Miscellaneous pigments in foods and food products

RP-HPLC with DAD and MS detection has also been employed for the determination of anthraquinone pigments in the extract of Rubia tinctorum. The names and chemical structures of anthraquinone pigments found in R. tinctorum are compiled in Table 2.110. 

RP-HPLC has been applied for the determination of betalain pigments in various plants too. The researches were motivated by the commercial importance of betalain pigments as natural food colourants. An RP-HPLC method was developed for the measurement of betalain pigments in prickly pear (Opuntia ficus-indica) fruits. 

The chemical structures of betanin and indicaxanthin found in the prickly pear are depicted in Fig. 2.150. Pigments were extracted by homogenizing fresh fruit flesh with methanol (1 5, w/v). The suspension was fdtered and the liquid phase was applied for spectrophotometry and RP-HPLC. Liquid chromatographic separation was performed in an ODS column (250 X 4.6 mm i.d. particle size 5 pan) at ambient temperature. Gradient elution started with 1 per cent aqueous acetic acid and changed to 12 per cent solvent B in 

Gel filtration chromatography carried out on a Sephadex stationary phase has also been employed for pigment analysis. The decolourization of molasses spent wash (MSW) by the white-rot fungus Flavodon flavus was followed with this technique. Untreated and treated MSW samples were diluted up 10 per cent and were loaded into a Sephadex G-50 

EMODIN. CHRYSOPHANOL AND PHYSCION IN VEGETABLES. HERBS AND HERBAL FLAVOURED LIQUORS (K1 - Kll). ANALYSED BY RP-HPLC AND GC-MS. DATA ARE GIVEN AS RANGE. IN MG/KG (N 3) AND WERE NOT CORRECTED FOR RECOVERY 

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