: (Effect of different nitrogen fertilization on yield and bread-making quality of winter wheat)

Abstract

In the “International Long-term Organic Nitrogen Fertilization Experiment” (IOSDV) the organic and mineral fertilization showed a distinct influence on yield formation and quality parameters of winter wheat, though modified by annual weather conditions. Grain yield was affected by annual weather conditions in the first place, followed by mineral N-fertilization and organic fertilization respectively. This result was due to soil conditions at the experimental site. Dry periods during the stages of spikelet formation and flowering formation, which were caused by water deficiency, reduced the yield components strongly. The yield optimum was reached at the level of 110 and 160 kg ha^?1 mineral N on the sandy soil at the location of Berlin-Dahlem. The highest nitrogen level caused non effective or slight yield depressions, especially in the “green, straw and sugar beet leaf manure” fertilization system. Organic N-fertilization (farm yard manure, straw, green manure and beet leaf fertilization) led to significant increases of winter wheat yield in the course of which biggest differences were observed when combined mineral N-fertilization was missing. The bread-making quality of B-wheat variety Flair was primarily dependent on mineral N-fertilization. Necessary values for bread wheat were predominantly obtained only, when mineral N-fertilization rates of 110?–?160 kg ha^?1 were applied. Organic N-fertilization?–?especially farmyard manure?–?improved the bread-making quality of wheat as well in treatments without mineral-N as in combination with mineral-N-fertilization.     

Changes of β-glucan physicochemical characteristics in frozen and freeze dried oat bran bread and porridge

The ability of oat foods to lower serum cholesterol and post-prandial blood glucose concentrations has been linked to the physicochemical properties of the bioactive component, mixed linkage β-glucan. Oat foods frequently need to be shipped or stored prior to analysis and β-glucan characteristics may change over time. Reductions in β-glucan solubility or molecular weight lead to lower viscosity development which decreases bioactivity. Impact of freezing and freeze drying conditions on the β-glucan physicochemical characteristics in oat bran bread and porridge were studied. Two in vitro digestibility methods were used to produce physiological extracts and the results were compared. The β-glucan molecular weight, solubility and viscosity for oat bread stored at room temperature were unchanged for 3 days, followed by a gradual decline in these parameters. The extract viscosity for bread decreased significantly after freezing at −80 °C and freeze drying after freezing at −18 and −80 °C, whereas freezing in liquid nitrogen did not significantly influence viscosity. Freezing of oat bran porridge did not affect extract viscosity, but freeze drying resulted in reduction of extract viscosity compared to the fresh porridge. Freezing and freeze drying did not dramatically affect the molecular weight or solubility of β-glucan in either product. The rapid visco analyzer was more effective and reliable for sample digestion than when physiological extraction was conducted in the shaking water bath. Generally, freezing at −18 °C or by submersion in liquid nitrogen maintained the physicochemical characteristics of β-glucan in food products either for commercial products or subsequent analysis.     

Improvement in gluten-free rice bread quality by protease treatment

The wide prevalence of gluten-related disorders has led to increase in the demand for gluten-free foods. Rice is a gluten-free and less allergenic cereal. However, bread made from rice flour, i.e., gluten-free rice bread, is generally of poor quality because rice flour cannot develop a network with gluten-like properties. In this study, we investigated the effects of protease treatment on gluten-free rice to improve the quality of its bread. Bread treated with a commercial protease from Bacillus stearothermophilus (thermoase) was of higher quality, i.e., good crumb appearance, high volume, and soft texture, depending on the amount of enzyme added. Rice proteins in the protease-treated bread were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, which showed that glutelins and prolamins were hardly digested by thermoase in comparison with other proteins. Scanning electron microscopy revealed that many cellular structures were formed in the thermoase-treated bread; however, these structures were rare in the untreated control. Bread crumb color was not affected by the treatment. The staling rate was much lower for the thermoase-treated bread than for the control. These results indicate that thermoase treatment can be successfully used to improve the quality of gluten-free rice bread by partial digestion of rice proteins.     

Effect of sodium selenite addition and sponge dough fermentation on selenomethionine generation during production of yeast-leavened breads

The effect of sodium selenite addition and fermentation times on production of selenomethionine (SeM) during sponge bread production was evaluated. Doughs were supplemented with sodium selenite (Na₂SeO₃) and fermented with yeast, avoiding addition of sulfur salts. The effect of Na₂SeO₃ on yeast activity was evaluated using a pressurometer. Results showed that there were not statistical differences (p < 0.05) in CO₂ production and dough pH at all the sodium selenite concentrations tested. HPLC-fluorescence data showed that SeM production was higher with the increase of fermentation times, while less significant effects were observed due to changes in Na₂SeO₃ concentration. Two slices of Se-enriched bread can provide about 200 μg SeM, the dose recommended to prevent cancer and oxidative stress. The physical features (water absorption, bread weight, bread volume, color, density, oven spring, etc.) and organoleptic evaluations for the enriched loaves were evaluated. In all these parameters, the experimental enriched breads had practically identical attributes compared to the control. The breads rich in SeM have potential to be used as functional foods because this amino acid is synthesized into higher quantities of glutathione peroxidase, an enzyme considered as one of the most protective mechanisms against oxidative stress and preventive of cancer and chronic diseases.     

全橙果渣面包工艺优化及受欢迎度评价

橙子切块加水打浆后,将橙子渣添加到高筋小麦粉中制得全橙果渣面包,在单因素试验的基础上进行响应面分析优化全橙果渣面包工艺。结果表明,全橙果渣面包的最佳工艺为:高筋小麦粉500 g,全橙果渣140 g,牛奶200 g,白砂糖72 g,酵母10 g,食盐7 g,黄油31 g,焙烤温度为上火210℃、下火180℃,焙烤时间12 min,得到具有鲜橙特殊色泽、香气、滋味的营养面包。此工艺条件下烘烤出的全橙果渣面包纤维素含量增加了60%,经过模糊数学计算,受欢迎度值80.68,为非常喜欢。