CHANGES IN LIGHTNESS OF PORCINE LEAN MEAT BATTERS DURING PROCESSING

The pattern of changes of lightness (L) for porcine lean meat batters (PLMBs) with time was divided in two phases: chopping process (Phase 1) resulting in a sharp increase of L, and the subsequent storage of the batters for 24 h at 15-degrees-C (Phase 2). During Phase 2, L-val ues decreased with time approximating a plateau. The subjects of study were effects on the course of L of: (1) added sodium chloride and p hosphate in Phase 2, (2) the fate of air bubbles embedded in the batte rs in Phases 1 and 2, and (3) changes in light absorption by the pigme nt myoglobin in Phase 2. (1) Sodium chloride and phosphate appeared to have very little impact on the changes in L during storage of the PL MBs at 15-degrees-C, although microstructural changes were distinct. ( 2) Continuous entrapment of air during the chopping process had a majo r effect on the increase of L in Phase 1, air bubbles being scatterin g elements in the PLMB. Disproportionation caused a decrease in the nu mber of small air bubbles, resulting in a decrease of L during the ea rly stage of Phase 2 (about 35 min), immediately after the chopping st age was finished. (3) Strong evidence was obtained that shifts in the absorption traits of pigments (red nitric oxide myoglobin was formed a t the cost of grey metmyoglobin) during the period from 1 to 5 h, caus ed a marked decrease in the pattern of L during Phase 2.