Specifications for identity and purity of certain food additives: antioxidants, enzyme preparations, flavouring agents, flavour enhancers, food colours, sweetening agentsthickening agents and miscellaneous food additives ; 31stsession of the Joint FAO/WHO Expert Committee on Food Additives, Geneva, 16-25 February 1987 and 33rd session of the Joint FAO/WHO Expert Committee on Food Additives, Geneva, 21-30 March 1988. (FAO food and nutrition paper ;, 1986)