9/21/08

Ability of NIR spectroscopy to predict meat chemical

In contrast to conventional methods for the determination of meat chemical composition and quality,
near infrared spectroscopy (NIRS) enables rapid, simple and simultaneous assessment of numerous meat properties.
The present article is a review of published studies that examined the ability of NIRS to predict different
meat properties. According to the published results, NIRS shows a great potential to replace the expensive and
time-consuming chemical analysis of meat composition. On the other hand, NIRS is less accurate for predicting
different a�ributes of meat quality. In view of meat quality evaluation, the use of NIRS appears more promising
when categorizing meat into quality classes on the basis of meat quality traits for example discriminating between
feeding regimes, discriminating fresh from frozen-thawed meat, discriminating strains, etc. The performance of
NIRS to predict meat properties seems limited by the reliability of the method to which it is calibrated. Moreover,
the use of NIRS may also be limited by the fact that it needs a laborious calibration for every purpose. In spite of
that, NIRS is considered to be a very promising method for rapid meat evaluation.

SUCROMAT VIS/NIR® Dual Wavelength Automatic Saccharimeter

Measures lead free or con-ventionally prepared samplesSince our world is becoming more and more industrialized, protection of human health and of the environment have gained an ever increasing importance. Sugar technologists world-wide have been searching for alter-native clarification methods of polarimeter samples to eliminate the use of toxic lead subacetate. Presently, most trade analyses by ICUMSA methods still require lead clarified samples and Pol measurements at visual (VIS) wavelengths. However, there is a strong trend to lead free clari-fication methods, at least in factory control applications.
As these methods frequently produce coloured filtrates that are too dark for measurement at VIS, but are transparent enough for near infrared (NIR) light, the SUCROMAT VIS/NIR Dual Wavelength Automatic Sacchari-meter is the right choice for all kinds of present and future sugar polarization measurements
Offers high performance and the capability of measuring extremely dark solutionsWhen operated in the VIS mode, the SUCROMAT VIS/NIR has all features of the standard model of SUCROMAT, see our leaflet. Coloured samples up to an optical density of OD 3 (0.1% transmission) at 589 nm can be measured.
In the NIR mode, extremely dark coloured samples, e.g. lead free filtered raw sugar solutions, can be analyzed up to OD 7 at 589 nm (0.00001% transmission). While dark sample colour is no problem, turbidity (cloudiness) due to suspended or colloidal matter has to be removed before measurement which is usually done by filtration. If necessary, filter aid, e.g. Celite 577, has to be added. The reason why samples must not be turbid is that turbidity causes depolarized straylight which considerably reduces the sensitivity of every polarimeter.
Complies with present and future standardsICUMSA standards concerning the International Sugar Scale (ISS), and quartz control plates used for calibrating and testing saccharimeters, are presently only available for VIS wave-lengths. Standards for NIR wavelengths are expected to come in 1998 when the next ICUMSA session will be held. The user calibration facility of SUCROMAT VIS/NIR being part of the instrument setup menu, is easy to use, however its access is protected by an authorization code. The procedure complies with present and future stand-ards: The VIS range can be calibrated by means of available quartz control plates certified for ISS (°Z) at 589.44 nm.
Calibration of the NIR range is presently possible by means of a normal sugar solution, but a quartz plate can be used as soon as ISS conversion data are available for NIR wavelengths.

Non-destructive measurement of reducing sugar of apple using Vis/NIR-spectroscopy techniques

In this research, the potential of using the Visible/Near Infrared Spectroscopy (Vis/NIRS) was investigated for measuring the reducing sugar of Fuji apple (from Shanxi of China), and the relationship was established between nondestructive Vis/NIR spectral measurement and the reducing sugar of apple. Intact apple fruit were measured by reflectance Vis/NIR in 325-1075 nm range. The data set as the logarithms of the reflectance reciprocal (absorbance (logl/R)) was analyzed in order to build the best calibration model for this characteristic, using some spectral pretreatments and multivariate calibration techniques such as partial least square regression (PLS). The models for the reducing sugar (r= 0.915), standard error of prediction (SEP) 0.562 with a bias of 0.054; shown the excellent prediction performance. The Vis/NIR spectroscopy technique had significantly greater accuracy for determining the reducing sugar. It was concluded that by using the Vis/NIRS measurement technique, in the spectral range (325-1075 nm), it is possible to assess the reducing sugar content of apple.

Study on fast measurement of sugar content of yogurt using Vis/NIR-spectroscopy techniques

In order to measuring the sugar content of yogurt rapidly, a fast measurement of sugar content of yogurt using Vis/NIR-spectroscopy techniques was established. 25 samples selected separately from five different brands of yogurt were measured by Vis/NIR-spectroscopy. The sugar content of yogurt on positions scanned by spectrum were measured by a sugar content meter. The mathematical model between sugar content and Vis/NIR spectral measurements was established and developed based on partial least squares (PLS). The correlation coefficient of sugar content based on PLS model is more than 0.894, and standard error of calibration (SEC) is 0.356, standard error of prediction (SEP) is 0.389. Through predicting the sugar content quantitatively of 35 samples of yogurt from 5 different brands, the correlation coefficient between predictive value and measured value of those samples is more than 0.934. The results show the good to excellent prediction performance. The Vis/NIR spectroscopy technique had significantly greater accuracy for determining the sugar content. It was concluded that the Vis/NIRS measurement technique seems reliable to assess the fast measurement of sugar content of yogurt, and a new method for the measurement of sugar content of yogurt was established.

Quality Control During Processing of Feta Cheese—NIR Application

This work examines the possibility of using near infrared (NIR) spectroscopic method for the production process control of the traditional Greek feta cheese. A NIR apparatus (Instalab 600-Dickey–John) was employed. Moisture, fat and protein determinations were selected as calibration set for the instrument. Samples were drawn from well-defined critical points of production. In all the samples conventional chemical methods were applied for the quantitative determination of the above ingredients. Results were compared with the respective data from NIR apparatus. All data were processed by a suitable computer program so that the calibration constants could be calculated and then stored in the apparatus. Their accuracy was verified using an independent set of analyzed samples. Because the NIR apparatus used in this work was not suitable for liquid products, a novel technique was developed using “quartz fine granular washed and calcined GR” (pro analysi). This technique proved to be reliable with a significant accuracy. From this study it can be concluded that NIR technique can be applied successfully for the on-line quality control of the feta cheese production. The reliability, significant reduction of human errors, precision and quickness of NIR spectroscopy experienced during this work, support the implementation of this method.

APPLICATION OF NEAR-INFRARED SPECTROSCOPY FOR DETERMINING LINEN CONTENT IN LINEN/COTTON FABRIC BLENDS.

Fourier transform near-infrared (FT-NIR) spectroscopic method was used to determine linen content in woven linen/cotton blend fabrics. In the textile industry, flax fiber is used as a natural fiber and blended in certain proportions with cotton to enhance the performance and improve the qualities of fabrics. In the US, most of the linen/cotton blend fabrics are imported from other countries. Current analytical methods, microscopy or wet analysis, for determining correct fiber content in the fabrics are very time-consuming, thereby a rapid analytical method is needed. In this study, we used a FT-NIR spectroscopic method and developed a standard calibration model using ground fiber-cotton mixtures with a range of 0-100% fiber contents. The model was applied to the carded blends, yarns, denims, undyed and dyed fabrics to predict fiber contents. Fabrics that have undergone the scouring process have differences in absorption spectra compared to non-scoured fabrics. An independent caliabration model was developed for scoured and dyed fabrics.

Light bent the wrong way--can an invisibility cloak be far behind?

Researchers have taken the next step on the road to constructing a cloak of invisibility or a powerful "superlens" capable of capturing fine details undetectable to current lenses. A group from the University of California, Berkeley, this week is publishing the first demonstrations of materials capable of bending visible or near-visible light the "wrong" way in three dimensions. Both are examples of metamaterials—specially designed structures that cause light to do things it normally wouldn't—in this case, bending backward, an effect called negative refraction. Researchers have built metamaterials capable of negatively refracting microwaves, but despite some successes bending visible light in two dimensions, they've had a harder time making three-dimensional versions.In a study to be published in Nature, the Berkeley group led by Xiang Zhang, bent red light using a fishnet-shaped stack of 21 layers of silver and magnesium fluoride, each a few tens of nanometers thick (see diagram). (One nanometer is a billionth of a meter.) The group will also report in Science that it bent near-infrared light using a thinner sheet of aluminum oxide containing silver nanowires. The researchers believe the second material ought to work on red light as well.
Both devices absorbed relatively little of the incoming light—a problem in earlier metamaterials, the group says.In school we learned that a beam of light passing from air to water or glass at a shallow angle will slow down and bend away from the surface of the denser medium it passed through. On the way out, that angle shrinks again. The result: A straw in a glass of water takes on a zig-zag shape as seen from outside.
But this only holds true for materials that have a positive index of refraction—a measure of the speed of light in a material. The new metamaterials both exhibit a negative index of refraction. A straw placed in a glass of negative-index material would look like a ">".One potential application of negative refraction is a superlens capable of picking up fine details in reflected light and magnifying them—another area where Zhang's group has had some success.For invisibility, researchers need their metamaterials to have an index less than one (the index of air). This makes it possible to channel light around a region like air around an airplane wing. No light inside means there is no reflection to reveal the contents of the space, hence, invisibility.In 2006 a group at Duke University demonstrated partial cloaking in two dimensions with a pizza-size disk of copper rings. Look for researchers to try that soon with visible light.

9/17/08

Near Infra Red Diode Array Spectrometers for On-Line Applications - An application paper in the field of agriculture using our LowCost NIR-Spectromete

AbstractThe introduction of affordable NIR diode array spectrometers now make the measurement of several parameters that are critical to product value readily available. Over the last decade we have seen the introduction of several affordable spectrometers using silicon based sensors, in the 200nm to 1100nm range. This has spawned a host of new applications, including at line/ on line measurements for product quality and process control which were not affordable before. With the introduction of this NIR diode array spectrometer in a similar price range as its visible counterparts, we expect to see similar results. Since the product has just been introduced, not many applications have been developed. Preliminary results by Dr. Arnold Schumann, CREC-UFL show that this spectrometer may be used successfully for the determination of N content (protein) and water in citrus leaves. The spectrometer is currently undergoing application development for use in the corn, soybean and feed industries.This paper also presents the advantages of NIR diode array technology and highlights the performance characteristics of this affordably priced NIR spectrometer.Description of InstrumentThe getSpec NIR 0117 basic spectrometer is a fixed diffraction grating, post disperse device, with a 128 element InGaAs photodiode array. A polychromatic tungsten halogen light source is positioned over the sample and the dispersed light from the sample is collected by a collimating lens and fed back to the spectrometer via fibre optic cable. The measurement range of the spectrometer is 900nm to 1700nm (Fig 1).Presentation of Results for N (protein) and Moisture Analysis in Citrus LeavesThe data presented here is the result of a one-week instrument test by Dr. Arnold Schumann, CREC-UFL. Due to the short test period, these results are somewhat preliminary and conclusions should be considered tentative. They were obtained by Dr. Schumann primarily to test the performance of this particular model of a low-cost NIR spectrometer in performing a specific task - the measurement of protein-N in citrus leaf tissue.Tests were conducted with the instrument after a 45-min warm-up period. Briefly, the geometric alignment of the light - sample - collimator lens triangle must be optimised for maximum collection of dispersed light by the spectrometer. This is easily done interactively by adjusting the light platform while observing the sensor output graphically on the computer screen. The measurement integration time used was 0.008 s. The instrument was then referenced for background light/sensor correction using a white reflective Halon / Abrilon reference. The reference was re-sampled after every ten leaf samples.Results of the calibration and validation runs are presented in Figures 2-9. Figure 10 shows the typical precision which we currently can expect with a Kjeldahl - steam distillation unit. These duplicate N results were from various orange, tangerine and grapefruit leaf samples analysed in 2001. Because the Kjeldahl N is the primary method on which we rely for the NIR calibration, we should not expect the NIR calibrations for dry leaf N to be much better than R 2 =0.89,SE=0.101.Valencia orange dry leaf samples calibrated well (R 2 =0.89, SE=0.08) before outlier removal.Removal of five outliers improved the fit to R 2 =0.93, SE=0.068 (Figure 2). Removal of outliers is usually justified because of the expected variability introduced from Kjeldahl N results. The Valencia calibration was validated with an independent set of dry leaf samples from grapefruit and tangerine trees (Figure 3). The fit was less successful (R 2 =0.73, SE=0.268), and showed considerable bias (slope=0.63), but should be expected when comparing varieties. To correct the bias problem, either a larger global calibration should be developed with more varieties, or a separate calibration should be developed for each variety.Individual fresh Valencia orange leaves were calibrated for water content and N concentration on a fresh weight basis. Leaves were scanned on both upper and lower surfaces. After outlier removal, good, nearly identical calibrations were obtained for water content using both leaf surfaces (Figures 4-5). The outlier samples appearing on scatter plots of both leaf surfaces were the same, implying that there were not errors with the NIR spectra, but more likely that errors were introduced during the gravimetric water measurement. A comparison plot of NIR-predicted leaf water for both leaf surfaces showed the generally good agreement - even including the outliers. Validation of a similarly developed water calibration with tangerine leaves, using the independent Valencia samples, was good once the 12 outliers mentioned previously were removed (Figure 7).NIR-calibrations for fresh leaf N were less successful than dry leaf N or leaf water, probably for two reasons. First, the N concentration in fresh leaves is about half of that in dry leaves, and the abundant water can mask the N features in NIR spectra. Secondly, lab data used in these calibrations consisted of derived leaf N values (% FW), obtained from both Kjeldahl leaf N (% DM), and gravimetric water content. Thus the derived variable %N FW had at least two cumulative sources of error, more than any other calibrated variable. Nevertheless, the calibration was still satisfactory for tangerines (R 2 =0.89, SE=0.049) (Figure 8) after eliminating four outliers. However, validation of tangerine lower leaf N using the upper leaf N calibration equation was much less successful (R 2 =0.63, SE=0.105) after removal of some 19 outliers (Figure 9). Unfortunately leaf N was not determined for individual leaves of the Valencia orange samples, so that they could not be used for validation of tangerine fresh leaf N equations.The instrument performed very well during these tests, and these preliminary results were mostly as expected - very good calibrations for water (abundant concentrations, large NIR peaks), less well for dry leaf N, and worst for fresh leaf N. Validations still need to be improved before one could use this technique for routine measurement. The challenge to measure fresh leaf N may however still be achieved by careful tuning of some instrument operating conditions (e.g. integration time, scan averaging), sample preparation and presentation (e.g. desiccation of dry samples before analysis, flattening of leaves before scanning), and improving the precision of the primary data (Kjeldahl N, leaf water). If this NIR method were adopted for routine leaf analysis, the problem of outliers could be overcome by repeated measures (e.g. quadruplicate NIR scanning and automatically [with software] eliminating any outliers which deviate from the mean by > 2SE). Since each NIR measurement takes less than a second, the additional time required for repeated measures is very acceptable.
Advantages of Diode Array SpectroscopyThere are several advantages of diode array spectroscopy over conventional scanning spectrometers.The following is a list of advantages:
Fast! Fixed grating diode array spectrometers look at all wavelengths of the spectrum simultaneously. This allows us to take a complete spectrum in less than a millisecond. For most applications, 50 to 100 spectra/sec is a reasonable expectation.
Sensitive! Since we look at all the wavelengths simultaneously, one can integrate longer and not pay the penalty like a scanning system that would require separate integrations per wavelength interval.
No Moving Parts! Being a fixed grating device, there are no moving parts and so there is no variability in wavelength between different spectra. This is a great help for calibration transfer between instruments.
Fibre Optic Input! Allows the spectrometer to be located away from the sampling optics, if the environment is hostile. Allows the use of fibre optic probes.
Portable and Lightweight! Our NIR spectrometers can be configure on an ISA pc plug-in card (wt ~ 1lb) or a stand alone unit with USB interface (~ 2lbs).
Low Cost! This is truly a low priced NIR spectrometer with all the features and
performance of higher priced instruments. The instrument is temperature stabilized, allowing a max integration time of 1sec to 2 sec. For almost all applications, this is not a problem at all as the typical integration time is between 1 msec to 50 msecs.ApplicationsApart from being a very versatile laboratory instrument, the getSpec NIR 0117 basic spectrometer is undergoing laboratory and field tests for numerous applications, including the following:
Moisture content in corn
Moisture, Fat and Protein content in Soy Beans
In-Situ monitor for Thin Film deposition
Monitoring of Erbium Doped Amplifier outputWe expect the number of different applications to increase rapidly, as potential users become aware of the product.ConclusionThe getSpec NIR 0117 basic spectrometer, with its high performance specifications/features and affordable pricing, should make NIR spectroscopy available for numerous process and quality control applications. It also provides instrument makers and system integrators a very cost effective and viable platform on which to base their products. This device also provides researchers, especially at Universities with an affordable NIR spectrometer.

Assessment of Agricultural Commodities with a Handheld NIR Spectrometer

Interpretive Summary: Although there have been a multitude of good laboratory methods of analysis developed on large instruments, the one limitation is that the sample must be taken from the field to the laboratory. This requires keeping the sample viable while transporting and evaluation that often fails to maintain relevance for the grower. These limitations can be overcome by the use of handheld portable instruments that can be taken to the sample in the field environment. A handheld near-infrared spectrometer has been developed that meets many of the agricultural growers and research genetist¿s needs. This work demonstrates the use of this type of instrument in assessing four diverse materials: analysis for fiber in flax, measurement bio-oil in bio-diesel, classification high versus low oleate in peanuts and latex in dandelion roots. All of the results demonstrated that the essential analyses could be accomplished in the field thus providing timely on-site quality information.
Technical Abstract: Several handheld spectrometers have recently appeared on the market. These include Raman, mid- and near-infrared systems. Most of them are aimed at providing rapid identification of unknown materials for security issues. Many of them can also be used for quantitation and classification in the same manner as with laboratory based instruments making remote analysis a reality. This work will discuss the application of a handheld near-infrared (NIR) spectrometer for assessing the fiber content of flax stems, the measurement of bio-oil in petrodiesel, and classification of high versus low oleate in shelled peanuts and latex in dandelion roots

NEAR-INFRARED (NIR) RESEARCH AT THE BELTSVILLE AGRICULTURAL RESEARCH CENTER

For many, the application of near-infrared spectroscopy (NIRS) to agricultural products started at the Beltsville Agricultural Research Center (BARC) with the research by Karl Norris on forages and other agricultural products. While research on NIRS is still ongoing at BARC, the focus has changed over the years and today no forage or animal related NIRS research is performed. Also, at the present time, NIRS research is performed in four different and for the most part independent research laboratories: Hydrology and Remote Sensing, Instrumentation and Sensing, Food Composition (human nutrition) and Environmental Management and By-Products Utilization (recently Animal Manure and By-Products). Within the Hydrology and Remote Sensing Lab, the programs primarily involve the use of NIR and remote sensing, while for the Food Composition Lab, the interest is in the development of new applications for differentiation and analysis of new value-added functional foods or dietary supplements from conventional products. Projects within the Instrumentation and Sensing Lab range from development of automated inspection systems for poultry, fruits and vegetables, to research on the quality and safety of small grains and oilseeds. Finally research in the Environmental Management and By-Products Utilization Lab is centered on environmental issues related to animal manures and carbon sequestration (Program divided with the Hydrology and Remote Sensing Lab.). In summary, NIRS research at the Beltsville Agricultural Research Center today centers more on human nutrition, health concerns related to food quality, and environmental issues than in the past when efforts were more related to forages and similar agricultural products.

Series 3000 NIR Food Analyser

Graintec Pty Ltd - The Series 3000 NIR Food Analyser is a NIT (Near Infrared Transmission) spectrometer designed to measure protein, fat, water, sugar, alcohol and other compounds in foods. The key to the Series 3000 Food Analyser is the sample draw that provides a means of analysing a wide range of materials, ie, granules, powders, liquids, slurries, emulsions, films and solids.
The rotating sample drawer provides a means of collecting NIT spectra over a wide area and then averaging the spectra to give more accurate results. Samples can be loaded into Lexan dishes or disposable plastic petri dishes.
The Series 3000 Food Analyser is ideal for measuring meat, dough, cheese, butter, cream, yogurt, ice cream, milk powder, granules or any other sample that can be loaded into a dish. Analyses generally take 1 minute.
Features Benefits
NIR Transmission technology - Provides measurement of liquids, granules and powders in one instrument.
Broad Spectral Range, 720-1100nm Multiple constituent analysisOptimum PLS calibrations1st and 2nd derivative spectral dataQualitative and quantitative analysis
No Moving Parts Unaffected by vibrationIndependent of orientationRugged, stable and compact
Internal Computer, Keyboard, LCD Stores calibrations and predicts constituents onto a LCDSave results using alpha/numeric characters
RS232 Serial Port - provides a convenient method to upload stored data to a PC or to download calibrations to the instrument Rotating Sample Drawer - Scans large sample areaWith 3 Optional Sample Cells - 5mm, 10mm and 20mm Lexan Dishes
Small Footprint = Requires less bench space
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