Illuminant d65

CIE-Lab redness (a^*) values of washed pork muscle were determined by Chroma meter (Model CR-400; 8 mm diameter aperture, Illuminant D65, 2° observer; Konica Minolta, Japan). This instrument was adjusted with a white correcting board before measuring. Six different points were selected from the sample for determination, and the results were averaged.

To assess meat quality, the color, shear force, thawing, and cooking loss were determined. The thawing loss was calculated by comparing the meat quality before and after thawing according to the method of [24 (link)]. The surface CIE (L*, a*, and b*) values were measured by a chroma colorimeter (CM-600D, Illuminant D65, 10⁰ viewing angle, 2.54 cm diameter aperture, Konica Minolta Sensing Americas Inc., Ramsey, NJ, USA). The lightness (L*), redness (a*), and yellowness (b*) were recorded in the manner recommended by [25 ]. Shear force values were determined using the C-LM3 digital meat tenderness meter (Tenovo International Co., Limited, Beijing, China) in accordance with [26 (link)]. In brief, each muscle sample was cooked inside the cooking bag in a water bath at 80 °C until the core temperature reached 72 °C, then cooled to room temperature. Before and after cooking, the difference in quality was used to calculate the cooking loss [26 (link)]. After that, six cores (1 × 1 × 2 cm) were removed from each treatment sample parallel to the muscle fiber direction. The cross-head speed of the knife blade was 5 mm/s. The output was listed in grams (g).

CIE L* (lightness), a* (redness) and b* (yellowness) values of dried pork loin were assessed using a colorimeter (Model CR-400; Konica Minolta, Osaka, Japan) with a 30 mm diameter measurement area, an Illuminant D65, and a 0° observer angle. The surface sample color was measured perpendicularly at three different sites. The instrument was calibrated to standard white and black tiles before analysis.