The effects of reaction parameters on the non-enzymatic browning reaction between l-ascorbic acid and glycine

Yan Yang,Ai-Nong Yu,Liang Feng,Bao-Guo Sun,Yu-Ping Liu,Ya Li

doi:10.1515/ijfe-2019-0189

Abstract

Abstract The non-enzymatic browning (NEB) reaction between l-ascorbic acid (ASA) and glycine (Gly), including the effects of temperature (110–150 °C), time (10–150 min) and pH (4.5, 6.8, 8.0 and 9.5) on the formation of un-colored intermediate products (UIPs), browning products (BPs) and volatile products (VPs), were investigated. The results showed that pH had a remarkable effect on the reaction. The characteristics of zero-order kinetics for the formation of UIPs and BPs were discussed, and the corresponding activation energy (E a ) was also calculated. When the pH was 4.5, the E a for the formation of UIPs was approximate 53.76 kJ/mol and less than that at other pH values; while the E a for BPs formation was approximate 94.06 kJ/mol and much higher than that at other pH values. The results suggested that an acidic environment facilitated the generation of UIPs, but did not remarkably promote the formation of BPs. The possible reaction pathway between ASA and Gly was proposed according to the experimental results.

Highlights

The non-enzymatic browning (NEB) reaction is one a very important reaction in the food industry that significantlyEnvironmental Engineering, Hubei Minzu University, Enshi, 445000, China, and Beijing Key Laboratory of Flavor Chemistry, BeijingTechnology and Business University, Beijing, 100048, China, Laboratory of Flavor Chemistry, Beijing Technology and BusinessYa Li, Liang Feng and Ai-Nong Yu, School of Chemistry & EnvironmentalEngineering, Hubei Minzu University, Enshi, 445000, ChinaBao-Guo Sun, Beijing Key Laboratory of Flavor Chemistry, BeijingTechnology and Business University, Beijing, 100048, China License.affects the color, flavor, taste and nutritional quality of food [1,2,3]
The results clearly showed that the concentration of ascorbic acid (ASA)/Gly decreased, and the absorbance of un-colored intermediate products (UIPs)/
The decrease in concentrations of ASA/Gly and the increase in the absorbance of UIPs/browning products (BPs) were slow at relatively low temperatures (110 °C); while these changes occurred rapidly at higher temperature (150 °C)

Summary

Introduction

The non-enzymatic browning (NEB) reaction is one a very important reaction in the food industry that significantlyEnvironmental Engineering, Hubei Minzu University, Enshi, 445000, China, and Beijing Key Laboratory of Flavor Chemistry, BeijingTechnology and Business University, Beijing, 100048, China, Laboratory of Flavor Chemistry, Beijing Technology and BusinessYa Li, Liang Feng and Ai-Nong Yu, School of Chemistry & EnvironmentalEngineering, Hubei Minzu University, Enshi, 445000, ChinaBao-Guo Sun, Beijing Key Laboratory of Flavor Chemistry, BeijingTechnology and Business University, Beijing, 100048, China License.affects the color, flavor, taste and nutritional quality of food [1,2,3]. The non-enzymatic browning (NEB) reaction is one a very important reaction in the food industry that significantly. Technology and Business University, Beijing, 100048, China, Laboratory of Flavor Chemistry, Beijing Technology and Business. The NEB reaction has attracted widespread attention, and extensive related researches have been conducted in the heat treatment of food. ASA is widely found in fresh fruits, vegetables and many other organisms. This compound has a potential carbonyl structure and is usually used as a food additive and an antioxidant to protect against oxidative damage in the food industry. ASA has high biological activity and participates in many metabolic processes [13,14,15]

Methods

Results

Conclusion