Effect of UV-C irradiation on inactivation of Aspergillus flavus and Aspergillus parasiticus and quality parameters of roasted coffee bean (Coffea arabica L.)

ABSTRACT

This study investigated the antifungal effect of ultraviolet-C (UV-C) against Aspergillus flavus and Aspergillus parasiticus on roasted coffee beans. Also, any changes in the quality of the roasted coffee beans were measured after UV-C irradiation. As UV-C irradiation time increased (0–2 h), the number of surviving A. flavus and A. parasiticus spores significantly (P < .05) decreased. The reduction values of A. flavus in round part, crack part, and whole roasted coffee beans were 2.16, 0.71, and 1.58 log₁₀ CFU g^?1, respectively, and the reduction values of A. parasiticus in round part, crack part, and whole roasted coffee beans were 1.03, 0.37, and 0.72 log₁₀ CFU g^?1, respectively, after 2 h of UV-C irradiation. Field emission scanning electron microscopy showed that the morphology of A. flavus and A. parasiticus spores included expanded wrinkles that were deformed by UV-C irradiation. The Hunter colours were significantly reduced (P < .05). There was no significant change (P > .05) in moisture content, but the pH was significantly decreased (P < .05). Most of the sensory parameters did not change, but there was a significant difference (P < .05) in flavour. Based on this study, 2 h of UV-C irradiation was effective in reducing 90% of A. flavus, but it was not effective against A. parasiticus present on roasted coffee beans. Also, Hunter colour, pH, and sensory parameters (flavour) were changed by UV-C irradiation.     

关于提升装载机电子秤检定结果测量准确度的探讨

装载机电子秤广泛应用于货场、建筑工地,如何使检定结果准确可靠,本文对自动衡器检定装置标准器量值的管理方法进行了一些探讨。     

吐哈盆地克尔碱凹陷煤层煤质特征与成煤环境

为了揭示吐哈盆地克尔碱凹陷不同矿区煤质形成条件，探讨该区煤质与成煤环境的关系，基于对主采煤层样品工业分析、有害组分及灰成分指标等数据分析，在对克尔碱凹陷地层分布、含煤岩系特征等基本地质条件分析的基础上，运用煤地质学、煤岩学、煤化学等理论和方法，系统总结凹陷内各矿区煤层赋存特征、煤质特征，探讨区内煤岩煤质与成煤环境的关系。结果表明：研究区自西向东划分6个主要矿区,区内煤层主要发育于中侏罗统西山窑组（J2x）和下侏罗统八道湾组（J1b）地层之中。研究区煤质呈低灰、低硫、高挥发分特征，煤灰成分以SiO2、Al2O3为主。综合分析表明，研究区中-下侏罗统主要煤层形成于湖泊-河流三角洲淡水沉积环境，具陆相成煤特征，成煤环境温暖潮湿。     

不同水分工夫红茶贮藏过程中主要内含成分及感官品质变化研究

目的研究不同水分工夫红茶贮藏品质变化规律,为工夫红茶贮藏的适宜水分条件提供理论参考。方法系统比较不同水分工夫红茶(国家标准范围内)在自然贮藏条件下其主要内含成分及感官品质的变化。结果 1年贮藏期内,初始水分含量越低,含水率增长速度越快,总体上,茶叶初始水分含量高低决定贮藏过程中水分的高低。在短期贮藏(≤6月)时含水量越高的红茶中茶多酚、水浸出物保留量越多;长期贮藏(6月)时水分较低的红茶中茶多酚、水浸出物保留量越多。咖啡碱、可溶性糖在短期贮藏(≤6月)中水分含量适中的红茶中下降速度越慢;长期贮藏(6月)含水量较高的保留量越高。氨基酸含量在含水量越低的红茶中越高。初始水分含量高的红茶L*、a*、b*值均稍高于水分低的红茶。结论从综合品质的变化来看,本实验中以处理3含水率为5.93%的处理最好,处理2含水率为4.1%次之,处理1含水率为2.33%最差。     

Sparse non-convex Lp regularization for cone-beam X-ray luminescence computed tomography

Cone-beam X-ray luminescence computed tomography (CB-XLCT) is an attractive hybrid imaging modality, and it has the potential of monitoring the metabolic processes of nanophosphors-based drugs in vivo. However, the XLCT imaging suffers from a severe ill-posed problem. In this work, a sparse nonconvex L_p (0?p?L₁ regularization. Further, an iteratively reweighted split augmented lagrangian shrinkage algorithm (IRW_SALSA-L_p) was proposed to efficiently solve the non-convex L_p (0?p?p-values (1/16, 1/8, 1/4, 3/8, 1/2, 5/8, 3/4, 7/8) in both 3D digital mouse experiments and in vivo experiments. The results demonstrate that the proposed non-convex methods outperform L₂ and L₁ regularization in accurately recovering sparse targets in CB-XLCT. And among all the non-convex p-values, our L_p(1/4?p?相似文献   

Health risk assessment of chlorpyrifos inhalation exposure among chilli-growing farmers in Na-Krasaeng Sub-District,Det Udom District,Ubon Ratchathani Province,Thailand

The paper reports a health risk assessment of pesticide exposure among chilli-growing farmers living in Na-Krasaeng Sub-District, Det Udom District, Ubon Ratchathani Province, Thailand. Personal air samples were collected from 46 participants spraying pesticide. These samples were analysed to investigate the farmers’ exposure by inhalation of the organophosphate, chlorpyrifos, which is the predominant pesticide used in the study area. The potential health risk of the farmers through inhalation was estimated by calculating the Hazard Quotient (HQ). The results showed that chlorpyrifos concentrations in inhaled air samples from the farmers ranged from less than the limit of detection, <LOD, to 0.041 mg/m3 with an average of 0.0072 mg/m3. Average daily doses (ADD) of exposure were calculated to be in the range 0–0.007 mg/kg/day with a mean value of 0.0014 mg/kg/day. The estimated risk quotient was 0 to 2.35 and the mean value was 0.84. Accordingly, the chilli-growing farmers were not considered to be a population at risk (mean value of HQ ≤ 1). But, the estimated risk of 17.38% of the study population was higher than the acceptable level (HQ > 1). This indicated that some participants were considered as an individual risk which should be of concern.     

Local body cooling to improve sleep quality and thermal comfort in a hot environment

The effects of local body cooling on thermal comfort and sleep quality in a hot environment were investigated in an experiment with 16 male subjects. Sleep quality was evaluated subjectively, using questionnaires completed in the morning, and objectively, by analysis of electroencephalogram (EEG) signals that were continuously monitored during the sleeping period. Compared with no cooling, the largest improvement in thermal comfort and sleep quality was observed when the back and head (neck) were both cooled at a room temperature of 32°C. Back cooling alone also improved thermal comfort and sleep quality, although the effects were less than when cooling both back and head (neck). Mean sleep efficiency was improved from 84.6% in the no cooling condition to 95.3% and 92.8%, respectively, in these conditions, indicating good sleep quality. Head (neck) cooling alone slightly improved thermal comfort and subjective sleep quality and increased Stage N3 sleep, but did not otherwise improve sleep quality. The results show that local cooling applied to large body sections (back and head) could effectively maintain good sleep and improve thermal comfort in a hot environment.     

钢板表面花斑缺陷的分析与控制

针对山东钢铁集团莱芜分公司生产的中厚板表面存在的"花斑"缺陷,分析了其成因,通过优化加热工艺、控制加热炉内氧化气氛、降低钢中Si含量、规范除鳞使用等一系列措施,有效提升了钢板的表面质量,存在"花斑"问题钢板的比例由攻关前17%降低为3%。