Glutamic acid known as a umami component and many amino acids are known as taste components. Recently, various physiological activities of amino acids have attracted attention and  some amino acid are taken as functional food. HPLC and LC-MS are mainly used for analysis of amino acids, and suitable systems are selected according to the samples to be analyzed and purpose.

Analysis of Amino Acids in Black Vinegar (LC)

Food products contain amino acids with a variety of flavors. Their types and component ratios have a significant impact on the flavor of the food product. This example shows the analysis of the amino acids in black vinegar using a pre-column derivatization amino acid analysis system. Pretreatment is automated by using the SIL-30AC autosampler with its pretreatment function. This saves on labor, and at the same time, enables analysis with high accuracy.

Analysis of D/L Amino Acids in Yogurt Drinks (LC-MS/MS)

It has been reported that D-amino acids other than aspartic acid, glutamic acid, and proline give sweet taste, and that when there are multiple D-amino acids with taste embellishing effects in a food product, they create a composite flavor quality. This example shows the analysis of D/L amino acids in yogurt drinks from different manufacturers. For some amino acids, the D-amino acid ratio is relatively high, and significant differences in the component ratio of D/L amino acids are evident depending on the manufacturer.

D/L amino acids in yogurt drinks

D/L Component Ratio
Yogurt A Yogurt B
Alanine 164.0% 40.2%
Arginine 6.9% 36.5%
Asparagine 43.2% 16.5%
Aspartic acid 38.1% 15.3%
Cysteine - -
Glutamine 0.6% 19.8%
Glutamic acid 4091.1% 5069.6%
Histidine - 5.2%
Isoleucine 0.8% 1.0%
Alloisoleucine 59.4% 39.3%
Leucine 1.0% -
Lysine 73.5% 3.5%
Methionine 0.9% -
Phenylalanine 0.5% 1.5%
Serine 14.4% 29.3%
Threonine 1.5% 4.6%
Allothreonine 42.5% 23.7%
Tryptophan 1.9% 13.3%
Tyrosine 2.1% 107.4%
Valine 0.4% 0.9%

Amino acids