Instrumental reflectance values of fresh pork are dependant on aperture size.

The effect of aperture size on instrumental pork color measurements was studied. Pork longissimus chops (n=30) were cut, aerobically packaged, and allowed to bloom overnight. Chops were measured once with each of four aperture ports (4.45, 2.54, 1.27, and 0.64cm diameter) on a HunterLab LabScan. Reflectance values measured with smaller aperture sizes were reduced (P<0.05) for most visual wavelengths (10nm intervals), and the percent reduction was greatest in the range of the longer, redder wavelengths. Values for L(∗), a(∗), b(∗), and saturation index were reduced (P<0.05) with decreasing aperture size under illuminants A, C, and D(65). Using illuminant A, hue angle increased (P<0.05) as aperture size decreased. For illuminants C and D(65), hue angles were similar (P>0.05) for the three largest aperture sizes, but negative a(∗) values found with the smallest aperture size skewed the hue angle data.