Cultivar variation in response of strawberry fruit to high carbon dioxide treatments

The influence of cultivar on responses of strawberry fruit to 20 kPa CO₂ or air storage at 2 °C was measured for 7 days. CO₂ storage increased firmness of all cultivars over air storage, but the degree of increase was affected by cultivar and days in storage. CO₂‐treated fruit were lighter colored and less intensely red than air‐treated fruit. Accumulations of acetaldehyde, ethanol and ethyl acetate in CO₂‐treated fruit were strongly affected by cultivar, with those in ‘Annapolis’ having the lowest and those in ‘Governor Simcoe’ having the highest concentrations. Genetic variation in this response provides useful material for investigating the metabolic basis of CO₂ effects in strawberry fruit. © 1999 Society of Chemical Industry     

香蕉膳食纤维的研究进展

概述香蕉膳食纤维（DF）的成分及功能，着重介绍其中的抗性淀粉，比较3种香蕉DF的含量以及贮藏过程中蕉皮DF的变化情况，简介香蕉膳食纤维的加工现状。     

聚木糖酶在溶解浆制备中的应用研究

本文通过对毛竹预水解浆与非预水解浆的对比研究发现：预水解处理后浆料的灰分含量、铁离子含量高，锰酸钾值高，白度较低，不利于后续蒸煮和漂白。非预水解浆性能优于预水解浆，但聚戊糖含量偏高。实验在此前提下探索非预水解浆生物处理降低聚戊糖的可行性及其浆料性质，结果表明：细菌性聚木糖酶和真菌性木聚糖酶能降低聚戊糖含量18．8％左右，二者差异不显著（P〉0．05），但EDTA和Tween80的加入可以进一步降低聚木糖酶处理后浆料中聚戊糖含量、铁离子含量和灰分含量，同时可以提高溶解浆白度。     

富硒酵母菌株的选育

以酿酒酵母Saccharomyces cerevisiae L-11为出发菌株,通过DES多次诱变,Na2SeO3和乙硫氨酸抗性平板选择,得到一株高硒和高蛋氨酸含量的菌株L-11-7-2,其蛋氨酸含量达到1.37%,是L-11的169%.对L-11-7-2进行富硒培养,细胞内总硒和硒蛋氨酸分别为2452μg/g和1650μg/g,分别为出发株的280.2%和369.1%.     

Effects of high-pressure treatment on free fatty acids release during ripening of ewes' milk cheese

The free fatty acid (FFA) profile of high pressure treated ewes' milk cheeses were studied to assess the effect of pressure treatment on cheese lipolysis. Cheeses were treated at 200, 300, 400 or 500 MPa (2P to 5P) at two stages of ripening (after 1 and 15 days of manufacturing; P1 and P15) and FFA were assayed at 1, 15 and 60 d ripening. On the first day of ripening, 3P1-cheeses showed levels of FFA twice that of the control cheeses. However, no significant differences were found between 3P1 and control cheeses at 60 d ripening. On the contrary, 4P1 and 5P1-cheeses had the lowest total FFA levels. The point at which pressure treatment was applied influenced the FFA profile of cheeses; cheeses pressurized at pressures<400 MPa on the first day of ripening were more similar to untreated cheeses than their homologues treated at 15 d.     

Comparative Study of Monoclonal and Recombinant Antibody-Based Immunoassays for Fungicide Analysis in Fruit Juices

A comparative study of the analytical performance of enzyme-linked immunosorbent assays (ELISAs), based on monoclonal and recombinant antibodies, for the determination of fungicide residues in fruit juices has been carried out. To this aim, three murine hybridoma cell lines secreting specific monoclonal antibodies against (RS)-2-(2,4-dichlorophenyl)-3-(1H-1,2,4-triazol-1-yl)propyl-1,1,2,2-tetrafluoroethyl ether (tetraconazole), 2-(4-triazolyl)benzimidazole (thiabendazole), and (RS)-1-(β-allyloxy-2,4-dichlorophenylethyl)imidazole (imazalil) were used as a source of immunoglobulin gene fragments for the production of single-chain variable fragment (scFv) and fusion scFv-pIII recombinant antibodies in Escherichia coli. Selected recombinant antibodies displayed cross-reactivity profiles very similar to those of the parent monoclonal antibodies. Imazalil and tetraconazole recombinant antibodies showed one order of magnitude lower affinity than their respective monoclonal antibodies, whereas the thiabendazole recombinant antibodies showed an affinity similar to that of their parent monoclonal antibody. On the other hand, scFv-pIII fusion fragments showed similar analytical properties as, and occasionally better than, scFv recombinant antibodies. Finally, ELISAs developed from each antibody type showed similar analytical performance when applied to the analysis of the target fungicides in fruit juices.     

安徽省部分城乡居民血清维生素A水平及相关因素分析

了解安徽省部分城乡地区6周岁以上居民维生素A营养状况及其相关因素分析。通过多阶段分层与人口成比例的整群随机抽样的方法抽取安徽省合肥市某区和安庆市某农村年龄在6周岁以上居民468名,于2010年8月至2010年10月进行问卷调查,并采集清晨空腹静脉血分离血清,用超高效液相色谱(UPLC)测定血清视黄醇浓度水平,同时测定部分生理生化指标。研究对象血清维生素A缺乏及边缘性缺乏率为15.6%(血清视黄醇0.3μg/mL),维生素A正常率为84.4%(血清视黄醇0.3μg/mL)。调查对象的维生素A水平在地区、性别、年龄、受教育程度、人均年收入、BMI、DBP、SDP、TC和TG分布上存在差异(P0.05)。单因素线性回归分析发现血清视黄醇浓度水平与地区、年龄、受教育程度、BMI、DBP、SBP、TC、TG和Hb呈正相关。多元线性回归分析发现血清视黄醇浓度水平与地区、年龄、TC和TG呈正相关。安徽省部分城乡地区6周岁以上居民存在一定比例的维生素A缺乏状况,并可能受地区、年龄、性别、TC和TG等因素影响。     

烟叶质量评价指标间的典型相关分析

以湖南主产烟区烤烟样本为材料,通过对烟叶外观质量和评吸质量的量化评定以及对烟叶物理性状和化学成分的测定,应用典型相关分析方法分析了烟叶外观质量、物理性状、化学成分和评吸质量评价指标间的典型相关性.结果表明:烟叶外观质量、物理性状、化学成分和评吸质量评价指标间均存在显著典型相关关系,烟叶化学成分与评吸质量关系最密切,其次是外观质量与物理性状;烟叶质量不同评价指标的关系程度是不一样的,在烟叶质量组间关联上起主要作用的外观质量评价指标是成熟度、叶片组织结构和发育状况,物理性状评价指标是叶片厚度、单叶重和叶质重,化学成分评价指标是烟碱和还原糖,评吸质量评价指标是香气量、香气质和灰色.利用典型相关分析来简化烟叶质量评价指标是可行的.