采用Box-Behnken设计优化玫瑰花酵素发酵工艺及其抗氧化活性的测定

本研究以玫瑰干花瓣为主要原料，采用复合乳酸菌发酵，优化玫瑰花酵素发酵工艺技术。以发酵时间、初始pH、接种量、发酵温度为考察因素，以SOD（超氧化歧化酶）酶活力及总酚含量作为评价指标，采用响应面优化结合Box-Behnken设计试验获得最佳发酵工艺条件。此外，研究还利用DPPH（1, 1-二苯基-2-三硝基苯肼）、ABTS（2, 2'-联氮-双-3-乙基苯并噻唑啉-6-磺酸）和FRAP（铁离子还原法）法检测玫瑰花酵素液发酵前后的体外抗氧化活性，并测定了玫瑰花酵素液发酵前后的SOD酶活力、总酚含量、黄酮含量、花色苷含量、pH和可滴定酸等指标。结果表明，玫瑰花酵素液发酵最佳工艺条件为:发酵时间68 h，初始 pH 5.4，接种量1 g，发酵温度32 ℃。该条件下测得玫瑰花酵素液SOD酶活力为132.07 U/mL，总酚含量为6.28 mg/mL，总黄酮含量为3.48 mg/mL，花色苷含量为5.64 mg/100 mL，可滴定酸为2.82 g/100 g，较发酵之前均有较大的提高。当发酵前后玫瑰酵素液、8 mg/mL Vc体积分数为0.45%时，DPPH自由基清除率分别为73.32%、83.70%、35.05%，ABTS自由基清除率分别为82.18%、92.74%、52.82%，FRAP值分别为0.25、0.28、0.115。DPPH、ABTS、FRAP三种不同的抗氧化方法结果均表明玫瑰酵素液发酵后的抗氧化能力最强。

Fermentation Technology Optimization of Rose Flower Enzyme Using Box-Behnken Design and Its Antioxidant Activity Determination

In this study, dried rose petals were used as the main raw material, and compound lactic acid bacteria were used for fermentation to optimize the fermentation technology of rose flower enzymes. Taking fermentation time, initial pH, inoculum amount, and fermentation temperature as investigation factors, SOD (superoxide dismutase) enzyme activity and total phenol content as evaluation indicators, response surface optimization combined with Box-Behnken design experiment to obtain the best fermentation process conditions. In addition, the research also used DPPH (1, 1-diphenyl-2-trinitrophenylhydrazine), ABTS (2, 2'-diazo-bis-3-ethylbenzothiazolin-6-sulfonic acid) and FRAP (ferric ion reduction method) method to detect the in vitro antioxidant activity of rose flower enzymes before and after fermentation, and to determine the SOD enzyme activity, total phenol content, flavonoids content, anthocyanin content, pH and titratable acid. The results showed that the optimal process conditions for the fermentation of rose flower enzyme liquid were: Fermentation time 68 h, initial pH5.4, inoculation amount 1 g, and fermentation temperature 32 ℃. Under these conditions, the SOD enzyme activity of the rose flower enzyme solution was 132.07 U/mL, the total phenol content was 6.28 mg/mL, the total flavonoid content was 3.48 mg/mL, the anthocyanin content was 5.64 mg/100 mL, and the titratable acid was 2.82 g/100 g, which was a greater improvement than before fermentation. When the rose enzyme liquid before and after fermentation and 8 mg/mL Vc volume fraction were 0.45%, the DPPH free radical scavenging rates were 73.32%, 83.70%, 35.05%, and the ABTS free radical scavenging rates were 82.18%, 92.74%, 52.82%, respectively. The FRAP values were 0.25, 0.28, and 0.115, respectively. The results of three different antioxidant methods, DPPH, ABTS, and FRAP, all showedthat rose enzyme liquid hadthe strongest antioxidant capacity after fermentation.