【作者】 吴古飞；

【导师】 杨爱梅；

【作者基本信息】 兰州理工大学 ， 微生物与生化药学， 2011， 硕士

【摘要】 枸杞鲜果皮薄,含水量、含糖量很高,易发生霉变,极不易保存,因此,市售枸杞产品常是枸杞干果。目前,在我国西北地区枸杞干燥最常用的方法是太阳能干燥装置,该方法发挥了西北地区干旱少雨及日照充足的优势,但其缺点是干燥周期相对较长,尤其是极易受到天气的影响,干燥过程中枸杞霉变的问题十分严重,平均霉变率在20%左右,阴雨天时在50%,甚至达到80%以上。本文结合生产实际,针对防止枸杞霉变进行如下研究。首先,采用微生物学的实验方法,分离鉴定了致枸杞霉变的霉菌主要有细交链格孢（Alternaria alternata）,毛霉（Mucor sp.）,草芽枝霉（Cladosporium herbarnm）,并研究了这3种霉菌的生物学特性,通过感染途径实验证实这3种霉菌能以不同的途径感染枸杞鲜果。其次,通过抑菌环实验筛选了22种防霉剂对这3种霉菌的抑制效果,结果表明:对羟基苯甲酸乙酯及其钠盐、对羟基苯甲酸丙酯钠和过氧化氢对这3种霉菌均有抑制效果,具有较低的最小抑菌浓度。将有效防霉剂按不同比例配制成复合防霉剂,确定对羟基苯甲酸乙酯钠与对羟基苯甲酸丙酯钠的质量比为1:2时,防霉效果较好且相对经济,复合防霉剂对3种霉菌的最小抑菌浓度依次为:0.16%,0.16%,0.08%,考察二氧化氯对干燥大棚的消毒效果,确定二氧化氯浓度达到8mg/L时具有较好防霉变效果。最后,确定了太阳能干燥装置干燥枸杞的最佳防霉变处理工艺:将枸杞鲜果浸入质量分数为3%的Na₂CO₃或一定比例的复合脱蜡剂中1min,然后浸入质量分数为0.16%的复合防霉剂水溶液中约1min,并使二氧化氯浓度达到8mg/L时对大棚内部进行定期消毒。可使枸杞的霉变率降低,提高枸杞品质。更多还原

【Abstract】 The pericarp of Lycium barbarum L. is very flimsy, the fruits content highly moisture and sugar, are moldy easily, and very difficult to save, so the products are often the dried fruits in the market. At present, the installation of solar dryer is the most common method in the northwestern China, the method makes used of the advantages that the weather is dry and little rain, the sunlight is plenitudinous in the regions. But the method has a disadvantage that the drying cycle is long relatively, especially be influenced by the weather. The problem of mildew is very severe in the drying process, the average mildew rate at 20%, in rainy days at 50%, even to 80%. The research combines with the problems of practical production, aiming to prevent fruits mildewing, the contents of the research as following.Firstly, the microbiological experiment methods were used, and three kinds of molds were separated and identified that could cause the fruits mildew, Alternaria alternate, Mucor sp. and Cladosporium herbarnm, and the three kinds of mold were confirmed that they were able to infect the fruits in different ways through the biological property experiment.Secondly, the inhibition effect of twenty-two kinds of antiseptics to the three kinds of molds were studied, through the bacteriostatic experiment and minimum inhibitory concentration experiment. The results showed that ethyl p-hydroxybenzoate, sodium ethyl p-hydroxybenzoate, sodium propyl p-hydroxybenzoate and hydrogen peroxide had antibacterial effect to the three kinds of molds, and the numerical value of minimum inhibitory concentration was lower. The effective antiseptics were confected to different compositions,and a composition that the weight of sodium ethyl p-hydroxybenzoate to the weight of sodium propyl p-hydroxybenzoate equal one to two was confirmed that had a better inhibition effect and lower cost, minimum inhibitory concentration of the composition to the three kinds of molds were respective 0.16%, 0.16%, 0.08%, and the results of simulation cabin experiment showed that chlorine oxide had a better inhibition effect when its concentration up to 8mg/L.Finally, the best process of the installation of solar dryer was confirmed that the fruits were put into 3% solution of Na₂CO₃ or a complex dewaxing agent for 1 minute, and then were put into 0.16% solution of the composition for 1 minute, and the drying cabin was disinfected by 8mg/L chlorine oxide termly. That can reduce the rate of mildew, and improve the quality of fruits.更多还原