Betacyanins stability

Herbach, K.M. et ah. Effects of processing and storage on juice colour and betacyanin stability of purple pitaya (Hylocereus polyrhizus) juice, Eur. Food Res. TechnoL, 224, 649, 2007. 

During fermentation, the betacyanins turned out to be more stable than the betaxanthins, which is assumed to be due to their thermal stability rather than different tendencies of pigments toward microbial degradation. Besides these biological tools, beet extracts may also be purified by column chromatographic techniques. After removal of sugars, salts, and phenolics, the nature-derived color preparation will, however, require E number labeling. ... 

Castellar, R. et al., Color properties and stability of betacyanins from Opuntia fruits. J. Agric. Food Chem., 51, 2772, 2003. 

Havlikova, L., Mikova, K., and Kyzlink, V, Heat stability of betacyanins, Ztschr. Lebensm. Unters. Forsch., 177, 247, 1983. 

It has only recently been discovered that acylated betacyanins exhibit intramolecular co-pigmentation that may also lead to stabilization of the chromophor, betanidin (Schliemann and Strack, 1998), a phenomenon which is well-known for anthocyanins (Brouillard and Dangles, 1993). Esterification of the sugar moieties of betanin (betanidin 5-0-glucoside), gomphrenin I and bougainvillein-v with hydroxycinnamates leads to bathochromic shifts... 

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