Study On The Variation Of Nitrate In Vegetables And The Evaluation Of Dietary Exposure In Hangzhou

Most of the nitrate consumption of human beings comes from vegetables.The problem of nitrate pollution in vegetables has always been a major concern of the society.Nitrate is a key precursor that will further cause carcinogenesis,teratogenesis and mutagenesis.The statistics of the survey of Hangzhou citizens based vegetable consumption and dietary nitrate pollution status,nitrate contamination of salt in residents of high consumption of vegetable species and varieties,and then to the typical vegetables to study on the change rule of various forms of nitrogen and nitrate content in food processing and storage process,preliminary exploration the change mechanism of nitrate and nitrite,and the main kinds of vegetables storage factor and processing factors for preliminary calculation,finally,based on the statistical data of dietary intake of vegetable nitrate intake of residents of Hangzhou public exposure assessment,the vegetable nitrate intake amount of risk,in order to guide consumers a healthy diet.The results of the study:(1)according to the conclusion of the investigation on vegetable dietary consumption data of Hangzhou residents,leafy species for the largest consumption market,combined with the random sampling of nitrate content in vegetables,various types of vegetable nitrate pollution level,nitrate accumulation were investigated.The results showed the most serious vegetable species with leafy.The vegetables for the nitrate contamination in the largest variety of leafy vegetables.(2)the vegetables stored at different temperatures(20 ? ambient temperature,low temperature 4 ?),under different packaging conditions(household fresh-keeping film packing and packaging),under different treatments(divided into complete fresh and fresh cut processing,processing into fried,steamed,boiled way)to explore the changes in the contents of research factors of vegetables nitrite,nitrate,ammonium nitrogen,free amino acid content index change characteristic and its influence,and explores the influence of each variable has a certain function to produce nitrite during storage period.The results showed that: nitrite,nitrate,free amino acids and ammonium nitrogen all showed significant difference at different temperatures,different packaging methods and different storage days(P < 0.01).The variation of nitrite content has significant difference under the interaction of various factors(P < 0.01),which has considerable research value for subsequent research.In terms of index correlation,it is found that no matter in fresh storage or processing(frying,steaming or boiling),no matter which processing methods,nitrate and free amino acids have a very significant positive correlation,nitrite and ammonium nitrogen have significant correlation.Therefore,there is a certain relationship between free amino acids and nitrate in any storage period.It can be considered that the production of nitrate may be related to free amino acids.(3)the nitrate intake of vegetables in the residents was evaluated and evaluated by probability.The evaluation results were compared and evaluated,results showed that the difference of nitratecontent in vegetables of different types of large(P < 0.05),the nitrate content in vegetables from high to low in turn arranged for leafy vegetables(2223 mg kg-1)and rhizome(1091 mg kg-1),cauliflower(689 mg.Kg-1),qiegua(452 mg kg-1),beans and vegetables(399 mg kg-1),edible fungus(73 mg kg-1).The exposure values of nitrate in different population were also significantly different(P < 0.05),and the distribution of exposure was more than that of women.Where regardless of gender,with 18-30 years old young group population exposed to the highest value.The evaluation results show that the per capita total risk index of%ADI was 0.992,not beyond the standard risk,but the%ADI part of the young population beyond the limit value;the probability assessment showed that 99% of the people may not exceed ADI,and one of the more than 1% of men ages 18-30 people over dosage might.Therefore,the risk level of nitrate dietary intake in Hangzhou residents is better,only a few people may be exposed to nitrate exposure risk.