Crocin-a water soluble carotenoid-is found in the fruits of gardenia (Gardenia jasminoides Ellis) and in the stigmas of saffron (Crocus sativus Linne). For crocin purification, gardenia fruits are extracted with 50% acetone, followed by ether washing, ion exchange, and separation by preparative HPLC. Purified crocin with purity of >99.6% has an antioxidative activity at concentrations up to 40 ppm. At 20 ppm the antioxidative activity of crocin is comparable to that of BHA. The antioxidant property of crocin as evaluated by the thiocyanate method was better than with the thiobarbituric acid method. The adduct between the linoleic acid radical and crocin was detected by LC-MS. When crocin reacted with oxygen in the presence of FeSO(4), intermediates such as monohydroperoxides and dihydroperoxides of crocin were formed and detected by LC-MS.

Color and thermal‐ and pH‐stability of anthocyanins from a grape cell suspension culture were compared with those of commercial food colorants using Hunter and spectrophotometric analysis. At pH 3, grape cell anthocyanins showed color vividness (Chroma) similar to red cabbage and higher than that of other samples and a hue (Theta) similar to purple corn and redder than other samples. Brown oxidized phenolics were absent from the cell culture and red cabbage preparations, but were found in other samples. Color loss during incubation at 30 and 95°C, pH 3 and during an increase in pH from 3 to 5 was more severe for cell culture than red cabbage anthocyanins probably indicating they were intrinsically more sensitive.