槲皮素是一种类黄酮,存在于许多类型的水果和蔬菜中,在所研究的pH范围(6.0-8.0)内稳定不超过4.5h,即使在黑暗中4°C。在更高的温度下,降解/氧化过程要快得多。简单但有效的前脂质体包封用于保护槲皮素免受环境条件如pH。通过这种方法,65至90%的纯槲皮素和富含槲皮素的洋葱提取物在>60天后在有利于其氧化的条件(pH7.4)下保存。此外,包封的槲皮素使脉冲紫外光诱导的脂质过氧化降低>50%。槲皮素与脂质的质量比为1:100(w/w),脂质体在溶液中保持完整6个月。槲皮素在脂质双层中同时保护不饱和脂质免受过氧化。
Quercetin is a flavonoid that occurs in many types of fruit and vegetables and is stable for no longer than 4.5 h in the investigated pH range (6.0-8.0), even at 4 °C in the dark. At higher temperatures, the degradation/oxidation process is much faster. Simple but effective proliposomal encapsulation was used to protect the quercetin from environmental conditions such as pH. With this approach, 65 to 90% of pure quercetin and quercetin-rich onion extract was kept after >60 days under conditions that favoured its oxidation (pH 7.4). In addition, the encapsulated quercetin decreases the lipid peroxidation induced by pulsed UV light by >50%. At a mass ratio of 1:100 quercetin to lipids (w/w), the liposomes remained intact in solutions for six months. Quercetin in lipid bilayers simultaneously protects the unsaturated lipids from peroxidation.