Investigations on Fusarium spp. and their mycotoxins causing Fusarium ear rot of maize in Kosovo

After wheat, maize (Zea mays L.) is the second most important cereal crop in Kosovo and a major component of animal feed. The purpose of this study was to analyse the incidence and identity of the Fusarium species isolated from naturally infected maize kernels in Kosovo in 2009 and 2010, as well as the mycotoxin contamination. The disease incidence of Fusarium ear rot (from 0.7% to 40% diseased ears) on maize in Kosovo is high. The most frequently Fusarium spp. identified on maize kernels were Fusarium subglutinans, F. verticillioides/F. proliferatum and F. graminearum. Maize kernel samples were analysed by LC-MS/MS and found to be contaminated with deoxynivalenol (DON), DON-3-glucoside, 3-acetyl-DON, 15-acetyl-DON, zearalenone, zearalenone-14-sulphate, moniliformin, fumonisin B₁ and fumonisin B₂. This is the first report on the incidence and identification of Fusarium species isolated from naturally infected maize as well as the mycotoxin contamination in Kosovo.     

湿度换算软件包在干湿球温湿度计算中的应用

利用Visual Basic语言开发了湿度换算软件包软件,利用该软件包计算的各参量值与<湿度查算表>中所查的各参量值相差甚小(相对湿度绝对误差范围≤±0.5%RH),基本可以替代<湿度查算表>.     

不同干燥条件下挂面烹饪特性比较分析

干燥温度和相对湿度是影响挂面产品烹饪特性的主要控制条件。为明确不同温度、相对湿度及其互作对挂面烹饪特性的影响程度,分析不同干燥条件组合下挂面烹饪特性的变化规律,本文以小麦品种宁春4号为原料,实验室仿工业小试规模制作挂面,设计温度(40、60、80℃)和相对湿度(65%、75%、85%)的两因素三水平全排列干燥工艺实验,测定挂面产品最佳煮制时间、烹调吸水率、烹调损失率等煮制特性,以及煮熟挂面TPA质构特性。研究发现,不同干燥温度、相对湿度条件下,挂面煮制特性、TPA质构特性等烹饪特性存在显著差异(p0.05)。随干燥温度、相对湿度升高,挂面烹饪特性变化趋势不尽一致。温度是影响挂面烹饪特性的主要因素,其次为交互作用,以及相对湿度。干燥温度对挂面最佳煮制时间、熟挂面质构特性等有极显著影响,方差贡献率超过70%。与传统干燥工艺条件(40℃/75%)相比,干燥组合60℃/75%条件下,产品整体烹饪质量得到一定程度的改善或提高。研究结果可以为挂面干燥工艺设计与优化、产品质量控制提供参考。     

The effect of light and temperature on glucosinolate concentration in the leaves and roots of cabbage seedlings

In previous studies it was shown that the concentration of total and individual glucosinolates in brassicaceous plants can vary significantly over a 24-h period grown either in the field or under controlled conditions. The present study shows total and individual glucosinolate variation during a single day. Seedlings of cabbage grown under controlled conditions and at 14 and 15 days after emergence were moved to 20°C (Exp A) and 30°C (Exp B), with a constant photosynthetic photon flux density of 480 μmol m⁻² s⁻¹ and 75% relative humidity, over a 2-day period, during which time aerial parts and roots were sampled at regular intervals. Whilst the glucosinolate patterns of the aerial part of the plant and of the roots remained the same, the levels of major glucosinolates in the aerial part, averaged over all sampling times and 2 days, were 233 ± 60 μmol 100 g⁻¹ DW for 3-methylsulphinylpropyl and 72 ± 22 for 2-propenyl; in the roots, 2-phenylethyl and 1-methoxyindol-3-ylmethyl showed the highest average concentrations, with 678 ± 355 μmol 100 g⁻¹ DW and 411 ± 122, respectively. Total and individual glucosinolate levels showed very high significant differences between the two plant parts. Despite the constant temperature, light and relative humidity, glucosinolates varied within a 24-h period, showing ultradian rhythms that are common to several metabolic processes in plants. The results confirm previous observations that at a temperature of 20°C, close to the optimum for growth and development, the diurnal variation in glucosinolate concentration, was smaller than at 30°C. © 1998 Society of Chemical Industry     

Effect of temperature and relative humidity on yellowing rate of paddy

The effects of temperature and relative humidity (or water activity) in storage chambers on yellowing rate of paddy were investigated and then an empirical equation for predicting the yellowing rate was developed. Paddy was conditioned using saturated salt solutions at relative humidities ranging from 0.80 to 0.95 and temperatures of 35, 45, 55, 60 and 65°C. The yellowing rate was found to follow the zero order kinetics. The yellowing constant value (k) increased exponentially with temperature and increased linearly with water activity. The magnitude of apparent activation energy varied from 130–145 kJ/mol. A predictive equation for determining yellowing rate was ln k=−δa_w−/T+(γa_w)/T where a_w was water activity (valid from 0.80 to 0.95), T was absolute temperature (valid from 308 to 338 K) and , δ, and γ were constants. The results of variance analysis showed that temperature, water activity and their interaction significantly influenced the yellowing rate of paddy.     

醒发温湿度对馒头感官评定影响

选择对馒头醒发起关键作用两个关健因素:温度和相对湿度,以感官评分作为指标,找出较佳醒发温度和醒发相对湿度;结果表明,馒头醒发时最佳条件为:醒发温度40℃,醒发相对湿度85%。     

Biofilm formation and exopolysaccharide (EPS) production by Cronobacter sakazakii depending on environmental conditions

Biofilm matrices are formed largely of extracellular polymeric substance (EPS). This study was conducted to investigate biofilm formation and EPS production by Cronobacter sakazakii under various conditions (media, nutrition, and relative humidity (RH)) by quantification of EPS and cell populations, Field Emission Scanning Electron Microscope (FE-SEM), and colony observation. Various agar media conditions (TSA without dextrose (W/D), M9 minimum salt medium (MSM) agar, and M9 MSM agar with 3% glucose, 3% NaCl, 3% Tween 80, 3% sucrose, and adjusted to pH 5 with HCl) were prepared. C. sakazakii biofilm formed on the surface of stainless steel coupons (SSCs) immersed in TSB W/D and M9 MSM with or without 0, 1, 3, and 5% sucrose and subsequently exposed to various RH levels (23, 43, 68, 85, and 100%). EPS production by C. sakazakii on TSA W/D was significantly higher than that on other media after 1 and 2 days. However, C. sakazakii ATCC 12868 produced the highest levels of EPS (209.18 ± 16.13 and 207.22 ± 4.14 μg/mL after 1 and 2 days, respectively) on M9 MSM agar with 3% sucrose. Regarding C. sakazakii ATCC 12868 biofilm formed on the surface of SSCs immersed in M9 MSM with 0, 1, 3, and 5% sucrose and subsequently exposed to various RHs, populations were significantly different among the various RHs and sucrose concentrations, and EPS production was significantly higher (4.69 mg/L) compared to other sucrose concentrations (0%:0.71 mg/L and 1%:0.98 mg/L), except for M9 MSM with 3% sucrose (2.97 mg/L) (P ≤ 0.05). From these results, biofilm formation and EPS production by C. sakazakii differed depending on the nutrient or environmental conditions provided to the cells.     

不同相对湿度对板栗“石灰化”及活性氧代谢的影响

以新鲜板栗为试材,研究在不同相对湿度(50%、70%、90%)条件下进行常温(25℃)贮藏过程中,板栗的水分含量、“石灰化”指数、超氧阴离子自由基(O2－ ·)产生速率、过氧化氢(H2O2)含量、超氧化物歧化酶(super oxidase dimutase,SOD)和过氧化氢酶(catalase,CAT)活性及膜脂过氧化产物丙二醛(malondialdehyde,MDA)含量的变化,以探讨不同相对湿度对板栗“石灰化”及活性氧代谢的影响。结果表明：在高湿(90%)条件下贮藏的板栗水分含量的减少和“石灰化”指数均受到显著抑制,O2－ ·生成速率、H2O2含量和MDA含量均极显著低于在低湿(50%)条件贮藏的板栗,而SOD活性、CAT活性则极显著高于在低湿条件下贮藏的板栗。表明板栗采后贮藏在高湿环境中能有效控制“石灰化”发生,维持较高活性氧清除能力,使板栗过氧化作用较低。     

温湿度对不同吸湿剂吸湿特性及动力学模型影响

采用静态吸附法研究了无水氯化钙、六偏磷酸钠、山梨糖醇、魔芋葡甘聚糖、壳聚糖、活性氧化铝粉和膨润土等7种吸湿剂在不同温度(2、10、18℃)和相对湿度RH(76%、86%、96%)下放置15 d时的吸湿特性。结果表明,温度一定时,吸湿量随RH升高而增加;RH一定时,吸湿量随温度变化略有差异。采用Weibull模型拟合吸湿量数据,得到吸湿动力学参数M∞和β,通过线性回归得到M∞和温湿度的关系。除山梨糖醇外,Weibull模型与吸湿量拟合精度较高。M∞较高的吸湿剂为无水氯化钙(1.117~2.137g H2O/g)、六偏磷酸钠(0.297~0.856 g H2O/g)和山梨糖醇(0.083~38.567 g H2O/g),其β值范围为:无水氯化钙(25.5~119.8 h)、六偏磷酸钠(91.2~290.0 h)和山梨糖醇(1.1~185.6 h)。壳聚糖和膨润土的M∞受温度、RH的共同影响,而六偏磷酸钠和山梨糖醇的M∞仅受RH的影响。研究结果可为双孢蘑菇MA贮藏期间RH控制提供理论依据。     

Modeling and optimizing the frictional behavior of woven fabrics in climatic conditions using response surface methodology

Frictional characteristics of woven fabrics can determine smoothness and softness values of textiles. In this paper, we have studied the influence of factors such as temperature, relative humidity, fabric structure, type of fiber material, and direction of motion on roughness properties of fabric surface using response surface method (RSM). For this purpose, woven fabrics with plain, rib2/2, twill2/2, twill1/3, twill3/1, twill1/7, and twill7/1 were produced with polyester warp yarn and two different weft yarns (cotton and polyester). Then, a statistical model (RSM) was used for the experimental plan (with these variables) to determine the runs of experiment (or selected points). Next, the frictional forces measurement was carried out on the fabrics in those directions. The experimental results showed that fabric-to-fabric friction (static frictional resistance, kinetic frictional resistance, and smoothness of woven fabrics) is highly sensitive to factors like relative humidity, fabric structure, type of fiber material, and direction of motion while temperature factor (in the range 0–50°C) has no sensitive effect on frictional parameters.     

Wetgrass项目——合成草皮球场的性能及运动员舒适度的重要一步

葡萄牙纺织和服装工业技术中心(CITEVE)长期以来一直从事产业用和功能性纺织品领域的研究。CITEVE参与的Wetgrass项目旨在开发一种新的足球场合成草皮系统,以避免草坪在炎热的晴天过热,减少球员滑倒时对皮肤的磨损影响,主要目标是在提高球员的舒适度和安全性的情况下,不影响运动表现和球的正常行为。Wetgrass项目由国家创新局(ANI)和指定的2家葡萄牙公司——Safina公司(葡萄牙合成草坪制造和品牌公司)、Exporplás公司(葡萄牙单丝生产和品牌公司)共同资助,2个STC实体单位、纳米技术和智能材料中心(CeNTI)及CITEVE为项目合作人。     

不同储藏温、湿度对稻谷霉菌生长的影响及生长预测模型的建立

实验以粮仓中安全水分稻谷为研究对象,探究稻谷在不同储藏温、湿度中的霉菌生长规律,采用Logistic方程拟合稻谷霉菌在不同储藏条件下的生长动力学模型,并对模型的适用性进行评价。结果显示,在20℃及以下,霉菌数量增长缓慢,稻谷处于安全状态;25℃时,43%和75%的湿度为安全储藏条件;30℃时,仅43%的湿度为安全储藏条件;40℃时稻谷霉菌数量变化较小。Logistic方程所拟合出的各个储藏条件中霉菌生长方程的决定系数R~2为0.987±0.017,适用于描述稻谷中霉菌的生长曲线。结合B_f和A_f值,同一温度下,环境相对湿度越高,模型的准确性越低;在10～30℃范围内,随着温度的升高,模型准确性下降。     

温湿度对嗜卷书虱实验种群生长发育的影响

本文报道了不同温湿度组合条件对嗜卷书虱实验种群生长发育的影响,结果表明：温湿度对嗜卷书虱实验种群的生长发育影响极其显著。各虫态发育历期一般随着温湿度的升高而变短,温度的影响更显著;各期的存活率则随着温湿度的升高而升高,湿度的影响更大。把嗜卷书虱的世代历期与世代存活率与温度（X1）和湿度（X2）作回归得方程为：世代历期＝105．3252－3．9006X1＋0．0392X^21－0．0003X^22(R＝0．9822,P＜0．01）;世代存活率＝－330．1287＋8．7139X1＋6．7602X2－0．2290X^21－0．0497X^22＋0．0585X1X2（R＝0．9792,P＜0．01）。嗜卷书虱卵发育的起点温度为9．93℃,有效积温187．15日度;若虫发育的起点温度13．77℃,有效积温184．52日度;完成一个世代所需的有效积温为371．67日度。     

沙葱采后贮藏保鲜效果研究

目的 分析沙葱采后贮藏的特性, 建立沙葱的采后高效保鲜方法。方法 通过Spurr树脂半薄切片的方法观察沙葱的组织结构, 利用低温冷库摸索沙葱采后最适贮藏温度, 研究硬质塑料盒、硬纸盒和塑料筐等包装形式对沙葱采后保鲜的影响, 研究不同的气体组分对沙葱采后保鲜效果的影响。结果 通过对沙葱组织树脂切片的显微观察, 发现沙葱的木质部细胞壁较薄, 组织纤维化程度较低, 这导致其质地脆嫩、口感上乘, 但是同时导致其易出现失水、断节和腐烂等现象。结果表明0 ℃是贮藏沙葱的最佳温度, 在此温度下保鲜期可达15 d。沙葱通过硬质纸盒内衬软质硫酸纸包装, 常温下保鲜期可达到4 d。4% CO2+2% O2的气调组分可以有效延长沙葱的采后保鲜期, 常温保鲜期可达7 d。结论 0 ℃是沙葱最佳采后贮藏温度; 硬质纸盒内衬软质硫酸纸包装形式有利于沙葱采后贮藏; 4% CO2+2% O2是沙葱最佳气调贮藏条件。     

不同相对湿度环境条件下玉米醇溶蛋白膜的稳定性研究

以不同蛋白浓度、甘油添加量和成膜温度制备玉米醇溶蛋白膜,研究其在不同相对湿度(RH)条件下24 d储藏过程中的机械性能变化。结果表明:不同条件下制备的玉米醇溶蛋白膜,在中低相对湿度(34%、43%、54%)条件下24 d的储藏过程中,膜的抗拉强度(TS)呈现先增加后减少的趋势,而断裂延伸率(EB)则呈现先减少后增加的趋势。而在80%的高湿度环境中,不同蛋白浓度和不同成膜温度制备的蛋白膜,储藏期间TS呈现逐渐增加的趋势,EB则快速减少;不同甘油含量的膜,在RH80%环境中TS和EB的变化趋势与RH34%、RH43%和RH54%一致。RH65%环境条件下蛋白膜的机械性能的变化受成膜条件的影响较大。整体上看,储藏过程中环境湿度对玉米醇溶蛋白膜的机械性能的影响大于制备条件的影响。因此,在蛋白膜的研究中,应用的环境湿度也是需要考察的重要因素之一。     

挂面干燥特性与模型拟合研究

为研究挂面的干燥特性,采用实验室食品水分分析技术平台,研究不同温度(30,40,50℃)和相对湿度(65%,75%,85%)条件下挂面的干燥特性及其变化规律;利用数学模型拟合挂面干燥过程的含水率曲线。结果表明,温度越高,挂面的干燥速率越快,平衡含水率越低;相对湿度越低,挂面的干燥速率越快,平衡含水率越低;相对湿度对挂面干燥过程的影响大于温度的影响。干燥前期,挂面干燥速率有一个提升过程;随后,干燥速率呈线性逐渐降低。分析认为,干燥速率提升过程是挂面内外温度趋于一致的过程所致。试验证明,温度40℃,相对湿度75%,是较为合理的挂面干燥工艺;在此低温干燥条件下,热能利用率较高,也便于生产干燥工艺的调节和控制。通过对挂面干燥过程含水率模型拟合分析发现,Page模型能够很好地反映挂面干燥过程含水率的变化(R^2=0.9996)。本研究结果为进一步了解挂面的干燥特性,确定最佳干燥工艺参数提供了技术依据,为挂面干燥过程标准化、自动化提供理论和技术依据。     

不同运行参数下平房仓粮堆表层控温系统的隔热性能试验

该研究以粮食平房仓为研究对象,建立了粮堆控温试验系统,进行了不同工况下的隔热试验,研究在炎热气候下影响系统隔热效果的因素。结果表明:粮堆由外界传入热量引起的温升集中在装粮线以下10 cm的表层粮堆,粮堆表层控温系统可以有效减少外界突发高温对于表层粮温的影响,最优工况下,表层粮堆温度降低1.67℃。在送风温度、风速和层间高度诸因素中,系统送风温度对粮堆表层温升影响较大,而系统送风风速与层间高度影响较小。工程中可采取低风速、低风温的送风形式,使吨粮单位成本降低至5.6元,同时可减少能源消耗。由特征长度定义的努谢尔特数(Nu=hl/λ)表示了系统换热的强弱,无量纲过余温度Θ位于0.4～1时,Nu随Θ的增加而增加,变化范围为45～85。Nu受无量纲高度H影响不大,当H位于0.05～0.09之间时,Nu的变化范围仅为82～89。试验期间送风温度22℃,靠近系统上表面的仓内空气湿度与初始值相比下降13%,高于外界湿度5%,粮堆内部未发生结露情况。     

可持续性纸质文物保存环境温湿度调控策略研究

本研究分析了华北平原12间恒温恒湿库房和45间温湿度轻控制库房的历史温湿度,并计算了纸质文物在上述历史温湿度下保存的预期寿命和机械损伤风险。结果表明,恒温恒湿控制时,允许保存温度在推荐范围内随外界气候变化存在一定的季节波动,能够在不影响纸质文物安全的情况下,提高温湿度控制的能源经济性和保存环境的温湿度稳定性。在华北平原,大部分时段轻控制温湿度能保证纸质文物安全。凉爽/干燥季节低温保存,当大气湿度升高致保存湿度接近允许上限时,提高温度设定值,当保存温度达到允许上限后再同时控制温湿度,是全年或季节性凉爽/干燥地区的一种可持续性纸质文物保存温湿度调控策略。