partial least squares regression

偏最小二乘回归
  • 文章类型: Journal Article
    浮游动物是影响淡水生态系统的压力的关键指标。我们分析了不同子流域类型-源头的浮游动物群落的响应,自然,城市,城市农业,和农业-在波兰北部的ubeyna河湖系统内。利用分类群和功能性状(体型,喂养策略),我们应用偏最小二乘回归(PLS-R)来阐明环境条件之间的关系,土地利用,和浮游动物的群落结构。双向聚类分析(TWCA)确定了具有特征模式的局部子集,而指标物种分析(ISA)确定了特定区域的分类单元。天然河流带表现出显著的生境异质性和摄食生态位,而城市地区创造了浮游动物的功能同质化,以小为主,广泛饮食的噬菌体。农业区促进了大型滤食动物(甲壳类动物)的多样性,主动吸虫(轮虫),和变形虫(原生动物)。然而,加强农业活动,浮游动物数量大幅减少,生物量,分类学丰富度,和整体生态系统功能。土地覆被变化的影响在小规模子集水区比在整个集水区更为明显。因此,评估这些影响需要在流域一级进行详细的空间和时间分析,以确定受影响最严重的地区。这项研究引入了基于子流域的生态系统健康评估新观点,并强调了浮游动物作为生态变化的有力指标的作用。
    Zooplankton are critical indicators of pressures impacting freshwater ecosystems. We analyzed the response of zooplankton communities across different sub-catchment types-headwaters, natural, urban, urban-agricultural, and agricultural-within the Łyna river-lake system in Northern Poland. Using taxonomic groups and functional traits (body size, feeding strategies), we applied Partial Least Squares Regression (PLS-R) to elucidate the relationships between environmental conditions, land use, and zooplankton metacommunity structure. Two-Way Cluster Analysis (TWCA) identified local subsets with characteristic patterns, while Indicator Species Analysis (ISA) determined area-specific taxa. The natural river zone exhibited significant habitat heterogeneity and feeding niches, whereas urban areas created functional homogenization of zooplankton, dominated by small, broad-diet microphages. Agricultural areas promoted diversity among large filter feeders (Crustacea), active suctors (Rotifera), and amoebae (Protozoa). However, intensified agricultural activities, substantially diminished the zooplankton population, biomass, taxonomic richness, and overall ecosystem functionality. The impact of land cover change is more pronounced at small-scale sub-catchments than at the catchment level as a whole. Therefore, assessing these impacts requires detailed spatial and temporal analysis at the sub-catchment level to identify the most affected areas. This study introduces a new sub-catchment-based perspective on ecosystem health assessment and underscores the zooplankton\'s role as robust indicators of ecological change.
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  • 文章类型: Journal Article
    偏最小二乘(PLS)回归与气相色谱(GC)结合使用时,是一种有价值的化学计量学工具。由于分离运行时间和固定相选择对于有效的PLS建模至关重要,我们研究了这些GC参数对粘度预测的影响,50种航空航天燃料的密度和氢含量。由于燃料中化合物的多样性(主要是烷烃,环烷烃,和芳烃),我们探索了极性和非极性固定相柱。通过交叉验证的归一化均方根误差(NRMSECV)评估PLS模型的稳健性。为1分钟粘度建立的PLS模型,3-min,7-min,和10分钟时间窗口(TW)高速GC分离产生了几乎相同的NRMSECV,其极性柱数据的平均值(标准偏差)为4.41%(0.34%),而非极性柱数据为4.69%(0.15%)。相比之下,虽然使用极柱数据进行密度建模的NRMSECV比粘度模型变化更大,平均7.54%(0.67%),非极柱数据产生的平均NRMSECV显著较高,为10.06%(0.35%).同样,对于氢含量,具有极柱数据的NRMSECV平均为9.50%(0.87%),显着低于NRMSECV,非极柱数据平均为12.10%(0.88%)。我们还研究了平滑GC数据对相应PLS模型的影响。通过应用不同程度的平滑,我们可以在较短的TW中有效地获得相似的色谱峰模式。例如,10分钟平滑的色谱图看起来像1分钟的分离,没有平滑,但导致几乎相同的NRMSECV。总的来说,1分钟TW的快速分离产生了具有任一固定相柱的粘度的稳健PLS模型,而对于密度和氢含量,极性固定相柱产生了优异的PLS模型,因此,通过适当的固定相位选择,快速分离运行时间可以很容易地应用于最佳PLS属性建模结果。
    Partial least squares (PLS) regression is a valuable chemometric tool for property prediction when coupled with gas chromatography (GC). Since the separation run time and stationary phase selection are crucial for effective PLS modeling, we study these GC parameters on the prediction of viscosity, density and hydrogen content for 50 aerospace fuels. Due to the diversity of compounds in the fuels (primarily alkanes, cycloalkanes, and aromatics), we explore both polar and non-polar stationary phase columns. The robustness for the PLS models was evaluated by their normalized root mean square error of cross-validation (NRMSECV). PLS models built for viscosity across 1-min, 3-min, 7-min, and 10-min time window (TW) high-speed GC separations produced nearly the same NRMSECV with the polar column data with an average (standard deviation) of 4.41 % (0.34 %) versus the non-polar column data of 4.69 % (0.15 %). In contrast, while the NRMSECV of density modeling with the polar column data varied more than the viscosity models, averaging 7.54 % (0.67 %), the non-polar column data produced a significantly higher average NRMSECV of 10.06 % (0.35 %). Similarly, for hydrogen content, the NRMSECV with the polar column data averaged 9.50 % (0.87 %), which was significantly lower than the NRMSECV with the non-polar column data averaging 12.10 % (0.88 %). We also investigated the impact of smoothing the GC data on the corresponding PLS models. By applying varying degrees of smoothing, we can effectively obtain similar chromatographic peak patterns in a shorter TW. For example, a 10-min smoothed chromatogram appears like the 1-min separation with no smoothing but resulted in nearly the same NRMSECV. Overall, the fast separation with a 1-min TW produced robust PLS models for viscosity with either stationary phase column, whereas for density and hydrogen content the polar stationary phase column produced superior PLS models, thus with proper stationary phase selection, a fast separation run time could be readily applied with optimal PLS property modeling results.
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  • 文章类型: Journal Article
    在电气设备的制造过程中,确保技术表面的清洁度,如直接接合铜基板,至关重要。用于质量检查的在线监测系统必须在短时间内提供足够解析的横向数据。紫外高光谱成像是一种很有前途的在线快速成像方法,非接触式,和大规模的污染检测;因此,UV高光谱成像(225-400nm)用于以非破坏性方式表征直接键合铜的清洁度。总的来说,准备了11个级别的清洁度,总共测量了44个样本,以开发用于表征和预测清洁度水平的多变量模型。设置包括一个推扫帚成像仪,氘灯,和用于横向分辨测量铜表面的传送带。主成分分析(PCA)模型基于前两个主成分有效地区分了样本类型,解释方差约为100.0%。偏最小二乘回归(PLS-R)模型,以确定最佳的超声处理时间显示出可靠的性能,R2cv=0.928和RMSECV=0.849。该模型能够预测测试样本集中每个像素的清洁度,示例了直接接合铜基板的制造工艺中的步骤。结合多变量数据建模,在线UV原型系统显示出进一步发展其在现实世界中应用的巨大潜力,大规模的过程。
    In the manufacturing process of electrical devices, ensuring the cleanliness of technical surfaces, such as direct bonded copper substrates, is crucial. An in-line monitoring system for quality checking must provide sufficiently resolved lateral data in a short time. UV hyperspectral imaging is a promising in-line method for rapid, contactless, and large-scale detection of contamination; thus, UV hyperspectral imaging (225-400 nm) was utilized to characterize the cleanliness of direct bonded copper in a non-destructive way. In total, 11 levels of cleanliness were prepared, and a total of 44 samples were measured to develop multivariate models for characterizing and predicting the cleanliness levels. The setup included a pushbroom imager, a deuterium lamp, and a conveyor belt for laterally resolved measurements of copper surfaces. A principal component analysis (PCA) model effectively differentiated among the sample types based on the first two principal components with approximately 100.0% explained variance. A partial least squares regression (PLS-R) model to determine the optimal sonication time showed reliable performance, with R2cv = 0.928 and RMSECV = 0.849. This model was able to predict the cleanliness of each pixel in a testing sample set, exemplifying a step in the manufacturing process of direct bonded copper substrates. Combined with multivariate data modeling, the in-line UV prototype system demonstrates a significant potential for further advancement towards its application in real-world, large-scale processes.
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  • 文章类型: Journal Article
    金纳米间隙基底用于使用表面增强拉曼散射(SERS)测量各种果汁中的硫美双和西维因残基。金纳米间隙基底可以检测西维因和福美双,检出限为0.13ppb(0.13μgkg-1)和0.22ppb(0.22μgkg-1)。首先对原始SERS数据进行预处理,以减少噪声和不良影响,后来用于模型创建,实施分类,和回归分析技术。对于两种农药感染的果汁样品,偏最小二乘回归模型的预测相关系数(R2)最高为0.99,预测值均方根最低均低于0.62ppb。此外,区分受农药和对照(无农药)污染的果汁样品,产生了逻辑回归分类模型,对于含有福美双的受污染果汁,其最高分类准确率为100%和99%,对于含有西维因的受污染果汁,其结果为100%。这表明金纳米间隙表面在检测食品样品中的痕量污染物方面具有实现高灵敏度的显著潜力。
    A gold nanogap substrate was used to measure the thiram and carbaryl residues in various fruit juices using surface-enhanced Raman scattering (SERS). The gold nanogap substrates can detect carbaryl and thiram with limits of detection of 0.13 ppb (0.13 μgkg-1) and 0.22 ppb (0.22 μgkg-1). Raw SERS data were first preprocessed to reduce noise and undesirable effects and, were later used for model creation, implementing classification, and regression analysis techniques. The partial least-squares regression models achieved the highest prediction correlation coefficient (R2) of 0.99 and the lowest root mean square of prediction value below 0.62 ppb for both pesticide-infected juice samples. Furthermore, to differentiate between juice samples contaminated by both pesticides and control (pesticide-free), logistic-regression classification models were produced and achieved the highest classification accuracies of 100% and 99% for contaminated juice containing thiram and 100% accurate results for contaminated juice containing carbaryl. This indicates that the gold nanogap surface has significant potential for achieving high sensitivity in detecting trace contaminants in food samples.
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  • 文章类型: Journal Article
    背景:由于其蛋白质含量高,因此在无谷物的狗饮食中,脉冲成分通常会代替谷物。然而,确定这种修改的好处的研究是有限的。
    目的:将一种含玉米的对照饮食(Ctl)和三种无谷物饮食中的食物化合物与增加的全豆类内含物(高达45%;Pulse15,Pulse30,Pulse45)相关联,在20周内,健康犬的餐后氨基酸(AA)可以满足类似的宏量和微量营养素目标。
    方法:使用串联MS分析饮食中的生化化合物。二十八个户外住宅,健康,成年西伯利亚爱斯基摩犬在基线和第2,4,8,16和20周进行饮食和膳食反应,在禁食和用餐后15,30,60,90,120和180分钟收集样本.通过UPLC分析血液AAs,并在周之间进行差异分析,在SASStudio中分析治疗和餐后时间。在SASStudio中使用饮食中的生化化合物作为预测变量并使用血液AA作为响应变量进行偏最小二乘回归。
    结果:在血浆中,与Pulse15相比,Pulse45的餐后Asn高出32%,Ctl的餐后Leu高出34%,与Pulse15相比Pro高出35%(P<0.05)。在全血中,Pulse30的餐后Lys比Ctl高23%,与Pulse45和Pulse30相比,Ctl餐后Met高21%,Pro高18%(P<0.05)。几种磷脂与餐后AAs相关。“尿素循环”和“甘氨酸和丝氨酸代谢”中的化合物在血浆和全血中更富集(P<0.05),分别。
    结论:在大量和微量营养素平衡的犬饮食中,它们包含玉米和豆类来源的成分,餐后循环AA的变化在很大程度上表明了饮食AA。这有助于我们进一步了解饲喂无谷物饮食的健康狗的AA代谢。
    BACKGROUND: Pulse ingredients often replace grains in grain-free dog diets owing to their high-protein content. However, research to ascertain the benefit of this modification is limited.
    OBJECTIVE: This study aimed to correlate food compounds in 1 corn-inclusive control diet and 3 grain-free diets with increasing inclusions of whole pulses (≤45%; Pulse15, Pulse30, and Pulse45), formulated to meet similar macronutrient and micronutrient targets with postprandial amino acids (AAs) in healthy dogs >20 wk.
    METHODS: Diets were analyzed for biochemical compounds using tandem mass spectrometry. Twenty-eight outdoor-housed, healthy, adult Siberian Huskies were allocated to diet, and meal responses were analyzed at baseline and weeks 2, 4, 8, 16, and 20 with samples collected at fasted and 15, 30, 60, 90, 120, and 180 min after meal presentation. Blood AAs were analyzed by ultra performance liquid chromatography and differences across week, treatment, and time postmeal were analyzed in SAS Studio. Partial least squares regression was performed in SAS Studio using biochemical compounds in the diet as predictor variables and blood AAs as response variables.
    RESULTS: In plasma, Pulse45 had ∼32% greater postprandial Asn than Pulse15, and the control diet had ∼34% greater postprandial Leu and ∼35% greater Pro than Pulse15 (P < 0.05). In whole blood, Pulse30 had ∼23% greater postprandial Lys than the control diet, and the control diet had ∼21% greater postprandial Met and ∼18% greater Pro than Pulse45 and Pulse30, respectively (P < 0.05). Several phospholipids were correlated with postprandial AAs. Compounds in the urea cycle and glycine and serine metabolism were more enriched (P < 0.05) in plasma and whole blood, respectively.
    CONCLUSIONS: In macronutrient-balanced and micronutrient-balanced canine diets that differ in their inclusion of corn-derived compared with pulse-derived ingredients, postprandial changes in circulating AAs are largely indicative of the dietary AAs. This helps further our understanding of AA metabolism in healthy dogs fed grain-free diets.
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  • 文章类型: Journal Article
    彩色马铃薯具有食品和蔬菜的功能。彩薯不仅含有人体所需的各种氨基酸和微量元素,还含有花青素。花青素有很多功能,如抗氧化,炎症抑制,视力改善,和癌症预防,因此彩色土豆深受消费者的喜爱,具有良好的市场前景。然而,目前,彩色马铃薯中花青素含量的检测主要依靠化学方法,费时费力,因此有必要研究一种快速准确的检测方法。在这项研究中,显微高光谱设备用于采集土豆外皮和内皮的光谱信息。原始光谱,预处理光谱,利用卷积神经网络(CNN)算法和偏最小二乘回归(PLS)算法对外皮和内皮的特征光谱变量进行预测,分别,并通过预测集相关系数(Rp)评估模型的性能,预测集均方根误差(RMSEP),校正集相关系数(Rc),校正集均方根误差(RMSEC),和残差预测偏差(RPD)。结果表明,在原始光谱数据下构建的内皮Raw+CNN模型是最优的,Rc=0.9508,RMSEC=0.0374%,Rp=0.9461,RMSEP=0.2361%,RPD=4.4933。由预处理光谱数据构建的内皮肤Savitzky-Golay(SG)+Detrend(DET)+CNN模型是最优的,Rc=0.9499,RMSEC=0.0359%,Rp=0.9439,RMSEP=0.2384%,RPD=4.6516。从基于特征的光谱数据构建的内部皮肤DET+竞争自适应重加权采样(CARS)+CNN模型是最优的,Rc=0.9527,RMSEC=0.0708%,Rp=0.9457,RMSEP=0.2711%,RPD=4.1623。可以看出,Rp,RMSEP,Rc,RMSEC,在三种不同的光谱数据下,用于模拟内部皮肤光谱信息的RPD值高于外部皮肤的光谱信息。CNN算法建立的模型预测精度优于传统的PLS算法,CNN算法在内皮中的应用可以实现马铃薯花青素含量的准确预测。
    The color potato has the function of both a food and vegetable. The color potato not only contains various amino acids and trace elements needed by the human body but also contains anthocyanins. Anthocyanins have many functions, such as antioxidation, inflammation inhibition, vision improvement, and cancer prevention, so colored potatoes are deeply loved by consumers and have good market prospects. However, at present, the detection of anthocyanin content in color potatoes mainly depends on chemical methods, which are time-consuming and laborious, so it is necessary to study a fast and accurate detection method. In this study, microscopic hyperspectral equipment was used to collect the spectral information of the outer skin and inner skin of potatoes. The original spectrum, pretreatment spectrum, and characteristic spectrum variables of the outer skin and inner skin were predicted by the convolution neural network (CNN) algorithm and partial least squares regression (PLS) algorithm, respectively, and the performance of the model was evaluated by the prediction set correlation coefficient (Rp), prediction set root mean square error (RMSEP), correction set correlation coefficient (Rc), correction set root mean square error (RMSEC), and residual prediction deviation (RPD). The results revealed that the inner skin Raw + CNN model constructed under raw spectral data is optimal with Rc = 0.9508, RMSEC = 0.0374%, Rp = 0.9461, RMSEP = 0.2361% and RPD = 4.4933. The inner skin Savitzky-Golay (SG) + Detrend (DET) + CNN model constructed from pre-processed spectral data is optimal with Rc = 0.9499, RMSEC = 0.0359%, Rp = 0.9439, RMSEP = 0.2384%, RPD = 4.6516. The inner skin DET + competitive adaptive reweighted sampling (CARS) +CNN model constructed from the feature-based spectral data was optimal with Rc = 0.9527, RMSEC = 0.0708%, Rp = 0.9457, RMSEP = 0.2711%, and RPD = 4.1623. It can be seen that the Rp, RMSEP, Rc, RMSEC, and RPD values for modeling the spectral information of the inner skin were higher than those of the outer skin under the three different spectral data. The prediction accuracy of the model built by the CNN algorithm was better than the conventional algorithm PLS, the application of the CNN algorithm in inner skin can achieve accurate prediction of anthocyanin content in potato.
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  • 文章类型: Journal Article
    在这项研究中,结合了主成分分析(PCA)和偏最小二乘回归(PLS),以确定确定直接压缩和碾压可压片性的关键材料描述符。生成了一个广泛的材料库,其中包括119种材料描述符和44种粉末的片剂拉伸强度以及具有不同药物负载的辊压材料,以系统地阐明不同材料描述符的影响。原料药和填料特性以及可压片性的工艺路线。创建了一个PCA模型,该模型突出了不同粉末描述符与各自表征方法之间的相关性,因此,可以减少分析,在一定程度上节约资源。随后,PLS模型的建立,以确定关键的材料属性,如密度和颗粒大小,以及表面能,内聚力和墙壁摩擦的工作,PLS首次证明这与碾压和直接压缩的压片性高度相关。Further,基于广泛的材料表征的PLS能够预测模型未知的材料的可压性。因此,这项研究强调了PCA和PLS是如何阐明粉末和可压性之间相关性的有用工具,这将在配方开发中实现更可靠的可制造性预测。
    Principal component analysis (PCA) and partial least squares regression (PLS) were combined in this study to identify key material descriptors determining tabletability in direct compression and roller compaction. An extensive material library including 119 material descriptors and tablet tensile strengths of 44 powders and roller compacted materials with varying drug loads was generated to systematically elucidate the impact of different material descriptors, raw API and filler properties as well as process route on tabletability. A PCA model was created which highlighted correlations between different powder descriptors and respective characterization methods and, thus, can enable reduction of analyses to save resources to a certain extent. Subsequently, PLS models were established to identify key material attributes for tabletability such as density and particle size but also surface energy, work of cohesion and wall friction, which were for the first time demonstrated by PLS as highly relevant for tabletability in roller compaction and direct compression. Further, PLS based on extensive material characterization enabled the prediction of tabletability of materials unknown to the model. Thus, this study highlighted how PCA and PLS are useful tools to elucidate the correlations between powder and tabletability, which will enable more robust prediction of manufacturability in formulation development.
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  • 文章类型: Journal Article
    病毒样颗粒(VLP)是一类有前途的用于疫苗和靶向递送的生物药物。从澄清的裂解物开始,VLP通常通过选择性沉淀来捕获。虽然通过逐步或连续添加沉淀剂诱导VLP沉淀,当前的监测方法不支持直接的产品量化,和分析方法通常需要各种,耗时的处理和样品制备步骤。这里,拉曼光谱与化学计量学方法相结合的应用可以允许同时定量沉淀的VLP和沉淀剂,因为它在分析原油方面具有明显的优势,复杂的混合物。在这项研究中,我们提出了一种基于拉曼光谱的过程分析技术(PAT)工具,用于乙型肝炎核心抗原VLP的分批和补料分批沉淀实验。我们进行了小规模的沉淀实验,提供了多样化的数据集,这些数据集具有由澄清的大肠杆菌来源的裂解物的初始稀释或加标引起的不同的沉淀动力学和背景。对于拉曼光谱数据,各种预处理操作被系统地组合在一起,允许识别预处理管道,这证明有效地消除了初始裂解物组成变化以及归因于沉淀物和溶液中存在的沉淀剂的大多数干扰。校准的偏最小二乘模型无缝预测了在分批和补料分批实验中R2为0.98和0.97的沉淀剂浓度,分别,并捕获了观测到的降水趋势,R2分别为0.74和0.64。尽管由于观察到的光谱数据和VLP浓度之间的非线性关系,实验之间的细微差异的分辨率受到限制,这项研究为使用拉曼光谱作为监测VLP沉淀过程的PAT传感器提供了基础,有可能将其适用性扩展到其他相位行为相关的过程或分子。
    Virus-like particles (VLPs) are a promising class of biopharmaceuticals for vaccines and targeted delivery. Starting from clarified lysate, VLPs are typically captured by selective precipitation. While VLP precipitation is induced by step-wise or continuous precipitant addition, current monitoring approaches do not support the direct product quantification, and analytical methods usually require various, time-consuming processing and sample preparation steps. Here, the application of Raman spectroscopy combined with chemometric methods may allow the simultaneous quantification of the precipitated VLPs and precipitant owing to its demonstrated advantages in analyzing crude, complex mixtures. In this study, we present a Raman spectroscopy-based Process Analytical Technology (PAT) tool developed on batch and fed-batch precipitation experiments of Hepatitis B core Antigen VLPs. We conducted small-scale precipitation experiments providing a diversified data set with varying precipitation dynamics and backgrounds induced by initial dilution or spiking of clarified Escherichia coli-derived lysates. For the Raman spectroscopy data, various preprocessing operations were systematically combined allowing the identification of a preprocessing pipeline, which proved to effectively eliminate initial lysate composition variations as well as most interferences attributed to precipitates and the precipitant present in solution. The calibrated partial least squares models seamlessly predicted the precipitant concentration with R 2 of 0.98 and 0.97 in batch and fed-batch experiments, respectively, and captured the observed precipitation trends with R 2 of 0.74 and 0.64. Although the resolution of fine differences between experiments was limited due to the observed non-linear relationship between spectral data and the VLP concentration, this study provides a foundation for employing Raman spectroscopy as a PAT sensor for monitoring VLP precipitation processes with the potential to extend its applicability to other phase-behavior dependent processes or molecules.
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  • 文章类型: Journal Article
    到目前为止,符合ISO3632标准规格的优质藏红花保证良好的农业和收获后的生产实践。跟踪早期氧化仍然具有挑战性。我们的研究旨在通过探索可见的,荧光,和第一类藏红花的近红外光谱。使用多光谱传感器,我们测试了粉末形式的新鲜和人工老化的藏红花。600-700nm处的高自发荧光强度允许校准“老化藏红花含量”。具有最小着色强度(200-220单位)的样品被分类为70%老化,而那些超过最大香气强度(50单位)的100%陈化。跨原点的一致模式,年龄,和加工历史表明了客观评估早期氧化标志物的潜力。进一步的分析发现了多种有贡献的荧光团,包括顺式载脂蛋白类,与基于FTIR的衰老标志物相关。我们的发现强调,感知交易藏红花的自发荧光提供了一种创新的质量诊断方法,为评估其供应链的剩余保质期铺平了新的研究道路。
    So far, compliance with ISO 3632 standard specifications for top-quality saffron guarantees good agricultural and post-harvest production practices. Tracking early-stage oxidation remains challenging. Our study aims to address this issue by exploring the visible, fluorescence, and near-infrared spectra of category I saffron. Using a multi-spectral sensor, we tested fresh and artificially aged saffron in powder form. High autofluorescence intensities at 600-700 nm allowed calibration for the \'content of aged saffron\'. Samples with minimum coloring strength (200-220 units) were classified as 70% aged, while those exceeding maximum aroma strength (50 units) as 100% aged. Consistent patterns across origin, age, and processing history indicated potential for objectively assessing early-oxidation markers. Further analyses uncovered multiple contributing fluorophores, including cis-apocarotenoids, correlated with FTIR-based aging markers. Our findings underscore that sensing autofluorescence of traded saffron presents an innovative quality diagnostic approach, paving new research pathways for assessing the remaining shelf-life along its supply chain.
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  • 文章类型: Journal Article
    了解储存的芝麻酱(SP)中香气的演变对于保持其质量至关重要。这项研究调查了SP的储存质量和指示感官降解的潜在香气标记。描述性感官分析显示了储存过程中香气属性的变化,从烤芝麻和坚果香气过渡到发酵和绿色香气。物理化学分析显示颜色加深,强化脂质氧化,降低生物活性成分的水平,增加颗粒聚集,并且在40°C下超过63天的流动性恶化。气相色谱-嗅觉-质谱法鉴定出37种芳香活性化合物,用吡嗪,醛类,和酚类被确定为主要成分。偏最小二乘回归分析显示2-乙基-3-甲基-吡嗪,2-甲氧基-4-乙烯基苯酚,苯甲醛是关键的香气活性化合物,对SP中发现的独特香气“烤坚果和烤芝麻”有重要贡献。相反,己醛和二甲基二硫化物是SP中不良香气的潜在标志物,包括“腐臭”,绿色,和发酵的“。这些发现提供了对存储过程中SP变化的见解,这对于保存和质量提升策略至关重要。
    Understanding the evolution of aroma profiles in stored sesame paste (SP) is essential for maintaining its quality. This study investigated the storage quality of SP and potential aroma markers indicative of sensory degradation. The descriptive sensory analysis demonstrated changes in aroma attributes during storage, transitioning from roasted sesame and nutty aromas to fermented and green aromas. Physicochemical analysis showed deepening color, intensified lipid oxidation, decreased levels of bioactive components, increased particle aggregation, and deteriorated flowability over 63 days at 40 °C. Gas chromatography-olfactometry-mass spectrometry identified 37 aroma-active compounds, with pyrazines, aldehydes, and phenols identified as the major constituents. Partial least squares regression analysis revealed 2-ethyl-3-methyl-pyrazine, 2-methoxy-4-vinylphenol, and benzaldehyde as key aroma-active compounds contributing significantly to the distinctive aromas \"roasted nut and roasted sesame\" found in SP. Conversely, hexanal and dimethyl disulfide emerged as potential markers of undesirable aromas in SP, including \"rancid, green, and fermented\". These findings provide insights into SP changes during storage, which is vital for preservation and quality enhancement strategies.
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