贮藏条件对超高压处理蓝莓汁酚类物质及抗氧化活性的影响

Effects of Storage Condition on Phenolics and Antioxidant Activity of High Hydrostatic Pressure Treated Blueberry Juice

摘要:

以经超高压处理（400 MPa/10 min）的鲜榨蓝莓汁为对象，研究其5周内在4 ℃、25 ℃、37 ℃贮藏条件下总酚、总黄酮、花色苷含量和抗氧化能力的变化。结果表明：随贮藏时间的延长，在以上三个贮藏温度下，总酚含量和抗氧化能力均呈显著下降趋势（p<0.05），总黄酮含量无显著变化，花色苷含量显著下降（p<0.05），且其降解过程符合一级反应动力学模型，其反应的活化能Ea为55.75 kJ/mol；抗氧化能力与总酚和花色苷含量显著相关。4 ℃贮藏条件下抗氧化能力与总黄酮含量无显著相关，25 ℃、37 ℃下则呈负相关。此外颜色分析显示不同储藏温度下蓝莓汁a*值、b*值、C值随贮藏时间的延长上升，L*值下降，37 ℃下贮藏4周后蓝莓汁的色差ΔE>2，已对其感官质量造成影响。由此表明低温短时贮藏有利于保持蓝莓汁中酚类物质含量及抗氧化活性。

Abstract:

The changes of total phenolics content, total flavonoids content, anthocyanins content, and antioxidant activity presented in blueberry juice treated with high hydrostatic pressure (HHP) (400 MPa/10 min) were investigated during storage for 5 weeks at 4 ℃, 25 ℃ and 37 ℃. The results showed that total phenolics content and antioxidant capacity were significantly decreased (p<0.05). In addition, total flavonoid content had less change, while anthocyanins content reduced obviously (p<0.05). The degradation of anthocyanins was followed pseudo-first-order reaction kinetics model with activation energy (Ea) of 55.75 kJ/mol. Total phenol content, anthocyanins content, and antioxidant capacity were highly correlated. No significant correlation existed between flavonoids and antioxidant capacity at 4 ℃, while it was negatively correlated at 25 ℃ and 37 ℃. Moreover, color analysis showed that the blueberry juice under different storage temperatures, had increasing a*, b* and C values with the extension of storage time, but L* value reduced. The chromatic aberration of blueberry juice (ΔE) was more than two after 4 weeks of storage at 37 ℃ which illustrated the quality and sensory of the juice had been influenced. The study indicated that low temperature and short storage time could help preserve phenolics content and the antioxidant activities of blueberry juice.