Determination Of Formaldehyde And Nitrite Changes In Storage Vegetables

Reported the detection of formaldehyde in foods mainly in seafood,mushrooms,and the provisions of its formaldehyde limits,but reported little change in formaldehyde determination and on vegetables,we studied vegetables formaldehyde detection method,several vegetables formaldehyde during storage and nitrite content in the following results:By studying the high-performance liquid chromatography(HPLC)determination of formaldehyde content in vegetables,Chromatographic conditions Column: C18 column(150mm × 4 6 mm,5?m,Waters,USA.);Mobile phase: methanol-water(70:30);flow rate: 1.0mL / min;column temperature: 40?;Detection wavelength: 365 nm.Formaldehyde concentration in the 0.1 ? 5.0mg / kg range,r=0.9997.Linear better,adding formaldehyde levels in the average recovery 79.15%?90.45%,the relative standard deviation(RSD)<5%.This method has a good recovery and precision,high accuracy values were determined in this range.But tedious sample preparation and long reaction time,on the instruments and experimental operations personnel requirements highly,not suitable for the storage experiment used methods.Determination of formaldehyde in Vegetables method in acetyl acetone method is validated,the concentration of formaldehyde found in 0 ? 80mg/L range,r = 0.9999.By the amount of acetyl acetone,water bath temperature and water bath time screening results,the optimum reaction conditions for the amount of acetyl acetone 2.5mL,water bath temperature 60?,water bath time 15 min.Adding formaldehyde levels in the average recovery 89.86%?92.41%,the relative standard deviation(RSD)<5%.Acetyl acetone method is simple,low detection cost,stable performance,but also more stable than color solution.Research on the change through several vegetables formaldehyde content during storage and related enzymes,and several vegetables used in experiments during storage were detected formaldehyde preliminary,formaldehyde content of cabbage during storage as a whole showed an increasing tendency,spinach formaldehyde content during storage decreased overall presentation,spinach formaldehyde content during storage as a whole showed the first increase after decreased.And formaldehyde metabolic-related ?-glut amyl(GGT)enzyme and cysteine sulfide lyase(C-Slyase)activity is consistent with the trend of converting formaldehyde content trends described by endogenous formaldehyde content GGT and C-Slyse Enzyme ActivityCabbage,spinach,water spinach stored under different conditions,the nitrite content and related activity,and found that its variation,by comparing the three vegetables at room temperature bagging at room temperature without bagging,4? bagging and 4? not bagging although time-varying relationship between nitrite four different storage conditions,found in vegetables stored at room temperature for more perishable deterioration,increased nitrite content.Initial storage,increased nitrate reeducates activity,increased nitrite content.Late storage,due to the dynamic growth of bacteria,the bacteria can be reduced to cabbage nitrate reeducates in vivo nitrate to nitrite,so that nitrite content increased.Found to be stored cabbage water spinach,spinach nitrite through experimental studies,content which is closely related to nitrate reeducates activity.