Pineapple juice often shows an unstable cloud and produces a solid precipitate that is not very attractive for consumers. Cloud stabilization by pectin addition is permitted by EU and Codex standards to counteract this effect. This additive must be labeled and its content should not exceed fixed maximum standards (Website of AIJN Code of Practice). Determination of water-soluble pectins by IFU method 26 (Website of International Fruit and Vegetable Juice Association) can be used for control of this parameter. Pectin addition to pineapple juice or juice concentrate, etc. may also be detected after its isolation by 13C isotopic analysis (Hammond, 2006) as explained later.
