Study On Analytical Methods Of Sweeteners And Synthetic Preservatives In Foods And Limits Standard In Health Foods

China is one of the top countries for food additives production and application in the world.Although Ministry of Health(MOH) of China promulgated hygienic standards for uses of food additives(GB2760-86) in 1986,and made significant amendment to it on 2007,there are a number of deficiencies in the standards to the new kind of foods, especially functional food.Since functional food was defined in 1996 in China,the usage of food additives in this kind of foods has been supervised referring to the relevant food categories,and there have not been the hygienic standards for used of food additives focusing on the functional foods.Owing to functional foods' features which are different with other kind of foods,i.e.formula products,low daily intake and high addition of food additives,the legal content limits of food additives in the functional food products should been evaluated seriously.After risk assessment according to actual use and dietary intake data,the limits can then be ascertained.In this paper,a series of research works were accomplished to develop the hygienic standards for uses of food additives focusing on the functional foods.The details are as follows:1) Neotame is the sweetest artificial sweetener at present time.Because its addition in health foods is low,the analysis and detection of neotame is a challenge,and the analytical method has been seldom reported.In this chapter,a solid phase extraction(SPE) method was developed for the first time for the sample pretreatment of neotame determination of health foods such as dairy beverages etc.Furthermore,HPLC method base on the universal homemade column were developed and the analytical conditions were optimized.The proposed SPE-HPLC method was reliable and widely applicable.The method has been proposed as a National Standardized Analytical Method.2) Based on the proposed SPE-HPLC method,a column-switching technology was introduced to increase the purification,enrichment,and anti-interference ability of the method.The proposed SPE-column-switching HPLC method owned advantages vs.SPE-HPLC method such as:(a) a large volume injection could be completed for the low content sample and neotame in the sample solution could be enriched in the first column.Consequently,the sensitivity of the method was increased.(b) Neotame and impurities in the sample solution could be separated.The procedure was same as on-line SPE purification of the sample solution.(c) After two steps separation,the anti-interference ability of the analytical method was increased significantly.The proposed SPE-column-switching HPLC method has been applied to analyze complicated matrix foods such as beverages,preserved fruits and cakes successfully.3) As several kinds of food additives can be added in one kind of food simultaneously,a simultaneous determination method is important for the inspection of food additives.Three different simultaneous analytical methods were established in this chapter:(a) HPLC-UV,and ultra-performance liquid chromatography(UPLC) method to the simultaneous determination of Acesulfame-K,aspartame,saccharin, alitame,sorbic acid,benzoic acid,neotame and stevioside was developed, respectively.(b) To solve UV detection problem of sodium cyclamate and sucralose because of absence of chromophore,a HPLC coupling with evaporative light scattering detection(ELSD) method was established for the simultaneous determination of saccharin,acesulfame-K,sodium cyclamate,sucralose,aspartame,alitame,neotame and stevioside.The pretreatment conditions were optimized to increase the anti-interference ability of the method.Compared with the methods reported,the proposed methods could simultaneously analyze 8 nonnutritive sweeteners, specially to sodium cyclamate,alitame,neotame and stevioside.4) A HPLC/ESI-MS method for the simultaneous determination of eight nonnutritive sweeteners including aspartame,saccharin,acesulfame-K, neotame,sucralose,cyclamate,alitame and stevioside in beverages, canned fruits and cakes was developed.The food samples were extracted by aqueous methanol solution(50:50,v/v),and further purification was unnecessary.Compared with traditional HPLC method,this method owned obvious merits such as simplicity,rapidity,high sensitivity,and specificity.The method can be used for the routine analyses of sweeteners in foods in the future.5) A survey on dietary intake of processed food was designed and put in practice in eight cities for the first time in China in order to match the requirement of risk assessment for the establishment the legal content limits of food additives.The dietary intake mode of processed food was established.In order to investigate China population's food additives daily intake,the gross intake was assessed according to the dietary intake mode and National Fifth Nutrition Survey data,respectively.This research provided the basic data for establishing food additives limits criteria in the next step.6) Based on risk assessment data and current application data,food additive limits criteria in health foods were proposed for first time in China.After reviewed by industries,related testing centers and experts, the revised criteria has been approved by National Food Additive Standardization & Technology Committee and will be published very soon.It is the first time to establish limits criteria with the help of risk assessment not only in the field of food additives but also in the field of healthy foods.