In vivo and in vitro evaluation of betanine mutagenicity.

Information about the mutagenic effect of natural food colors gives scientific support to their use as food additives. Two different forms of beet root colours were tested: form I without nitrate residues and form II with nitrate residues. Mutagenic effects were tested in vitro using the human peripheral blood lymphocyte system and in vivo using the Wistar rat cytogenetic test system. Mitotic index (MI), chromosome aberration (CA), sister chromatid exchange (SCE) frequencies were recorded in the in vitro assay, and MI, CA and micronucleus (MN) frequencies were recorded in the in vivo assay.The in vitro tests showed that form I was more effective as a clastogen and SCE inducer, but the in vivo tests failed to show mutagenic activity of either form, suggesting that beet colours may be safely used as food additives.