不同预冷方式对西兰花货架期品质的影响

Effect of Different Precooling Methods on Shelf Life Quality of Broccoli

本文研究了不同预冷方式对西兰花货架期品质的影响。将三组西兰花分别做如下三种预冷处理:冷库预冷(对照)、冰预冷、冷水预冷。西兰花中心品温度降至(1±1)℃后,将西兰花从箱中取出后将西兰花放入温度为(20±1)℃的库中贮藏。取降至(1±1)℃的西兰花作为初值,之后每24 h取一次样,用于各种指标的测定。测定结果表明:与冷库预冷比较,冰预冷和冷水预冷处理可以有效抑制西兰花黄化,保持西兰花的色泽和良好的感官品质;提高了西兰花VC含量、叶绿素和硫代葡萄糖苷含量,贮藏至4 d,冰预冷和冷水预冷处理西兰花的VC含量要比CK处理分别高出15.6%和39.2%,叶绿素含量分别是CK组的1.87倍和2.44倍,硫代葡萄糖苷的含量仍能达到0.71 mg/g;抑制了西兰花电导率和丙二醛(MDA)含量的上升;提高了西兰花抗坏血酸过氧化物酶(APX)、超氧化物岐化酶(CAT)和过氧化物酶(POD)的活性,其中冷水预冷的西兰花POD活性变化最为显著,保持在一个很高的水平,清除了西兰花体内的H2O2和过氧化物、促进了抗氧化系统中的物质,增强了西兰花的抗氧化能力。冰预冷和冷水预冷处理可提高西兰花感官品质,延缓西兰花衰老,延长货架期2~3 d。

The effect of different precooling methods on shelf life quality of broccoli was studied in this paper.The three groups of broccoli were precooled as follows:Cold storage precooling(control),ice precooling,cold water precooling.After the temperature of broccoli centropiece decreased to(1±1)℃,the broccoli was taken out of the box and stored in the warehouse with the temperature of(20±1)℃.The broccoli reduced to(1±1)℃was taken as the initial value,and then samples were taken every 24 h for the determination of various indicators.The results showed that compared with cold storage precooling,ice precooling and cold water precooling could effectively inhibit the yellowing of broccoli and maintain its color and good sensory quality.The contents of VC,chlorophyll and glucosinolates in broccoli was improved and stored for 4 d.The VC contents of broccoli precooled by ice and precooled by cold water was 15.6%and 39.2%higher than that of CK treatment,respectively.The chlorophyll content was 1.87 times and 2.44 times higher than that of CK group,respectively.The increasing of conductivity and MDA contents in broccoli was inhibited.The activity of broccoli APX,CAT and POD were improved.Among them,the activity of cold-water precooled broccoli was the most significant and kept at a high level,which cleared H2O2 and peroxide in the body of broccoli,promoted substances in the antioxidant system,and enhanced the antioxidant capacity of broccoli.Ice precooling and cold water precooling could improve the sensory quality of broccoli,delay the aging of broccoli,and extend the shelf life for 2~3 d.