Reduced asynchronism between regenerative cysteine and fragments of deoxyosones promoting formation of sulfur-containing compounds through extra-added xylose and elevated temperature during thermal processing of 2‑threityl-thiazolidine-4-carboxylic acid. (15th March 2023)

• Record Type: Journal Article
• Authors: Zhai, Yun; Xia, Xue; Deng, Shibin; Cui, Heping; Hayat, Khizar; Zhang, Xiaoming; Ho, Chi-Tang
• Is Part Of: Food chemistry. Volume 404:Part A(2023)
• Publication Date: 2023-03-15
• Subjects: d-xylose (PubChem CID: 135191) -- l-Cysteine (PubChem CID: 5862) -- Acetonitrile (PubChem CID: 6342) -- Methanol (PubChem CID: 887) -- Deuteroxide (PubChem CID: 24602) -- Ammonium formate (PubChem CID: 10904); 2‑Threityl-thiazolidine-4-carboxylic acid -- Reduced asynchronism -- Sulfur-containing flavor compounds -- Strecker degradation -- Cysteine -- α-Dicarbonyls; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; 664
• DOI: 10.1016/j.foodchem.2022.134420
• Languages: English
• ISSNs: 0308-8146

Abstract

Highlights: Asynchronism between regenerative cysteine and fragments of deoxyosones led to the block of Strecker degradation. Added xylose intensified the original flavor compounds derived from TTCA model under 100 °C. Released Cys catalyzed the transformation from extra-added Xyl to more carbohydrate fragments. Higher temperature was beneficial to the thermal degradation of Cys and provided more sulfur elements. Effect of elevated temperature and added xylose on flavor improvement was confirmed by isotope labeling technique. Abstract: The flavor intensity of thermally processed 2‑threityl-thiazolidine-4-carboxylic acid (TTCA) was significantly improved to 1.56 times of that generated from MRPs, but its flavor profile was not as desirable as that of fresh MRPs. The synergistic effect between the additional xylose (Xyl) and elevated temperature was proposed and confirmed via the quantitative analyses of regenerative cysteine (Cys) and fragments of deoxyosones (MGO/GO), which reduced the asynchronism between the formation of released Cys from degraded TTCA and retro -aldolisation products of the intermediate deoxyosones. This synergistic effect further enhanced the Strecker degradation of Cys as well as its thermal degradation and thereby promoted the formation of characteristic flavor substances including sulfur-containing compounds and pyrazines, and the total concentrations of TTCA reaction model reached 205.954 μg/L with additional Xyl at 140 °C. Model reaction systems were employed to verify this hypothesis and the proposed mechanism was further elucidated through isotope labeling technique.