微生物发酵剂对风鸭品质特性的影响

【作者】 许慧卿；

【导师】 汪志君；

【作者基本信息】 扬州大学 ， 生物化学与分子生物学， 2008， 硕士

【摘要】 风鸭是中国重要的传统自然发酵肉制品,深受消费者的喜爱。但存在生产周期长、季节性强、质量不稳定等缺点,限制了风鸭产品的发展。本文以米酒乳杆菌(Lactobacillus sake)、木糖葡萄球菌(Staphylococcus xylosus)和德巴利汉逊氏酵母(Dabaryomyces hansenii)三种发酵肉制品中常见的微生物为发酵剂加工风鸭,对发酵风鸭的品质特性进行研究。分析了单菌株发酵风鸭蛋白质的含量变化,结果表明:三株菌均有降解蛋白质的能力,并且木糖葡萄球菌>米酒乳杆菌>德巴利汉逊氏酵母。微生物发酵处理的总氮量变化不明显,但非蛋白氮和游离氨基酸总量均有增加,其中木糖葡球菌处理后其含量最高,分别为CK的1.9倍和1.73倍;德巴利汉逊氏酵母处理后必需氨基酸和甜味氨基酸含量均为CK的1.1倍;米酒乳杆菌处理后产鲜氨基酸含量为CK的1.4倍,且有效改善氨基酸的组成。单菌株发酵对风鸭中脂类物质影响的研究表明,磷脂的含量显著下降,德巴利汉逊氏酵母处理后下降最多,为CK的0.87;游离脂肪酸大幅度增加,其中米酒乳杆菌和德巴利汉逊氏酵母处理增加较多,为CK的1.6倍。游离脂肪酸的种类均发生变化。饱和脂肪酸的含量比未发酵前减少,略高于CK;不饱和脂肪酸均高于CK,其中单不饱和脂肪酸德巴利汉逊氏酵母处理最高,为CK的1.67倍;多不饱和脂肪酸米酒乳杆菌处理最高,为CK的1.6倍。处理后,游离脂肪酸均为棕榈酸、油酸和亚油酸。总体来看,米酒乳杆菌与德巴利汉逊氏酵母分解脂类物质生成游离脂肪酸的能力较强,而木糖葡萄球菌有较强的分解游离脂肪酸的能力。微生物发酵剂对风鸭脂类物质的影响是显著的。采用顶空固相微萃取和气质联用对单菌株发酵风鸭肌肉中的挥发性风味化合物种类与相对含量进行了分析。检测到风鸭风味化合物117种,包括酸10种、醛20种、醇17种、酮14种、酯类27种、烃20种、酚类2种和杂环7种。其中米酒乳杆菌、木糖葡萄球菌和德巴利汉逊氏酵母处理中分别检测到69、69和73种风味化合物,对照中检测到64种风味化合物。米酒乳杆菌处理的酸含量高,木糖葡萄球菌处理的醛含量高,德巴利汉逊氏酵母处理的醇和酯含量高,对照中烃类含量高。微生物对风鸭挥发性风味化合物的种类和含量均产生了明显的影响。三种菌联合发酵研究表明,游离氨基酸含量低于木糖葡萄球菌处理,高于米酒乳杆菌处理和德巴利汉逊氏酵母处理,游离脂肪酸则相反。复合微生物发酵剂使用后产品中风味物质增加,风味变佳。更多还原

【Abstract】 Dry-cured duck is a kind of Chinese traditional fermented meat product that is favored by consumer.There are such questions to be improved as outdated processing, long processing time, the instability in quality, singleness of product variety, and the control of quality, etc. According to this research, effects of Lactobacillus sake, Staphylococcus xylosus and Dabaryomyces hansenii on biochemistry quality of dry-salted duck were studied.Analysis of protein content changes of a single strain fermented dry-cured duck, results showed that three strains had the capacity of proteolysis, and S. xylosus> L. sake >D.hansenii. Contents of total nitrogen (TN) were not significant different, but non-protein nitrogen (NPN) and total free amino acids (FAA) were both increased, which sample by S. xylosus the highest level and 1.9 and 1.73 times as CK respectively. Contents of essential amino acid and FAA with sweet were the highest level in sample by D.hansenii and were 1.1 times as CK respectively; contents of FAA with relish in sample by L. sake was the highest level and was 1.4 times as CK and effectively improve the composition of amino acids.Analysis of effects of single strain fermentation on dry-cured duck, results showed that contents of phospholopid decreased significantly, which sample by D.hansenii the lowest level and 0.87 as CK. Substantial increased in free fatty acids, of which samples by L. sake and D.hansenii the increased more for the 1.6 times as CK. The types of FFA were all changing. Contents of saturated fatty acid(SFA) was decreased than that in unfermentation, slightly higher than CK; contents of unsaturated fatty acid(USFA) were higher than CK, which contents of single-unsaturated fatty acids (SUFA) the sample by D.hansenii the highest, 16.7 times as CK and contents of Poly-unsaturated fatty acids(PUFA) the sample by L. sake the highest, 1.6 times as CK. After production, the main types of FFA were palmitic acid, oleic acid and linoleic acid.In conclusion, L. sake and D.hansenii had a stronger ability to decomposite lipid to generate FFA, and S. xylosus had a stronger ability to decomposite FFA. The effects of the microorganism starter culture on liqid of dry-cured duck were significant.Headspace solid phase microextraction combined with gas chromatography-mass spectrometry (HS-SPME/ GC-MS) were used to identify the kinds and amount of volatile flavor compounds of dry-cured ducks. One hundred and seventeen flavor compounds were identified which include ten kind of acids, twenty kinds of aldehydes, seventeen kinds of alcohols, fourteen kinds of ketones, twenty-seven kinds of esters, twenty kinds of hydrocarbons, two kinds of phenols and seven kinds of heterocyclic. There were sixty-nine kinds of compounds in sample by L.sake, sixty-nine kinds of compounds in sample by S.xylosus, seventy-three kinds of compounds by sample D.hansenii and sixty-four kinds of compounds in CK. More acids compounds in sample by L.sake, more aldehydes compounds in sample by S.xylosus , more alcohols and esters compounds in sample by D.hansenii and more hydrocarbons compounds were in CK. It can be said that effects of microorganism on kinds and contents of flavor compounds of dry-cured duck were significant.Study on fermentation of the three joint, the results showed that it had lower contents of FAA than that in sample by S.xylosus, higher than that in sample by L.sake and D.hansenii, proportion of contents of FFA among three strains was reverse to that of FAA. The use of mixed starter culture made volatile flavor compounds of dry-cured ducks increased and flavor good.更多还原