榨前微波处理对油茶粕活性成分及抗氧化性的影响

通过不同微波功率和时间辐射油茶籽,测定油茶粕中茶皂素、蛋白质、粗多糖、总酚、糠氨酸含量以及DPPH自由基清除能力的变化规律,研究榨前微波处理对油茶粕活性成分及抗氧化性的影响。结果表明:随微波加热时间延长,低功率(245、420 W)微波处理油茶籽后,油茶粕中茶皂素含量稍有上升,随后下降;较高功率(560、700 W)微波处理后,茶皂素含量呈上升趋势;微波处理对油茶粕中蛋白质含量影响不大;微波处理后油茶粕中粗多糖含量整体呈下降趋势,但420、560、700 W处理20、5、10 min后含量分别比初始升高66.9%、79.6%和116.0%;微波处理后油茶粕中总酚含量呈先降低后升高再降低的趋势,且微波功率越高,总酚含量越高;微波功率较低(245 W)时,糠氨酸含量先降低后略有升高,微波功率较高(420、560、700 W)时,糠氨酸含量先升高后降低。245 W和700 W微波功率处理时油茶粕对DPPH自由基清除率先升高后降低,560 W时呈整体上升趋势,420 W呈波动状态。     

葵花籽粕综合利用研究进展

葵花籽粕是葵花籽提油后的副产品。葵花籽粕蛋白品质优,各氨基酸组成平衡,此外葵花籽粕中还含有绿原酸、黄酮等多种活性物质,营养价值高,具有广阔的应用前景。从葵花籽粕作为原料提取有效成分及作为饲料用原料两方面对葵花籽粕资源的综合利用情况进行了阐述,以期为葵花籽粕的进一步开发利用提供参考。     

破碎方式对白鲢鱼糜凝胶结构的影响

与斩拌方式对比,研究搅拌方式对鱼糜制品凝胶特性的影响。结果表明,搅拌破碎使白鲢鱼糜的凝胶强度及持水力增加,提高了硬度、黏附性、胶黏性和咀嚼性,但是对白度无明显影响。在2%和3%盐添加量的条件下,搅拌破碎对鱼糜制品的质构改善效果显著,凝胶强度分别提高了70.2%,66.7%。根据鱼糜的盐溶蛋白、肌动球蛋白的活性巯基含量、化学作用力和浊度结果可知,搅拌破碎可以增加活性巯基含量,使得更多的巯基氧化成二硫键,提高疏水相互作用,促进蛋白分子间的聚集,浊度增加,三维凝胶网络结构更致密。     

基于主动学习的离群点集成挖掘方法研究

离群点检测任务通常缺少可用的标注数据，且离群数据只占整个数据集的很小一部分，相较于其他的数据挖掘任务，离群点检测的难度较大，尚没有单一的算法适合于所有的场景。因此，结合多样性模型集成和主动学习思想，提出了一种基于主动学习的离群点集成检测方法OMAL（Outlier Mining based on Active Learning）。在主动学习框架指导下，根据各种基学习器的对比分析，选择了基于统计的、基于相似性的、基于子空间划分的三个无监督模型作为基学习器。将各基学习器评判的处于离群和正常边界的数据整合后呈现给人类专家进行标注，以最大化人类专家反馈的信息量；从标注的数据集和各基学习器投票产生的数据集中抽样，基于GBM（Gradient BoostingMachine）训练一个有监督二元分类模型，并将该模型应用于全数据集，得出最终的挖掘结果。实验表明，提出方法的AUC有了较为明显的提升，且具有良好的运行效率，具备较好的实用价值。     

Migration analysis,antioxidant, and mechanical characterization of polypropylene-based active food packaging films loaded with BHA,BHT, and TBHQ

Polypropylene (PP) based active composite films were prepared by adding butylated hydroxy anisole (BHA), butylated hydroxytoluene (BHT), and tertiary butylated hydroquinone (TBHQ) antioxidants using the extrusion molding process. All concentrations of BHT, 2% to 3% BHA, and 3% TBHQ significantly increased the tensile strength (TS) of the composite films compared with control films. Increasing antioxidant concentration decreased TS values for BHT films, whereas an opposite trend was observed for BHA and TBHQ films. BHA at < 2%, BHT at > 2%, and TBHQ at all added concentrations significantly reduced elongation at break (E_b) of the composite films compared to control films. Water vapor permeability (WVP) of 1% BHT film was not significantly different from control. However, other antioxidants especially at increased concentrations significantly increased WVP values. TBHQ films with 300% to 662% increase had the highest WVP and BHT films with 5% to 81% increase had the lowest WVP among composite films. All three antioxidants had a negative effect on the transparency of the films; however the effect of BHA at higher concentrations was greater. The antioxidants did not change the color attributes of the films. Films containing all antioxidants showed 2,2-diphenyl-1-picrylhydrazyl radical-scavenging activity, which increased with increase in their concentration, especially for those containing 3 wt.% BHT and TBHQ. Overall, incorporating BHA and BHT into a PP matrix improved mechanical, barrier, antioxidant properties, and film appearance and consequently were proposed for the development of antioxidant active PP films. TBHQ film is not recommended for food packaging because of its weak mechanical properties (lower E_b and TS values, higher WVP, and greater migration).     

不同品种谷子营养成分及功能活性成分差异化分析

对比研究了10个品种谷子营养及功能活性成分。以10个代表性谷子品种籽粒为原料,检测分析了淀粉、蛋白质、脂肪等营养组分,及多酚、黄酮、低聚糖等功能活性成分的含量。结果表明:不同品种谷子,营养成分及功能活性成分的含量差异不同,且功能性成分含量品种间差异较大。不同品种间谷子粗淀粉变异系数为5%,含量较为稳定;粗脂肪的变异系数为17.55%,品种之间差异显著(P0.05);粗蛋白的变异系数为7%,品种之间差异显著(P0.05);总黄酮变异系数最大,为51%,含量范围为0.55~2.01 mg/g;总多酚含量变异系数为25%,含量范围为0.65~1.41 mg/g;低聚糖含量品种间差异也较大。对选育优良品种谷子,及开发谷子相关食品和保健品具有指导意义。     

综采工作面活性磁化水防尘技术研究

煤矿生产是环境较为封闭的井下作业，具有一定的特殊性，作业空间湿度高、生产环境复杂，其中粉尘是危害最大的因素之一，会对机器和人体造成不同程度的损害。粉尘的危害主要由两方面决定:煤尘能够燃烧，在浓度较高时还会爆炸；粉尘会危害人的身体健康。以平煤股份十矿-320 m水平己四采区东翼下段的己_15-16-24130工作面为研究对象，研究磁化水除尘的方法及原理，通过对比分析优选出活性磁化水添加剂，在该工作面试验后具有良好的除尘效果，大大增加了可见度、降低了空气中悬浮的煤尘。研究对该矿井其他工作面除尘工作具有指导意义。     

2015—2018年上海市浦东新区食源性疾病主动监测病原学及流行病学特征分析

目的 了解上海市浦东新区特定病原体食源性疾病的流行趋势和特征,为制定食源性疾病防控策略提供参考。方法 采集2015—2018年于上海市浦东新区开展食源性疾病主动监测的数据,2家哨点医院采集以腹泻症状为主诉感染病例的粪便或肛拭子标本,进行副溶血性弧菌、沙门菌、志贺菌、致泻大肠埃希菌、空肠弯曲菌和诺如病毒检验,同时对患者进行相关信息采集、分析。结果 共监测和采集2 871例腹泻病例的粪便或肛拭子标本,病原体总体检出率为23.55%(676/2 871),其中,诺如病毒为20.04%(97/484)、致泻大肠埃希菌为11.84%(340/2 871)、空肠弯曲菌为7.21%(68/943)、副溶血性弧菌为4.01%(115/2 871)、沙门菌为3.27%(94/2 871)、志贺菌为0.28%(8/2 871)；第三季度的病原体检出率较高,呈现较明显的夏秋季高峰；可疑食物主要是混合/多种食品(41.12%,278/676),其次为水产动物及其制品(22.19%,150/676)和肉与肉制品(10.95%,74/676)。结论 诺如病毒和致泻大肠埃希菌是上海市浦东新区腹泻病例的主要病原体,应进一步完善食源性疾病主动监测,对特定病原体阳性病例开展流行病学个案调查,为开展有效防控提供技术支持。     

活性肽-N对D-半乳糖致衰老小鼠的作用效果

为了探讨一种新型抗衰老活性因子——活性肽-N食用后的抗衰老作用,本研究通过给小鼠连续皮下注射D-半乳糖(200 mg/(kg·d),以体质量计,下同)建立衰老模型,造模的同时开始灌胃2.5、25.0、125.0μg/(kg·d)活性肽-N复乳,连续9周。分别采用旷场实验和Morris水迷宫实验检测小鼠的运动探究能力和学习记忆能力。上述行为学实验后,对小鼠血清中谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-Px)活力、丙二醛(malondialdehyde,MDA)含量及脑组织中的乙酰胆碱酯酶(acetyl cholinesterase,ACh E)活力进行测定。结果表明,与衰老模型组相比,活性肽-N复乳高剂量组能显著提高衰老小鼠的运动探究能力,改善其学习记忆能力,提高血清中的GSH-Px活力28.38%(P0.05),降低MDA含量26.19%(P0.05),同时降低脑组织中的ACh E活力23.26%(P0.05)。综合结果表明该活性肽-N对D-半乳糖致衰老小鼠具有明显的抗衰老作用。     

Multifunctional catalysts with high catalytic activities: Flower-like Co9S8 microballs assembled with weak crystalline pea pod-shaped nanowires

The flower-like Co₉S₈ microballs assembled with weak crystalline pea pod-shaped nanowires were fabricated via a one-pot hydrothermal reaction. The high-resolution TEM image of pea pod-shaped nanowires revealed a weak crystalline structure. Some regions were amorphous and some regions showed well-resolved lattice fringe. Because flower-like Co₉S₈ microballs possessed the more catalytic active sites of the weak crystalline character and the fast electron transfer along the nanowires, they would be promising catalysts for reduction of I₃^? in DSSCs and electrochemical water splitting. As the counter electrode catalysts for I₃^? reduction, DSSCs based on the Co₉S₈ microballs got a high photoelectrical conversion efficiency of 7.0%, which was comparable with DSSCs based on standard platinum (7.48%). As the electrocatalysts for hydrogen evolution reaction, the Co₉S₈ microball electrode possessed an overpotential of 173.8 and 191.3 mV at the current density of 10 mA cm^?2 in acid and alkaline solution, respectively. Also, it displayed a superior catalytic activity for oxygen evolution reaction. The stability tests indicated that this microball could possess the high catalytic activity with long time. This kind of Co₉S₈ microballs assembled with weak crystalline pea pod-shaped nanowires paved a new way to low-cost catalyst for I₃^? reduction and water splitting.