title: Detection of adulteration in apple juice by L-malic/total malic acid ratio: collaborative study.
abstract: L-Malic acid is the predominate acid in pure apple juice and no D-malic acid should be present. Synthetic malic acid contains 50% D-malic acid, is inexpensive, and can be used to create nonauthentic apple juice. L-Malic/total malic ratios of 0.9 or less are indicative of a nonauthentic sample. Fourteen laboratories participated in a collaborative study to determine the L-malic/total malic acid ratio in apple juice. Ten samples of apple juice were sent to each laboratory. Authenticity of the samples varied from 0 to 100%. The coefficients of variation in all cases were acceptable, i.e., ca 5%. The method was adopted first action by AOAC INTERNATIONAL.
authors.affiliation: National Food Processors Association, Washington, DC 20005.
authors.forename: E R
authors.initials: ER
authors.lastname: Elkins
authors.forename: J R
authors.initials: JR
authors.lastname: Heuser
mesh_terms: D001628:Beverages / Q000032:analysis*; D005506:Food Contamination; D005638:Fruit / Q000737:chemistry*; D008293:Malates / Q000032:analysis* / Q000737:chemistry
chemical_list: D008293:Malates; C030298:malic acid