马铃薯淀粉基微孔炭微球的制备及其电化学性能

以存在广泛的生物质原料马铃薯淀粉为前驱体, 通过磷酸对淀粉分解的促进作用和KOH活化法制备微孔炭微球材料. 采用77 K条件下的N₂吸附、扫描电子显微镜(SEM)分别对所得样品的孔隙结构、形貌特征进行表征. 采用傅里叶变换红外(FT-IR)光谱对磷酸促进淀粉分解的机理进行研究. 在6 mol·L^-1 KOH 电解质溶液中的电化学测试表明了所得微孔炭微球材料的优异电容特性. 在50 mA·g^-1的电流密度下, 电容量为363.6 F·g^-1. 此外, 该材料表现出了优异的倍率性能, 在扫描速率为300 mV·s^-1的条件下, 所得循环伏安(CV)曲线仍能保持良好的矩形形状. 电化学测试结果表明, 马铃薯淀粉基微孔炭微球材料在高性能电化学电容器的电极材料领域具有广阔的应用前景.     

海带浆对马铃薯淀粉糊化及油炸膨化特性的影响

研究了海带浆体对马铃薯淀粉的糊化特性和油炸膨化特性的影响。研究表明，海带浆体对淀粉糊化的影响有利于膨化工艺操作，桨体含量５０％，糊化淀粉比例８～１０％，控制切片干燥后水份含量９％，可得到一种含碘≥５０μｇ／１００ｇ，且综合感官评定效果最好的海带马铃薯油炸膨化食品。     

高速逆流色谱制备分离紫甘薯花色苷

采用高速逆流色谱法分离纯化紫甘薯花色苷.以正丁醇-乙酸乙酯-0.5%乙酸(3:1:4,V/V)为溶剂体系,上相为固定相,下相为流动相,流速2mL/min,进样量300mg,分离得到两种花色苷的混合物;混合物再以0.2%三氟乙酸-正丁醇-甲基叔丁基醚-乙腈(6:5:2:1,V/V)为溶剂体系,上相为固定相,下相为流动相,...     

Hydrodynamic cavitation efficiently inactivates potato virus Y in water

Waterborne plant viruses can destroy entire crops, leading not only to high financial losses but also to food shortages. Potato virus Y (PVY) is the most important potato viral pathogen that can also affect other valuable crops. Recently, it has been confirmed that this virus is capable of infecting host plants via water, emphasizing the relevance of using proper strategies to treat recycled water in order to prevent the spread of the infectious agents. Emerging environmentally friendly methods such as hydrodynamic cavitation (HC) provide a great alternative for treating recycled water used for irrigation. In the experiments conducted in this study, laboratory HC based on Venturi constriction with a sample volume of 1 L was used to treat water samples spiked with purified PVY virions. The ability of the virus to infect plants was abolished after 500 HC passes, corresponding to 50 min of treatment under pressure difference of 7 bar. In some cases, shorter treatments of 125 or 250 passes were also sufficient for virus inactivation. The HC treatment disrupted the integrity of viral particles, which also led to a minor damage of viral RNA. Reactive species, including singlet oxygen, hydroxyl radicals, and hydrogen peroxide, were not primarily responsible for PVY inactivation during HC treatment, suggesting that mechanical effects are likely the driving force of virus inactivation. This pioneering study, the first to investigate eukaryotic virus inactivation by HC, will inspire additional research in this field enabling further improvement of HC as a water decontamination technology.     

半透射高光谱成像技术与支持向量机的马铃薯空心病无损检测研究

针对马铃薯空心病的难以检测问题, 提出了一种基于半透射高光谱成像技术结合支持向量机(support vector machine, SVM)的马铃薯空心病无损检测方法。选取224个马铃薯样本(合格149个, 空心75个)作为研究对象, 搭建了马铃薯半透射高光谱图像采集系统, 采集了马铃薯样本半透射高光谱图像(390~1 040 nm), 对感兴趣区域内的光谱进行平均和光谱特征分析。采用变量标准化(normalize)对原始光谱进行光谱预处理, 建立了全波段的SVM判别模型, 模型对测试集样本的识别准确率仅为87.5%。为了提高模型性能, 采用竞争性自适应重加权算法(competitive adaptive reweighed sampling algorithm, CARS)结合连续投影算法(successive projection algorithm, SPA)对光谱全波段520个变量进行变量选择, 最终确定了8个光谱特征变量(454, 601, 639, 664, 748, 827, 874和936 nm), 所选8个光谱变量建立的SVM模型对马铃薯测试集的识别率为94.64%。分别采用人工鱼群算法(artificial fish swarm algorithm, AFSA)、遗传算法(genetic algorithm, GA)和网格搜索法(grid search algorithm)对SVM模型的惩罚参数c和核参数g进行优化。经过建模比较分析, 确定AFSA为最优优化算法, 最优模型参数为c=10.659 1, g=0.349 7, 确定AFSA-SVM模型为马铃薯空心病的最优识别模型, 该模型总体识别率达到100%。试验结果表明: 基于半透射高光谱成像技术结合CARS-SPA与AFSA-SVM方法能够对马铃薯空心病进行准确的检测, 也为马铃薯空心病的快速无损检测提供技术支持。     

半透射高光谱成像技术与支持向量机的马铃薯空心病无损检测研究

针对马铃薯空心病的难以检测问题,提出了一种基于半透射高光谱成像技术结合支持向量机(support vector machine,SVM)的马铃薯空心病无损检测方法。选取224个马铃薯样本(合格149个,空心75个)作为研究对象,搭建了马铃薯半透射高光谱图像采集系统,采集了马铃薯样本半透射高光谱图像(390~1 040 nm),对感兴趣区域内的光谱进行平均和光谱特征分析。采用变量标准化(normalize)对原始光谱进行光谱预处理,建立了全波段的SVM判别模型,模型对测试集样本的识别准确率仅为87.5%。为了提高模型性能,采用竞争性自适应重加权算法(competitive adaptive reweighed sampling algorithm, CARS)结合连续投影算法(successive projection algorithm, SPA)对光谱全波段520个变量进行变量选择,最终确定了8个光谱特征变量(454,601,639,664,748,827,874和936 nm),所选8个光谱变量建立的SVM模型对马铃薯测试集的识别率为94.64%。分别采用人工鱼群算法(artificial fish swarm algorithm,AFSA)、遗传算法(genetic algorithm,GA)和网格搜索法(grid search algorithm)对SVM模型的惩罚参数c和核参数g进行优化。经过建模比较分析,确定AFSA为最优优化算法,最优模型参数为c=10.659 1,g=0.349 7,确定AFSA-SVM模型为马铃薯空心病的最优识别模型,该模型总体识别率达到100%。试验结果表明：基于半透射高光谱成像技术结合CARS-SPA与AFSA-SVM方法能够对马铃薯空心病进行准确的检测,也为马铃薯空心病的快速无损检测提供技术支持。     

Acrylamide concentrations in grilled foodstuffs of Turkish kitchen by high performance liquid chromatography-mass spectrometry

For over ten years, there has been a considerable interest in determination of acrylamide in foodstuffs. It was known that both protein-rich and carbohydrates-rich foods cooked at high-temperatures can cause acrylamide formation. However, carbohydrates-rich foods such as potato chips and biscuit samples have been the common studied foods compared with protein-rich foods such as meat samples.In this study, determination of acrylamide in these two group foods was examined using HPLC-MS. For this purpose, firstly, the parameters that are thought to affect the response in the HPLC-MS analysis were optimized. The optimized conditions were found to be 0.3 ml min^{− 1} for flow rate of mobile phase, 40 µl for injection volume, 5 °C for column temperature and 70 V for fragmentor potential. The optimized method was applied for the determination of acrylamide levels in Turkish foodstuffs including grilled meat and chicken samples, potato chips, coffee and biscuit. The obtained concentrations for all studied foods were in the range of 20–250 µg kg^{− 1}. The results showed that acrylamide concentrations highly varied depending on the kind of food samples.     

基于卫星波段的马铃薯植株氮素含量估测

植株氮素浓度是反应作物氮素营养状况的关键指标,对作物的产量与品质具有重要的影响。作物大面积氮素营养的实时监测不仅对区域上氮肥投入提供决策,而且还对区域上氮素循环的估算提供依据。传统的地面传感器虽然有较高的精度,但很难在区域尺度上大面积获取数据,且目前存在的高光谱卫星影像如MODIS,Hyperion的空间分辨率普遍不高。随着卫星遥感的发展,近些年来高空间分辨率的多通道卫星逐渐发射升空,这些高分辨率的卫星遥感数据将对大尺度上植被生理生化指标反演提供可能。该研究从2014年-2016年在内蒙古阴山北麓武川县进行了三年不同氮水平的马铃薯田间试验,借助地面马铃薯冠层高光谱实测数据,模拟近几年发射的具有红边波段的多通道卫星WorldView-2和VENμS不同宽度波段,并构建多种光谱指数,建立光谱指数与马铃薯地上部植株氮素浓度的估测模型,进行马铃薯关键生育期冠层氮素营养的实时监测。结果表明,波段宽度和波段位置的选择决定着光谱指数对氮素浓度的响应程度,基于红边波段的光谱指数具有更高的灵敏性。生育时期显著影响光谱指数对马铃薯地上部氮素浓度的估测能力,苗期土壤背景对光谱反射率具有显著干扰,马铃薯块茎形成期后植株氮素浓度的预测效果最佳。基于WorldView-2和VENμS卫星红光、红边和近红外特定波段构成的融合光谱指数NDRE/NDVI相对其他指数来说在马铃薯植株氮素浓度估测上更具优势,与不同生育时期马铃薯植株氮素浓度都具有较高的相关性,相关系数r在0.63～0.81之间。其中,生殖生长期基于VENμS卫星红光、红边和近红外通道构成的融合光谱指数VENμS-NDRE/NDVI与马铃薯植株氮素浓度相关性最高（r=0.81）,模型验证结果的决定系数为0.56,且验证误差较小,RMSE和RE%分别为0.38%,10.45%,模型估测值与实测值的验证斜率最接近1,为0.82;WorldView-2-NDRE/NDVI与马铃薯植株氮素浓度也具有较高的相关性（r=0.74）,模型验证结果的决定系数为0.49,验证误差RMSE和RE%分别为0.41%和11.12%,模型估测值与实测值的验证斜率为0.78。多通道卫星模拟的结果证明,基于红边宽波段的融合光谱指数能用来进行马铃薯植株氮浓度的监测。     

低温冷冻和机械损伤条件下马铃薯高光谱图像特征响应特性研究

开展了低温冷冻和机械损伤条件下马铃薯高光谱图像特征响应特性研究。采用卓立汉光公司Image~λ“谱像”系列高光谱相机获取完好的、低温冷冻和机械损伤条件下的光谱波段范围为387～1 035 nm的马铃薯高光谱图像;截取校正后的像素尺寸大小为60×60的马铃薯高光谱中部完好的图像并计算该区域平均反射率值;冻伤的马铃薯样本的反射光谱曲线在440,560和680 nm附近有明显吸收峰;机械损伤样本在560和680 nm附近有明显吸收峰,在680 nm附近吸收峰谷值明显低于冻伤样本;完好的马铃薯样本反射光谱曲线相对较为平滑,在560和680 nm附近未见明显吸收峰;撞伤样本在440,560和680 nm附近存在吸收峰,而在410 nm附近有一个明显的反射峰。四类马铃薯样本的反射光谱曲线特征峰值表现出一定的指纹特性,因而可以被用于后续品质特征检测分析使用。由于仪器或检测环境、光照强弱等因素影响,光谱数据中掺杂噪声,因此采用化学计量学预处理方法消除噪声的影响;随机选取70%的马铃薯四类样本的反射光谱作为训练数据,剩余的30%作为测试集;接着,利用极端梯度提升算法、类型提升算法和轻量梯度提升机算法来获取马铃薯高光谱图像的有效特征波谱,减少高维海量高光谱数据对后续品质分类模型的影响;最后,将提取到的有效特征波长构建马铃薯品质判别模型。在建立的分类模型中,使用的轻量梯度提升机+逻辑斯蒂回归达到最高的判别精度98.86%。该研究为将来高光谱图像成像技术在现代农业生产加工过程中马铃薯品质有效监测与控制提供理论基础和技术支撑。