【作者】 单继航；

【导师】 许学勤；

【作者基本信息】 江南大学 ， 食品科学， 2010， 硕士

【摘要】 海蜇是一种名贵的海洋产品,广泛分布在我国的南海、东海、黄海和渤海四大海域,我国是世界上最早食用海蜇的国家。目前市场上海蜇产品主要有盐渍和即食两种,盐渍海蜇保存方便且保存时间长,但食用前需脱盐；即食海蜇食用方便,但保藏时间短且对保藏条件有一定的限制。即食海蜇在储藏过程中会受到各种因素的影响,这些因素会对海蜇丝的品质,如重量、结构、持水能力、微生物和质构等产生重要的影响,从而影响其商品价值。本文研究了影响即食海蜇在储藏过程中品质变化的一些主要因素,其中包括：温度、加工卫生条件、产品包装方法和醋酸处理过程；并利用几种矿物质盐离子对即食海蜇丝的质构进行了改善,对改善海蜇品质的工艺进行了探索,从而对即食海蜇产品的生产加工提供理论指导。首先研究了影响即食海蜇品质变化的一些主要因素,及这些因素对即食海蜇产生影响的原因,结果表明：温度、不同包装方式和加工的卫生条件对海蜇产品品质变化起着重要的作用,在即食海蜇丝中单独添加防腐剂山梨酸钾效果不明显。通过真空封口包装、塑料薄膜袋和玻璃瓶常压封口包装和加水常压封口几种不同包装方法对海蜇品质影响试验表明,将海蜇进行瓶装,并加入一定量水(以刚没过海蜇丝体为准)可以在很大程度上降低脱盐海蜇丝的失重率,同样保藏条件下品质维持最好；通过不同操作卫生条件的比较,发现脱盐和包装两个步骤对终产品中的微生物数量起着重要的作用,严格控制这两个步骤的卫生条件可以有效降低产品中微生物数量。脱盐用水和包装用水的卫生指标起着重要的作用,如果这两种水没有经过灭菌处理,海蜇丝品质即可在随后的保藏过程中加速被破坏,大大缩短保质期。考虑到生产中对水进行彻底杀菌将会消耗大量能源并造成热源污染,因此对防腐剂和低浓度醋酸浸泡这两种抑菌方式进行了比较。结果显示,如果没有经过除菌处理,包装后直接常温保藏,单独加入防腐剂并不能起到很好的抑菌作用；脱盐后海蜇丝利用0.1%醋酸浸泡5min,可以大大减少微生物数量,并且在25℃及以下温度,海蜇产品保藏6个月仍具有较好品质。因此,在即食海蜇加工过程中用醋酸溶液进行浸泡可以很好地起到除菌效果。其次研究了几种凝固剂对脱盐海蜇丝质构的改善作用,通过单因素和正交试验得出,KCl、MgCL2和CaCl2可以在一定程度上改善海蜇的质构,并且MgCl2起着最主要的作用,最终三种盐的添加比例为：KCl (0.1%), MgCl2 (0.4%), CaCl2 (0.05%)。在即食海蜇添加一定比例的上述盐溶液可以在一定程度上改善储藏期间海蜇丝的品质,使其保持较好的硬度和颜色。更多还原

【Abstract】 Jellyfish which is wide distributed in the East China Sea,South China Sea,the Huanghai sea and Nanhai sea is a precious ocean food.China is the first country to use it as food in the world.There are two kinds of jellyfish food in the market now:salting and ready-to-eat. Each kind product has its advantage and disadvantage.Salting jellyfish can be stored for a long time-approximately 1-2 years,but it is not convenient to eat.Ready-to-eat jellyfish can be easily eaten,but it cannot be stored for a long time.Many kinds of factors will affect the qualities of ready-to-eat jellyfish such as weight,structure,water holding capacity,colour and mouthfeel etc.These main factors that affecting the qualities of ready-to-eat jellyfish are studied in this paper.The factors includ temperature,sanitary condition,package methods,acetic acid and mineral solution.At first, the main factors that affecting the qualities of ready-to-eat jellyfish and how does the factor affect the qualities are studied.The results show that temperature,different package methods and sanitary condition are the main factors that affecting the qualities of ready-to-eat jellyfish.Three kinds of package method in processing ready-to-eat jellyfish are studied, including plastic film bag that is sealed at vaccum condition,plastic film bag and glass bottle that are sealed at ordinary pressure.Results show that desalted jellyfish that packaged by glass bottle and added some water has the best quality and the lowest weight loss.The analysis of critical point of processing show that desalting and package are the most important procedure in process.Exercising strict control over this two procedures can efficiently reduce the number of microorganism in product. When the cfu of desalting water and water that adding to the package exceed 150cfu/ml, the desalted jellyfish cannot be stored for a long time and deteriorated by microorganism.Adding perservative patassium sorbate only cannot efficiently reduce the number of microorganism.Desalted jellyfish that soaked by 0.1% acetic acid for 5min has low number of cfu and good quality during storage.Desalted jellyfish that proceed by this method can be stored for 6 monthes at or below 25℃.At last,three kinds of mineral salt for improving the structure of jellyfish are studied.The result of single factor experiment and orthogonal experiment show that KCl,MgCl2 and CaCl2 can improving the structure of jellyfish and MgCl2 has the main effect among three salt.The additive amount are KC1 (0.1%), MgCl2 (0.4%), CaCl2 (0.05%).The qualities such as colour,structure,brittleness can be improved by adding these kinds of mineral salt.更多还原