半连续液态深层发酵红枣醋及其抗氧化活性

Semi-continuous submerged fermentation of jujube vinegar and its antioxidant activity

以红枣酒为原料,采用巴氏醋酸杆菌(Acetobacter pasteurianus)进行半连续液态深层发酵,研究不同接种量和溶氧量对醋酸发酵的影响,并对发酵过程中有机酸的变化和红枣醋的抗氧化活性进行分析。结果表明,采用半连续液态深层发酵酿制红枣醋,在溶氧量10%、分割留种量50%的条件下,发酵周期可缩短到14.5~15.5 h。红枣酒醋酸发酵初期奎宁酸和苹果酸含量均增加1倍以上,但在后续的快速产酸阶段又逐渐降低至发酵前的水平,乳酸在发酵初期被转化,最终降低至43.55 mg/100 m L。红枣酒经过醋酸菌发酵后,其中的总酚和总黄酮含量以及1,1-二苯基-2-苦肼基(DPPH)自由基清除能力、Fe3+还原能力、2,2’-联氮双(3-乙基苯并噻唑啉-6-磺酸)(ABTS)自由基清除能力分别提高16.59%、42.98%、24.66%、27.87%和38.07%,因此可作为增强红枣产品功能特性的加工手段。

Using jujube wine as raw material and Acetobacter pasteurianus as fermentation strains,Semi-continuous submerged fermentation was conducted and the effects of different inoculum and dissolved oxygen on acetic acid fermentation were studied.The changes of organic acids and antioxidant activity of jujube vinegar in the fermentation process were analyzed.The results showed that jujube vinegar was brewed with semi-continuous submerged fermentation,the fermentation cycle could be shortened to 14.5-15.5 h at the optimum dissolved oxygen amount of 10%and splitting inoculation amount of 50%by using semi-continuous submerged fermentation.In the early stage of acetic acid fermentation,the contents of quinic acid and malic acid were more than double at the early stage of acetic acid fermentation,but then decreased to the level of pre-fermentation during fast acid production stage,while the lactic acid was converted at the initial stage and declined to 43.55 mg/100 ml.The content of total phenolics,flavonoids as well as antioxidant capacity assayed by DPPH,ferric reducing antioxidant power,ABTS were increased by 16.59%,42.98%,24.66%,27.87%and 38.07%,respectively.Therefore,acetic acid fermentation could be a processing method to enhance the functional characteristics of jujube products.