超声波协同萌发处理富集黑青稞多酚的工艺优化及其酚酸组成分析

研究以黑青稞为原料,采用单因素实验及Box-Behnken响应曲面法优化超声波协同萌发处理富集黑青稞多酚的最佳工艺参数,并在此基础上比较超声波协同萌发处理前后黑青稞的酚酸组成差异。结果表明,超声协同萌发富集黑青稞多酚的最佳工艺为：超声预处理功率350 W、超声处理温度30℃、超声处理时间25 min、萌发时间64 h,在此条件下黑青稞的总酚含量（688.84±5.30 mg/100 g DW）最高。酚酸物质结果表明,萌发处理显著提高了主要酚酸物质中原儿茶酸（游离和结合）、对羟基苯甲酸（游离）、香草酸（游离）、咖啡酸（游离）、丁香酸（游离）、对香豆酸（游离）的含量,分别提高为未处理组的14.49、1.54、4.73、1.67、1.46、3.73、11.49倍;而超声波协同萌发处理显著增加了尿黑酸（结合）、咖啡酸（结合）、对香豆酸（结合）、阿魏酸（结合）的含量,分别提高为未处理组的39.24、1.09、1.60、1.13倍。抗氧活性结果表明,经萌发处理及超声波协同萌发处理的黑青稞其DPPH·清除能力均显著增加,分别提高为未处理组的11.66%、21.55%。综上分析,萌发处理及超声协同萌发...

Process Optimization of Ultrasonic Co-germination for Enriching Black Highland Barley Polyphenols and Analysis of Phenolic Acid Composition

In this study, the single factor experiment and the Box-Behnken response surface method were employed to find the optimum process parameters of ultrasonic co-germination on enriching black highland barley polyphenols, and the differences in phenolic acid composition were compared before and after ultrasonic co-germination treatment on the basis. The results showed that the optimal process parameters were obtained with ultrasonic pretreatment power 350 W at 30 ℃ for 25 min, and germination time 64 h. The total phenolic content of black highland barley (688.84±5.30 mg/100 g DW) was the highest under the conditions. The results for phenolic acids showed that the contents of protocatechuic acid (free and bound), p-hydroxybenzoic acid (free), vanillic acid (free), caffeic acid (free), syringic acid (free) and p-coumaric acid (free) were increased significantly in the main phenolic acids, which was 14.49, 1.54, 4.73, 1.67, 1.46, 3.73 and 11.49 times of the untreated group respectively after germination treatment. The contents of homogentisic acid (bound), caffeic acid (bound), p-coumaric acid (bound) and ferulic acid (bound) were increased significantly after ultrasonic co-germination treatment, which was 39.24, 1.09, 1.60 and 1.13 times of the untreated group respectively. The DPPH-scavenging capacity treated with germination and ultrasonic co-germination increased significantly by 11.66% and 21.55%, respectively. In summary, both treatments were effective means for enriching phenolic substances and improving antioxidant activity in black highland barley, and suitable enrichment methods could be selected according to different phenolic acid monomers and forms. This study could provide the reference for further improving the utilization value of black highland barley.