Food additives
Traditional food additives
General principles
special toxicological problems may arise with food additives,that is,
with compounds intentionally added to food for improvement of its various characteristics.Some of the food additives such as sodium chloride, acetic acid,or various spices have been used already for centuries.Despite that,to date thephysiological effects of sodium chloride are being investigated,leading often to discoveries of new adverse effects on human health. By now,a purposeful addition of various compouds to food has becom really extensive,that is aout 25500 food additives are in use. in Europe , to keep track of them and for the sake of brevity,every food additive has a so-called E-number.In the unified schme,many food additives not officially confirmed in Europe but allowed, for example,in the United States or Australia or anywhere else also have,with the help of Codex Alimentarius Committee, the number.In addition to substanes that stood the test have stood the test of time and are labeled as generally regarded as safe (GRAS),new food additives are continuously appeaing,the physiological effects of which are not always very clearly established.
food additives can be divided, according to sources, into thee main groups:
1.Substances,isolated from edible plants or from other living material,for example, alginates(E401),agar (E406),and ated carragenan (E407) isolated from seaweeds,Iecithin (E322) from soybeans,pectin (E440) from Fruits,and so forth
2.Substances contained in foodstuffs, but the production of which by chemical synthesis is heaper,such as antioxidant ascorbic acid or vitamin C(E300) , yellow dya β-carotene (E160),and so forth
3.Substances not found in nature and which are obtained only synthetially,such as sweetener saccharin(E954) or antioxidant t-butyl-hydroxyanisole(E320)
In the system of E-numubers, the additivies have been divided into
classes cording to the main purpose of their use (seeTble 17.1 )
in addition to the classes listed in table 17.1 , a number of other groups of additives such as anticaking, antifoaming and foaming agents,fillers,color,stabilizers,glazing agents,propellants,and soforth exist
the function of food preservatives and the need for them are evident-reduction of the probability of bacterial or fungal infections. preservatives reduce both biological and chemical degradation and prolong the storage time of food. A special group of preservatives are the antioxidants that inhibit the oxidation of food components and also the cellular components of the consuming organism (see also section 3.3.6).addition of colorants is substantiated,first of all,from the manufacturer's viewpoint-making the product more attractive. besides these groups,the list of food additives contains substances of which the actual function is not very obvious.
many producers are advertisting their goods as additives-free or as containing only natural additives. the last statement,even if true,is by far not a sufficient argument. as wa have seen already,natural compounds may be at least of the same toxicity as synthetic ones. in principle,natural food additives should have also been tested from the toxicological point of view before starting their utilization. the respective tests ordinarily use a lifelong exposure of the test animals to various doses of the substance studied , the highest dose exceeding by several times the doses presumably ingested by humans. these tests are not always sufficient-it is well known that test animals may not have a response equal to that of humans to the effects, of the substance studied. organisms may vary in absorption,distribution,as well as metabolism of substances. Use of extremely hing doses may due to saturation of the metabolic and secretion routes,lead to accumulation.