Discovery and Identification of Tastants and Taste-Modulating N-Acyl Amino Acid Derivatives in Traditional Korean Fermented Dish Kimchi Using a Sensomics Approach

Abstract

Sensory-guided fractionation by means of ultrafiltration and gel permeation chromatography followed by high-performance liquid chromatography, synthesis, liquid chromatography–tandem mass spectrometry (LC–MS/MS) quantitation, and taste re-engineering experiments revealed taste-active and taste-enhancing compounds contributing to the umami, mouthful and complex taste profile of the fermented Korean dish, kimchi. Besides basic taste-active compounds, in particular, various N-acylated amino acids deriving from succinic acid and lactic acid imparted taste-modulating properties in food matrices. Taste threshold concentrations were determined to evaluate intrinsic and modulating effects. Quantitation of N-acylated amino acids in kimchi following synthesis revealed the presence of numerous derivatives showing taste–active properties. Sensory evaluation including recombination and partial addition experiments highlighted that both the N-lactoyl- and the N-succinoyl amino acid derivatives contribute to increasing the fullness, volume, and complexity of food matrices, whereas the latter directly contributes to the overall taste of kimchi in natural concentrations.

Discovery of N-l-Lactoyl-l-Trp as a Bitterness Masker via Structure-Based Virtual Screening and a Sensory Approach

“…The signals at m / z 159.0933, 188.0689, and 204.1555 corresponded to N-terminal b-COOH, and b-type and c-type fragments of N -lactoyl-Trp. The characteristic loss of the C-terminal y-type for the lactoyl moiety (72 Da) agreed well with previous reports. ,, …”

“…Subsequently, N -Lac-AAs were discovered as taste-active compounds and accumulated in the fermentation of cheese, in soy sauce, in coffee, and in meat products. , However, only a few reports revealed the explicit aroma and taste of N -Lac-AAs. Hofmann et al recently revealed the intrinsic taste of N - l- Lac -l -Gly, N - l- Lac -l -Ala, N - l- Lac -l -Glu, N - l- Lac -l -Gln, N - l- Lac -l -Asp, and N - l- Lac -l -Asn and added fullness, volume, and complexity to Korean kimchi . Our team also found that N - l- Lac -l -Phe from enzymatic synthesis exhibited strong kokumi properties .…”

“…On the contrary, there was a marked decrease in bitterness. A previous study showed that N - l -Lac- l -Glu (34 mg/L) and N - l -Lac- l -Gln (34 mg/L) increased the complexity and mouthfulness of the model broth, while N - l -Lac- l -Asp (74 mg/L) and N - l -Lac- l -Asn (76 mg/L) modulated the complexity only slightly . Our recent studies investigating the taste properties of N - l -Lac- l -Phe revealed that it has a pronounced kokumi-modulating effect .…”

“…A previous study showed that N-L-Lac-L-Glu (34 mg/L) and N-L-Lac-L-Gln (34 mg/L) increased the complexity and mouthfulness of the model broth, while N-L-Lac-L-Asp (74 mg/L) and N-L-Lac-L-Asn (76 mg/L) modulated the complexity only slightly. 11 Our recent studies investigating the taste properties of N-L-Lac-L-Phe revealed that it has a pronounced kokumimodulating effect. 12 The kokumi-modulating effect of N-L-Lac-L-Phe, N-L-Lac-L-Glu, N-L-Lac-L-Gln, N-L-Lac-L-Asp, and N-L-Lac-L-Asn (in descending order) agree well with docking affinity in virtual screening.…”

“…Hofmann et al recently revealed the intrinsic taste of N-L-Lac-L-Gly, N-L-Lac-L-Ala, N-L-Lac-L-Glu, N-L-Lac-L-Gln, N-L-Lac-L-Asp, and N-L-Lac-L-Asn and added fullness, volume, and complexity to Korean kimchi. 11 Our team also found that N-L-Lac-L-Phe from enzymatic synthesis exhibited strong kokumi properties. 12 In addition, N-L-Lac-GMP was recognized as a new umami molecule; N-L-Lac-4-hydroxyben zylamine, N-L-Lac-vanillylamine, and N-L-Lac-dopamine were described as novel taste-modulating substances.…”