改善夏秋绿茶滋味品质研究现状

本文在论述绿茶滋味构成和环境条件对滋味影响的基础上,总结了目前改善夏秋绿茶滋味品质的技术措施,并建议重点发展茶林间种、茶果间种、茶粮间作等模式的复合生态茶园,推广蒸汽杀青和微波干燥等技术措施,以进一步改善夏秋季绿茶滋味品质。     

One tube nested-PCR在SNP基因型分型中的应用

nested–PCR是一种在普通PCR基础上发展起来的专门用于检测单核苷酸多态性(SNP)的技术。结合nested–PCR技术在水稻中检测SNP的研究,以1个水稻香味基因Fgr和3个稻瘟病基因Pi–ta、Pi9、Pigm为例,把nested–PCR的4条引物同时加在一管PCR反应中进行扩增,在其序列内针对SNP位点设计功能标记,用来扩增含有突变位点的DNA片段。通过优化引物浓度梯度和改良反应程序,达到了一步快速检测SNP基因型的目的。     

草鱼柠檬酸合酶基因SNP筛选及与生长性状的关联分析

根据草鱼(Ctenopharyngodon idella)EST-SNP库中预测的柠檬酸合酶基因的1个Contig序列,设计引物扩增该基因的部分序列,然后采用PCR产物直接测序法筛选SNP突变点。测序的序列经比对后,共筛选到2个在内含子10上的SNP突变点:A-386G和C-499G。随机选择同批繁殖和同塘混养的144尾草鱼对2个SNP位点用Snapshot方法进行检测和分型,并统计基因型频率。A-386G位点的AA基因型占47.10%,AG基因型占38.41%、GG基因型占14.49%;C-499G位点的CC基因型占31.85%,CG基因型占46.67%,GG基因型占21.48%,均属于中度多态位点。利用一般线性模型(GLM)分析2个SNP位点与草鱼6个生长性状(体质量、体长、体高、头长、尾柄长和尾柄高)的相关性,结果显示,A-386G和C-499G位点的不同基因型在这6个生长性状均值有差异,但均不存在显著差异。将这2个SNP不同基因型两两组合,一共组成7种双倍型(去掉频率小于3%的组合D2和D5),GLM相关分析表明5种双倍型在5个生长性状(体质量、体长、体高、尾柄长和尾柄高)上均存在差异,其中在头长上存在显著差异,D6双倍型(A-386G/AG和C-499G/GG)在6个生长性状上均值均最大,属于生长优势双倍型。本研究显示,筛选到的柠檬酸合酶基因上的2个SNP位点具有用于草鱼生长性状的分子辅助育种的潜力。     

麻味与麻姜味营养型核桃调味油的配制

为全面提升核桃深加工技术,延长产业链、提高核桃产业整体经济效益,采用气质联用测定核桃油、紫苏油、花生油、菜籽油、米糠油、芝麻油等原料油内脂肪酸的构成,利用 Matlab 软件将核桃油与紫苏油等原料油调配成脂肪酸合理构成的调和油,再加入花椒精油、姜精油进行风味调配,通过正交试验优化麻姜味营养型核桃油的配方。结果表明：脂肪酸合理构成的调和油配方为核桃油30％,紫苏油1．64％,菜籽油41．13％,花生油27．24％;麻味营养型核桃调味油的花椒精油添加量为16％;麻姜味营养型核桃调味油的花椒精油和姜油添加量分别为16％和0．9％。该类调味油呈自然棕黄色,外观澄清透明,理化指标均符合国家一级压榨油标准,口感滋味宜人,兼有花椒的清新麻香味和生姜的辛辣芳香味。     

湖南浓香型产区烟叶口感特性感官评价

为明确湖南浓香型产区烟叶口感特性评价指标的区域状况和空间分布特征,对来自湖南浓香型产区21个主产烟县的44个烟叶样品进行感官评价。结果表明:①湖南浓香型产区烟叶刺激性和干燥感稍有,余味尚净尚舒适。②烟叶刺激性、干燥感和余味地区间差异不显著。③不同县之间刺激性标度值以嘉禾县最低,干燥感标度值以新田县最低,余味标度值以嘉禾县最高。④2012年烟叶刺激性和干燥感标度值极显著高于2011年,但余味在年际间差异不显著。⑤刺激性和干燥感标度值在空间上有从北向南递减的分布趋势,余味标度值在空间上有从南向北递减的分布趋势。⑥根据聚类分析结果将湖南浓香型产区烟叶口感特性分为好、较好和一般3种类型。     

M_(26)中间砧对‘泰山嘎拉’苹果果实品质和味感的影响

为了给‘泰山嘎拉’苹果的优质生产理论和技术提供基本资料,研究探讨了M26中间砧对‘泰山嘎拉’果实品质和味感的影响。结果表明:以八棱海棠为基砧,采用M26中间砧嫁接‘泰山嘎拉’,与未采用M26中间砧嫁接的对照相比,果实单果重由208.06g增加到232.83g,差异极显著,果皮花青苷、可溶性固形物和维生素C含量显著升高,果肉硬度显著增加,但果形指数没有显著性变化;在采用和未采用M26中间砧嫁接的‘泰山嘎拉’果实中均检测到3种糖与6种有机酸组分,其中糖组分均以果糖含量较高,葡萄糖、蔗糖次之,有机酸组分含量均以苹果酸最高,琥珀酸、草酸、乙酸、柠檬酸、酒石酸较低;采用M26中间砧嫁接的‘泰山嘎拉’果实果糖、葡萄糖含量及糖总量显著高于对照,其果实甜味指数绝对值与风味指数值分别为1 759和3 999,也显著高于对照值。上述结果表明,M26中间砧对提高‘泰山嘎拉’的果实品质和味感具有促进作用。     

Taste effects of oligopeptides in a Vietnamese fish sauce

ABSTRACT: A Vietnamese fish sauce Nuoc mam used in the present study was rich in oligopeptides of which nitrogen content accounted for 20% of total nitrogen. The high-molecular-weight peptide fractions fractionated by ion-exchange chromatographies and ultrafiltration enhanced sweetness and umami as well as sourness and bitterness of the fish sauce, and increased several flavor characteristics including continuity, first taste and aftertaste. Thus, it is apparent that large amounts of peptides produced during the long-term fermentation of fish sauce are responsible for the complicated taste of the sauce. From each fraction, 17 peptides in total were isolated and determined for their amino acid sequences. These di-, tri- and tetra-peptides synthesized by solid- or liquid-phase method gave any one of bitter, sour, umami taste, or practically no taste in the absence of salt. In the presence of 0.3% NaCl, however, almost all peptides showed sweet and umami tastes. Other than these 17 peptides, there existed many other kinds of peptides in the fish sauce. Thus, these peptides are thought to contribute to the overall taste of the fish sauce.     

Primary taste center in the goatfish of genus Parupeneus

ABSTRACT:   This study was carried out to obtain fundamental information on the morphology of the primary taste center in the goatfish of genus Parupeneus. The primary taste center includes a dorsal facial lobe (dFL), ventral facial lobe (vFL) and vagal lobe (VL). The dFL is extraordinarily developed rostrocaudally to occupy the dorsal surface of the medulla. The vFL extends as a longitudinal column between the dFL and VL, and its rostral end connects to the proximal portion of the dFL at the level of most anterior medulla. The VL appears slightly caudal to the rostral end of vFL as a longitudinal column and reaches more caudally than the facial lobe (FL). The dFL includes tubercular and laminated structures. Each tubercle consists of four layers: a marginal layer, a superficial molecular layer, a cell-cluster layer and a deep layer. Sublaminar organization was also found in the cell-cluster layer. No laminar organization was found in either the vFL or VL but distinct clusters of small cells were frequently seen throughout both the lobes. Tracing experiments with the carbocyanine dye diI show that the facial fibers end in the entire dFL and vFL and the anterior portion of the intermediate nucleus of the facial lobe (NIF), while glossopharyngeal fibers terminate in the dorsolateral portion of the anterior VL and the intermediate portion of NIF. Trigeminal fibers project only to the most lateral aspects of the anterior vFL in addition to normal targets such as spinal trigeminal and medial funicular nuclei.     

Genetic variants of IL-33 are associated with clinical phenotypes of inflammatory bowel disease in Han population of southern China

AIM：To investigate whether the single nucleotide polymorphisms (SNPs) of interleukin-33 (IL-33) gene are associated with inflammatory bowel disease (IBD) in the Han population of southern China. METHODS：Eight tag-SNPs were selected from the IL-33 gene using the HapMap database. These tag-SNPs were genotyped in 250 Crohn disease (CD) patients, 115 ulcerative colitis (UC) cases and 622 healthy controls by MALDI-TOF MS assay. RESULTS：No difference of the distribution frequencies of genotypes and alleles between the cases and the controls was observed (P>0.05). Genotype-phenotype analysis suggested that several sites were associated with clinical phenotypes of CD.The T allele of SNP rs10118795 was a protective factor for extra-intestinal manifestation (EIM; P<0.05, OR=0.513, 95% CI： 0.281~0.938), while the CC genotype of SNP rs7025417 (P<0.05, OR=1.363, 95% CI： 1.006~1.846) was a risk factor for EIM. The C allele of rs10118795 decreased the risk for developing perianal lesions (P<0.05, OR=0.480, 95% CI： 0.232~0.994), while the CC genotype of rs10975519 was a risk factor for perianal lesions (P<0.05, OR=2.054, 95% CI： 1.053~4.009). The G allele of rs10975509 increased the risk of upper gastrointestinal CD (P<0.05, OR=3.570, 95% CI： 1.328～9.600), and the A allele of it increased the risk for developing ileocolonic CD (P<0.05, OR=0.613, 95% CI： 0.377~0.996). In the aspect of treatment, the genotypes of rs10118795, rs10975509 and rs7025417 were associated with mucosal healing after infliximab treatment for 30 weeks (P<0.05, P<0.01 and P<0.05). In the UC patients, no significant effect of the selected 8 tag-SNPs on the UC phenotypes was observed. CONCLUSION：Eight polymorphisms of IL-33 do not increase the risk of CD and UC in the Han population of southern China, but some of them have an effect on the clinical phenotypes of CD, and 3 SNPs may be potential markers for prediction of effectiveness of infliximab treatment.