低温等离子体处理对华容大叶芥菜贮藏品质的影响

Effects of cold plasma treatment on storage quality of Huarong large leaf Brassica juncea

中文关键词:  芥菜  低温等离子体  抑菌  保鲜

英文关键词:Brassica juncea  Low-temperature plasma  Microbial inactivation  Fresh-keeping

中文摘要:

      目的 探究低温等离子体(cold plasma, CP)对华容芥菜的保鲜适用性。方法 采用不同工作电压的CP对芥菜进行处理，测定处理后芥菜的pH、还原糖含量、维生素C含量、菌落总数及过氧化物(peroxide,POD)酶活性。结果 随着放电电压的升高，芥菜的pH呈下降趋势，还原糖和维生素C含量则先上升后下降。色差实验中，芥菜的a*值和ΔE值随放电电压升高而上升，b*值和L*值随放电电压升高而逐渐下降。CP处理对芥菜抑菌作用随电压升高而加强，贮藏期间处理组的菌落总数显著低于对照组(P<0.05)，第8 d对照组的菌落总数为7.27 lg(CFU/g)，30 kV的处理组菌落总数为6.15 lg(CFU/g)。贮藏期POD酶活性呈先升后降的趋势，第4 d各组芥菜的POD酶活性达到最大值，其中放电电压为30 kV的处理组POD酶活性最高为84.56 U/(min·g)。结论 适当的CP处理能有效抑制微生物生长，延长芥菜的保鲜时间，30 kV电压的CP处理更适用于新鲜芥菜的保鲜贮藏。

英文摘要:

      Objective To explore the applicability of cold plasma treatment for the preservation of Huarong Brassica juncea. Methods Brassica juncea was treated with cold plasma of different working voltages. The pH, reducing sugar content, vitamin C content, total bacterial count, and peroxide (POD) enzyme activity of processed mustard were measured. Results As the discharge voltage increased, the pH of Brassica juncea showed a downward trend, while the content of reducing sugars and vitamin C first increased and then decreased. In the color difference experiment, the a* and ΔE values of Brassica juncea increased with the increasing discharge voltage, while the b* and L* value gradually decreased with the increasing discharge voltage. The antibacterial effect of cold plasma treatment on Brassica juncea increased with the increase of voltage. During the storage period, the total bacterial count of the treatment group was significantly lower than that of the control group (P<0.05). On the 8th day, the total bacterial count of the control group was 7.27 lg(CFU/g), and the total bacterial count of the 30 kV treatment group was 6.15 lg(CFU/g). The POD enzyme activity showed a trend of first increasing and then decreasing. On the 4th day, the POD enzyme activity of each group of Brassica juncea reached its maximum value, with the highest POD enzyme activity observed in the treatment group with a discharge voltage of 30 kV [84.56 U/(min g)]. Conclusion Appropriate cold plasma treatment can effectively inhibit microbial growth and prolong the preservation time of mustard, cold plasma treatment at a voltage of 30 kV is more suitable for the preservation and storage of fresh Brassica juncea.