为了明确苹果酵素自然发酵过程中理化指标和抗氧化活性的变化规律，阐明苹果酵素保健功能机理，研究了苹果酵素的可溶性固形物含量、pH、总酸含量、乙醇含量、DPPH自由基、羟基自由基、超氧阴离子自由基、ABTS自由基清除能力的动态变化。结果表明，随着发酵时间的延长，可溶性固形物含量和pH逐渐降低，发酵90 d时，可溶性固形物含量降为4.5 °Brix，pH下降至3.06，比发酵初期分别降低了70%和32%；总酸含量逐渐升高，发酵90 d时增加至42.9 g/L，较发酵初期增加了98%；乙醇含量先升高后降低，发酵90 d时为 1.0 g/L，符合QB/T5323-2018中有关乙醇的规定。发酵75～90 d时的抗氧化活性较好，DPPH自由基和羟基自由基在发酵90 d时的清除率分别为86.16%和79.03%，较发酵初期升高了44.5%、45.53%；超氧阴离子自由基和ABTS自由基的清除率发酵75 d时达到峰值，分别为65.06%和69.04%，较发酵初期分别升高了39.12%和46.47%。

In order to study the changes of physicochemical indexs and antioxidant activities of Apple Jiaosu during natural fermentation process and clarify the health function mechanism of malenzyme， the dynamic changes of the soluble solids content， pH， total acid content， ethanol content， DPPH free radicals， hydroxyl free radicals， superoxide anion free radicals， and ABTS free radicals were investigated. The results showed that the soluble solid content and pH value decreased gradually with the extension of fermentation time. After 90 days of fermentation， the soluble solid content dropped to 4.5 °Brix and the pH dropped to 3.06， which were reduced by 70% and 32% respectively compared with the initial stage of fermentation. The total acid content gradually increased， increased to 42.9 g/L after 90 days， and increased 98%. the ethanol content first increased and then decreased， it was achieved to 1.0 g/L， after 90 days， and complied with regulations of QB/T5323-2018. The antioxidant activities were reached the better in fermentation to 75～90 days. The free radical scavenging rates of DPPH and hydroxyl were reached to 86.16% and 79.03% after 90 days， and increased 44.5% and 45.53%， respectively. The superoxide anion and ABTS were peaked at fermentation 75 days(65.06% and 69.04%， respectively)， which were increased 39.12% and 46.47%. The study would provide some theoretical basis for further elucidating the health function mechanism and comprehensive development of Apple Jiaosu.

TQ925；S661.1

现代农业产业技术体系建设专项资金资助项目(CARS-27)；甘肃省林业科技计划项目(2017kj051)。