Abstract:Abstract：Lettuces，noodles，rice and streaky pork were selected as materials.The contents of nitrite，pH values and sensory quality of four kinds of foods were determined during 0 days to 5 days under 0℃refrigerator storage.Results showed that nitrite of four kinds of food decreased firstly and increased subsequently，and the level of nitrite reached minimum when storage 1 day.The nitrite content of all the foods exceeded 4 mg/kg at 5 days.pH values of all four kinds of foods decreased first and increased soon，and the change trend was similar to the amounts of nitrite in foods，which were positively correlated.With the extension of time，the foods'sensory quality declined continuously.