We have found in previous experiments that slaughter-fresh processed pork back fat enhances batter stability in frankfurter-type sausages. In an attempt to clarify whether the decrease-of batter stability with storage time of the fatty tissue is due to the fat oxidation a series of experiments was conducted using sodium nitrite and nitrate. 6-O-palmitoyl-L-ascorbic acid and DL-alpha-tocopherol as additives to the fatty tissue. It was found that sodium nitrite and nitrate, although the first is regarded as an antioxidant in meat, had a pro-oxidant effect when added to the fatty tissue. The palmitoyl-L-ascorbic acid showed the best antioxidative activity, and the DL-alpha-tocopherol was less effective as an antioxidant. Contrary to its effect on the increase in fat oxidation, sodium nitrite addition gave a remarkable improvement in batter stability, expressed as jelly and fat separation, which was more pronounced on the second day of storage of the fatty tissue. The pro-oxidant effect of nitrite increased up to a concentration of 375 ppm added to the fatty tissue. Concentrations of nitrite in fatty tissue up to 125 ppm had no influence on jelly release but at higher concentrations the jelly separation decreased. All nitrite concentrations, from 62.5 to 2250 ppm, showed significantly lower fat separation than for the control treatment, especially on the eighth and 15th day of storage of the fatty tissue. The results show that fat oxidation has little effect on batter stability. Further experiments are needed to clarify the mode of action of nitrite in improving batter stability.