Glycine-Xylose Amadori Compound Formation Tracing through Maillard Browning Inhibition by 2-Threityl-thiazolidine-4-carboxylic Acid Formation from Deoxyosone and Exogenous Cysteine

Abstract

The browning inhibition of cysteine on the Maillard reaction of glycine-xylose performed under stepwise increased temperature was investigated. The browning degrees of the final products prepared with cysteine addition at different time points were found dissimilar, and the addition time point of cysteine yielding the lightest browning products was consistent with the time when the glycine-xylose Amadori rearrangement product (GX-ARP) reached its maximum yield. To clarify the reason for browning inhibition caused by cysteine, the evolution of key browning precursors formed in the GX-ARP model with cysteine involved was investigated by HPLC with a diode array detector. The results on the browning degree of the thermal reaction products of GX-ARP with cysteine addition showed great inhibition of α-dicarbonyl generation, which resulted in a significant increase in the activation energy of GX-ARP conversion to browning formation during heat treatment. Strong evidence suggested that the additional cysteine got involved in GX-ARP degradation and reacted with the deoxyosones derived from GX-ARP to yield cyclic 2-threityl-thiazolidine-4-carboxylic acid (TTCA). TTCA formation shunted the degradation of deoxyosones into short-chain α-dicarbonyls, which were important browning precursors, and consequently inhibited the Maillard browning.

Cysteine-Induced pH-Dependent Formation of Thiols and Sulfides or 2-Acetylthiazole and Pyrazines during Thermal Treatment of N-(1-Deoxy-d-xylulos-1-yl)-alanine

“…Notably, Cys is widely used as a potent non-enzymatic browning inhibitor in most foods like egg albumin . It has been demonstrated that added Cys could react with deoxyosone fragments of ARP derived from glycine and xylose to form cyclic 2-threityl-thiazolidine-4-carboxylic acid (TTCA), and then changed the traditional pathways of the Maillard reaction and inhibited browning . Thus, Cys was combined with ARP to prepare light-colored Maillard flavoring.…”

Light-Colored Maillard Peptides: Formation from Reduced Fluorescent Precursors of Browning and Enhancement of Saltiness Perception

“…Hou et al 11 further demonstrated that the addition of L-cysteine could alter the degradation pathway of ARPs in glycine−xylose system and generate a relatively stable cyclic 2-threitylthiazolidine-4-carboxylic acid (TTCA), a structural analogue of ARPs, to inhibit browning. Similarly, Wei et al 33 proposed that L-cysteine could react with deoxyosones, the direct downstream products of ARPs in the glycine−xylose system, to form TTCA, which hindered the formation of short chain αdicarbonyl compounds. Hence it can be assumed that the difference in browning degree between deep-colored and lightcolored MPs was due to the cross-linking between αdicarbonyl compounds and amines, such as peptides.…”

Maillard Reaction Process and Characteristic Volatile Compounds Formed During Secondary Thermal Degradation Monitored via the Change of Fluorescent Compounds in the Reaction of Xylose–Corn Protein Hydrolysate

“…The preparation and characterization of MRIs derived from the model systems consisting of diverse amino acids (or peptides) and reducing sugars have been widely reported. , The formation time of ARPs and other intermediates can be indicated by the browning-inhibited effect of tracers such as cysteine in a simple model reaction system, thus assisting in the preparation and application of MRIs. , Moreover, for those simple model systems, the process of the Maillard reaction could be inferred by monitoring the substrate peptides or amino acids and sugars during the Maillard reaction. ARPs and their degradation products, such as α-dicarbonyl compounds and other intermediates, can also be isolated, purified, and quantified, which would help us to infer the process of Maillard reaction .…”