宣威火腿与金华火腿中游离脂肪酸组成比较分析

以两年宣威火腿和金华火腿为对象,采用气相色谱-质谱联用法(GC-MS)分别对宣威火腿和金华火腿的皮下和肌内脂肪中游离脂肪酸的组成进行分析。结果表明:宣威火腿和金华火腿的肌内脂肪和皮下脂肪中均检测出22种游离脂肪酸,含量较高的脂肪酸为棕榈酸(C16:0)、硬脂酸(C18:0)、油酸(C18:1n9c)与亚油酸(C18:2n6c),且不同火腿及不同部位间的脂肪酸组成含量存在明显差异;金华火腿肌内及皮下脂肪中总游离脂肪酸含量分别为29.24、102.68 μg/mg,分别比宣威火腿高34.58%(p<0.05)、29.09%(p>0.05);宣威火腿和金华火腿肌内脂肪中饱和脂肪酸含量高于不饱和脂肪酸含量,皮下脂肪中不饱和脂肪酸含量高于饱和脂肪酸含量。金华火腿肌内、皮下游离脂肪酸含量均高于宣威火腿相应部位游离脂肪酸含量。     

金华火腿生产过程中脂质水解特性研究

60只重量为6.2～6.9 kg的原料腿按传统工艺加工金华火腿.分别于原料腿、盐后、晒后、成熟中期、成熟结束、后熟1和后熟2七个工艺点随机取5只腿的股二头肌为样品,分析总脂肪、甘油酯、磷酯、游离脂肪酸和相关指标的变化.结果显示：生产过程中磷脂的变化较大,约有66.67%的磷酯发生了水解.相关性分析发现：磷酯和甘油酯含量与游离脂肪酸含量之间的R2分别为0.91和0.67,磷酯是脂类物质中最主要的风味前体物质.生产过程中总游离脂肪酸含量呈上升趋势,饱和脂肪酸和单不饱和脂肪酸的相对含量提高,多不饱和脂肪酸的相对含量下降,其中亚油酸的含量下降最明显,为4.48%.亚油酸可能是氧化形成风味成分的主要脂肪酸.     

金华火腿中肌间脂肪和皮下脂肪的脂肪酸分析

提取成熟金华火腿中的肌间脂肪和皮下脂肪 ,分离并测定了其中甘油酯、磷脂和游离脂肪酸的含量 ,并对其脂肪酸组成进行了分析 ,结果表明 :肌间脂肪含量为 12. 4 % ,甘油酯、磷脂和游离脂肪酸分别占 77. 3%、11 .2 %和 10 . 9% ;皮下脂肪含量为 90 .7% ,相应的 3部分分别占 88.7%、0 . 2 %和 10 .4 %。肌间脂肪和皮下脂肪的脂肪酸都以C16:0 、C18:1、C18:2 为主要成分。甘油酯里单不饱和脂肪酸的含量都远远高于其在磷脂和游离脂肪酸中的含量 ,而磷脂里多不饱和脂肪酸的含量明显高于其在甘油酯和游离脂肪酸中的含量。     

金华火腿加工过程中内源脂肪酶活力变化特点研究

以浙江兰溪两头乌杂交猪后腿为原料,按传统工艺加工金华火腿。分别在原料、腌制结束、晒腿结束、成熟中期、成熟结束、后熟-1和后熟-2七个工艺点随机取5条腿的股二头肌为样品,分别测定中性脂肪酶、酸性脂肪酶的活力变化,以及测定pH5.8时脂肪酶综合活力的变化;同时,利用响应曲面法研究温度、盐含量、硝酸盐含量、亚硝酸盐含量对脂肪酶活力的影响,并利用所得回归方程预测金华火腿加工过程中脂肪酶的实际表现活力。结果表明,加工过程中,脂肪酶活力持续降低,在后熟-1工艺点,酸性脂肪酶和中性脂肪酶活力残留分别是8.16%和3.0%,至后熟-2已测不到酶活;温度、盐含量及其交互项是脂肪酶活力的显著影响因子(P<0.05),硝酸盐和亚硝酸盐含量对脂肪酶活力影响不显著(P>0.05)。加工过程中,预测的脂肪酶实际表现活力在成熟中期工艺点之前低于酸性脂肪酶及中性脂肪酶的潜在活力,之后则高于潜在活力,其变化规律与酸性和中性脂肪酶完全不同。     

利用帕尔玛火腿生产线生产金华火腿工艺初探

金华火腿是世界著名的干腌火腿之一,历史悠长,但目前仍以手工操作为主,产量为400万只/年。帕尔玛火腿生产原理虽与金华火腿近似,但自20世纪50年代开始实行机械化生产,目前产量可达4 000万只/年。将金华火腿传统工艺进行改良,其中上盐腌制次数由原来的5~6次,改为2次,并在2次腌制结束后都进行洗腿风干工艺,同时利用引进的帕尔玛火腿生产设备生产金华火腿,得到的火腿成品优质率提高了20%,含盐量降低了2%。     

金华火腿的加工工艺技术

火腿是肉制品中的主要产品,中外都有制作。尤其是我国的火腿闻名世界,早在清朝末年已远销南洋和日本等地。其中金华火腿最负盛名,因其独特的“色、香、味、形”曾荣获1917年巴拿马国际博览会金奖,近年来更是畅销海内外。金华火腿选用金华地区两头乌猪为原料,在选形及加工技术方     

应用响应曲面法研究金华火腿生产过程中磷脂酶的变化

取 6 0条杂交猪后腿作原料按传统金华火腿生产工艺进行生产 ,分别在原料、盐后、晒后、成熟中期、成熟后期、后熟 (1)、后熟 (2 )工艺段随机取 5条腿的股二头肌作为样品测定潜在的磷脂酶活力 ,结果显示潜在的磷脂酶活力在生产过程中不断下降 ,原料中酶活为 3 0 5 ,到后熟 (1)酶活为 0 . 16 ,在后熟 (2 )已测不到酶活。利用响应曲面法研究磷脂酶在生产过程中实际酶活的变化情况并建立酶活变化数学模型 ,结果表明 ,温度和盐含量是影响磷脂酶活力的显著因子 ,通过模型预测 ,生产过程原料中的实际酶活为 0. 2 1,盐后为 0 . 13,之后酶活不断提高 ,到成熟后期达最高 ,为 0 . 4 1,之后再开始下降。     

金华火腿新工艺的研究

报告金华火腿工艺流程、操作方法和工艺要点     

金华火腿加工过程中肌肉肌内脂的水解变化研究

研究了金华火腿股二头肌 (bicepsfemoris)肌内脂肪在加工过程中不同时期的水解变化情况。肌内脂使用氯仿 甲醇溶液提取 ,采用固相萃取法将中性脂 (主要为甘油脂 )、游离脂肪酸和磷脂分离 ,用毛细管气相色谱分别分析甘油脂、游离脂肪酸和磷脂脂肪酸的种类与比例。通过比较不同时期样品的色谱结果 ,发现在金华火腿原料中磷脂脂肪酸的不饱和脂肪酸百分含量较高 ,尤其是多不饱和脂肪酸的含量高达 4 9 2 2 %。且在金华火腿成熟过程中 ,磷脂水解作用显著 ,而甘油脂脂肪酸百分比例比较稳定 ,说明甘油脂水解作用相对较弱。     

Lipolysis in dry-cured ham: Influence of salt content and processing conditions

Fatty acid composition of neutral lipids (NLs), polar lipids (PLs) and free fatty acids (FFA) from the intramuscular fat of Semimembranosus and Biceps femoris muscles was analysed in 46 Iberian dry-cured hams processed with different amounts of salt (6% high salt batch – HS vs. 3% low salt batch – LS w/w) and different processing systems (traditional – T vs. modified – M).

Total amounts of saturated (SFA), monounsaturated (MUFA) and polyunsaturated (PUFA) fatty acids in NLs decreased in similar proportions during processing of the hams as well as SFA, MUFA and PUFA in the PL fraction, whereas the amounts of SFA, MUFA and PUFA of FFAs significantly increased in Semimembranosus and Biceps femoris muscles. The amount of total fatty acids (TFA), from NLs and PLs, decreased in both muscles throughout the processing. Such a decline was more intense in HS hams than in LS ones, which could be a sign of a promoting effect of sodium chloride on lipolysis. However, the increase in FFA content throughout processing was not more intense in HS hams. Processing conditions studied in this work did not affect the changes in the fatty acid content of each fraction.     

Changes in flavor compounds of dry-cured Chinese Jinhua ham during processing

Sixty experimental Jinhua hams were processed by a traditional method using green hams from local Liangtouwu cross-bred pigs. Samples of Biceps femoris were taken from five hams randomly at each of the key stages of production, i.e., green ham, end of salting, end of sun-drying, middle of loft-aging, end of loft-aging, post-aging-1 and post-aging-2. Analysis of flavor compounds showed 89 compounds at the green ham stage and at the end of salting, 90 at the end of sun-drying, 91 at the middle of loft-aging, 96 at the end of loft-aging, 93 at the post-age-1 and 94 at the post-age-2. The flavor compounds could be clustered in the following chemical families: alkanes and alkenes, aromatic hydrocarbons, alcohols, aldehydes, ketones, carboxylic acids, esters, oxygenous heterocycle compounds, nitrogenous compounds, sulphur compounds, chloride compounds, amides, and terpenes. During processing, the concentrations of aldehydes and carboxylic acids increased; while the concentrations of alcohols, ketones, alkanes, alkenes, aromatic and cyclic hydrocarbons decreased. Sulphur compounds and pyrazines were formed and increased continuously during processing. In the final Jinhua ham, the contents of aldehydes, carboxylic acids, alcohols and ketones were 45.07%, 18.39%, 13.93% and 9.00% of the total flavor substances, respectively. The first principal component was a group dominated by five unbranched aldehydes; the second principal component was a group dominated by five branched and unbranched alcohols, two branched ketones, toluene, hexane and 4-nitrophthalamide. The two principal components explained 90.6% of the total flavor variance in Jinhua ham.     

金华火腿现代化生产过程中脂质及内源酶的变化特点

考察在控温控湿的现代化生产中,金华火腿脂质的变化情况.以期为优化工艺提供理论基础.取预腌、腌制结束、风干中期、风干结束、成熟1、成熟2、成熟3和后熟阶段的金华火腿的股二头肌部位的样品,分别测定样品中脂肪酶活力、磷脂酶活力、酸价和TBA值.结果显示,在整个生产过程中,脂肪酶活力不断下降,在成熟1之前的下降速率要明显快于之后的阶段;酸价分别从预腌时期1.695 mg KOH/g样品上升到后熟阶段的4.623 mg KOH/g样品;而TBA值开始上升,在风干阶段出现最大值,而后下降,但下降变化不明显.与传统工艺相比,各指标的变化上并没有太大的区别,但在生产的时间上大大缩短了.     

羊肉火腿加工过程中蛋白质的降解

对羊肉火腿加工过程中蛋白质的降解变化进行了研究。结果表明,总氮的含量在加工过程中先降低后升高,非蛋白氮含量和蛋白质水解指数在加工过程中持续增加;通过SDS-PAGE图谱分析,肌浆蛋白和肌原纤维蛋白均发生了降解,其中肌浆蛋白的降解主要发生在腌制期和发酵中期,肌原纤维蛋白则是在腌制期和发酵初期;各种游离氨基酸含量随着加工工艺的进行呈现不同程度增加,其中大部分游离氨基酸含量变化最显著的时期是在发酵初期和中期。     

Microstructural changes in Teruel dry-cured ham during processing

Dry-cured ham, "Protected Designation of Origin (PDO)" Teruel, is a high quality meat product processed using a traditional dry-curing procedure. The objective of this paper was to study the microstructure of the Biceps femoris and Semimembranosus muscles during "PDO Teruel" dry-cured ham processing using electron microscopy techniques (Cryo-SEM, SEM and TEM). The Semimembranosus and Biceps femoris muscles from raw ham show the typical structure of muscle tissue in meat. The muscle fibres appear firmly attached to one another by the endomysial connective tissue; the myofibrils inside the cells are strongly attached to each other and to the sarcolemma. In raw ham, the typical structural elements that constitute the sarcomere can be observed by TEM. Important microstructural changes are observed following salting; reflected in the fact that the Z-disks inside the myofibrils are no longer in line and there is important degradation of the cell membranes in this stage. At the end of the process, an accumulation of solutes, which could be products from proteolysis occurring mainly in the last stage of ripening, could be observed in both muscles. Thus the proteolysis and dehydratation phenomena that take place during "PDO Teruel" dry-cured ham processing occur at an ultrastructural level, and this is the basis to produce a product with the sensory features appreciated by consumers.     

Changes in proteins during Teruel dry-cured ham processing

The aim of this work was to investigate the degradation of the water-soluble and myofibrillar proteins during the production of "PDO Teruel" cured ham using SDS-PAGE, and measurement of proteolytic activities (cathepsins B+L, cathepsin L, cathepsin D), as factors that influence the sensory characteristics of this product. This paper contributes to the specific characterisation of a product included in the European Union list of special quality products. The results showed that water-soluble proteins decrease considerably due to salting out and drainage after salting. The degradation of myofibrillar proteins is more pronounced during the ripening process, particularly in the last four months when the main proteins responsible for the structure of muscular tissue are affected. There is an important residual enzymatic activity for cathepsin B, L and D, which must be a decisive factor in the proteolysis observed during "PDO Teruel" ham processing.     

低钠传统金华火腿加工过程中理化特性的变化

为了降低传统金华火腿中钠含量,本研究采用与食盐相比钠含量降低了40%~50%的新型低钠盐和食盐制备传统金华火腿,对比加工过程中低钠盐和食盐对火腿水分含量、水分活度、p H、钠及钾含量、蛋白降解指数、TBA值、色泽和感官品质的影响。结果表明:在加工过程中,低钠组成熟后期水分含量为43.86%,与食盐组差异不显著(p>0.05),成熟后期食盐组p H显著低于(p<0.05)低钠盐组,成熟后期低钠盐组蛋白降解指数比食盐组高14.71%。终产品中低钠组TBA值显著高于食盐组(p<0.05),终产品钠含量降低了52.94%,且两组的各项感官指标均无显著差异(p>0.05)。低钠金华火腿在保证了火腿传统风味品质基础上,又降低了钠的含量。      

Biochemical changes during processing of traditional Jinhua ham

Jinhua ham is the most famous traditional meat product of China and one of the most famed dry-cured hams in the world. Its processing consists of six stages: green ham preparation, salting, washing and sun-drying and shaping, ripening, and post-ripening. Intense proteolysis and lipolysis occur during processing period. As a result, the content of free amino acids in final ham products is 14-16 times that of green ham, and 191 volatile compounds have been identified during processing, which make a major contribution to the flavor of Jinhua ham.     

Use of computed tomography to study raw ham properties and predict salt content and distribution during dry-cured ham production

Varying salt content in hams of equal brand is a major challenge for Norwegian dry-cured ham producers. This study was thus undertaken to test existing computed tomography (CT) calibration models for salt on entire hams, regarding predictability of salt content at different processing times including final ham and to study salt distribution during processing of dry-cured ham. Twenty-six hams were scanned by computed tomography (CT) 11 times during dry-curing for this purpose. However, previously established calibration models had to be adjusted as they overestimated salt in dry samples. Prediction of ultimate salt content was more accurate approaching the end of the dry-curing process (RMSEP = 0.351-0.595% salt). Inclusion of remaining weight loss improved the prediction accuracy in un-dried samples by approximately 0.1% NaCl. The prediction errors were sufficiently low to be of practical interest.