碧螺春老叶多酚对桃果实保鲜效果研究

Study of polyphenol from Biluochun(Camellia sinensis(L.)O.Ktze.)old leaves on peach fruit preservation

以‘白凤’水蜜桃为试材,研究碧螺春老叶茶多酚对其保鲜效果的影响。通过实验确定茶多酚粗提液保鲜的最佳应用质量浓度(1.25 mg/mL),再分别用1.25 mg/mL老叶多酚提取液、1.25 mg/mL老叶多酚提取液+0.1%溶菌酶浸泡桃果实10 min,以去离子水浸泡作为对照,在室温下[(25±2)℃]贮藏6 d。通过测定失重率变化,超氧化物歧化酶(superoxide dismutase,SOD)、过氧化氢酶(catalase,CAT)、过氧化物酶(peroxidase,POD)活性变化,总酚、黄酮、花青素含量变化以及桃果实中多酚对DPPH自由基和羟自由基清除能力的变化,研究茶多酚提取液对桃果实保鲜效果的影响。实验结果表明,茶多酚处理能激活桃果实SOD、CAT、POD的活性,提高了总酚、花青素和黄酮含量,同时增强DPPH自由基和羟自由基清除能力,有效提高桃果实的抗氧化能力。此外,茶多酚和溶菌酶混合使用能显著提高CAT和POD活性,提高羟自由基清除能力,并且抑制失重的进行,保鲜效果更佳。

In this study,the polyphenols from Biluochun(Camellia sinensis(L.)O.Ktze.)tea old leaves were extracted and the optimal application concentration(1.25 mg/mL)was determined.Taking‘Baifeng’peach as experimental material,immerged in 1.25 mg/mL phenolic extract and 1.25 mg/mL phenolic extract+0.1%lysozyme for 10 min,and then stored at room temperature[(25±1)℃]for 6 d,respectively.Fruit soaked with deionized water at the same time was taken as control.The changes in weight loss,superoxide dismutase(SOD),catalase(CAT),and peroxidase(POD)activities,total phenols,flavonoids,anthocyanins content,and the changes of DPPH free radicals and hydroxyl radical scavenging ability were determined.Results showed that polyphenols from Biluochun could activate the activities of SOD,CAT,and POD,elevate the contents of total phenols,anthocyanins and flavonoids,and enhance the scavenging capacity of DPPH free radicals and·OH.In addition,polyphenols and lysozyme treatment could effectively improve the activities of CAT and POD,enhance·OH scavenging activity,inhibit the progress of weightlessness,and shows a better fresh-keeping effect.