热处理对红肉火龙果色素稳定性及其清除羟基自由基能力的影响

Effects of Heat Treatment on Stability and Hydroxyl Radical Scavenging Activity of Red Pitaya Pigment

摘要:

本文研究了异维生素C、柠檬酸、六偏磷酸钠对火龙果色素热稳定性的影响及热处理后火龙果色素清除羟基自由基能力的变化。研究发现异维生素C和柠檬酸对保护火龙果色素在热处理时的色素损失方面作用有限，而六偏磷酸钠能有效的抑制热处理造成的色素损失。pH 3~6时，β-花青素（Betacyanins）清除羟基自由基的能力比较稳定，而pH 2时下降。90 ℃热处理10 min使色素清除羟基自由基能力下降50%以上，且pH越低，清除羟基自由基的能力越弱。β-花青素的稳定性与其清除羟基自由基能力之间有直接的相关性。

Abstract:

The effects of isoascorbic acid, citric acid, and sodium hexametaphosphate on heat stability and hydroxyl radical scavenging activity of red pitaya pigment were studied and the results showed that isoascorbic acid and citric acid were not efficient in protecting pigment from heat degrading, while sodium hexametaphosphate can effectively inhibit pigment from decoloring during heat treatment. The hydroxyl radical scavenging activity of betacyanins was relative stable at pH 3.0~6.0, but decreases at pH 2.0. Heat treatment of the pigment at 90℃for 10 min remarkably reduced its radical scavenging activity up to 50% and this reducing effect increased with decreasing pH. The results also showed that there was some dependence between the heat degrading stability and hydroxyl radical scavenging activity of the pigment.