Near-infrared Reflectance Method Research Articles

The impact of lignin downregulation on alfalfa yield, chemical composition, and in vitro gas production.

Lignin is a complex, phenolic polymer found in plant cell walls that is essential for mechanical support, water and mineral transport, and defense in vascular plants. Over ten different enzymes play a role in the synthesis of lignin in plants. Suppression of any one enzyme or combinations of these enzymes may change the concentration and composition of lignin in the genetically transformed plants. Two lines of alfalfa that were downregulated for caffeoyl coenzyme A O-methyltransferase were used to assess the impact of lignin downregulation on chemical composition and fermentation rate and extent using an in vitro gas production technique. A total of 64 samples consisting of two reduced lignin (RL) and two controls (CL), four field replicates, two cutting intervals (CIs; 28 and 35 days), and two cuts (Cut-1 and Cut-3) were used. No differences were detected in yield, crude protein, neutral detergent fiber (aNDF), and acid detergent fiber between the lines when harvested at the 28-day CI. The acid detergent lignin (ADL) concentration in RL alfalfa lines was significantly (P < 0.001) lower than in the CL. In alfalfa harvested at the 35-day CI, the RL alfalfa resulted in lower (P < 0.001) yield than CL. RL alfalfa lines had 24% and 22% lower (P < 0.001) ADL in Cut-1 and Cut-3 respectively than CL lines. The in vitro dry matter digestibility and aNDF digestibility (both as determined by the near-infrared reflectance method) were greater (P < 0.001) in RL than in CL lines harvested at the 35-day CI. In alfalfa harvested at the 35-day CI, extent of in vitro gas production and metabolizable energy content were greater in RL than in CL alfalfa. RL lines had 3.8% indigestible aNDF per unit ADL, whereas CL had 3.4% (P < 0.01). The positive effect of lignin downregulation was more pronounced when intervals between harvests were longer (35-day CI compared with the 28-day CI). Lignin downregulation in alfalfa offers an opportunity to extend harvesting time (CI) for higher yield without compromising the nutritional quality of the alfalfa forage for dairy and livestock feeding. However, the in vitro results reported here warrant further study using in vivo methods. © 2018 Society of Chemical Industry.

Genome-wide association for mapping QTLs linked to protein and oil contents in soybean

Abstract: The objective of this work was to identify single-nucleotide polymorphism (SNP) markers linked with quantitative trait loci (QTLs) associated with increased contents of protein and oil in soybean. A total of 169 Brazilian soybean varieties, genotyped with 6,000 SNP markers, were evaluated. Protein and oil contents were obtained with the near-infrared reflectance method. Correlation and multiple linear regression analyses were used to identify linkage disequilibrium between SNP markers and the QTLs associated with the two characteristics. Seven QTLs were found to be associated with protein content, on six chromosomes (2, 6, 11, 12, 13, and 16), explaining 60.9% of the variation in this trait. For oil content, eight QTLs were identified on six chromosomes (1, 4, 5, 6, 17, and 19), explaining 78.3% of the variation in the trait. The correlation between the number of loci containing favorable alleles and the evaluated characteristics was 0.49 for protein content and 0.60 for oil content. The molecular markers identified are mapped in genomic regions containing QTLs previously mapped for both characteristics, which reinforces the association between these regions and the genetic control of oil and protein contents in soybean.

CONTENT UNIFORMITY DETERMINATION OF IBUPROFEN INTACT TABLETS BY REFLECTANCE NIR SPECTROSCOPY

Content uniformity (CU) is a critical quality attribute in tablet manufacturing process. The active pharmaceutical ingredient (API) is usually determined off-line techniques such as, high performance liquid chromatography (HPLC) which is a slow, destructive technique and requires sample preparation. Therefore, Near Infrared (NIR) spectroscopy was employed as a process analytical technology (PAT) tool to determine the API and consequently the content uniformity of tablets. NIR spectroscopy is a fast, non-destructive technique and requires minimal sample preparation. The purpose of this work was to develop and validate NIR reflectance method for the determination of the ibuprofen content (mg) for the content uniformity for ibuprofen tablet. Partial least squares (PLS) model for the NIR reflectance was constructed by using calibration laboratory tablets with different ibuprofen (IBU) contentsspanning from 146.47 mg to 243.91 mg. The predictive performance of the proposed method was evaluated by traditional chemometric criteria. The corresponding values for the root mean square error of prediction (RMSEP) were equal to 0.96% for NIR reflectance method. Besides, the proposed NIR method was successfully validated and implemented for the determination of the content uniformity for three batches that represent three levels of IBU content (160 mg, 200 mg and 240 mg).

Sensing of Moisture Content of In-Shell Peanuts by NIR Reflectance Spectroscopy

It was found earlier that moisture content (MC) of intact kernels of grain and nuts could be determined by Near Infra Red (NIR) reflectance spectrometry. However, if the MC values can be determined while the nuts are in their shells, it would save lot of labor and money spent in shelling and cleaning the nuts. Grain and nuts absorb low levels of NIR, and when NIR radiation is incident on them, a substantial portion of the radiation is reflected back. Thus, studying the NIR reflectance spectra emanating from in-shell peanuts, an attempt is made for the first time to determine the MC of in-shell peanuts. In-shell peanuts of two different market types, Virginia and Valencia, were conditioned to different moisture levels between 6% and 26% (wet basis), and separated into calibration and validation groups. NIR absorption spectral data from 1000 nm to 2500 nm in 1 nm intervals were collected from both groups. Measurements were obtained on 30 replicates within each moisture level. Reference MC values for each moisture level in these groups were obtained using standard air-oven method. Partial Least Square (PLS) analysis was performed on the calibration data, and prediction models were developed. The Standard Error of Calibration (SEC), and R2 of the calibration models were computed to select the best calibration model. The selected models were used to predict the moisture content of peanuts in the validation sets. Predicted MC values of the validation samples were compared with their standard air-oven moisture values. Goodness of fit was determined based on the lowest Standard Error of Prediction (SEP) and highest R2 value obtained for the prediction models. The model, with reflectance plus normalization spectral data with an SEP of 0.74 for Valencia and 1.57 for Virginia type in-shell peanuts was selected as the best model. The corresponding R2 values were 0.98 for both peanut types. This work establishes the possibility of sensing MC of intact in-shell peanuts by NIR reflectance method, and would be useful for the peanut and allied industries.

The Quantized Characterization of Cooked Rice Hardness and Research on the Automatic Measurement Technology

The hardness of cooked rice is one of the most important criteria which determine the rice quality. The commonly used near-infrared reflectance (NIR) method is still in argument due to its indirectness and possible error. In this paper, a mechanical method was proposed and its principle, automation, components and operative reliability were evaluated and compared with the NIR method. The results showed that the mechanical testing method can accurately detect the rice quality and were consistent with the NIR testing data. This new mechanical method can be effectively used in rice quality testing and branding with the advantage of simplicity, accuracy and reliability.

NIR Reflectance Spectroscopy for Nondestructive Moisture Content Determination in Peanut Kernels

There are some commercial instruments available that use near-infrared (NIR) radiation measurements to determine the moisture content (MC) of a variety of grain products, such as wheat and corn, without the need of any sample grinding or preparation. However, to measure the MC of peanuts with these instruments, the peanut kernels have to be chopped into smaller pieces and filled into the measuring cell. This is cumbersome, time consuming, and destructive. An NIR reflectance method is presented here by which the average MC of about 100 g of whole kernels could be determined rapidly and nondestructively. The MC range of the peanut kernels tested was between 8% and 26%. Initially, NIR reflectance measurements were made at 1 nm intervals in the wavelength range of 1000 to 1800 nm, and the data were modeled using partial least squares regression (PLSR). The predicted values of the samples tested in the above range were compared with the values determined by the standard air-oven method. The predicted values agreed well with the air-oven values, with an R2 value of 0.93 and a standard error of prediction (SEP) of 1.18. Using the PLSR beta coefficients, five key wavelengths were identified, and MC predictions were made using multiple linear regression (MLR). The R2 and SEP values of the MLR model were 0.91 and 1.09, respectively. Both methods performed satisfactorily and, being rapid, nondestructive, and noncontact, may be suitable for continuous monitoring of MC of grain and peanuts as they move on conveyor belts during their processing.

Measurement and analysis of soil nitrogen and organic matter content using near-infrared spectroscopy techniques

Near infrared reflectance (NIR) spectroscopy is as a rapid, convenient and simple nondestructive technique useful for quantifying several soil properties. This method was used to estimate nitrogen (N) and organic matter (OM) content in a soil of Zhejiang Province, Hangzhou County. A total of 125 soil samples were taken from the field. Ninety-five samples spectra were used during the calibration and cross validation stage. Thirty samples spectra were used to predict N and OM concentration. NIR spectra of these samples were correlated using partial least square regression. The regression coefficients between measured and predicted values of N and OM was 0.92 and 0.93, and SEP (standard error of prediction) were 3.28 and 0.06, respectively, which showed that NIR method had potential to accurately predict these constituents in this soil. The results showed that NIR spectroscopy could be a good tool for precision farming application.

Freshness Assessment of Thawed and Chilled Cod Fillets Packed in Modified Atmosphere Using Near-infrared Spectroscopy

Near-infrared reflectance (NIR) spectra was recorded of 105 samples of cod mince prepared from chill stored thawed cod fillets of varying quality in modified atmosphere packaging (MAP). Traditional chemical, physical, microbiological and sensory quality methods developed for assessing fresh fish products were determined on the same cod fillets. The purpose was to evaluate the potential of NIR spectroscopy for estimating (i) frozen storage temperature, (ii) frozen storage period and (iii) chill storage period of thawed-chilled MAP Barents Sea cod fillets. Furthermore, the potential for measuring of selected quality attributes as drip loss, water holding capacity and content of dimethylamine by NIR was evaluated. The results of the investigation were presented using multivariate modelling methods such as partial least-squares regression (PLSR) and discriminant partial least-squares regression (DPLSR). Systematic differences in the NIR measurements on minced cod fillets were primarily due to the chill storage duration (days at 2°C) on thawed-chilled MAP fillets. PLSR models based on wavelengths selected by a new Jack-knife method resulted in a correlation coefficient of 0.90 between measured and predicted duration of chill storage period (days at 2°C). The root-mean-square error of cross-validation (RMSECV) was 3.4 d at 2°C. NIR measurements provided promising results for evaluation of freshness for thawed-chilled MAP cod fillets completing the traditionally quality methods. However, it is necessary to study the effect of e.g. sample preparation, season, fishing ground and cod size together with more sophisticated pre-treatments of NIR spectra before the NIR method can be integrated as a method for evaluation of thawed-chilled MAP cod fillets.

Freshness Assessment of Thawed and Chilled Cod Fillets Packed in Modified Atmosphere Using Near-infrared Spectroscopy

Near-infrared reflectance (NIR) spectra was recorded of 105 samples of cod mince prepared from chill stored thawed cod fillets of varying quality in modified atmosphere packaging (MAP). Traditional chemical, physical, microbiological and sensory quality methods developed for assessing fresh fish products were determined on the same cod fillets. The purpose was to evaluate the potential of NIR spectroscopy for estimating (i) frozen storage temperature, (ii) frozen storage period and (iii) chill storage period of thawed-chilled MAP Barents Sea cod fillets. Furthermore, the potential for measuring of selected quality attributes as drip loss, water holding capacity and content of dimethylamine by NIR was evaluated. The results of the investigation were presented using multivariate modelling methods such as partial least-squares regression (PLSR) and discriminant partial least-squares regression (DPLSR). Systematic differences in the NIR measurements on minced cod fillets were primarily due to the chill storage duration (days at 2°C) on thawed-chilled MAP fillets. PLSR models based on wavelengths selected by a new Jack-knife method resulted in a correlation coefficient of 0.90 between measured and predicted duration of chill storage period (days at 2°C). The root-mean-square error of cross-validation (RMSECV) was 3.4 d at 2°C. NIR measurements provided promising results for evaluation of freshness for thawed-chilled MAP cod fillets completing the traditionally quality methods. However, it is necessary to study the effect of e.g. sample preparation, season, fishing ground and cod size together with more sophisticated pre-treatments of NIR spectra before the NIR method can be integrated as a method for evaluation of thawed-chilled MAP cod fillets.

The prediction of C and N content and their potential mineralisation in heterogeneous soil samples using Vis-NIR spectroscopy and comparative methods

The development of a rapid, accurate and cost-effective method for the prediction of constituents related to soil nitrogen (N) supply is considered important. The potential of using visible (Vis) and near infrared reflectance (NIR) spectroscopy (400–2500 nm) as such a method was investigated. Vis–NIR calibrations were performed for organic carbon (Corg) and total N (Ntot) content and their potential mineralisation using 80 grassland soil samples of rather heterogeneous origin. Prediction accuracy was tested using a 'take-out-four' validation strategy (48 samples). Within investigated variables a ratio of standard deviation of reference data to standard error of bias corrected prediction (RPD) within 1.7 (r2=0.65) and 2.7 (r2=0.87) were achieved. Apparent differences in Vis–NIR prediction accuracy among the variables were partly due to errors in the reference values. Thawed moist samples tend to be more accurately predicted than dried samples, and no benefit was derived from the grinding of sieved (4 mm) and dried samples. Prediction accuracy did not differ using two different systems for sample presentation to the Vis–NIR analyses. Comparative predictions of Corg and Ntot and their potential mineralisations were performed using the take-out-four validation strategy and simple linear regression to loss on ignition (LOI) values and hot KCl extracted NH4-N (NhotKCl) values as predictors. Likewise, the reference values of Corg and Ntot were also used as predictors for each other and for the potential C and N mineralisation constituents. Accuracy obtained for the Vis–NIR predictions of investigated constituents was in general equal or better than prediction accuracy obtained by these comparative methods. The Vis–NIR method provided promising predictions of variables important for the soil N supply.

Use of the Near-Infrared Reflectance Method for Measurement of Moisture Content During Granulation

The purpose of this study was to demonstrate the use of a near-infrared (NIR) method for in-process control of a placebo formulation. An NIR setup with a multichannel detector was applied in the measurement of water during fluidized bed granulation. The effects of two critical granulation parameters were studied using the central composite design. The present NIR setup with three wavelengths proved applicable for in-line moisture measurement. The 1990 nm signal was used for measurement of water and the 1745 and 2145 nm signals were used to correct the change in spectra baseline during granulation. Variations in inlet air conditions proved to be critical factors, explaining differences in the granule size distributions. Differences in granule moistening and drying rates resulting from varying inlet air conditions could be measured with the NIR setup. The moisture content of granules at the end of the spraying phase explained part of the differences in granule size distributions. The moisture content of granules at the end of the drying phase affected the tableting behavior of granules. The results suggested that direct measurement of granule moisture content facilitates the in-process control of the granulation.

Near‐Infrared Reflectance Correlated to 100‐g Wet‐Milling Analysis in Maize

ABSTRACTAn understanding of the genetic control of starch, protein, and oil concentrations in the corn (Zea mays L.) kernel is essential for improvement of grain quality. Because large numbers of progenies are needed for genetic studies, a rapid, accurate, analytical procedure is necessary. As part of a study to identify chromosomal regions associated with starch and protein, a rapid near‐infrared reflectance (NIR) method and a more labor‐intensive 100‐g wet‐milling procedure were compared for consistency in ranking families and identifying quantitative trait loci (QTL) using a set of 200 F2S1 families from the cross of the 70th generations of the Illinois High Protein (IHP) × Illinois Low Protein (ILP) corn strains. NIR starch and wet‐milling starch values were highly correlated (r = 0.80), as were NIR protein and gluten measured by wet‐milling (r = 0.72). Chromosomal regions associated with NIR starch and wet‐milling starch were generally the same. Fiber concentration was significantly negatively correlated with starch and positively correlated with protein. Chromosome regions with significant associations with starch also had significant associations with fiber. The NIR method is satisfactory for measuring starch and protein in material with a wide range of variability in the early stages of a corn‐breeding program.

Determination of moisture content of ginseng by near infra-red reflectance spectroscopy

Near infra-red reflectance (NIR) spectroscopy was used to measure the moisture content in the hot-air dried Asian ginseng (Panax ginseng) roots, freeze-dried Asian ginseng roots, red Asian ginseng roots and hot-air dried American ginseng (Panax quinquefolium) roots. The convection drying method was used as the reference method. The calibration equation was obtained using the wavelength segment 1100-2500 nm with first derivative and scatter correction. A high correlation was obtained between the two analytical methods (R2 = 0.998), with a standard error of prediction (SEP) of 0.14% for the NIR method. The bias between the two methods was insignificant, being only 0.12%. © 1997 Elsevier Science Ltd

A Novel and Rapid Method for the Determination of Glycogen in Pitching Yeasts

The use of near-infrared reflectance (NIR) spectrometry is demonstrated as a rapid method for the measurement of yeast glycogen. The reproducibility of the NIR method is as good as the chemical met...

Nondestructive and Noninvasive Monitoring of Deoxyhemoglobin in the Vein by Use of a Near-Infrared Reflectance Spectrometer with a Fiber-Optic Probe

Near-infrared reflectance (NIR) spectroscopy, which has become a widely used technique in food analysis, also holds considerable promise as a nondestructive and noninvasive probe for clinical diagnosis and examinations. Since the light in the near-infrared region is able to penetrate human tissues sufficiently, the use of the NIR technique may enable one to extract useful information directly from a human body without any pain and injury. However, in spite of the potentiality of NIR spectroscopy in medicine, its applications to clinical problems are still very limited; so far, most near-infrared spectroscopic studies in the medical field are concerned with the estimation of body fat and with the quantification of cerebral oxygenation and hemodynamics. Therefore, we have started working toward novel applications of the NIR method to medical problems. In this note we demonstrate the usefulness of NIR spectroscopy with fiber optics in the noninvasive monitoring of deoxyhemoglobin in the vein; it is possible to obtain in vivo NIR spectra of venous blood from various parts of the human body surface, with a high signal-to-noise ratio.

Comparative study of methods of determining oil content of sunflower seed

AbstractAn extraction‐gravimetric method (AOCS Official Method Ai 3‐75) was compared with 2 instrumental techniques, near‐infrared reflec‐tance (NIR) spectroscopy and wide‐line nuclear magnetic resonance (NMR), for the determination of the oil content of oilseed‐type hybrid sunflower seed. Eight sunflower seed samples of varying oil contents, replicated 5 times, were analyzed by the 3 procedures. The overall mean oil contents and standard deviations for the 8 samples were: AOCS method, 44.5% ± 0.33%; NMR, 44.8% ± 0.27%; and NIR, 44.2% ± 0.81%. Analysis of variance of the means of the 3 methods of analysis indicated no difference (p&gt;0.05) in oil content due to the method. However, there was a difference (p&gt;0.001) in total oil content due to replicated analyses of the same sample with the NIR method. With the AOCS and NMR methods, no effect (p&gt;0.05) of replicated analyses of the same sample was found. The NMR method was more precise and repro‐ducible than the other 2 methods. Although the NIR mean oil contents were not significantly different from the means of the other 2 methods, the coefficient of variations for all samples were consistently higher for the NIR analyses than for the AOCS and NMR analyses.