米渣生酱油具有明显的抗氧化活性.采用还原力、对1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-pierylhydrazyl,DPPH)自由基清除能力、金属螯合能力和抗脂质过氧化能力等体外抗氧化活性为评价指标,探究了发酵温度与米渣生酱油的抗氧化活性的相关性,并利用Folin-Ciocalteu法、高效液相色谱(High Performance Liquid Chromatography,HPLC)法等对生酱油中总酚、5-羟甲基糠醛(5-hydroxymet hylfurfural,5-HMF)等抗氧化活性成分进行分析,以阐明发酵温度对米渣生酱油中抗氧化活性成分的影响规律,从而阐释其抗氧化机制,并应用于猪肉保鲜试验.结果表明,米渣生酱油的还原能力、金属螯合能力以及抗脂质过氧化能力均随发酵温度的升高而增强,而对DPPH自由基清除能力顺序为50℃＞20℃＞35℃;抗氧化活性成分的变化规律与抗氧化活性变化规律相同,均以50℃发酵的米渣生酱油含量最高,其中50℃发酵时5-HMF含量显著高于35℃和20℃,对米渣酱油抗氧化活性有重要贡献.综合分析,在一定温度范围内,高温发酵有利于提高米渣生酱油的抗氧化能力,并通过抗氧化增强食品的保鲜效果.

Raw sauce from rice dreg protein (RDP) has significant antioxidant activity.Antioxidant activity of RDP raw sauce was evaluated by detecting reducing power,DPPH radical scavenging activity,metal ions chelation ability and anti-lipid peroxidation ability.Correlation between antioxidant activity and fermentation temperature of RDP raw sauce was examined.Some antioxidants such as total phenols and 5-HMF were analyzed by Folin-Ciocalteu and HPLC to clarify influence of fermentation temperature on antioxidants in RDP raw sauce,and then different RDP raw sauce fermented under different temperature were applied to preserve pork.The results showed that reducing power,metal ions chelation and anti-lipid peroxidation ability of RDP raw sauce increased with increasing of fermentation temperature,but DPPH radical scavenging activity from high to low at different temperature was 50 ℃ ＞ 20 ℃ ＞ 35 ℃.Contents of antioxidants kept the same tendency width antioxidant activity,namely,the content of antioxidants in RDP raw sauce fermented under 50 ℃ was the highest.Wherein the content of 5-HMF at 50 ℃ was significantly higher than those at 35 ℃ and 20 ℃,so it could be an important contributor to antioxidant activity of RDP raw sauce.It could be concluded that high temperature fermentation was helpful for improving antioxidant activity of RDP raw sauce,and enhancing food preservation effect due to its antioxidant activity.