切割方式对鲜切莴苣品质及抗氧化活性的影响

Effect of Cutting Styles on Quality and Antioxidant Activity of Fresh-Cut Lettuce

研究了不同切割方式对鲜切莴苣在贮藏期间品质及抗氧化活性的影响。将莴苣切成片、1/4片和丝后置于5℃贮藏48 h。结果表明,不同切割方式对菌落总数、色泽、叶绿素和抗坏血酸含量的变化无显著影响,但鲜切加工能显著促进苯丙氨酸解氨酶活力的上升,在贮藏前24 h提高了总酚含量和1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基清除能力,其中切丝处理的酚类物质含量和DPPH自由基清除能力最高。因此,不同切割方式对鲜切莴苣品质无显著影响,但鲜切加工可显著诱导酚类物质的合成,从而提高鲜切莴苣的抗氧化活力。

The effects of different cutting styles on the quality and antioxidant activity of fresh-cut lettuce were investigated. The lettuce was cut into slices, quarter slices and shreds and then stored at 5 ℃ for 48 h. The results showed that cutting styles had no significant effect on total bacterial count, color values, chlorophyll or vitamin C contents. However, the freshcut processing significantly induced the activity of phenylalanine ammonia-lyase and enhanced total phenolic content and DPPH（1,1-diphenyl-2-picrylhydrazyl） free radical scavenging activity during the initial 24 h of storage, with the shreds having the highest total phenolic content and DPPH free radical scavenging activity. These results demonstrated that cutting styles did not have much effect on the quality, but significantly induced the synthesis of phenolic compounds, thereby improving the antioxidant activity of fresh-cut lettuce.