干腌羊火腿工艺过程蛋白质水解及其理化性状相关性研究

通过对羊火腿工艺过程中总氮、可溶性氮及非蛋白氮的分析研究,来确定其蛋白质水解与工艺过程产品水分、NaC1含量及温湿度条件的相关性;结果表明:工艺过程中非蛋白氮的变化与工艺过程温度和产品水分的降低、温度和NaG1含量的提高呈正相关,且蛋白质在工艺过程中发生了持续降解.成品火腿的蛋白质降解指数在2～7未间.     

三川焐灰火腿和风干火腿发酵过程中理化性质变化

研究三川焐灰火腿和风干火腿发酵过程中理化性质的变化,分析发酵方式不同的2 种火腿在发酵6～12 个月期间主要理化性质,如pH值、水分含量、水分活度、总挥发性盐基氮（total volatile basic nitrogen,TVB-N）含量、NaCl含量、蛋白质含量、色差（亮度值（L*）和红度值（a*））及游离氨基酸含量的变化。结果表明：发酵6～12 个月期间,三川焐灰火腿的pH值由6.05升至6.13,风干火腿由6.02升至6.09,在发酵成熟过程中,焐灰火腿的pH值始终高于风干火腿;焐灰火腿的水分含量由54.2%降至43.0%,水分活度由0.71降至0.65,风干火腿的水分含量由50.3%降至41.4%,水分活度由0.69降至0.65;焐灰火腿的TVB-N含量由30.1 mg/100 g上升至65.1 mg/100 g,风干火腿由31.7 mg/100 g上升至60.9 mg/100 g;焐灰火腿的NaCl含量由4.48%上升至5.40%,风干火腿由4.60%上升至5.52%;焐灰火腿的蛋白质含量由28.8%上升至38.4%,风干火腿由30.2%上升至40.9%;焐灰火腿和风干火腿的色差值呈一系列复杂变化;焐灰火腿和风干火腿发酵过程中均检测出17 种游离氨基酸,各游离氨基酸含量变化趋势与游离氨基酸总含量相似,且各游离氨基酸含量在发酵过程中的变化有明显的差异性。     

风鹅现有工艺加工过程中品质的变化规律

通过对风鹅现有工艺加工过程中pH值、色泽、盐分含量、水分含量、硫代巴比妥酸还原物(thiobarbituric acidreactive substance,TBARS)值、总氮含量、非蛋白氮含量、游离氨基酸含量和游离氨基酸态氮含量等指标的测定,研究风鹅肌肉中品质变化规律及脂肪氧化和蛋白质水解可能对风味产生的影响.结果表明,盐分含量在加工过程中不断上升,水分含量不断下降;pH值和TBARS值在一定范围内波动;总氮含量、非蛋白氮含量、游离氨基酸含量、游离氨基酸态氮含量变化差异显著,风干结束后风鹅肌肉中蛋白质水解指数约为3.8％,游离氨基酸含量占非蛋白氮含量的78％以上,含量最多的游离氨基酸含量为Arg、Thr、Glu、Leu和Ala等,而增加较多的游离氨基酸含量是Asp、Leu、Tyr、Val、Ile和Lys等,大部分游离氨基酸的含量都超过其阈值很多倍,可能对风鹅的风味产生重要影响.     

基于框鳞镜鲤形体和营养特征的分类研究

根据不同季节框鳞镜鲤的形体参数、背部和腹部肌肉的营养成分,采用因子分析和系统聚类对框的鳞镜鲤进行特征分类研究。结果表明：框鳞镜鲤在春、夏季的主要形体特征是体形较大,内脏比例较高,鱼皮比例较低;而秋、冬季的特征主要是体形较小,鱼鳞、内脏比例较低而肌肉比例较高。腹部肌肉在春、夏季的主要特征是蛋白质、游离氨基酸、灰分含量较低,而水分含较高;秋季的主要特征是蛋白质和灰分含量较高,水分含量较低;冬季的主要特征是蛋白质、粗脂肪、总糖含量较高,水分较低。背部肌肉在春季的特征是蛋白质、粗脂肪、总糖和灰分含量较低,游离氨基酸和水分含量较高;在夏季的主要特征是粗脂肪和总糖含量较高,游离氨基酸、灰分、水分较低;而在秋、冬两季的特征主要是粗脂肪、总糖和水分含量较低,蛋白质、游离氨基酸及灰分含量较高。     

不同卤制次数的盐焗鸡卤汁中的营养成分变化规律

对不同卤制次数的盐焗鸡卤汁中的蛋白质、脂肪、NaCl、总酸、总糖、游离氨基酸等成分进行分析。结果表明:随着卤制次数的增加,卤汁中蛋白质、脂肪、总酸以及游离氨基酸的含量不断上升,卤汁中NaCl和总糖含量则出现下降。卤制7次后,卤汁中蛋白质含量达到5.47%,总酸为1.42 g/kg,鸡油含量达到3.01%,并在卤汁表面形成较厚的一层浮油,NaCl和总糖则下降了50%左右,卤制6次后,卤汁中游离氨基酸总含量达到了321.75 mg/100 mL。     

小色拉米发酵过程研究

从微生物、pH值、水分含量、水分活度、食盐含量、酸价和过氧化值等方面分析了小色拉米在发酵过程中发生的理化变化,此外还比较了发酵前后产品中的游离氨基酸含量。结果发现发酵后游离氨基酸的含量增加了94%。     

国内外大豆肽产品分析

分析了4种国内外大豆肽产品的感官指标、理化指标,结果表明,各肽产品色泽、风味、蛋白质含量、水分含量、粗脂肪含量、灰分、游离氨基酸含量、肽含量、脲酶活性、肽相对分子量分布及氨基酸组成差异不大,即国内外大豆肽产品品质接近.     

金华火腿加工过程中的理化特性

以传统金华火腿为原料 ,跟踪测定了火腿加工全过程中半膜肌和股二头肌的水分、NaCl、非蛋白态氮 ,水溶性氮和游离氨基酸含量的变化情况。结果表明 ,半膜肌和股二头肌的水分含量逐渐降低 ;NaCl含量逐步上升 ,水溶性氮的含量在加工过程中先降低后升高 ,非蛋白态氮的含量也逐步上升。各种游离氨基酸随着加工的进行 ,含量逐渐增加 ,尤其是谷氨酸 ,金华火腿主要的鲜味物质 ,在加工过程中含量显著增加。     

乳酸菌发酵香肠pH值、水分活度(Aw)及游离氨基酸含量变化研究

本文探索了乳酸菌发酵香肠的ｐＨ值、水分活度（Ａｗ）、乳酸菌数量及游离氨基酸含量的变化,研究结果表明,发酵过程明显影响ｐＨ值变化,试验组与对照组存在显著差异;在发酵和烘烤过程中,两组之间Ａｗ变化无明显差异;肠馅中的乳酸菌在发酵期间均会迅速生长繁殖;游离氨基酸含量试验组比对照组增加２２．８４％,表明发酵有利于蛋白质水解产生氨基酸。     

乳酸菌发酵香肠在加工过程中的变化

探索乳酸菌发酵香肠的pH值、水分活度、乳酸菌数量及游离氨基酸含量的变化。研究结果表明：发酵过程明显影响pH值变化,试验组与对照组存在显著差异;在发酵期间和烘烤过程中,两组之间Aw变化无明显差异;肠馅中的乳酸菌,在发酵期间均会迅速生长繁殖;游离氨基酸含量试验组比对照组增加22．84％,表明发酵有利于蛋白质水解产生氨基酸。     

现代工艺金华火腿中游离氨基酸含量的研究

通过跟踪金华火腿的现代化工艺生产过程,选取原料腿、预腌结束、腌制结束、风干中期、风干结束、成熟前期(成熟1)、成熟中期(成熟2)、成熟结束(成熟3)和后熟结束9 个工艺点对金华火腿股二头肌中游离氨基酸的含量进行测定。结果表明：肌肉中的游离氨基酸(FAA)含量都随金华火腿加工进程逐渐升高;成熟过程中升高最快。FAA 总量比腌制前提高5 倍左右,多数FAA 浓度为腌制前的10 倍,含量较高的FAA 有Glu、Leu、Ala、Arg 等,增加比例较大的有Glu、Thr、Val、Ile 和Pro 等。     

肌肉非蛋白氮和游离氨基酸在金华火腿加工过程中的变化

以60只浙江兰溪当地杂交猪后腿为原料,按传统工艺加工金华火腿,分析了股二头肌中非蛋白氮(Non-proteinnitrogen,NPN)和游离氨基酸(Freeaminoacids,FAA)浓度随加工时间而变化的规律。结果表明,肌肉中的NPN和FAA含量都随金华火腿加工进程逐渐升高;NPN在后熟期和晒腿期间升高速度最快,而FAA在成熟过程中升高最快,成品火腿的蛋白质降解指数在14～20之间;成品火腿中的FAA占NPN的70%以上,其中以Arg、Glu、Leu、Lys、Ala和Val等含量较高。FAA总含量比腌制前提高13.8倍,火腿中大部分FAA浓度为腌制前的10～20倍,其中增加比例较大的FAA有Lys、Asp、Ser、Tyr和Ile等。火腿中大部分游离氨基酸的浓度多倍于其感觉阈值,因此可能对火腿风味的形成有重要贡献。     

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.     

近红外光谱法测定金华火腿生产过程中的品质参数

以金华火腿为研究对象,采用傅里叶近红外光谱分析技术检测火腿生产过程中的品质参数.火腿样品经万能机粉碎,在AntarisⅡ傅里叶变换近红外光谱仪上扫描,获得其近红外光谱.参照国标法测定对应样本的过氧化值和水分含量,用Norris导数平滑滤波及一阶导数对光谱预处理,建立火腿过氧化值和水分含量的偏最小二秉(PLS)回归模型.其中过氧化值模型中样品预测值与实测值的相关系数r2=0.99091,预测均方差(RMSEP)0.436,平均相对标准偏差0.34％,与化学测定值无显著差异.水分含量模型中样品的预测值与实测值的相关系数r2= 0.93537,RMSEP为0.0184.本实验结果表明近红外光谱技术可快速检测金华火腿生产过程中的品质参数.     

Changes of alanyl aminopeptidase activity and free amino acid contents in biceps femoris during processing of Jinhua ham

Sixty experimental Jinhua hams were processed by a traditional method. The potential alanyl aminopeptidase (AAP) activity in biceps femoris was determined. The effects of temperature, salt content, sodium nitrate content and pH on muscle AAP were evaluated using response surface methodology. Porcine muscle was found to possess very strong potential AAP activity that decreased gradually during processing from 201,635 U g⁻¹ before salting to 6147 U g⁻¹ after aging. Temperature, pH and salt content had significant exponential effects on AAP activity (P < 0.001). Both temperature and salt content interacted with pH in their effects on AAP activity (P < 0.01). However, 0–50 mg L⁻¹ sodium nitrate had no detectable effect on AAP activity (P > 0.05). The regression model showed muscle AAP maintaining its activity all through Jinhua ham processing, indicating that muscle AAP may generate free amino acids during the processing and storage of Jinhua ham. The concentrations of free amino acids increased significantly (P < 0.05) during Jinhua ham processing, except for arginine and cystine. The concentrations of most free amino acids were 5–20 times higher in the final product than in hams before salting. Final concentrations exceeded thresholds for sensory detection, thus implicating an important role of free amino acids in the determination of Jinhua ham flavor.     

采用同时蒸馏提取法分析不同加工时期金华火腿香味成分

腌制时间对金华火腿的风味与质量十分重要 ,文中采用同时蒸馏提取法比较了成熟火腿(发酵 1a)和生火腿 (未经发酵 )中的风味成分 ,分别得到了 77种和 62种化合物。结果显示 ,成熟火腿中的醛醇类物质 (3 4种 )尤其是烯醛和烯醇的种类和数量明显多于生火腿 (1 5种 )。同时 ,文中还讨论分析了各类组分及它们的风味贡献。     

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。     

Studies on time-related changes of dipeptidyl peptidase during processing of Jinhua ham using response surface methodology

Sixty experimental Jinhua hams were processed by traditional methods using green hams from local cross-bred pigs of Lanxi, Zhejiang province, PR China. Biceps femoris was sampled from five hams randomly taken after each processing stage. Potential activities of DPP I and IV in addition to the changes of some enzyme influencing factors were determined. The effects of temperature, sodium chloride content, sodium nitrate content and pH value on the activities of muscle DPP I and IV were evaluated using Response Surface Methodology (RSM) and the actual activities of muscle DPP I and IV during Jinhua ham processing were estimated. The results showed that potential activity of muscle DPP I decreased gradually from 8608.23 to 1842.06 Ug(-1) before loft-aging and then increased gradually from 1842.06 to 12196.60 Ug(-1) at the end, while that of muscle DPP IV decreased continuously and about 11% of the initial potential activity was left at the end of processing. Most of the chemical components analyzed in Biceps femoris as well as physical parameters changed greatly during processing. Temperature, sodium chloride concentration and pH value influenced DPP I and IV activities significantly. However, nitrate concentration from 0 to 50 mgkg(-1) showed little effect. By regression analysis, two quadratic regression equation models were built. The models showed that DPP I could have strong activity during Jinhua ham processing, whereas the activity of DPP IV was always very weak despite its strong potential for activity. In conclusion, muscle DPP I may be a key enzyme responsible for the generation of dipeptides in Jinhua ham processing while the effect of DPP IV was possibly very limited.     

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.     

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。