低温等离子体在不同时间条件下对黄曲霉孢子灭活作用的研究  

Study on the deactivation of low temperature plasma with different treatment time on Aspergillus flavus spores

作　　者：郁明明 谢岩黎[1] YU Mingming;XIE Yanli(College of Food Science and Engineering,Henan University of Technology,Zhengzhou 450001,China)

机构地区：[1]河南工业大学粮油食品学院,河南郑州450001

出　　处：《河南工业大学学报（自然科学版）》2023年第2期49-55,共7页Journal of Henan University of Technology：Natural Science Edition

基　　金：河南省高校科技创新团队支持计划(20IRTSTHN023)。

摘　　要：黄曲霉孢子能抵抗食品灭菌处理,并产生对动物和人类有毒的黄曲霉毒素。探索在不影响食品品质的条件下使孢子失活,降低真菌毒素污染造成的风险。利用介质阻挡放电产生低温等离子体装置在不同时间(30、60、90 s)条件下处理黄曲霉孢子,研究等离子体对细胞膜完整性和通透性的影响,进行了SEM、细胞内容物含量测定、胞外电导率及细胞外pH值的测定试验。结果表明:黄曲霉孢子在处理30、60、90 s后显示出孢子停止萌发的现象;扫描电镜显示,随着处理时间从30 s延长至90 s,孢子表面发生变形,皱缩更加严重;黄曲霉孢子经等离子体处理30、60、90 s后出现内容物泄漏、pH值下降、电导率上升等现象,细胞膜发生损伤,通透性增加。此外,通过荧光显微镜和荧光分光光度计的分析证实了处理后的黄曲霉菌胞内产生了大量活性氧(ROS),说明等离子体处理造成了黄曲霉的氧化损伤,导致ROS在细胞内积累,这是黄曲霉孢子失活的主要因素之一。总之,介质阻挡放电低温等离子体处理可以在数分钟内使真菌孢子失活。Fungal contamination is a concern of food industry.Aspergillus flavus(A.flavus)spores can resist food sterilization and produce aflatoxin which is toxic to animals and humans.Therefore,it is advisable to explore technologies of inactivating spores and toxins without affecting food quality.In this paper,the spores of A.flavus were treated by a low temperature plasma device produced by dielectric barrier discharge for different time.Firstly,the inhibition effect of plasma on A.flavus spores was studied.Compared with the control group,the inhibition effect of plasma on A.flavus spores was confirmed by inverted microscope and microplate analysis.The mycelial growth and of spore germination were inhibited after 30 s treatment.When the treatment time reached 90 s,A.flavus spores aggregated.It was speculated that A.flavus spores were damaged by oxidative stress.This discovery provides a new idea for the subsequent study on the inactivation mechanism of plasma against A.flavus.The scanning electron microscopy chracterization showed that the spore surface was deformed and shrunk after plasma treatment for 30 s,and the degree of deformation was strengthened with the extension of treatment time.When the treatment time was increased to 90 s,the spore morphology of A.flavus changed significantly compared with the control group,such as depression and shrinkage,and the cell surface tended to be smooth,and the number of membrane proteins decreased.These results showed that plasma treatment changed the morphology of A.flavus spores,and this effect was dose-dependent and increased with treatment time.Therefore,it is of great significance to study the effect of plasma on the cell membrane of A.flavus to explore its antifungal mechanism.Cell membrane permeability plays an important role in maintaining cell microenvironment and normal metabolism.After plasma treatment,A.flavus spores showed leakage of cellular constituent,decrease of pH and increase of conductivity,which indicated that the cell membrane of A.flavus spores was damaged

关 键 词：黄曲霉 低温等离子体 孢子灭活 细胞膜通透性 活性氧 

分 类 号：TS201.3[轻工技术与工程—食品科学]