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。     

五种云南火腿游离脂肪酸含量比较分析

采用气相色谱-质谱联用仪(GC-MS)对宣威火腿、诺邓火腿、鹤庆圆腿、撒坝火腿及三川火腿共5种云南干腌火腿肌内及皮下部位进行游离脂肪酸种类及含量比较分析。结果表明,5种火腿中的游离脂肪酸种类最多检测出16种,棕榈酸(C16∶0)、硬脂酸(C18∶0)、油酸(C18∶1 n-3)、和亚油酸(C18∶2)是5种云南火腿的主要脂肪酸,且不同火腿及不同部位间的脂肪酸组成及含量存在差异(P 0. 05);以诺邓火腿和三川火腿的含量最高,诺邓火腿肌内及皮下脂肪部分的游离脂肪酸总量分别为40. 378 mg/g、79. 959 mg/g,三川火腿的为42. 336 mg/g与77. 548 mg/g,其次分别为撒坝火腿(30. 147 mg/g、62. 049 mg/g),宣威火腿(28. 446 mg/g、62. 078 mg/g)与鹤庆圆腿(27. 361 mg/g、55. 953 mg/g);肌内及皮下的不饱和脂肪酸总含量与必需脂肪酸含量,诺邓火腿与三川火腿均高于其余火腿,因此诺邓火腿与三川火腿的脂肪组成较其他3种火腿更为合理。     

传统金华火腿加工过程中肌内脂肪的变化

分别提取0、32、60、160、240d的金华火腿中的肌内脂肪,分析其甘油酯、磷脂、游离脂肪酸的含量和脂肪酸组成。结果表明:磷脂的含量从23.3%减少到11.2%,游离脂肪酸的含量从1.6%增加到11.5%,甘油酯的含量没有发生显著性变化;甘油酯和磷脂中的饱和脂肪酸(SFA)、单不饱和脂肪酸(MUFA)、多不饱和脂肪酸(PUFA)都无显著性变化;游离脂肪酸中,PUFA的含量显著减少,MUFA的含量减少,但其变化不显著,SFA的含量显著增加。     

金华火腿中肌内脂肪的提取和脂肪酸分析研究

通过正交实验,确定金华火腿中肌内脂肪的最佳提取条件是:氯仿和甲醇(2:1,v/v)的用量为样品重量的14倍,振荡1.5h,取滤液加其1/2体积的1%NaCl溶液.处理60d的金华火腿中肌内脂肪的含量为12.4%,甘油酯、磷脂、游离脂肪酸分别占76.5%、18.8%、4.7%.甘油酯中单不饱和脂肪酸的含量最高,为47.89%;而磷脂中多不饱和脂肪酸的含量最高,为50.94%;游离脂肪酸中则含有较多的饱和脂肪酸(41.56%).甘油酯、磷脂和游离脂肪酸中都是以C16.0、C18:1、C18:2为主要成分.     

不同部位荣昌猪肉中脂肪含量和脂肪酸组成对比

研究不同部位猪肉中脂肪含量和脂肪酸组成的变化规律,以荣昌猪4个不同部位的肌肉为原料,对比四者脂肪含量和肌内总脂、甘三酯、磷脂、游离脂肪的脂肪酸组成。结果显示：4部位肌内总脂和甘三酯含量有显著差异(P＜0.05),而磷脂和游离脂肪酸的含量差异不显著(P＞0.05);4部位总脂肪酸和游离脂肪组成有显著差异(P＜0.05),而甘三酯和磷脂的脂肪酸组成差异不显著(P＞0.05)。由于游离脂肪酸在肌内脂肪中比较很小,不足以对总脂肪酸组成产生显著影响,因此不同部位荣昌猪样品间肌内脂肪含量和脂肪酸组成的显著差异主要都是由肌内甘三酯含量的显著差异引起的。     

盐含量对金华火腿中脂质水解的影响

考察盐含量对金华火腿中的内源酶活力及游离脂肪酸含量的影响.将原料腿分成2组,分别进行低盐(8%)和高盐(浓度12%)处理.取原料腿、腌制结束期、风干结束期、成熟1期、成熟2期、后熟期的股二头肌部位分别测定其中盐含量、内源酶活力和游离脂肪酸的含量.结果显示:在整个生产工艺中,盐含量不断升高,低盐样品从0.19%上升到8.42%,高盐样品从0.19%上升到9.77%:内源酶活力不断下降,且高盐处理的样品的内源酶活力低于低盐处理样品;总的游离脂肪酸含量呈现上升趋势,其中棕榈酸、油酸和亚油酸是主要的脂肪酸,亚油酸是重要的风味前体物质.盐含量对脂质水解作用的影响不大.     

GC-MS法测定宣威火腿中脂肪酸组成

以宣威火腿为对象,通过提取成熟宣威火腿的肌间脂肪和皮下脂肪,采用气相色谱-质谱联用法(GC-MS)对宣威火腿肌间脂肪与皮下脂肪中脂肪酸的组分进行探讨。结果表明:宣威火腿肌间脂肪中含11种饱和脂肪酸,占总脂肪酸的34.75%,15种不饱和脂肪酸,占总脂肪酸含量的64.78%,主要的脂肪酸为油酸(C18∶1)、棕榈酸(C16∶0)、硬脂酸(C18∶0)、亚油酸(C18∶2),含量分别为33.44%、23.37%、8.44%、20.55%;皮下脂肪中含11种饱和脂肪酸,占总脂肪酸的36.23%,15种不饱和脂肪酸,占总脂肪酸含量的63.47%,主要的脂肪酸为油酸(C18∶1)、棕榈酸(C16∶0)、硬脂酸(Cl8∶0)、亚油酸(C18∶2),含量分别为31.47%、21.90%、11.13%、22.39%。     

超高压结合热处理对猪肉肌内脂肪酸组成的影响

为研究高压结合一定的温度处理对肉中肌内脂肪酸组成的影响,以猪背最长肌为原料,经不同压力(300~700 MPa)、温度(20~50℃)和时间(10~20 min)结合处理后,测定各样品总脂、甘油三酯、磷脂和游离脂肪的脂肪酸组成变化。结果表明:压力对猪肉脂肪酸组成的影响最显著,其次是温度,两者的交互作用也显著,而时间的作用不显著;脂肪酸组成变化主要由磷脂和游离脂肪酸引起,而总脂和甘油三酯在整个处理中变化很小;300 MPa及以上的压力结合热处理使磷脂发生明显的降解作用,且其中较多的PUFA发生降解导致其在磷脂中的比例显著降低,而SFA和MUFA的比例显著增加,游离脂肪酸组成的变化与磷脂恰好相反。因此,高压结合热处理对肌内总脂肪、甘油三酯的脂肪酸组成影响不大,而主要影响磷脂和游离脂肪酸。     

金华火腿传统加工过程中的脂肪氧化研究

取0、30、62、160和240d的金华火腿,提取肌内脂肪和皮下脂肪,分别测定脂肪中各组分的含量和氧化指标。结果表明,肌内脂肪中磷脂含量较多,皮下脂肪中甘油酯含量较多;在金华火腿加工过程中,肌内脂肪和皮下脂肪的酸价一直上升,过氧化值、羰基价和TBA值有升有降,但总体呈上升趋势,脂肪氧化程度不断增强。同时发现,肌内脂肪比皮下脂肪的氧化程度更高。     

Lipolysis in intramuscular lipids during processing of traditional Xuanwei ham

Lipolysis in intramuscular lipids during the processing of Chinese Xuanwei ham has been studied by analyzing the changes of glycerides, phospholipids and free fatty acids in biceps femoris muscle. Results showed that the glycerides accounted for 73.2% of total lipid content in fresh ham, the phospholipids represented 25.3% and the free fatty acids 2.3% of the total lipid content, respectively. A rapid lipolysis of phospholipids occurred during the first 4 months of processing and slowed down during the rest period. A preferential hydrolysis for palmitic, linoleic and arachidonic acids in phospholipid fraction was observed. Glycerides only changed a little throughout the process, while an increase of free fatty acids during processing was observed. The results suggest that phospholipids are the main substrate of lipolysis in the intramuscular lipids of Chinese Xuanwei ham.     

Changes in intramuscular lipids during ripening of Iberian dry-cured ham

Thirty-one thighs were obtained from Iberian pigs fattened with acorns and were processed during 22 months in the traditional dry-curing process. Lipolysis affecting intramuscular fat during the processing of Iberian dry-cured ham has been analyzed by studying the changes of glycerides, phospholipids and free fatty acids in lipids from Biceps femoris muscle. Little change affected the fatty acid composition of glycerides during processing. A double-phased increase in the acidity values and a decrease in the quantity of fatty acids of phospholipids during the processing were observed. There seems to be a relationship between the extension of the lipolysis taking place during the maturing and the processing conditions and raw material used.     

传统金华火腿加工过程中皮下脂肪的变化

分别提取0、32d、60d、160d、240d的金华火腿中的皮下脂肪,分析其甘油酯、磷脂、游离脂肪酸的含量和脂肪酸组成。结果表明:甘油酯的含量从95.7%减少到85.4%,游离脂肪酸的含量从2.1%增加到14.3%,磷脂的含量没有发生显著性变化;甘油酯中的SFA有显著性变化,MUFA和PUFA无显著性变化;磷脂中的SFA、MUFA和PUFA都没有显著性变化;游离脂肪酸中,PUFA的含量显著减少,MUFA的含量减少,但其变化不显著,SFA的含量显著增加。     

Proteolysis in biceps femoris during Jinhua ham processing

Sixty experimental Jinhua hams were processed by a traditional method. The nitrogen fractions and free amino acids in biceps femoris were analyzed. Intense proteolysis was found in ham muscle and totally more than 10% of muscle proteins were degraded during the course of Jinhua ham processing. The proteolytic index of Jinhua ham was between 14 and 20. Both insoluble and soluble proteins were degraded to some degree and the later showed more intense degradation. In the soluble fraction, the percentage of non-protein nitrogen (NPN) increased gradually whereas that of protein nitrogen decreased during processing (P<0.05). However, very small amount of peptides larger than 1kDa was accumulated during the whole course of processing, which proved that intense degradation reactions were also happened to them, especially at the post ripening stage when dramatic decrease of nitrogen fraction from all the peptides larger than 1kDa was found. As a result, more than 90% of the NPN products from muscle proteolysis were free amino acids and peptides of MW less than 1kDa that might make important contribution to Jinhua ham taste and provide precursors for the generation of volatile flavor compounds in ham muscle. The pattern of muscle proteolysis coincided with the reported changes of muscle proteolytic enzymes during processing, seemingly indicating that the enzymes could have played important roles in ham muscle proteolysis.     

Effect of intensifying high‐temperature ripening on proteolysis,lipolysis and flavor of Jinhua ham

BACKGROUND: The flavor quality of dry‐cured ham comes from proteolysis, lipolysis and lipid oxidation, Maillard reaction and Strecker amino acid degradation. Intense proteolysis, lipolysis and lipid oxidation make major contributions to flavor development of dry‐cured ham. Increasing the temperature in fermenting and ripening could promote these reactions and accelerate flavor development in dry‐cured hams. The specific aroma flavor of Jinhua ham is developed only during long‐time high‐temperature ripening in July and August. Our objective was to effectively shorten the process time by intense high‐temperature ripening based on the flavor and quality features of traditional Jinhua ham. RESULTS: Muscle dehydration rate of 80‐day ripened hams (29.43 ± 1.16%) was higher than that of the traditional process (P < 0.05). The total free fatty acids in ripened hams of 45–80 days were all higher than that of traditional hams (P < 0.05) and the level of TBARS was significantly lower (P < 0.01). The flavor profile of modern‐processed hams was different from that of the traditional Jinhua ham. The contents of carboxylic acids and aldehydes were obviously higher than those of the traditional products (P < 0.05). The results of organoleptic evaluation for flavor and quality showed that 80‐day ripened hams reached the first‐grade level of traditional Jinhua ham. CONCLUSION: Long‐time (25–30 days) intensifying high‐temperature ripening (35–37 °C) could accelerate the proteolysis, lipolysis, lipids oxidation, flavor development and effectively shorten the process time based on the traditional flavor and quality features of dry‐cured ham. Copyright © 2009 Society of Chemical Industry     

外源酶调控生产金华火腿风味调味料的研究

采用中性蛋白酶和中性脂肪酶组合水解腌制猪后腿肉,制备火腿风味前体物。利用单因素和响应曲面分析法优化双酶组合的作用条件。优化的酶解工艺条件为:2.7%的中性脂肪酶,4.3%的中性蛋白酶,43.4℃水解4h。得到的酶解液中游离脂肪酸为2.5%,氨基态氮2.4%。该酶解液32℃发酵5d,所得风味料具有较好的稳定性,感官评定结果表明其风味与金华火腿具有较好的一致性。该调味料的硫代巴比妥酸值为(TBA)0.203mg/100g样品,羰基值1.26meq/kg,水分含量62.3%,pH值5.52。     

Chemical and lipid composition of deboned pieces of dry-cured pork forelegs as affected by desalting and boiling: The effects of vacuum packaging

The effects of desalting and boiling, with or without vacuum packaging, on the composition (mainly in relation to lipids) of the muscles of deboned pieces of dry-cured pork forelegs were investigated. The muscles of boiled, desalted, dry-cured foreleg pieces showed lower ash, chloride, nitrates and nitrites contents and higher protein contents than those of dry-cured forelegs. No significant changes were observed in lipid content and in lipid fraction proportions (glycerides, phospholipids and free fatty acids). The culinary treatment (desalting and boiling) caused a decrease of thiobarbituric acid values and an increase in polyunsaturated fatty acids proportions of the three fractions (glycerides, phospholipids and free fatty acids), especially at C-18:2 and C-20:4. Only the ash contents were significantly different between samples boiled with and without vacuum packaging.