FOOD SCIENCE ›› 2020, Vol. 41 ›› Issue (2): 306-314.doi: 10.7506/spkx1002-6630-20190625-316

• Safety Detection • Previous Articles     Next Articles

Rapid Detection of Carminic Acid in Yogurt and Lactobacillus-Containing Beverage by Al3+ -Based Fluorescence Enhancement

LIU Lanxiang, YI Guandong, LI Kai, MA Jinju, XU Juan, SUN Yanlin, ZHANG Hong   

  1. (1. Research Institute of Resources Insects, Chinese Academy of Forestry, Kunming 650224, China;2. Faculty of Chemical Engineering, Kunming University of Science and Technology, Kunming 650500, China)
  • Online:2020-01-25 Published:2020-01-19

Abstract: The effects of solvents, carminic acid concentration, pH and metal ions on the fluorescence properties of carminic acid were systematically studied. The fluorescent intensity of carminic acid was the strongest at a concentration of 2.0 × 10-4 mol/L in an aqueous solution at pH 4. The selectivity of carminic acid to metal ions indicated that the addition of Al3+ could significantly enhance the fluorescence intensity of carminic acid thus improving the sensitivity of detection. A 2.0 × 10-3 mol/L aqueous solution of Al3+ (at) was used as the standard solution. The ?uorescence intensity of carminic acid was linear with its concentration ranging from 1.0× 10-5 to 8.0× 10-5 mol/L, and the limit of detection (LOD) was 5.0 × 10-6 mol/L. When the fluorescence method was applied to determine carminic acid in yogurts and Lactobacillus-containing beverages, the recoveries ranged from 96.6% to 110.5%, relative standard deviation (RSD) no more than 5.9%. This study provides an effective approach to rapidly and quantitatively detect carminic acid in foods.

Key words: carminic acid, ?uorescence;?enhancement, fast?detection

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