N-(1-Deoxy-d-xylulos-1-yl)-glutathione: A Maillard Reaction Intermediate Predominating in Aqueous Glutathione-Xylose Systems by Simultaneous Dehydration-Reaction

Abstract

The effect of simultaneous dehydration-reaction (SDR) on Amadori rearrangement product (ARP) N-(1-deoxy-d-xylulos-1-yl)-glutathione and its key degradation products, 3-deoxyxylosone (3-DX) and 1-deoxyxylosone (1-DX), were investigated in an aqueous glutathione-xylose (GSH-Xyl) system. The yield of ARP was increased to 67.98% by SDR compared with 8.44% by atmospheric thermal reaction at 80 °C. Reaction kinetics was applied to analyze the mechanism and characteristics of ARP formation and degradation under SDR. ARP formation and degradation rate was highly dependent on temperature, and the latter was more sensitive to temperature. By regulating the reaction conditions of temperature and pH, the ratio of ARP formation rate constant to its degradation rate constant could be controlled to achieve an efficient preparation of ARP from GSH-Xyl Maillard reaction through SDR.

Interaction of (−)-Epigallocatechin Gallate and Deoxyosones Blocking the Subsequent Maillard Reaction and Improving the Yield of N-(1-Deoxy-d-xylulos-1-yl)alanine

“…32 The dehydration process could stimulate the k 1 or k 1 ′ in both reaction pathways, and this mechanism has been explained in our previous research on kinetics under the VDR system. 23,25 The formation of ARP and DPs follows a zero-order reaction in the VDR system. 23 In the present reaction model, the formation rate k 2 of dominating product ARP and its degradation rate k 4 were calculated to be 8.5 and 1.7 mmol/L min −1 without EGCG, while the formation rate k 2 ′ was 15.8 mmol/L min −1 and the degradation rate k 4 ′ was 0.9 mmol/L min −1 in the presence of EGCG.…”

“…Our previous work revealed that the formation and degradation of ARP followed zero-order kinetics in VDR systems. 23 Thus, ARP or DP contents were described by c = c 0 − kt, where c is the concentration of ARP or DPs at time t (min), c 0 is the initial concentration, and k is the reaction rate constant (min −1 ). The activation energy E a (kJ/mol) was evaluated by means of the Arrhenius equation.…”

Key Aspects of Amadori Rearrangement Products as Future Food Additives

“…Cui et al proposed a combination of thermal controlled reaction and successive vacuum dehydration which could provide a synergistic effect and improved the yield of phenylalanine-xylose-ARP from 13.6% to 47.23% after 30 min of vacuum dehydration [ 29 ]. Such a yield improving method was also applied to various subsequent studies of the group, such as glycine-ribose-ARP (0.77% to 64.5%), glutathione-xylose-ARP (8.44% to 67.98%) and proline-glucose-ARP (3.63% to 69.15%) [ 14 , 30 , 34 ]. However, not all the system is suitable for controlled thermal dehydration coupled with vacuum dehydration.…”

“…The glutathione-glucose system produced less roasted and nutty aroma with the same quantity as the glutamic acid-cysteine-glycine-glucose system, resulting from a slower release of hydrogen sulfide and ammonia participating in the subsequent volatile formation [ 70 ]. Glutathione-xylose-ARP was produced with a high yield of 67.98% by simultaneous dehydration reaction and produced more ketones, alcohols, and mainly furans (caramel-like and sweet flavor) than the mixture of the ARPs of the three amino acid constituents [ 30 , 71 ]. Additionally, the glutathione-xylose-ARP produced a few sulfur-containing compounds while the mixture of cysteine-xylose-ARP and three amino acid ARP mixture generated a potent meaty flavor, supporting the aforementioned suggestions that cysteine-xylose-ARP is capable of forming meaty flavors and the process is strengthened by glycine addition, possibly split from glycine-xylose-ARP.…”

Magnesium-Accelerated Maillard Reactions Drive Differences in Adjunct and All-Malt Brewing

“…S4 and S5). The Maillard reaction proceeded through a nucleophilic addition between the carbonyl group of the reducing sugar and the amino group of the amino acid to produce a Schiff base which rearranged to form an Amadori product, 47,[53][54][55][56] seen at m/z 440.0258 (C17H30NO12) (Figure 8). The reaction continued via decarboxylation and dehydration to yield products at m/z 396.0127 (C16H30NO10) and m/z 378.0646 (C16H28NO9) respectively.…”