Relatively large amounts of imidazole dipeptide are found in chicken breast and tuna, bonito, and whale meat. It is said to have strong antioxidant effects and effective in preventing aging and reducing fatigue, considered as a functional food ingredient.
In this application, standard sample solutions of L-carnosine and L-anserine, which are representative imidazole dipeptides, were analyzed using the cation analysis column IC YS-50. A good linearity was obtained in the concentration range of 1 to 100 mg/L. In the next step, L-carnosine and L-anserine in a commercial processed meat supplemented with imidazole dipeptide was analyzed using the same conditions.
Imidazole dipeptides can also be analyzed using a polymer-based amino column (Asahipak NH2P-50 4E). However, salicylic acid used for protein removal remains in the sample solution and is strongly retained by the amino functional group. Salicylic acid takes more than 60 minutes to elute. On the other hand, YS-50 column, modified with carboxyl functional group, let salicylic acid elute by ion exclusion mode before the other components, and completes the analysis within 20 minutes. Quantification of imidazole dipeptide in the commercial process meat showed near 100% recovery compared to the value shown in the manufacturer's product label.

Refer to "Analysis of Imidazole Dipeptides (NH2P-50 4E)"

Sample pretreatment

1. 1.Weight 2 g of a commercial processed meat supplemented with imidazole dipeptide.
2. 2.Add 5 mL of 5 % salicylic acid and homogenize.
3. 3.Add 95 mL of deionized water. Leave it for 30 minutes.
4. 4.Filter the supernatant through a 0.45 μm membrane filter. Use it as an injection sample.

Sample: 2 μL
Pretreated sample
Standard solution (20 µg/mL each)

1. 1.L-Carnosine
2. 2. L-Anserine