不同发酵方式制备树莓-石榴复合果汁酵素的抗氧化活性研究

Antioxidant activity of Rubus idaeus-Punica granatum compound juice enzyme prepared by different fermentation technologies

以树莓、石榴复合果汁为原料,采用自然发酵、单一添加嗜热链球菌(Streptococcus thermophilus)、单一添加干酪乳杆菌(Lactobacillus casei)及同时添加嗜热链球菌和干酪乳杆菌发酵四种方式制备酵素,并对其发酵过程中的p H值、总酚、总黄酮及抗氧化能力(·OH、O2^-·及DPPH自由基清除率)变化进行研究,以评价不同制备方式对树莓-石榴复合果汁酵素抗氧化活性的影响。结果表明,混菌发酵方式优于单菌发酵和自然发酵方式,能增加树莓-石榴复合果汁酵素中总酚含量、总黄酮含量,并提高其抗氧化能力。混菌发酵72 h时,总酚含量(0.57 mg/m L)、·OH清除率(67%)及O2^-·清除率(54%)最高;发酵60 h时,总黄酮含量(0.41 mg/g)及DPPH自由基清除率(94%)最高;p H值变化最小,利于发酵进行。

The Rubus idaeus-Punica granatum (raspberry-pomegranate) compound juice enzyme was prepared by natural fermentation, with single addition of Streptococcus thermophilus, Lactobacillus casei, respectively and simultaneous addition of S. thermophilus and L. casei. The changes of pH, total phenols, total flavonoids and total antioxidant capacity (·OH, O2^-· and DPPH free radical scavenging rate) during fermentation were studied to evaluate the effect of different preparation methods on the antioxidant activity of the R. idaeus-P. granatum compound juice enzyme. The results showed that the mixed fermentation method was superior to the single fermentation and natural fermentation methods, which could increase total phenols and total flavonoids contents in the R. idaeus-P. granatum compound juice enzyme, and improve antioxidant capacity. The total phenols content (0.57 mg/ml),·OH scavenging rate (67%) and O2^-·scavenging rate (54%) were the highest after mixed fermentation for 72 h;the total flavonoids content (0.41 mg/g) and DPPH free radical scavenging rate (94%) reached the highest after mixed fermentation for 60 h;the change of pH was the smallest, which was favorable for fermentation.