【作者】 张伟伟；

【导师】 陆剑锋；

【作者基本信息】 合肥工业大学 ， 水产品加工及贮藏工程， 2010， 硕士

【摘要】 斑点叉尾鮰原产于北美洲,是一种具有重要商业价值的淡水鱼,受到了世界广大消费者的青睐。近年来,我国斑点叉尾鮰的养殖生产发展迅速,2007年产量已达14万吨左右。斑点叉尾鮰肉味鲜美,没有肌间刺,主要用于生产鮰鱼片。斑点叉尾鮰内脏是鱼片加工的主要副产物之一,其粗蛋白含量为8.58%,粗脂肪含量达到28.14%,因此,斑点叉尾鮰内脏不仅是良好的蛋白质资源,也是重要的鱼油资源。本文主要研究了鱼油的提取方法,然后对粗鱼油进行精炼,最后研究了抗氧化剂的添加对鱼油氧化稳定性的影响。以斑点叉尾鮰内脏为原料,鱼油提取率为主要指标,研究了钾法和水酶法两种鱼油提取方法,结果表明,钾法提取鱼油的最佳工艺条件为：初始pH 7.0,料液比1：1.5,水解温度65℃,水解时间35 min,氯化钾用量4%,盐析时间10 min,该条件下鱼油的提取率达到82.09%。水酶法提取鱼油的最佳工艺条件为：初始pH 7.5,液料比为1：1,加酶量3500 U/g,酶解时间0.5 h,酶解温度55℃,在此条件下的鱼油提取率为80.94%。在两种提取方法的最佳工艺条件下,鱼油的提取率相差很小,而比较两种提油方法得到的粗鱼油的理化指标,发现水酶法提油工艺得到的粗鱼油品质总体较好,因此选择水酶法作为最终的提油工艺。通过脱胶、脱酸、脱色、脱腥工艺处理后,精炼鱼油澄清透明,略显淡黄色,并有淡淡的鱼腥味,除了碘价低于我国水产行业行业标准SC/T3502-2000精制鱼油的一级标准外,其它鱼油指标均符合精制鱼油的一级标准。脂肪酸分析表明,斑点叉尾鮰内脏油主要是由C14-C22,共19种脂肪酸组成,其中饱和脂肪酸6种,单不饱和脂肪酸5种,多不饱和脂肪酸8种。精炼鱼油中的饱和脂肪酸含量为20.37%,单不饱和脂肪酸为65.20%,多不饱和脂肪酸为13.66%。以过氧化值为指标,采用Schaal烘箱法研究了D-异抗坏血酸钠、迷迭香、茶多酚对斑点叉尾鮰精炼鱼油的抗氧化效果,结果表明当抗氧化剂的添加浓度均为0.02%时,抗氧化性能为茶多酚>迷迭香>D-异抗坏血酸钠,茶多酚的抗氧化效果与其浓度呈剂量效应关系。添加维生素C和柠檬酸对茶多酚的抗氧化效果均有协同增效作用,其中维生素C对茶多酚抗氧化能力的增效大于柠檬酸。更多还原

【Abstract】 Channel catfish(Ictalurus punctatus), originally found in North America, is one of the most commercially import freshwater fish species well-accepted by consumers all over the world. In recent years, Channel catfish has been widely cultured in China. The statistic data shows that in 2007, the estimated yield of channel catfish was at least 140,000 tonnes in China. Being delicious in taste and lack of inter-muscular bones, the most of the channel catfish processed in China is sold as fresh or frozen fillets. The viscera of channel catfish are one of the primary by-products of filleting processing. The amount of protein content and lipid in the viscera was up to 8.58% and 28.14%, respectively. Thus it can be seen that the viscera are not only fish oil resource but also protein resource. This paper was mainly concerned with the extraction method of fish oil from the viscera of channel catfish, then the crude fish oil was refined, at last, effects of antioxidant on the stablility of the refined fish oil were systematically studied.Crude fish oil was extracted in this study from the viscera of channel catfish by a modified potassium hydroxide hydrolysis method and aqueous enzymatic extraction method, which was evaluated with the index of extraction ratio of fish oil. The two different extraction methods were compared and analysed. Based on the technology of Potassium-method, the results showed that the optimal extraction conditions were that:initial hydrolysis pH 7.0, ratio of viscera to water 1:1.5, hydrolysis temperature 65℃, hydrolysis time 35 min, the amount of potassium chloride 4%, the salt out time 10 min. The extraction ratio of fish oil was up to 82.09% under optimal conditions. The optimum parameters of aqueous enzymatic extraction method were as follows:initial hydrolysis pH 7.5, ratio of viscera to water 1:1, amount of papain 3500 U/g, hydrolysis time 0.5 h, hydrolysis temperature 55℃. Under these conditions, the extraction ratio of fish oil was as much as 80.94%. The extraction ratios of crude fish oil, which was made by the optimum conditions of two methods, were almost the same. According to the physicochemical indices of rude fish oil, it can be believed that the quality of crude fish oil gained by aqueous enzymatic extraction method were better than that of crude fish oil gained by Potassium-method. Therefore, aqueous enzymatic extraction method was chosen as ultimate fish oil extraction process.The crude fish oil was refined by degumming, neutralizing, bleaching and deodorizing. The refined fish oil was yellowish and transparent with very light fishlike smell. The physicochemical indices of crude fish oil were determined, which reached to the fist-grade of SC/T 3502-2000 criterion of aquatic industry of refined fish oil except the iodine value. The compositions and contents of fatty acid in the refined fish oil were analyzed by gas chromatography-mass spectrometry. The results showed that there were mainly 19 kings of fatty acid including C14-C22 in refined fish oil, in which there were 6 kinds of saturated fatty acids,5 kinds of single unsaturated fatty acids, and 8 kinds of polyunsaturated fatty acids. The content of saturated fatty acids, single unsaturated fatty acids and polyunsaturated fatty acids were 20.37%,65.20%, and 13.66% respectively.By using the peroxide value as an index, the antioxidant effect of sodium D-isoascorbate、tea polyphenols and rosemary on refined fish oil was studied by Schaal oven-storage test. The results demonstrated that, the capability order of antioxidation is:tea polyphenols> rosemary>D-isoascorbate when the antioxidants amount added accounting for 0.02% of the oil. The antioxidant effect of tea polyphenols increased with the enhancement of concentration. No matter whether citric acid or vitamin C added as the accessory, the antioxidant effect of tea polyphenols was improved, and Vitamin C exhibited more remarkable synergistic antioxidation effect than citric acid.更多还原