Nix Pro Color Sensor Comparison to HunterLab MiniScan for Measuring Lamb Meat Colour and Investigation of Repeat Measures, Illuminant and Standard Observer Effects

Abstract

Specific for lamb, this study aimed to test the effect of Nix Pro Color Sensor (NIX) repeat measures on the precision of L*, a*, b*, hue and Chroma (colour traits); compare colour traits captured using the NIX and HunterLab MiniScan (HUNTER) instruments; and establish the impact of NIX settings (Illuminant and standard observer) on retail colour stability. This used the longissimus lumborum muscles from the right-side of 150 Merino carcasses were sampled and then aged in vacuo for 5 days. It was found that six repeat measures were appropriate in general to achieve precise colour data for lamb meat. Observed colour trends over retail display were analogous, but not interchangeable between NIX and HUNTER instruments-except for a* data which was comparable between instruments. Only b* and hue were found to be impacted by NIX Illuminant and standard observer settings, and Illuminant A captured the greatest magnitude change in b* over retail display. These findings support the reproducible and robust assessment of lamb meat colour using the NIX.

Detecting color differences in lentil flour samples using an inexpensive, hand-held colorimeter

“…Differences in absolute values of L*, a*, and b* scores between instruments and illuminants were expected and previously reported (Dang et al, 2021; Holman et al, 2021; Stiglitz et al, 2016; Ugarčic-Hardi et al, 1999). However, the absolute values are irrelevant in this use-case as the main goal was to differentiate color among lentil samples and to accurately identify genotypes with higher a* scores.…”

“…Holman et al, (2021) and Jha et al, (2021) proposed that using more slide repetitions for Nix colorimetric analysis would improve data precision to account for smaller structural dimensions. We also expected to have differences among slides (technical reps) due to flour structural variation; however, these were not found with either illuminant.…”

“…The Nix is routinely used for color assessment of paints, coatings, cosmetics, manufacturing, printing, packaging, and textiles. Recent studies with research applications in food science have used the Nix to measure color in beef, fish, and lamb (Dang et al, 2021; Holman et al, 2021; Holman et al, 2018). Jha et al, (2021) used the Nix Pro color sensor to assess color in soil and develop prediction models for soil iron content.…”

Spectro 1—A Potential Spectrophotometer for Measuring Color and Myoglobin Forms in Beef

“…For instance, a * decreased with increasing storage time ( Figure 2 B), an effect that was detected by both instruments. Differences in a * between Spectro 1 and MiniScan could be partially attributed to the use of a different source of illumination in each instrument [ 22 , 23 ], with MiniScan utilizes a Xenon light source while Spectro 1 uses LED light. In addition, Spectro 1 utilizes a 45/0° measurement geometry, which may under- or overestimate color values depending on the texture of the surface.…”

Machine Vision Requires Fewer Repeat Measurements than Colorimeters for Precise Seafood Colour Measurement

“…The aperture size, observer angle, and light source vary between models and brands of instruments [24][25][26][27][28][29][30][31][32][33]. The nature of the material being measured and the retail display environment determine the instrument settings, such as whether to include specular reflection and choice of illuminant, which all influence the measured colour [11,27,30,34]. Colour measurements are also influenced by sample thickness, background colour behind a sample, the pressure of the colorimeter on the sample, differences in myofibril orientation, and external light [13,35,36].…”