【作者】 党亚丽；

【导师】 王璋；

【作者基本信息】 江南大学 ， 食品科学， 2009， 博士

【摘要】 随着我国经济和生活水平的提高,人们健康意识的增强,消费者对高质量（不添加任何香料或香辛料）的火腿制品的消费量日渐提高,风味是干腌火腿质量的重要指标之一。研究干腌火腿的特征风味物质,对生产高质量干腌火腿具有很大的理论意义和实用价值。本论文选用中式金华火腿和西式巴马火腿,对它们的特征挥发性风味物质和特征性滋味物质进行鉴定,并采用酶解技术制备两种火腿水不溶物中的呈味肽,研究了呈味肽的构效关系,主要研究内容如下:采用同时蒸馏萃取（SDE）和固相微萃取（SPME）法提取火腿中的挥发性风味物质,用气质联用仪对其进行分析,结果发现,醇、醛、酮、酯、烷烃、含硫及杂环化合物是两种干腌火腿的共有物质。两种方法都能检出火腿的重要香味物质,3-甲基丁醛、戊醛、己醛、庚醛、苯乙醛、2-辛烯醛、壬醛、辛醛、2, 3-辛二酮、乙酸乙酯、1-辛烯-3-醇和癸酸等;金华火腿中醛类和酸类含量比巴马火腿多,而巴马火腿中醛类和烷烃类或醇类的含量比金华火腿多。SPME法检出金华火腿的酸类物质种类和含量比巴马火腿高,而SDE法检出巴马火腿的醇类物质的种类和含量比金华火腿高。分别用SPME法和SDE法提取两种火腿中的挥发性风味物质,用时间强度（OSME）和稀释分析（AEDA）两种GC/O方法鉴定其中的特征挥发性风味物质,发现了金华火腿4种新特征风味物质,（E）-2-辛烯醛、十六醛、辛酸和3-甲基-丁酸乙酯和巴马火腿2种新特征风味物质,十八碳二烯酸乙酯和2, 3-二羟基-十六酸丙酯。金华火腿SDE提取物主要的特征风味是油脂香、肉香、腌制味和焦味;SPME提取物的特征风味主要是腌制味、青草味、果香和焦香。巴马火腿SDE提取物主要的特征风味是油脂香、果香、青草味和腌制味;SPME提取物主要的特征风味是青草味、果香和油脂香。金华火腿和巴马火腿特征风味物质的主要区别在于金华火腿特征风味物质中醛类和杂环化合物类较多,醛类主要是烯醛类,如（E）-2-辛烯醛、（E, E）-2,4-癸二醛、（Z）-2-庚烯醛、（E）-2-己烯醛、（E）-2-癸烯醛、（E）-2-辛烯醛和支链醛类,如2-甲基-丁醛、2-甲基-丙醛、2-甲基-丁醛、（E）-2-十一醛等。此外,金华火腿中含有的杂环化合物的种类较多,如5-戊基-二氢-2（3H）-呋喃酮和3-甲硫丙醛等。而巴马火腿特征风味物质中酯类较多,如十六酸乙酯、十六碳二烯酸甲酯、（Z）-3-十八烯酸乙酯、十六酸-2,3-二羟基-丙酯和亚油酸乙酯等。研究了烹调前后金华火腿中挥发性风味物质的变化。电子鼻测定结果表明不同的加工方式、加工时间对金华火腿的挥发性风味有显著影响。蒸1h、煮1h的火腿和煮2h的火腿汤的风味特征与原火腿接近,而蒸2h、3h,煮2h的火腿和煮1h,3h的火腿汤的风味与原火腿风味差异较大,感官评价也得到相似的结果。经煮制后,金华火腿生成了长链的醛、酸等衍生物。金华火腿烹调前腌制味、油脂香、肉香、清香、酸味更浓,烹调后火腿酸味、清香和腌制味的评分降低,而油脂香、肉香、焦味、烤肉香的评分升高,更具熟火腿浓郁的香味。蒸后火腿的主要气味是肉香、烤肉香和油脂香;煮后火腿的主要气味是肉香、油脂香和腌肉味;煮后火腿汤的主要气味是肉香和焦味。采用酸醇法、温水法、醇法、碱法和沸水法五种方法提取火腿的水溶性呈味物质（WSE）,结果发现温水法提取物中小分子肽的含量和粗肽回收率较高,风味与原火腿的风味最为接近,安全性高,前处理简便,成本较低,适于在规模化制取高档火腿风味料工艺中使用,并适宜火腿WSE中呈味物质的研究。对温水法的提取条件优化后确定的最佳条件为:温度40℃,pH6.0,料水比1: 7。通过单因素试验和响应面试验确定了巴马火腿水不溶物的最佳酶解条件:温度60℃,pH7.34,复合蛋白酶Protamex的添加量3.65%（w/w）,复合风味蛋白酶Flavorzyme的添加量为4.65%（w/w）。此条件下酶解物的粗肽含量为76.55%,相对分子质量主要在200～1,000之间,2～5个氨基酸的小分子肽比例约占93%,且水解物无苦味,滋味评分最高。采用凝胶层析、半制备和分析型RP-HPLC,分离得到七个有呈味活性的组分。它们的氨基酸序列分别为Ala-His-Ser-Val-Arg-Phe-Tyr、Asn-Gly-Lys-Glu-Thr、Leu-Ser- -Glu-Tyr -Pro、Asn-Arg-Thr-Phe、Cys-Cys-Asn-Lys-Ser-Val、Pro-Asp-Leu-Pro-Asn-Thr、Asn-Gly-Lys- Glu-Thr。它们都含有1个带正电荷的氨基酸,主要是Asn,符合鲜味肽的特征。对七个呈味肽合成后研究了它们的呈味特性,发现Ala-His-Ser-Val-Arg-Phe- -Tyr和Asn-Gly-Lys- Glu-Thr具有火腿滋味。此外,Ala,Arg,Glu,Gly,Na⁺,K⁺,Cl^-,PO₄^3-对火腿的特征滋味也有重要贡献。更多还原

【Abstract】 With improvement of the economy and living standards in our country, consumers have become conscious of their health and are now consuming greater quantities of high quality ham product. Flavor is one of the important indexes of dry-cured ham’s quality. The research on characteristic flavor compounds of dry-cured hams can provide theoretical sense and applicational value.Jinhua ham and Parma ham were used to identify the aroma-active compounds and taste-active compounds, and moreover, the taste-active peptide was prepared by enzyme hydrolysis from two hams, the correlation of taste-active peptide’s structure and characteristics were finally studied. Main content of this paper was as following.Volatile compounds from the Jinhua ham and Parma ham by simultaneous distillation extraction （SDE） and solid-phase microextraction （SPME） methods respectively, and identified by the gas chromatography-mass spectrometry. Results showed that the alcohols, aldehydes, ketones, esters, hydrocarbons, sulphur-contained and heterocyclic compounds were the common components. Twelve compounds among them 3-methyl-butanal, pentanal, hexanal, heptanal, benaldehyde, and 2-octenal were all identified by the two techniques. There were more aldehydes and acids but less hydrocarbons and alcohols in Parma ham. Comparing differences in extraction methods, there were more acids and alcohols in Jinhua ham and Parma ham by SPME and SDE respectively.The intention of this research was to characterize the aromatic compounds of the two hams as extracted by SPME and SDE respectively. In Jinhua ham, four new aroma-active compounds were found, （E）-2-octenal、hexadecanal、octanoic acid and 3-methyl- ethyl butyrate, and two new aroma-active compounds were found in Parma ham, octadecadienoic acid ethyl ester and 2,3-dihydroxy-hexadecanoic acid propyl ester. The OSME （a Greek word） showed that the SPME extract could be described as cured, green/grassy, fruity and burnt compared to fatty, meaty, roast, cured and caramel for the SDE one. The Aroma Extract Dilution Analysis （AEDA） suggested that 1) （z）-2-heptenal as the main source of fatty odor for the fully cooked ham; 2) 3-（methylthio）- propanal, 2, 6-dimethyl-pyrazine and 2-pentyl-furan for the meaty odor; 3) 3-（methylthio）-propanal, 2, 6-dimethyl-pyrazine and （E, E）-2, 4-decadienal for the roast odor; and 4) 2-pentyl- furan as the main source of cured odor.The effect of three traditional cooking methods, steaming （B）, boiling （C） and stewed ham soup （S） on the volatiles in Jinhua ham was evaluated which was identified by SPME-GC-MS and the flavor profile detected by electronic nose analysis （EN）. Results from the principal components analysis （PCA） showed A, B1, B2, C1 and C3 had same volatiles, while B3, C2 and S1 , S3; S2 showed negative correlation with A, C1, C3, B1 and B2. Most importantly, many unsaturated hydrocarbons, such as 3-methyl-2-butenal, 2-heptenal were generating by different types of heating. The EN analysis indicated that C2 appeared to have profile similar to the raw ham; however, C3 had different flavor profile from that for S1 and S2. The main source of the difference was that profiles appeared to be high in sulfur-containing content in S1 and S2.The main taste compounds of the water-soluble extract （WSE） of dry-cured ham were extracted with warm water, HCl-ethanol, ethanol, alkaline and boiled water as solvent. Results showed the WSE of Jinhua ham extracted using warm water, had the highest percentage （19.57%） of the peptides with molecular weight of 200-300 Da. Most important it was most similar in taste characteristics to the raw ham during the sensory evaluation; with salty and sweet taste. In addition, the recovery of peptides was high （36.11%）, though the alkaline method was much more effective for extraction （37.05%）, the astringent taste dominated during the sensory evaluation. Otherwise, from the viewpoint of FAAs, we could see they mainly provided the umami taste. Considering the interactions between taste compounds and the aroma compounds, the latter obtained using the five methods were identified and significant differences were noted.The single factor test and response surface analysis was used water insoluble substance of Parma Ham was hydrolyzed. Results indicated that the optimum conditions were reaction temperature 60oC, starting pH 7.45 and the dose of Protamex 2.34% and Flavorzyme 4.17%, and adding two enzymes simultaneously. Under these conditions, crude peptide content was 76.55%, the molecular weight of enzyme-hydrolysate was mainly 200-1,000 and the proportion of small peptide was high about 93%. Moreover, the hydrolysate had the highest scores in the taste of sensory evaluation without any bitterness.Fractions of seven taste-active peptides were obtained by gel filtration chromatography, semi-preparative RP-HPLC chromatography and analytical RP-HPLC chromatography. The amino acid sequences of 7 peptides were gained using MS/MS analysis. It was found that one positive charge amino acid was included in the sequence of peptides, with the highest appearance incidence of Asn, which was in accordance with the umami peptide. They were all synthetic produced and the taste activity was verified. The peptide with the sequence of Ala-His-Ser-Val-Arg-Phe-Tyr and Asn-Gly-Lys-Glu-Thr were verified with the ham taste. In addition, Ala,Arg,Glu,Gly,Na⁺,K⁺,Cl^-,PO₄^3- were also identified to have great contribution on the characteristic taste of ham.更多还原