次氯酸钠溶液对南瓜表面微生物的杀菌条件探索

Exploration on Bactericidal Conditions of Pumpkin Surface by Sodium Hypochlorite Solution

为延长南瓜的贮藏时间,降低微生物致腐败的影响,采用两因素方差设计,比较不同浓度次氯酸钠溶液、不同浸泡时间条件下南瓜表面的杀菌率,确定最佳有效杀菌浓度和浸泡时间;通过回接侵染试验,从腐败的南瓜中分离纯化致腐败的优势霉菌,验证最佳浓度次氯酸钠及其浸泡时间的杀菌效果。结果表明:有效氯为200 mg/kg的次氯酸钠溶液浸泡10 min是最佳杀菌条件。从腐败南瓜中分离出3株优势腐败霉菌g1、w2、w3,经鉴定分别为黑曲霉(Aspergillus niger)、西瓜蔓枯病菌(Stagonosporopsis cucurbitacearum)、芽枝霉属(Cladosporium);含有效氯200 mg/kg的次氯酸钠溶液浸泡10 min对g1、w2、w3的杀菌率均在99.1%及以上,能有效抑制南瓜表面微生物的生长,可作为延长南瓜贮藏时间的有效的前处理手段。

In order to prolong the storage period of pumpkin and reduce the influence of microbial corruption,a two-factor variance design was used to compare the sterilization rate of pumpkin surface under different concentrations of sodium hypochlorite solution and different soaking time,so as to determine the best effective sterilization concentration and soaking time.Through the back infection experiment,the dominant fungi causing pumpkin corruption were isolated and purified from rotten pumpkin,and the bactericidal effects of best concentration of sodium hypochlorite and its soaking time were verified.The results showed that the best sterilization condition was to soak sodium hypochlorite solution with effective chlorine concentration of 200 mg/kg for 10 min.Three dominant spoilage fungi g1,w2,w3 were isolated from spoilage pumpkin,and identified as Aspergillus niger,Stagonosporopsis cucurbitacearum and Cladosporium,respectively.The sterilizing rate of g1,w2 and w3 was 99.1%or more after soaked in sodium hypochlorite solution with 200 mg/kg effective chlorine for 10 min,which could effectively inhibit the growth of microorganisms on pumpkin surface,and could be used as an effective pretreatment method to prolong the storage time of pumpkin.