The Loss Of Folic Acid Caused By Storage And Cooking

Folic acid is a kind of important vitamin which can promote bone marrow cells of mature.The newborn neural tube defects is due to the pregnant women lack of folic acid.Therefore,according to the characteristics of Chinese diet,studying the influence of processing methods for food folic acid and forwarding reasonable dietary recommendations are meaningful.In this paper,the object of study was seasonal vegetables(mainly spinach),establishing the folic acid detection method,researching the influence on food folic acid of cooking methods,storage conditions,digestive environment and the dietary situation of Dalian bearing-age females.The following aspects were mainly studied:The microbial detection was optimized and more sensitive,the limit of detection was estimated at 0.9?g/100g;The extraction condition of fluorogenic assay was determined;A method for testing vegetables folic acid by high performance liquid chromatography(HPLC)was established:the limit of detection was estimated at 0.25?g/100g,the recovery rate was 95.02%.The spinach is stored in the condition of normal temperature,cold storage and frozen.Respectively the folic acid loss rate was 36.7%,25.6%and 10.2%.The linear relationship of the spinach chromaticity and folic acid content was established,the correlation coefficient was 0.97,0.79 and 0.96 respectively.The vegetables were processed by different cooking methods,folic acid content was declined,save rate of folic acid also decreased with the increase of the processing time.The most significant influence on folic acid was boiling,the loss rate was 56%-81%.The least significant was steaming.In vitro digestion,all samples folic acid loss were serious.The digestion rate of raw material folic acid was 23.96%,the digestion rate of cooked material folic acid was 12.71%.In the 193 Dalian bearing-age females daily diet,the average energy intake was 2244 kcal/d.The energy ratio of protein,fat,carbohydrate was 16.19%,33.34%,50.47%respectively.The folic acid intake was 326.89?g/d,below the national recommended levels.And the actual intake of folic acid should be less than 20.77?g/d considering the influence of other factors such as cooking and digestion.In conclusion,vegetables folic acid will be significantly affected by storage conditions,cooking methods and digestive environment.Therefore,low temperature preservation,cooking methods not with water as the heating medium and the heating temperature relatively lower such as steaming,microwave were advocated.The suggestions about increasing the intake of vegetables,cereal,and the folic acid supplements,reducing the intake of meat and fats were given for having a reasonable and balance dietary habit.