Quantitative analysis of crocetin colorants in gardenias (Gardenia jasminoides Ellis) by LC/DAD/MS

For the quantification of yellow coloring materials in gardenia utilized as natural food colorants and for dyeing fabrics, the fruits of fully matured Gardenia jasminoides were characterized by LC/DAD/MS analysis. The five yellow coloring materials with crocetin chromophore were analyzed by HPLC and characterized by DAD and MS analysis. The molar compositions of each crocetin colorant were measured as follows; trans-crocetin di(β-gentiobiosyl) ester 1 [58 mol %], trans-crocetin mono(β-gentiobiosyl) monoglucosyl ester 2 [13 mol %], trans-crocetin diglucosyl ester 3 [20 mol %], crocetin 4 [7 mol %] and trans-crocetin monoglucosyl ester 5 [2 mol %]. With molar absorptivity of the major colorant 1 that was first measured as ε 103000 dm³ mol^-1 cm^-1 at λ_max 440 nm, total crocetin content per mass of dried whole gardenia fruit was quantified as 3.4 μmole/g of crocetin aglycone.