低强度UV-A光循环辐照对4℃下鲜切菠菜品质及抗氧化能力的影响

The effect of cyclic irradiation of low intensity UV-A on quality and antioxidant capacity of fresh-cut spinach at 4℃

为探究长波紫外线UV-A光照对鲜切菠菜保鲜效果的影响,从6组初筛试验中选出最佳单日照射总量,其中在420 s(1.764 kJ/m ^2)的照射条件下,可将鲜切菠菜货架期延长至10 d,因此分别设置间隔24 h(A组)、8 h(B组)、4 h(C组)3组试验处理鲜切菠菜,随后测定总菌、水分变化、抗氧化酶等理化指标,研究不同照射频率对鲜切菠菜的影响。结果表明:在6 d内,A组保鲜效果最好,保鲜效果依次为A组>B组>C组。在6 d后,B组贮藏第12天时各营养指标含量、抗氧化酶活性最高,这表明B组更利于菠菜的长时间贮存,其次为C组。UV-A光照能够显著提升鲜切菠菜的抗氧化能力从而延缓衰老,可根据不同的保鲜目的,选择不同的照射方式,为商超物流、贮运等过程中鲜切菠菜保鲜工艺的改良提供了新的发展方向。

This paper was conducted to investigate the irradiation effects of UV-A light on the fresh-cut spinach.Based on primary screening experiment,420s(1.764 kJ/m ^2)was chosen as the best daily irradiation dose with the shelf life extended to 10 d.The fresh-cut spinach was irradiated for 24h(group A),8h(group B)and 4h(group C)by UV-A.Physicochemical indexes including total viable counts,changes of water content and activities of antioxidant enzymes were determined to explore the effects of different irradiation frequencies on fresh-cut spinach.The results showed that the preservation effect was arranged in descending order of group A>group B>group C in the first 6 days.After 6 days,the content of each nutrient index and activities of antioxidant enzymes were the highest in group B on the 12th day,which indicated that group B was more conducive to long-term storage of spinach,followed by group C.UV-A light can significantly improve the antioxidant capacity of fresh-cut spinach,and different irradiation methods can be selected according to different fresh-keeping purposes,which provides a new improvement on the fresh-cut spinach preservation for supermarkets in the process of logistics and transportation.