Effects of lactate-enhancement on surface reflectance and absorbance properties of beef longissimus steaks.

A completely randomized block design was used to assess the effects of lactate-enhancement on surface reflectance and absorbance properties of beef longissimus steaks. Loins were divided into sections, assigned to one of four treatments (non-enhanced day 0, non-enhanced day 5, water-enhanced, and 3% lactate), vacuum packaged, stored for 5 days at 4 degrees C, and then cut into steaks that were used to prepare 100% of deoxy-, oxy-, met-, and carboxymyoglobin according to AMSA (1991). Surface color was analyzed using a HunterLab Miniscan Plus Spectrocolorimeter. Lactate-enhanced steaks had the least overall surface reflectance and the darkest surface color (lower L*; P<0.05). For 100% of each myoglobin form, K/S values and ratios (isobestic wavelengths/525 nm) at 474, 525, 572, and 610 also were influenced by lactate-enhancement. Hence, when estimating surface myoglobin forms using K/S ratios, separate 100% myoglobin reference standards should be prepared from both non-enhanced and enhanced steaks.