Stability of limonin glucoside in beverage matrices

BACKGROUND: We completed a study over a 200-day period examining the stability of limonin glucoside formulated into three beverage matrices. RESULTS: Beverages containing limonin glucoside were found to contain limonin (0.13–20.10 mg L−1) during their initial testing; however, these concentrations were directly attributable to the presence of contaminating limonin in the particular lot of limonin glucoside used to prepare the beverage and did not increase over the test period. Likewise, limonin glucoside concentrations did not vary significantly, with the exception of the beverage matrix that included vitamin B2. Exposure of the vitamin B2-containing beverages to light resulted in a rapid reduction in the limonin glucoside content. Liquid chromatographic–mass spectrometric and nuclear magnetic resonance results from the analyses of preand post-light exposed beverages suggest photooxidation of the furan moiety as the likely degradation pathway. CONCLUSION: Results from this study indicate that limonin glucoside is resistant to degradation into limonin, the stability of limonin glucoside formulated into beverages exceeds six months and that limonin glucoside should not be formulated into beverages containing vitamin B2 unless the beverages are protected from light. Published in 2008 by John Wiley & Sons, Ltd.