光照和湿度对西兰花硫苷代谢及生物活性物质的影响

Effect of fluorescence irradiation and relative humidity on the glucosinolate metabolism and contents of bioactive substance in fresh-cut broccoli

为探索可有效提升鲜切西兰花生物活性成分的光照及湿度条件,首先在超市货架低温[(13±1)℃]条件下,研究了不同光照[光密度5~8、25~35、75~85μmol/(m^(2)·s)]联合不同湿度(50%~60%、70%~80%、90%~100%)条件对鲜切西兰花的保鲜效果。通过分析表型、感官评分、色泽、总硫代葡萄糖苷(硫苷)和总异硫氰酸酯(isothiocyanate,ITC)的含量,筛选出光密度25~35μmol/(m^(2)·s)协同湿度70%~80%条件可有效提升西兰花品质。然后,以此条件处理鲜切西兰花,以超市实际销售环境[光密度:5~8μmol/(m^(2)·s);湿度:50%~60%]为对照组,研究光照和湿度对西兰花硫苷代谢及生物活性物质的影响。结果表明,光密度25~35μmol/(m^(2)·s)协同湿度70%~80%条件可有效保持鲜切西兰花中主要的硫苷物质含量,同时保持较高的黑芥子酶活性和ITC含量;此外,该条件下的西兰花花球中总酚、花色苷、叶绿素及类胡萝卜素含量较高。因此,光密度25~35μmol/(m^(2)·s)协同湿度70%~80%条件可有效保持鲜切西兰花品质,并维持其组织硫苷等生物活性物质含量,为其贮藏和销售提供理论及技术支持。

The aim of this study was to explore the condition of fluorescence irradiation and relative humidity(RH)that were beneficial for promoting the bioactive substance content of fresh-cut broccoli.Firstly,the effect of different conditions of fluorescence irradiation[optical density:5-8,25-35,75-85μmol/(m^(2)·s)]along with different RH(50%-60%,70%-80%,90%-100%)on the phenotype,sensory score,color,and the contents of total glucosinolate and isothiocyanate(ITC)of fresh-cut broccoli were investigated.By analyzing the results of these indexes,the condition of fluorescence irradiation with an optical density at 25-35μmol/(m^(2)·s)and RH at 70%-80%were selected for the following experiment.Secondly,the fresh-cut broccoli was stored under the selected environment,and the actual condition of supermarket shelf[optical density:5-8μmol/(m^(2)·s),RH:50%-60%]was used as control.The effects of fluorescence irradiation and RH on the glucosinolate metabolism and contents of bioactive substance in fresh-cut broccoli were studied.The results showed that the treatment of fluorescence irradiation with an optical density at 25-35μmol/(m^(2)·s)together with RH at 70%-80%significantly enhanced the main glucosinolates,myrosinase activity and ITC.What’s more,the sample in this selected condition of fluorescence irradiation and RH displayed higher contents of total phenols,anthocyanin,chlorophyll and carotenoid than those of control.Therefore,the suitable condition of fluorescence irradiation[optical density:25-35μmol/(m^(2)·s)]together with RH(70%-80%)could maintain the quality and bioactive substance of fresh-cut broccoli,which can provide theoretical and technical support for the storage and sale of broccoli.