采用近红外高光谱成像技术(900~1700 nm)结合线性回归算法对牛肉掺假快速无损检测。将鸡肉糜掺入牛肉糜中制备牛肉掺假样品,掺假比例为2%~98%(w/w),掺假间隔为2%。采集掺假样品的光谱图像,提取光谱数据,并利用偏最小二乘回归(Partial le...采用近红外高光谱成像技术(900~1700 nm)结合线性回归算法对牛肉掺假快速无损检测。将鸡肉糜掺入牛肉糜中制备牛肉掺假样品,掺假比例为2%~98%(w/w),掺假间隔为2%。采集掺假样品的光谱图像,提取光谱数据,并利用偏最小二乘回归(Partial least squares regression,PLSR)和多元线性回归(Multiple linear regression,MLR)算法建立掺假样品的定量预测模型。为了减少高维共线性问题,提高模型运算效率,分别采用PLS-β系数法、逐步回归法(Stepwise)和连续投影算法(Successive projection algorithm,SPA)筛选最优波长建立优化预测模型。结果表明,基于SPA算法结合MLR建模方法得到的掺假牛肉预测模型,其预测效果最优,校正集决定系数(R2C)和均方根误差(Root mean square error of calibration,RMSEC)分别为0.99和3.23%,验证集的决定系数(R2P)和均方根误差(Root mean square error of prediction)RMSEP分别为0.97和5.31%,预测偏差(Residual predictive deviation,RPD)为6.82。综上,近红外高光谱成像技术结合线性回归算法可以实现对掺假牛肉的快速无损定量检测。展开更多
The action of Cornu Cervi Pantotrichum (CCP), Cornu Cervi (CC) and Cornu Saigae Tataricae (CST) on Escherichia coli growth were investigated using microcalorimetry to find the heat change regularity of microbial growt...The action of Cornu Cervi Pantotrichum (CCP), Cornu Cervi (CC) and Cornu Saigae Tataricae (CST) on Escherichia coli growth were investigated using microcalorimetry to find the heat change regularity of microbial growth. The similarity of thermogenic curves and thermodynamics parameters were investigated as evaluation index, such as the growth rate constant in the first expo- nential phase (k1), maximum power in the first exponential phase (P1), maximum power in the secondary exponential phase (P2), peak time in the first exponential phase (T1), peak time in the stationary phase (T2) and the total heat production in stage 1 (Q1), and the total heat production in stage 2 (Q2). Chemometric analysis was used as a reference for the bioactivity evaluation of medicinal animal horns. The results indicated that the similarity between CST and the control was smaller than that between CCP, CC and the control. Both CCP and CC could increase the heat in the microbial growth, whereas CST decreased it. The biotic thermal activity of different medicinal animal horns was objectively, qualitatively, and quantitatively evaluated by the similarity of thermogenic curves and thermodynamics parameters analysis.展开更多
为探究不同干制工艺对牡蛎干特征气味的影响及其形成机制,该研究以焯水牡蛎为对照(CK),研究了真空冷冻干制(vacuum freeze drying,VFD)、热风干制(hot air drying,HAD)、真空干制(vacuum drying,VD)、自然晒干(solar drying,SD)4种干制...为探究不同干制工艺对牡蛎干特征气味的影响及其形成机制,该研究以焯水牡蛎为对照(CK),研究了真空冷冻干制(vacuum freeze drying,VFD)、热风干制(hot air drying,HAD)、真空干制(vacuum drying,VD)、自然晒干(solar drying,SD)4种干制工艺对牡蛎干脂肪酸组成和挥发性物质的影响。结果表明,牡蛎经干制加工后脂肪酸含量显著减少(P<0.05),VFD、VD、SD、HAD组总脂肪酸含量分别减少19.45%、49.27%、27.69%、46.63%,其中饱和脂肪酸减少21.39%~45.17%,不饱和脂肪酸减少20.66%~52.21%。电子鼻结果显示5组样品的香气特征明显不同,高温干制(HAD、VD)显著增加了氮氧化合物的浓度。采用气相色谱-离子迁移谱(gas chromatography-ion mobility spectrometry,GC-IMS)从5组样品中共鉴别出71种挥发性化合物,主成分分析和指纹图谱表明,5组样品的挥发性物质存在显著差异,通过偏最小二乘回归模型(partial least squares regression model,PLS-DA)和变量投影重要度(variable importance for the projection,VIP)筛选了31种差异性挥发性化合物,包括庚醛、丁醛、2-甲基-2-戊烯醛、2-庚酮、1-戊烯-3-酮、2-丁酮、1-辛烯-3-醇等,Pearson相关性分析表明,游离脂肪酸中的C15:0、C16:1、C16:0、C18:3、C18:4、C20:0、C20:1、C20:2与牡蛎干中的多种特征挥发性化合物的形成密切相关。展开更多
文摘采用近红外高光谱成像技术(900~1700 nm)结合线性回归算法对牛肉掺假快速无损检测。将鸡肉糜掺入牛肉糜中制备牛肉掺假样品,掺假比例为2%~98%(w/w),掺假间隔为2%。采集掺假样品的光谱图像,提取光谱数据,并利用偏最小二乘回归(Partial least squares regression,PLSR)和多元线性回归(Multiple linear regression,MLR)算法建立掺假样品的定量预测模型。为了减少高维共线性问题,提高模型运算效率,分别采用PLS-β系数法、逐步回归法(Stepwise)和连续投影算法(Successive projection algorithm,SPA)筛选最优波长建立优化预测模型。结果表明,基于SPA算法结合MLR建模方法得到的掺假牛肉预测模型,其预测效果最优,校正集决定系数(R2C)和均方根误差(Root mean square error of calibration,RMSEC)分别为0.99和3.23%,验证集的决定系数(R2P)和均方根误差(Root mean square error of prediction)RMSEP分别为0.97和5.31%,预测偏差(Residual predictive deviation,RPD)为6.82。综上,近红外高光谱成像技术结合线性回归算法可以实现对掺假牛肉的快速无损定量检测。
基金supported by the National Natural Science Foundation of China (30625042 and 30873385)the Key Technology of the National Great New Drugs Development Project of China (2009ZX09502-003 and 2009ZX09308-005)
文摘The action of Cornu Cervi Pantotrichum (CCP), Cornu Cervi (CC) and Cornu Saigae Tataricae (CST) on Escherichia coli growth were investigated using microcalorimetry to find the heat change regularity of microbial growth. The similarity of thermogenic curves and thermodynamics parameters were investigated as evaluation index, such as the growth rate constant in the first expo- nential phase (k1), maximum power in the first exponential phase (P1), maximum power in the secondary exponential phase (P2), peak time in the first exponential phase (T1), peak time in the stationary phase (T2) and the total heat production in stage 1 (Q1), and the total heat production in stage 2 (Q2). Chemometric analysis was used as a reference for the bioactivity evaluation of medicinal animal horns. The results indicated that the similarity between CST and the control was smaller than that between CCP, CC and the control. Both CCP and CC could increase the heat in the microbial growth, whereas CST decreased it. The biotic thermal activity of different medicinal animal horns was objectively, qualitatively, and quantitatively evaluated by the similarity of thermogenic curves and thermodynamics parameters analysis.
文摘为探究不同干制工艺对牡蛎干特征气味的影响及其形成机制,该研究以焯水牡蛎为对照(CK),研究了真空冷冻干制(vacuum freeze drying,VFD)、热风干制(hot air drying,HAD)、真空干制(vacuum drying,VD)、自然晒干(solar drying,SD)4种干制工艺对牡蛎干脂肪酸组成和挥发性物质的影响。结果表明,牡蛎经干制加工后脂肪酸含量显著减少(P<0.05),VFD、VD、SD、HAD组总脂肪酸含量分别减少19.45%、49.27%、27.69%、46.63%,其中饱和脂肪酸减少21.39%~45.17%,不饱和脂肪酸减少20.66%~52.21%。电子鼻结果显示5组样品的香气特征明显不同,高温干制(HAD、VD)显著增加了氮氧化合物的浓度。采用气相色谱-离子迁移谱(gas chromatography-ion mobility spectrometry,GC-IMS)从5组样品中共鉴别出71种挥发性化合物,主成分分析和指纹图谱表明,5组样品的挥发性物质存在显著差异,通过偏最小二乘回归模型(partial least squares regression model,PLS-DA)和变量投影重要度(variable importance for the projection,VIP)筛选了31种差异性挥发性化合物,包括庚醛、丁醛、2-甲基-2-戊烯醛、2-庚酮、1-戊烯-3-酮、2-丁酮、1-辛烯-3-醇等,Pearson相关性分析表明,游离脂肪酸中的C15:0、C16:1、C16:0、C18:3、C18:4、C20:0、C20:1、C20:2与牡蛎干中的多种特征挥发性化合物的形成密切相关。
