Marion O'Farrell

On-line determination and control of fat content in batches of beef trimmings by NIR imaging spectroscopy

An NIR imaging scanner was calibrated for on-line determination of the fat content of beef trimmings. A good calibration model was obtained for fat in intact beef (R=0.98, RMSECV=3.0%). The developed model could be used on single pixels to get an image of the fat distribution, or on the average spectrum from each trimming/portion of trimmings passing under the scanner. The fat model gave a rather high prediction error (RMSEP=8.7%) and a correlation of 0.84 when applied to 45 single trimmings with average fat content ranging from 1.6 to 49.3% fat. Test measurements on streams of trimmings making up batches varying from 10 to 24 kg gave a much lower prediction error (RMSEP=1.33%). Simulations based on true measurements indicate that the RMSEP decreases with increasing batch size and, for the present case, reached about 0.6% for 100 kg batches. The NIR scanner was tested on six batches of intact trimmings varying from 145 to 210 kg and gave similar fat estimates as an established microwave system obtained on the ground batches. The proven concept should be applicable to on-line estimation of fat in trimmings in order to determine the batch fat content and also to control the production of batches to different target fat levels. A possible requirement for the concept to work properly is that the trimming or layer of trimmings on the belt is not too thick. In this study maximum thickness was about 8 cm. Thicker trimmings might be measured, but careful hardware adjustments are then required.

On-Line Fat Content Classification of Inhomogeneous Pork Trimmings Using Multispectral near Infrared Interactance Imaging

A novel system for on-line measurement of fat content in inhomogeneous pork trimmings is presented. The system allows near infrared (NIR) energy to interact with the meat using non-contact optics while it is travelling in large plastic boxes on a conveyor belt. A comparison was made between the log of the inverse of the interactance NIR spectra [log(1/T)], standard normal variate (SNV) and extended multiplicative signal correction (EMSC) as techniques for the correction of physical light scattering due to colour and textural differences, height variation and temperature fluctuations, depending on whether the meat was warm-cut or cold-cut. EMSC gave the best prediction results; a robust partial least squares regression using two factors resulted in a root mean square error (RMSEP) of 1.9% on 20 kg batches of inhomogeneous meat trimmings. The model was fully tested twice in an on-line environment at a slaughter house and performed with a RMSEP of 3.4% for a fat range of 8–55% in the first industrial trial and 2.82% in the second industrial trial.

Near-Infrared (NIR) Interactance System for Non-Contact Monitoring of the Temperature Profile of Baked Liver Pâté

This article investigates the possibility of using non-contact interactance as a method for profiling the temperature in a processed meat product (liver pâté) as it comes out of the oven. The application was defined by an industrial partner, Nortura SA, Tønsberg, Norway, where more control of the cooking process was desired. The optical system employs low spectral resolution to achieve high enough signal-to-noise ratio (SNR) to depths of 2 cm into the product. The partial least squares (PLS) method was applied to interactance spectra in the region 760–1040 nm and a root mean square error of 1.52 °C was obtained. The model was tested on five different validation sets spread over 18 months and a root mean square error of prediction of 2.66 °C was achieved. The output of this model was based on the weighted average of two temperatures in the first 2 cm of the liver pâté, one of which is the core temperature. A comparison was also made with two other models: a model based on the core temperature alone and a model based again on the weighted temperature but using the shorter wavelength range of 905.5–1047 nm. These two models gave less favorable prediction errors.

Measuring Water Holding Capacity—A Comparison between a Miniature near Infrared System and an Energy Dispersive X-Ray Scattering System

The results presented here describe a comparative study on pork loins with drip loss varying from 0.25% w/w to 10.69% w/w. Thirty samples were measured using both near infrared (NIR) interactance and X-ray scattering. Partial least squares regression was used to build calibration models for each method. Results show that the correlation for the calibration model between NIR interactance and drip loss was R2 = 0.47 (leaving out three outliers) while that for X-ray and drip loss was R2 = 0.72 (leaving out three outliers).

Quasi-imaging spectrometer with programmable field of view and field of illumination

8 Introduction t his article details the development of a robust, quasi-imaging spectrometer that reduces the effects of stray light from the background and nearby objects. In an industrial setting, samples are seldom well-ordered, making accurate spectral measurements more challenging than in a controlled, laboratory setting. objects may vary in size, shape and reflectance properties. Furthermore, background levels can fluctuate when, for example, measuring unordered objects in a bin or objects with unknown positions in a scene. thorough analysis of the measurement situation requires knowledge of spatial resolution, spectral resolution, wavelength band of interest and so forth. the solution to such problems may be a scanning point measurement or some kind of imaging spectrometer, often including a dispersive element, a camera and a scanning action; this latter may be achieved by either using a mirror device, such as a Digital Micro-mirror Device (DMD), or by moving the sample itself (the latter being more time-consuming). the system described here includes two digital micro-mirror devices (DMD) to dynamically select both the field of illumination (FoI) and the field of view (FoV) in a scene as shown in Figure 1. A DMD is an array of micro mirrors with two angle positions. the illumination DMD selects the illumination pattern, which can consist of sub-millimetre areas. the detection DMD selects the detector type; here a camera or spectrometer. the system can be programmed to operate in both reflection and remote interactance modes for increased flexibility. In Figure 1, the system is looking at an apple on a reflective surface. the entire image is illuminated in order to locate the region of interest, in this case the apple, and this image is sent to the camera (light path represented by dashed arrows). After this, the field of illumination is reprogrammed to illuminate only the apple (solid arrows), avoiding stray light from both the reflective surface and the apple’s green leaf. the detected light can again be sent to either the camera or spectrometer (in this case the spectrometer). Some preliminary results were conducted in three areas that could be considered advantageous as a result of the use of DMDs in an imaging/spectrometry system: 1) reference banking—to correct for variation across the image; 2) 3-D measurements for improved region-of-interest location and reference-bank selection; and 3) remote interactance measurements—for increased absorption information.

UTOFIA: an underwater time-of-flight image acquisition system

In this article the development of a newly designed Time-of-Flight (ToF) image sensor for underwater applications is described. The sensor is developed as part of the project UTOFIA (underwater time-of-flight image acquisition) funded by the EU within the Horizon 2020 framework. This project aims to develop a camera based on range gating that extends the visible range compared to conventional cameras by a factor of 2 to 3 and delivers real-time range information by means of a 3D video stream. The principle of underwater range gating as well as the concept of the image sensor are presented. Based on measurements on a test image sensor a pixel structure that suits best to the requirements has been selected. Within an extensive characterization underwater the capability of distance measurements in turbid environments is demonstrated.

Developments in Robust Range-gated Imaging for Low-visibility Applications

Range gated systems have the potential to increase range in low-visibility applications but are not widely used since the use of specialized optical components makes them large and costly. SINTEF presents recent developments towards commercially viable range-gated imaging. Article not available.