傅立叶变换近红外光谱法快速测定葡萄酒中的酒精度

建立快速、简便的测定葡萄酒中酒精度的方法.以蒸馏水为背景,利用傅立叶变换近红外光谱透射法直接对葡萄酒样液进行测定,建立了葡萄酒酒精度定量分析模型.该方法具有良好的线性相关性,近红外光谱法与实验室标准分析方法测定结果基本一致,其预测相关系数(R2)和平均相对误差为0.998、0.5401%.该方法重复性好,具有操作简单、快捷、无污染等诸多优点.     

Extraction of Polyphenols from Red Grape Pomace Assisted by Pulsed Ohmic Heating

The present work is devoted to the investigation of the effect of pulsed ohmic heating (POH) on cells membrane damage and intensification of polyphenols extraction from red grape pomace. Untreated, POH-treated and freeze-thawed samples were compared. The effects of electric field strength (E?=?100–800 V/cm) and the percentage of ethanol in water (E/W?=?0–50 %) on polyphenols extraction were discussed. Measurements of electrical conductivity and electric energy consumption were performed for POH pretreatment optimization. Results show that POH treatment results in cells membrane denaturation. This permeabilization increases with the elevation of electric field strength and temperature. POH pretreatment accelerates the extraction kinetics of total polyphenols from grape pomace. Freeze-thawed samples are always accompanied with a high degree of cell damage and high concentration of polyphenols in the extract. The highest extraction yields were obtained with a POH pretreatment at 400 V/cm followed by a diffusion step for 60 min at 50 °C and with a solvent composed of 30 % of ethanol in water. In these conditions, the polyphenol content was 36 % more than untreated samples. The proposed technique (POH pretreatment) appears to be promising for future industrial applications of polyphenols extraction from pomace.     

提高面粉附加值

所有的制粉公司经常需要解决一个相同的重要问题:我们的公司应当怎样来开发新产品和拓展服务,以超过竞争对手,获取最佳投资回收.     

Determination of Branched-Amino Acid Content in Fermented Cordyceps sinensis Mycelium by Using FT-NIR Spectroscopy Technique

This research investigated the feasibility of Fourier transform near-infrared (FT-NIR) spectral technique in determining branched-amino acid contents (Leucine, Isolecucine, and Valine) in fermented Cordyceps sinensis (C. sinensis) mycelium. A comparison of two variable selection methods, namely competitive adaptive reweighted sampling (CARS) and genetic algorithms, showed that CARS achieved better performance calibrating by partial least square regression or least squares support vector machine methods, with the effective wavelengths mainly concentrated around 12,010–10,050, 7,500–6,000, and 5,000–4,000 cm^?1. For the quantitative determination of Val, Ile, and Leu by the established models, root mean square error of prediction were 0.0662, 0.0594, and 0.0678; correlation coefficients were 0.80, 0.83, and 0.90; residual predictive deviation were 1.66, 1.78, and 2.30, respectively. This study showed that the FT-NIR spectral technique has a potential to determine branched chain amino acids in fermented C. sinensis mycelium and further to facilitate quality control during its production.     

Application of Fourier Transform Near Infrared Spectroscopy (FT-NIR) to thermally modified wood

A close relationship between the chemical changes and the NIR spectra of thermally modified beech wood makes clustering easy and provides a possibility for quality control.     

Application of Fourier Transform Near Infrared Spectroscopy (FT-NIR) to thermally modified wood

A close relationship between the chemical changes and the NIR spectra of thermally modified beech wood makes clustering easy and provides a possibility for quality control.     

近红外法测定大豆脂肪酸值方法的研究

脂肪酸值是衡量大豆品质重要指标.将近红外光谱技术与化学计量方法结合,建立大豆样品脂肪酸值的定标方程,并对定标方程进行了验证,优化得到大豆脂肪酸值的定标方程,交互定标决定系数(1-VR)为0.948 2,外部验证决定系数(R2)为0.915 0,定标标准偏差(SEC)为1.205 8,交叉验证标准偏差(SECV)为1.591 2,现有数据预测标准偏差(SEP)为1.395.通过外部验证,表明该方法也可以应用于实际检测.     

日毛绒狗信息重组价值增

一只毛绒狗的故事 “大红狗”是正流行在日本京都白领女性圈子里的一款玩具。它选用毛巾布料，因此手感良好，据宣传称它的红色能够刺激脑细胞，使人充满活力，所以兼具一定的医疗保健作用。很多白领女性都喜欢将它摆放在办公室的写字台上，而现在东京都三鹰市内各大商店正以2100日元（含税）的价格热销中。     

后处理工艺对红葡萄酒多酚物质和色度的影响

研究了后处理工艺对葡萄酒色度和多酚物质含量的影响,为合理制定工艺提供依据.实验表明,下胶、冷冻和膜过滤等后处理工艺都不同程度的降低了葡萄酒的色度和总酚含量,降低了葡萄酒的外观颜色和品质,其中大的下胶量和长时间冷冻处理对葡萄酒的色度和总酚含量影响最大,最大下降比率分别为16.0％、6.7％和14.7％、14.2％,而从勾兑到灌装,所有处理使色度和总酚累计下降25.3％、18.8％;对如何降低后处理工艺对葡萄酒色度和多酚的影响,提出了可行性建议.     

利用印后加工实现数码印刷品增值

彩色数码印刷品经紫外线照射后往往容易出现色块裂痕,并且会持续较长时间。因此,对印刷品的涂布及覆膜保护将成为印刷服务供应商的主要利润点。名片、宣传册、菜单、桌牌、直邮等需要对手指接触部分和其他环境破坏具有一定的抵抗能力。采用涂布或覆膜技术能够有效地阻抗印刷品的划伤、裂纹、磨损,同时提高其防水性。     

Iodine Value and Fatty Acids Determination on Pig Fat Samples by FT-NIR Spectroscopy: Benefits of Variable Selection in the Perspective of Industrial Applications

In this work, FT-NIR spectroscopy was employed to determine iodine value (IV) and fatty acids (FA) content of pig fat samples, through the combined use of signal preprocessing, multivariate calibration, and variable selection methods. In particular, the main focus was on the use of variable selection methods, both in order to improve the predictive performance of the calibration models, and to identify relevant wavelengths that could be subsequently used for the development of simple, fast, and cheap hand-held devices, able to measure IV and FA content directly on the fat without the need of any sample pretreatment. Firstly, for each property of interest, partial least squares (PLS) multivariate calibration models were calculated considering the whole spectral range and testing different signal preprocessing methods. Then, once chosen the optimal signal preprocessing method, a two-step variable selection procedure was applied. In the first step, the interval-PLS variable selection algorithm was used to calculate a set of calibration models, whose outcomes were considered altogether in the second step, in order to select the optimal calibration model. The variable selection procedure allowed to lower the number of spectral variables retained by the model, and often led to an increase of the performance in prediction of the external test set samples.     

先进的连续叠层技术赋予非织造材料附加值

对如何高速有效地进行稳定连续不停机的卷绕和使用A.Celli非织造公司制造的可与市场上已有的不同工艺相结合的卷绕设备作了说明,与传统的生产线相比,该生产线的投资少,且灵活性好,特别是可增加产品附加值,因而该工艺过程不再是一个更薄弱的环节,而变成了增加附加值的一个契机。     

苦杏仁多肽对红葡萄酒陈酿抑菌规律初探

山杏仁在干燥、粉碎、除油脂后,经蛋白酶水解、超滤分离,可制备成苦杏仁多肽.以苦杏仁多肽为防腐物质,抑制红葡萄酒陈酿时杂菌的生长.结果表明,短肽的抑菌效果强于长肽或大肽,并且对酒体稳定性基本无影响;苦杏仁短肽的最适添加浓度为600 mg/mL;苦杏仁多肽对红葡萄酒中杂菌的抑制作用具有选择性,对于革兰氏染色阴性菌株生长的抑制作用强于阳性菌株.     

利用近红外光谱技术对葡萄酒原产地进行Fisher判别

以中国昌黎、烟台和沙城干红葡萄酒样本为试验材料,利用近红外光谱分析技术,建立一种可对葡萄酒产地进行辨别的方法。试验中对原产自上述3地的共计60份干红葡萄酒样本进行近红外光谱采集,通过主成分分析后获得14个主成分,利用逐步回归筛选方法最终确定其中5个主成分,建立Fisher判别函数,并进行判别模型验证。结果表明,通过利用原始样本和留一交叉验证法对预测模型进行验证,准确率分别为90%和86.7%。所有预测结果的准确率均达到80%以上,可以满足定性判别的要求。     

FTIR Spectroscopy and Direct Orthogonal Signal Correction Preprocessing Applied to Selected Phenolic Compounds in Red Wines

The composition of phenolic compounds plays an important role in food science and nutrition; thus, there is a need of a new method of analysis that is able to speed up the monitoring of product quality parameters. In this view, the amount of selected color components of 145 commercial red wines (total wine color, polymeric pigments, total anthocyanins, and copigmentation index) was investigated using Fourier transform mid-infrared spectroscopy (MIR) combined with partial least squares (PLS) regression. The feasibility of several preprocessing algorithms (first and second derivative, standard normal variate, and direct orthogonal signal correction) was compared in terms of coefficient of determination (R ²) and root mean square error of prediction using an independent test set of wines. The composition of red wines showed great difference in terms of total color (5.07 ± 1.95 AU at 520 nm) compared to copigmentation index (0.66 ± 0.58 AU at 520 nm). The best prediction model was obtained using direct orthogonal signal correction (DOSC) preprocessing. In particular, the prediction of total wine color, total anthocyanins, and polymeric pigments showed a good fitting (R ² ≥ 0.82), whereas copigmentation index was more difficult to be predicted by FTIR (R ² = 0.57). This preliminary study showed the potential of MIR spectroscopy with DOSC–PLS algorithm to successfully analyze selected color components of red wine on a large number of samples in short time with almost no sample preparation and no chemical waste is created.     

Identification of Wine According to Grape Variety Using Near-Infrared Spectroscopy Based on Radial Basis Function Neural Networks and Least-Squares Support Vector Machines

This paper describes how near-infrared (NIR) spectroscopy combined with radial basis function neural networks (RBFNN) and least-squares support vector machines (LS-SVMs) based on principal component analysis (PCA) can be used to classify wines from grape varieties. The effects of different preprocessing methods (standard normal variate (SNV) and multiplicative scattering correction (MSC)) on classification results were also compared. The results show that the use of NIR preprocessing spectral data with optimum RBFNN parameters produced a very high level of correct classification rate, 90.16–98.36%. For RBF LS-SVM, identification rates were from 91.80 to 98.36%. The results demonstrate that, combined with chemometrics with appropriate spectral data pretreatment, NIR spectroscopy has potential to rapidly and nondestructively differentiate wine according to grape variety. The results of this study are helpful to develop a more rapid and nondestructive detection method of wine.     

Evaluation of the Ability of Polyphenol Extracts of Cocoa and Red Grape to Promote the Antioxidant Response in Yeast Using a Rapid Multiwell Assay

Saccharomyces cerevisiae has been used as a model organism to study the capacity of cocoa and red grape extracts to trigger an antioxidant response. A methodology adapted to microtiter plates has been developed to monitor yeast growth after culture preincubation with food ingredients and exposure to oxidative stress by hydrogen peroxide and menadione. This methodology proved effective in measuring the ability of cocoa and red grape extracts to promote an antioxidant response in yeast, and also the prospect of conducting dose–response studies. Additionally, the method has proven useful to perform studies with mutant strains lacking genes that may be related to the mechanism of action underlying the antioxidant properties. Thus, in a single assay, it is possible to elucidate the sensitivity of strains to oxidative stress, the ability of an ingredient to promote an antioxidant response, and the possible implication of certain genes. Results of assays using strain hst3Δ showed that the antioxidant protection provided by exposure to cocoa and red grape extracts was not present in the strain lacking gene HST3 when H₂O₂ and menadione were used as oxidizing agents. This effect was previously reported for cocoa extract only, with H₂O₂ as stressor. Moreover, the results showed that the mutant strain hst3Δ is more resistant to menadione and H₂O₂ in the absence of preincubation with cocoa and red grape extract, hinting at the possible implication of sirtuin Hst3 in the antioxidant cellular response.     

Profiles of Phenolic Acids and Flavan‐3‐ols for Select Chinese Red Wines: A Comparison and Differentiation According to Geographic Origin and Grape Variety

The profiles of phenolic acids and flavan‐3‐ols for the selected Chinese red wines and the potential of using phenolic acids and flavan‐3‐ols to differentiate the geographic origin and grape variety of wines from China are investigated in this study. Significant differences and markers could be found according to the geographical origin and grape variety. Through a canonical discriminant analysis a good differentiation was developed according to the geographic origin or grape variety, and the accuracy of the discriminant model was 88.9% and 100%, respectively. According to the phenolic acid and flavan‐3‐ols profiles of the wine samples and good differentiation in the region and the variety discriminant analysis, minimal fraudulent claims were noted for the Chinese red wines investigated.