pH值对L-抗坏血酸与L-脯氨酸/L-丙氨酸Maillard反应产物抗氧化活性的影响

Antioxidative Activity of Maillard Reaction Products From a L-Ascorbic Acid and L-Proline/L-Alanine Model System as In?uenced by pH

摘要:

在L-抗坏血酸-L-脯氨酸/L-丙氨酸模型体系中研究了pH值对Maillard反应产物的抗氧化活性的影响。Maillard反应产物通过控制不同初始pH值（pH=4.0、5.0、6.0、7.0、8.0）在140 ℃下加热搅拌2h的条件下制备，并以还原力、1,1-二苯基-2-苦基偕腙肼自由基（DPPH）清除能力和Fe2 螯合能力为指标对其产物抗氧化活性进行分析评价。结果表明：产物的还原力、DPPH自由基清除能力在pH=5时达到最大，Fe2 螯合能力随着pH值的增大而增大，而且Maillard反应产物的还原力与在294nm处的紫外吸光度密切相关。

Abstract:

The objective of this investigation was to study the effect of pH on antioxidative activity of Maillard reaction products (MRPs) from the L-ascorbic acid(ASA)–L-proline(Pro)/L-alanine(Ala) model systems. MRPs were prepared by heating the solution containing ASA and Pro/Ala adjusted to different pHs (4.0, 5.0, 6.0, 7.0 and 8.0) at 140℃ for 2 h. The antioxidative activity of MRPs was evaluated by reducing power, 1,1-diphenyl-2-picryl-hydrazyl(DPPH) radical-scavenging activity and Fe2 chelating activity. The results indicated that reducing power and DPPH radical-scavenging activity reached a maximum with initial pH5. An increase in Fe2 chelating activity of MRPs derived from ASA-Lys/Met model systems was observed as the initial pH increased. Moreover, reducing power of MRPs correlated well the UV-absorbance at 294nm.