The acid value (AV) is an essential parameter for the quality and safety evaluation of peanut oil. In this study, for efficiently and real-time monitor of acid value (AV) in peanut oil, a portable ...spectroscopy system was first developed and combined with variables selection algorithms to measure acid value (AV) in peanut oils. Developed portable spectroscopy system was applied for transmittance spectrum data acquisition after which partial least squares (PLS) and several variables selection algorithms synergy interval partial least square (Si-PLS), genetic algorithm (GA), genetic algorithm combined with Si-PLS namely GA-Si-PLS, ant colony optimization (ACO) algorithms were systemically studied and comparatively used for modeling. The performances of these models were evaluated according to correlation coefficients squared in the prediction set (RP) and root mean square error of prediction (RMSEP). The results showed that the variables selection methods could select more significant variables and improve the model performance, especially for the GA-Si-PLS model with the best performance than other variables selection algorithms with RP=0.9426 and RMSEP=0.2980. Finally, the paper draws a conclusion that the developed portable spectroscopy system combined with a suitable variables selection methods could be used for the simultaneous and rapid measurement of acid value in peanut oil.
(1) Background: Portable NIR spectrometers gain more and more ground in the field of Process Analytical Technology due to the easy on-site flexibility and interfacing versatility. These advantages ...that originate from the instrument miniaturization, also come with a downside with respect to performance compared to benchtop devices. The objective of this work was to evaluate the performance of MicroNIR in a pharmaceutical powder blend application, having three active ingredients and 5 excipients. (2) Methods: Spectral data was recorded in reflectance mode using static and dynamic acquisition, on calibration set samples developed using an experimental design. (3) Results: The developed method accurately predicted the content uniformity of these complex mixtures, moreover it was validated in the entire calibration range using ±10% acceptance limits. With respect to at-line prediction, the method presented lower performance compared to a previously studied benchtop spectrometer. Regarding the in-line monitoring of the blending process, it was shown that the spectral variability-induced by dynamic acquisition could be efficiently managed using spectral pre-processing. (4) Conclusions: The in-line process monitoring resulted in accurate concentration profiles, highlighting differences in the mixing behaviour of the investigated ingredients. For the low dose component homogeneity was not reached due to an inefficient dispersive mixing.
A key quality and processing parameter for cotton fiber is micronaire, which is a function of the fiber's maturity and fineness. Near-infrared (NIR) spectroscopy has previously shown the ability to ...measure micronaire, primarily in the laboratory and using large, research-grade laboratory NIR instrumentation. International interest has been expressed by the industry in the measurement of fiber micronaire using small, portable NIR spectroscopy instruments for both laboratory and outside the laboratory (e.g., field or greenhouse) locations. New, very small NIR micro-spectrometers have been commercialized that offer the potential advantages of smaller size and lower weight, lower cost, and increased portability over current portable units. A program was implemented to determine the feasibility of a small NIR micro-spectrometer to measure fiber micronaire both in the laboratory and outside the laboratory, with initial emphasis on laboratory measurements prior to moving to field evaluations. In the laboratory, distinct spectral differences with increasing micronaire were observed. Optimal sampling and instrumental procedures and protocols for two units (different spectral wavelength capabilities) were established. Comparative evaluations established very good method micronaire agreement between the micro-spectrometer and a standard portable spectrometer, with high Regression (R) value, low residuals, and few outliers (less than 20%). The NIR micro-spectrometer measurements were fast (<1 min per sample), required no sample preparation, and were easy to perform. All end-state criteria were exceeded. The rapid and accurate laboratory measurement of fiber micronaire with a NIR micro-spectrometer was demonstrated.
The composition of animal slurries is basic information required to arrange fertilisation plans that allow satisfactory crop yields and avoid environmental pollution. Slurry management based on ...measured composition data requires the development and adoption of analytical methods that are rapid, affordable and applicable directly in the field. NIR spectroscopy is a candidate technique for this application. In the present work, the performances of four NIR spectrometers, differing in optics, detectors and price, were investigated and compared: one FT-NIR and one dispersive benchtop instrument; a less expensive diode array dispersive instrument also suitable for online applications; and a low-cost interferometric portable instrument. Ninety-nine slurries, collected from livestock farms in Lombardy (Italy), were characterised using reference methods for dry matter (DM), ashes (ASH), total nitrogen (TKN), ammonium nitrogen (AN), organic nitrogen (ON), total carbon (TC) and total phosphorus (TP) content, and were used to investigate the performance of the four NIR spectrometers. The calibrations obtained from the two benchtop instruments for DM, ASH, TKN and TC were classified “useful” or “moderately useful”, while for AN and TP they were “useful for screening purposes”. The two portable instruments provided less accurate calibrations, with the exception of DM and TC which, in the case of the diode array instrument, performed similarly to the benchtop spectrometers. The higher resolution and, to a lesser degree, the wider spectral range of the two benchtop spectrometers contribute to explain their better calibration performances for TKN and AN.
•The performance of four NIR spectrometers were investigated and compared.•Ninety-nine cattle slurries were characterised and used for instrument calibration.•Calibrations were at least moderately useful for dry matter, total C and organic N.•Benchtop instruments outperformed portable instruments for total and ammoniacal N.•The higher resolution of the benchtop instruments explained their better calibrations.
•NIR Spectroscopy provide useful information about organic and inorganic content of soil.•Calibration of C and N content by NIR, allowed their quantitative determination in situ.•Aquaphotomics ...approach was able detecting great differences among each studied area.
Advances in laboratory instrumentation and chemometrics provide alternatives to traditional methods of conducting soil chemical analysis. One of these is infrared diffuse reflectance spectroscopy in the near-infrared spectral range. The usefulness of Near Infra-Red Spectroscopy (NIRS), as a nondestructive, quick, and low-cost method to provide scientific expertise on a large scale, has been proved in several fields of applications. Soil samples were collected from alluvial and loess-sampling sites in the North Sardinia, where precipitation, climate, and land use conditions can be very similar. A total of 95 soil samples were collected from three study areas (Berchidda, Arborea, and Ottava). The C and N contents in the soil samples were determined using an elemental analyzer and spectra of soil samples were collected using microNIR 1700 spectrometer. Data processing was carried out using the NIR region of the first water overtone. PLSR applied for calibration of C and N content, allowed the quantitative determination of both elements with good performances. Areas with low Soil Organic Carbon (SOC) can be identified and mapped, thus facilitating the development of both remediation strategies in terms of application of fertilization, environmental protection, and methods for modeling soil properties with great potential for diagnosing the nutrient deficiency and assessing the risk of soil parameters on the environment. The Aquaphotomics approach was able to associate one specific water absorption spectral pattern (WASP) to each studied area, detecting great differences in particular between the Berchidda zone and the other two sampling areas (Arborea, Ottava).
A compact Near Infrared Continuous Wave Cavity Ring-down Spectrometer (near-IR-cw-CRDS) was developed as a candidate for future planetary surface missions. The optical cavity was made of titanium ...with rugged quartz windows to protect the delicate super cavity from the harsh environmental changes that it would experience during space flight and a Martian surface mission. This design assured the long-term stability of the system. The system applied three distributed feedback laser diodes (DFB-LD), two of which were tuned to the absorption line peaks of 12CH4 and 13CH4 at 6046.954cm−1 and 6049.121cm−1, respectively. The third laser was tuned to a spectral-lines-free region for measuring the baseline cavity loss. The multiple laser design compensated for typical baseline drift of a CRDS system and, thus, improved the overall precision. A semiconductor optical amplifier (SOA) was used instead of an Acousto-Optic Module (AOM) to initiate the cavity ring-down events. It maintained high acquisition rates such as AOM, but consumed less power. High data acquisition rates combined with improved long-term stability yielded precise isotopic measurements in this near-IR region even though the strongest CH4 absorption line in this region is 140 times weaker than that of the strongest mid-IR absorption band., The current system has a detection limit of 1.4×10–12cm−1 for 13CH4. This limit corresponds to ~7pptv of CH4 at 100Torr. With no further improvements the detection limit of our current near IR-cw-CRDS at an ambient Martian pressure of ~6Torr (8mbar) would be 0.25ppbv for one 3.3 minute long analysis.
•Portable ultra high precision NIR CRDS for ambient methane isotopic analysis.•The detection limit is down to 1.4×10−12cm−1.
Turmeric consumption is continually increasing worldwide. Curcuminoids are major active constituents in turmeric and are associated with numerous health benefits. A combination of spectroscopic ...methods and chemometrics shows the suitability of turmeric for food quality control due to advantages such as speed, versatility, portability, and no need for sample preparation. Five calibration models to quantify curcuminoids in turmeric were proposed using benchtop and portable devices. The most remarkable results showed that Raman and NIR calibration models present an excellent performance reporting RMSEP of 0.44% w/w and 0.41% w/w, respectively. In addition, the five proposed methods (FT-IR, Raman, and NIR) were compared in terms of precision and accuracy. The results showed that benchtop and portable methods were in good agreement and that there are no significant differences between them. This study aims to foster the use of portable devices for food quality control in situ by demonstrating their suitability for the purpose.
Reliable and user-friendly discrimination of coffee bean integrity and quantification of adulteration in the coffee bean processing value chain would be vital for ensuring consumer trust in quality ...control and traceability management. In this research, a portable short-wave NIR spectroscopy coupled with chemometric data analysis was employed under different pre-treatments to develop a rapid detection technique. Different pre-processing treatments (multiplicative scatter correction; MSC, standard normal variant; SNV, first derivative; FD) together with multivariate techniques; support vector machine (SVM), linear discriminant analysis (LDA), neural network (NN), and random forest (RF) were comparatively assessed using accuracy and correlation coefficient (R) for discrimination and quantification. The results showed that the FD-LDA model had 97.78% and 100 % in both the calibration set and prediction set. In comparison, the SPA-PLS model had R = 0.9711 and 0.9897 in both the calibration set and prediction set. The outcome of this study showed portable short-wave NIR spectroscopic techniques could be used for examining the integrity of coffee.
Near infrared spectra obtained from leaf surfaces of Eucalyptus grandis seedlings were calibrated against physiological measurements of plant water stress, namely: relative water content, leaf water ...potential and stomatal conductance. In a controlled environment facility, spectral data were obtained from both abaxial and adaxial leaf surfaces as well as upper and lower leaves in the stem. The strongest coefficients of determination using cross-validation were r2CV = 0.85 for relative water content, r2CV = 0.74 for leaf water potential and r2CV = 0.80 for stomatal conductance. The use of a portable NIR instrument enabled the rapid assessment of physiological status of seedlings and would enable in situ, non-destructive, high-throughput monitoring of drought and recovery in the field. This would be particularly useful for non-destructive measurement in longitudinal studies.
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