Identification of bitter‐taste compounds in class‐III caramel colours

Abstract

Caramel colours become one of the most widely used colorings in various foods and beverages due to their total miscibility with water and great coloring properties by containing colloidal aggregates. Bitterness in caramel colours can negatively influence their acceptability. The sequential solvent extraction (SSE) and semi‐preparative liquid chromatography (SP‐LC) combined with the taste dilution analysis were applied to identify the most intense bitter‐tasting compounds in class‐III caramel colours. Four main compounds with the highest bitterness intensity were isolated and structurally elucidated based on high resolution‐electrospray ionization‐mass spectrum (HR‐ESI‐MS), nuclear magnetic resonance (NMR) spectroscopy and gas chromatography‐mass spectrum (GC‐MS): 2,3‐dihydro‐3,5‐dihydroxy‐6‐methyl‐4(H)‐pyran‐4‐one (DDMP), 5‐(hydroxymethyl) furfural (HMF), furfural and 5‐methylfurfural (MF). The threshold concentrations of DDMP, HMF, furfural and MF were 14.3, 30.0, 4.4 and 17.5μmol L−1, respectively. Furthermore, two volatile bitter compounds were identified: [5‐(di‐methoxymethyl) furan‐2‐yl] methanol (DMFM) and 2,3,4,4‐tetramethyl‐pentane‐1,3‐diol (TMP). Based on the composition of the caramel colours and the structures of these compounds, Maillard reaction was supported to generate these bitter compounds in caramel colour‐III.

Effects of moisture content on the enolization products formation in glucose–proline Maillard reaction models

“…20 In HepG2 cells, HMF also induced DNA damage at low concentrations (8-25 mmol L −1 ) in the comet assay. 21 In addition, DDMP and HMF have been identified as the main bitter-tasting compounds in whole-wheat bread 22 and caramel colors, 23,24 which can negatively influence product acceptability. Therefore, these MRPs are still regarded as compounds that must be strictly controlled in many foods, and further insight into their formation pathways in different MR systems is very important to establish food processing and storage protocols in practical application.…”

A Novel Method for Quality Evaluation of Gardeniae fructus Praeparatus during Heat Processing Based on Sensory Characteristics and Chemical Compositions

“…However, deeper GFP processed products with a lower content of geniposide showed stronger bitterness, suggesting that other bitter substances would be produced during the processing of GFP. Most likely, the Maillard reaction promoted the formation of various products with significant bitterness, such as 5-HMF [ 22 ]. Therefore, the tastes of bitterness, acidic–bitter aftertaste, and alkalescent bitterness negatively correlated to most iridoid glycosides, as well as showing high positive correlations with 5-HMF.…”