橙汁模拟体系非酶褐变产物及评价标准

以橙汁中糖、氨基酸、抗坏血酸、柠檬酸为变量构建不同的非酶褐变模拟体系，通过研究体系贮藏期间3-羟基-2-吡喃酮（3-hydroxy-2-pyrone，3OH2P）、5-羟甲基糠醛（5-hydroxymethylfurfural，5-HMF）、糠醛（furfural，2-F）3 种褐变产物的变化，确定褐变产物的可能来源；通过分析比较褐变度（A420 nm）、褐变指数（browning index，BI）、总色差值（ΔE）3 种非酶褐变评价标准的相关性，确定不同评价标准是否有一致性。结果表明：果糖降解是生成5-HMF的主要途径，3OH2P来源于抗坏血酸的降解，糖能促进2-F的生成；在含糖的模拟体系中，A420 nm、BI、ΔE相互之间均呈显著正相关（P＜0.05），这3 种评价标准具有一致性；然而在不含糖的体系中，A420 nm与BI、ΔE均无显著相关性（P＞0.05），这3 种评价标准存在差异性。

Reaction Products and Evaluation Criteria of Non-Enzymatic Browning in Model Orange Juice

A model solution of orange juice containing sugars, amino acids, ascorbic acid and citric acid was prepared. The
formation of non-enzymatic browning reaction products including 3-hydroxy-2-pyrone（3OH2P), 5-hydroxymethylfurfural
(5-HMF) and furfural (2-F) was examined during storage, and meanwhile the correlation analysis of browning evaluation
criteria including absorbance value at 420 nm (A420 nm), browning index (BI) and total color difference(ΔE) were also
measured. The results indicated that 5-HMF and 3OH2P mainly derived from fructose and ascorbic acid, respectively, while
the formation of 2-F was stimulated by sugars. Significant positive correlations (P < 0.05) were found among A420 nm, BI and
ΔE in system containing sugars, but no significant relationship (P > 0.05) was found in system lacking sugars.