【作者】 代敏；

【导师】 霍贵成；

【作者基本信息】 东北农业大学 ， 食品科学， 2006， 硕士

【摘要】 目前我国在保鲜乳风味方面的研究较少,尤其对挥发性风味物质缺乏全面的了解。对保鲜乳的挥发性风味物质进行分析,不仅可以了解风味物质的化学组成给消费者和生产者一个客观科学的乳制品风味物质的介绍,而且还可以为乳制品生产企业提高保鲜乳制品风味质量提供依据。本研究通过使用先进的分离方法和分析仪器对保鲜乳中的挥发性风味物质进行分析检测,探求这些挥发性风味物质的强度,然后通过调整鲜牛乳中蛋白质、脂肪、乳糖等挥发性风味前体物质的含量调控保鲜乳中的挥发性风味物质,达到改善保鲜乳风味的目的。本试验采用静态顶空法、固相微萃取法、吹扫-捕集法,三种方法分离提取鲜牛乳中挥发性风味成分,并用气相色谱-质谱(GC-MS)联用仪对其进行分析测定。三种方法提取的挥发性风味物质的定性、定量结果表明吹扫-捕集法为最佳的分离提取方法,并且在选定的色谱条件下,各物质能够获得较好的分离,各物质的回收率均达到90%以上,表明该技术准确可靠,可以用于保鲜乳中挥发性风味物质的分析。应用吹扫-捕集-GC-MS联用仪对我国三个大型乳制品企业:企业1、企业2、企业3生产的保鲜乳中的挥发性风味物质进行了定性、定量分析。分析结果显示三个品牌的保鲜乳中挥发性风味化合物的种类基本一致,包括醛类、酮类、内酯类、含氮化合物、含硫化合物。巴氏杀菌乳检出物中均以醛类物质最多。三种巴氏杀菌乳检出的挥发性成分总数之间不存在明显差异,分别为10种、8种、9种。三种巴氏杀菌乳中挥发性风味成分的定量结果显示,同一挥发性风味化合物在三种巴氏杀菌乳中含量无大的差异,检出的挥发性风味成分的含量在0.02-5.0μg/L之间。UHT乳检出物中均以酮类物质最多。三种UHT乳检出的挥发性成分总数之间不存在明显差异,分别为10种、9种、9种。从定量结果来看,三种UHT乳中检出的挥发性风味成分的含量在0.05-5μg/L。利用风味物质强度对保鲜乳中挥发性风味物质的强度进行了评定。巴氏杀菌乳和UHT乳的风味不存在大的差异,但由于巴氏杀菌乳和UHT乳中检出的挥发性风味化合物的含量较低,其风味强度值大多低于0.5,因此对风味贡献很小,导致两类保鲜乳的风味质量较差。只有由二甲基硫酮和粪臭素产生的蒸煮味和焦糖味,其它挥发性化合物不具有或只有很微弱的风味。试验对保鲜乳挥发性风味物质的调控方法进行了探索。对鲜乳中蛋白质、脂肪、乳糖的含量对保鲜乳挥发性风味物质的影响进行了分析,分析结果表明调整鲜牛乳中蛋白质、脂肪、乳糖等风味前体物的含量对保鲜乳中检出的挥发性风味物质的总数和含量都有很大的影响,可以明显改善保鲜乳的风味。试验还确定了生产具有良好风味的保鲜乳所使用的原料乳中蛋白质、脂肪、乳糖的含量分别为:4.8%、5.0%、4.0%。更多还原

【Abstract】 In current time there is only little research on the flavor of Fresh milk in China, especially there is no complete understanding on the volatile flavoring elements. To analyze the volatile flavoring elements in Fresh milk will provide not only understanding of chemical composition of flavoring elements as a scientific and impersonal representation of milk flavoring element to consumers and manufacturers, but also basis for milk manufacturing enterprises to enhance the quality of Fresh milk flavor. This research employs advanced extraction method and analysis instruments to detect and analyze the volatile flavoring elements in Fresh milk, study the intensity of those volatile flavoring elements, then control the volatile flavoring elements by changing the content of volatile flavour precusor, such as protein, fat and lactose in milk, to reach the objective of enhanced flavor of Fresh milk.This research uses SH, SPME and PTto extract the volatile flavoring elements in Fresh milk, and makes analysis with GC-MS. The qualitative and quantitative results of extracted volatile flavoring elements indicates that PT is the bet extraction method, and under selected chromatogram condition, various elements get relatively good separation with the recycle rate of more than 90%, which indicates that this technology is accurate and reliable, suiTab. for analysis of volatile flavoring elements in Fresh milk.Qualitative and quantitative analysis was made on Fresh milk manufactured by 3 major milk products enterprises: enterprise1, enterprise2 and enterprise3, using GC-MS. The analysis results indicate that the category of volatile flavoring elements in the 3 brands of milk is basically the same, including aldehydes, ketones, lactones, N compounds, and sulphur compounds. Aldehydes is the most detected elements in pasteurized milk, and the detected compounds are in accordance with foreign research results. There is no significant difference between the detected volatile elements in 3 types of pasteurized milk, which is 10, 8 and 9 types respectively. The quantitative results of volatile flavoring elements in 3 brands of pasteurized milk indicate that for the same volatile flavoring element, there is no significant difference between the contents in the 3 brands of pasteurized milk, the detected content of volatile flavoring element is in the range of 0.02-5.0μg/L. Ketones is the most detected element in UHT milk, and the detected compounds are in accordance with foreign research results. There is no significant difference between the total volatile elements detected from 3 brands of UHT milk. In quantitative results, the content of volatile flavoring elements detected in 3 brands更多还原