Relationship between the Changes in Color and the Existence Form and Oxidation State of Nitrogen during the Refrigeration Storage of Pork Slices

In this study,pickled pork slices were used to track and detect the color,physical and chemical indicators,free amino acids,biological ammonia and some oxidation indexes during cold storage. Principal component analysis was used to clarify the relationship among the change of color,the form of nitrogen and the state of oxidation. The results showed that the pork slices were significantly faded during cold storage(P<0.05). And brightness(L^*),redness(a^*),yellowness(b^*),hue(Hue),color saturation(C)and nitrosochrome(NH)changed significantly(P<0.05). Only tyramine(TYR),spermidine(SPD)and spermine(SPM)were significantly changed in biogenic amines(P<0.05). The sum of free amino acids(∑FAA)had no significant change during cold storage. Protein nitrogen(NPN),carbonyl(CARB)and conjugated diene values(DV)showed significant changes during cold storage(P<0.05). Through factor analysis,it could be seen that the sum of free amino acids was significantly(P<0.05)negatively correlated with other color indicators except for positive correlation with Hue(r=0.829). In addition to negatively correlated between tryptamine(TRY)and brightness(L^*)in biogenic amines,there were no significant correlation between other biogenic amines and color.