狼山鸡风干成熟工艺优化

以南通市狼山鸡为原料,通过Box-Behnken试验设计其风干成熟工艺,研究不同风干起始温度、风干时间、腌制用盐量与风干狼山鸡感官品质及蛋白质水解之间的关系.结果表明:风干起始温度、风干时间与蛋白质水解及感官品质之间呈显著正相关(P＜0.05);以风干狼山鸡的总体感官评分最大值为目标值进行回归优化分析,所得结果为风干起始温度12.5℃、风干时间93h、腌制用盐量2.6％,此时产品感官评分为92分,游离氨基酸总量(∑FAA)为1.54mg/100g,蛋白质水解指数(PI)为10.33％,水分含量为58.42％,剪切力为3.62kg/cm2,盐分为3.87％.     

鲈鱼风干成熟工艺及对蛋白质水解和感官品质影响

以鲈鱼(Japanese Sea Bass)为原料进行风干成熟工艺正交试验,研究风干成熟温湿度、时间、用盐量工艺因素对产品品质及蛋白质水解规律的影响。结果表明：蛋白质水解指数(PI)随着温度提高持续增加,而游离氨基酸总量(ΣFAA)表现出先升后降的趋势;风干成熟温度对PI 和ΣFAA 有极显著影响(P ＜ 0.01);以ΣFAA 为响应的回归优化结果为：风干成熟温度15～29℃、相对湿度70%～82%,工艺时间72h,加盐量4.5%,风干成熟产品的盐分含量为2.84%、水分含量为64.33%,与感官品质评定结果有良好的一致性。     

Alcalase协同强化高温风干成熟工艺对狼山鸡蛋白质水解的影响

以南通狼山鸡为原料,采用碱性蛋白酶（Alcalase）酶解结合强化高温风干成熟工艺制作风鸡,以游离氨 基酸总量（ΣFAA）、蛋白质水解指数为响应指标,采用响应曲面试验方法分析Alcalase协同强化高温风干成熟工 艺对狼山鸡蛋白质水解的影响,并优化狼山鸡强化高温风干成熟工艺。结果表明：Alcalase能显著促进原料的蛋白 质水解,鸡肉中ΣFAA随着Alcalase添加量与强化高温温度提高而显著提高;Alcalase添加量与强化高温温度和风 干温度对ΣFAA有显著的交互作用（P＜0.05）;在控制蛋白质水解指数小于11%的前提下,得到Alcalase酶解风干 狼山鸡的优化工艺为强化高温温度46 ℃、酶添加量1.88 U/g、风干成熟起始温度14.5 ℃,风干狼山鸡的ΣFAA为 2.02 g/100 g,蛋白质水解指数为10.42%。说明Alcalase酶解协同强化高温风干成熟工艺能有效促进狼山鸡蛋白质水 解,提高风味品质。     

干制工艺对鲢鱼品质及晚期糖化终末产物含量的影响

目的：探究干制工艺对鲢鱼食用品质及安全的影响。方法：以新鲜鲢鱼为材料,以腌制盐添加量(NaCl)、腌制温度、腌制时间、风干温度和风干时间为考察因素,探究不同加工条件对鱼干复水率、色泽、质构以及AGEs形成的影响。结果：腌制盐添加量和风干温度对鱼干制品的感官评定影响显著(P＜0.05),最佳加工工艺条件为腌制盐添加量9%,腌制温度4 ℃,腌制时间3 h,风干温度60 ℃,风干时间24 h。对鱼干风味贡献最大的为烷烃、芳香类化合物及含硫有机化合物,其中腌制盐添加量9%,腌制温度4 ℃,腌制时间3 h,风干温度60 ℃的鱼干制品的风味物质保留较好。鱼干制品色泽金黄,质地紧实,组织不松软。随着腌制盐添加量的增加,羧甲基赖氨酸(CML)和羧乙基赖氨酸(CEL)含量增加;但3%和9%腌制盐添加量下的鱼干的CML和CEL差别较小。结论：鲢鱼在不同干制工艺中所得品质与潜在危害物不同,在腌制盐添加量9%,腌制温度4 ℃,腌制时间3 h,风干温度60 ℃,风干时间24 h下所得的鱼干制品为最优产品。     

强化高温风干成熟对中式培根脂质氧化和感官品质的影响

以猪五花肉为原料,采用强化高温风干成熟工艺制作中式培根,研究强化高温风干成熟工艺对中式培根脂质氧化和感官品质的影响。结果表明：采用65℃强化高温处理可以显著激活脂肪氧合酶活力(P＜0.05),产品的硫代巴比妥酸值(0.17mg MDA/kg)比对照组降低26.1%、过氧化值降低了45%(P＜0.01),感官评分提高14.0%,说明强化高温可以促进脂质氧化和风味物质积累,降低产品氧化指标;以硫代巴比妥酸值和感官评分为目标函数的综合回归优化工艺结果为强化温度65℃、风干成熟温度18～29.5℃(每天升高1.5℃)、风干相对湿度72%～68.5%(每天降低0.5%)、风干时间8d,此时产品的盐分与水分含量分别为3.56%、52.2%,与感官分析结果有良好的一致性。     

狼山鸡腌制风干成熟过程中蛋白质分解及游离氨基酸变化规律

以狼山鸡为原料进行腌制风干成熟,分析测定加工过程中鸡胸肉中蛋白质分解和游离氨基酸变化情况,探究其蛋白质分解变化规律。结果表明：狼山鸡在风干成熟过程中蛋白质有显著的分解,蛋白质水解指数（proteolysisindex,PI）显著降低（P＜0.05）,肌肉肌浆蛋白和肌原纤维蛋白在腌制结束后显著分解（P＜0.05）;分子质量大于85 kD的蛋白被逐渐分解,20～25 kD的小分子蛋白逐渐累积,产品风干成熟过程中游离氨基酸总量呈显著上升趋势（P＜0.05）,说明蛋白质分解形成了风味前体物质;部分游离氨基酸在风干成熟后期出现降低的趋势,说明风干成熟后期较高的温度可以促进游离氨基酸进一步转化为风味物质。     

Alcalase对高沟捆蹄肌肉蛋白质水解变化规律研究

以猪后蹄肉为原料,在腌制过程添加Alcalase作为酶解剂,并通过响应曲面实验法优化酶解工艺;通过SDSPAGE电泳分析及游离氨基酸组分分析Alcalase对捆蹄蛋白质的酶解作用规律。结果表明,Alcalase在腌制温度为4~16℃时,对促进高沟捆蹄蛋白质水解及提高其感官品质有显著的促进的作用(p0.05),过量的Alcalase(大于1.6 U/g)会导致蛋白质过度水解,不利于产品的感官品质。响应曲面法优化捆蹄加工工艺结果为:Alcalase添加量1.32 U/g、腌制温度14.2℃、腌制时间21.3 d,产品蛋白质水解指数为14.81%,感官评分92.47。另外,添加Alcalase蛋白酶后,捆蹄中高分子蛋白(≥120 ku)有明显的分解作用,并且在30~40 ku及50~70 ku处,蛋白质条带逐渐累积;Ala、Leu、Val、Tyr、Phe、Ile、Gly、His有显著的增加,而Pro、Glu含量显著降低(p0.05)。因此,Alcalase能显著促进捆蹄中蛋白质的分解,提高产品的感官品质,可以应用于捆蹄产业的生产加工。     

KCl部分替代NaCl协同强化高温成熟火腿加工工艺优化

以强化高温温度、用盐量、强化高温时间、KCl替代比例为试验因素进行L9(34)正交试验,研究工艺因素对干腌火腿蛋白质水解和感官品质的影响。结果表明:蛋白质水解指数与强化高温时间呈显著正相关(P0.05);游离氨基酸(free amino acids,FAA)含量与强化时间呈显著正相关(P0.05),与用盐量呈显著负相关(P0.05);感官品质评分与强化时间呈极显著正相关(P0.01);强化温度与KCl替代比例对各指标均无显著影响(P0.05);强化时间与KCl替代比例、强化温度和强化时间的交互作用对感官评分有极显著负影响(P0.01);用盐量与KCl替代比例、强化温度和强化时间的交互作用对FAA含量有极显著正影响(P0.01)。综合分析,优化工艺组合为:强化温度35℃、用盐量5%、高温强化55 d、KCl替代比例30%。     

不同风干温度对风干草鱼品质特性的影响

研究2种风干温度对风干草鱼理化性质与食用品质的影响。以草鱼为原料,在5～6℃、20 mg/100g盐含量下腌制,然后分别在2种温度下风干,研究常温（22～25℃）风干与低温（6～10℃）风干对风干草鱼加工过程中鱼肉水分含量、盐含量、总挥发性盐基氮（total volatile base nitrogen,TVB-N）含量、pH值、硫代巴比妥酸反应物质（thiobarbituric acid reactive substances,TBARs）值和感官品质的影响。结果表明：在2种风干温度下,风干草鱼的水分含量呈下降趋势,盐含量、蛋白水解指数、TVB-N含量和TBARs值均呈上升趋势;常温风干草鱼的TVB-N含量与TBARs值在风干结束后明显高于低温风干草鱼,其最终TVB-N含量与TBARs值分别为35.61、2.46 mg/100g;低温风干草鱼的TVB-N含量与TBARs值在风干过程中无明显变化;2种风干草鱼pH值在风干过程中均呈上升趋势;低温风干草鱼的感官品质优于常温风干草鱼;除水分含量和TBARs值外,常温风干草鱼感官评分与其他理化指标均呈极显著负相关（P＜0.01）;低温风干草鱼感官评分与TVB-N含量、总氮含量、非蛋白氮含量呈显著正相关（P＜0.05）,与TBARs值、蛋白水解指数呈极显著正相关（P＜0.01）。     

温度对风干罗非鱼块品质的影响

以腌制后的罗非鱼块为原料,研究30、40、55、70℃四个干燥温度对风干罗非鱼块脂肪氧化、蛋白质分解及感官品质的影响.结果表明:热泵干燥温度对风干罗非鱼块非蛋白氮、氨基态氮、挥发性盐基氮、酸价、POV和TBA有显著性影响(p＜0.05),四种干燥温度干制罗非鱼块的非蛋白氮和蛋白质水解指数的顺序为:30℃＞40℃＞70℃＞55℃,且低温有利于蛋白质水解为氨基态含氮化合物.30℃和40℃干燥的风干鱼块脂肪氧化程度大于55℃和70℃干燥样品,虽然低温干燥下样品过氧化值和酸价高于高温干燥样品,但其过氧化值和酸价均未超过国家相关标准.研究结果表明,低温干燥风干罗非鱼块的组织状态、色泽、气味、鲜味和咀嚼度较好,样品可接受性高;低温有利于产品形成饱满的风味,且脂肪适度氧化及蛋白质的水解有利于促进产品风味的形成.     

Proteolysis in Manchego-type cheese salted by brine vacuum impregnation

A new salting procedure based on the brine vacuum impregnation of porous products was tested on Manchego-type cheese and compared with conventional brine immersion. Its effect on cheese proteolysis throughout a 90-d ripening period was determined. Three cheese regions were evaluated (the rind, the middle, and the internal regions). The parameters analyzed were total N, water-soluble N, soluble N in trichloroacetic acid and soluble N in phosphotungstic acid by using the Kjeldahl method, casein profile by urea-PAGE, and peptide profile of the water soluble nitrogen extract by reverse-phase HPLC. Free amino acid formation was monitored with a spectrophotometric method by using a Cd-ninhydrin reagent. Globally, proteolysis was significantly affected by ripening stage (increasing throughout all the maturation period studied) and cheese region (rind showed a proteolysis pattern different from the middle and internal regions). The salting procedure only affected cheese proteolysis in the rind, whereas conventional brine-salted cheeses showed lower proteolysis than vacuum-impregnated cheeses.     

Effect of some technological parameters on microbiological, chemical and sensory qualities of Civil cheese during ripening

The objective of this research was to determine the effects of different ripening methods [brine salting, dry salting, incorporating with Lor cheese (LR) and vacuum packaging] of Civil cheeses on its microbiological, chemical and sensory properties. Civil cheeses were analysed on the 2nd, 30th, 60th and 90th day of ripening. Chemical compositions of the cheeses were significantly different. While the highest dry matter and titratable acidity values were determined on dry salted cheeses, the highest fat and fat in dry matter contents were found in Civil cheese ripened together with LR. The water-soluble nitrogen and ripening index values were lower in cheese ripened incorporating with LR. Excessive proteolysis was not seen in any of cheese samples. The ripening in different methods affected microbiological and sensory properties of Civil cheese. Panellists preferred vacuum packaging and dry-salting cheeses compared to the other samples on the 90th day of ripening.     

Texture and flavour development in Ras cheese made from raw and pasteurised milk

Texture, proteolysis and flavour development in Ras cheeses made from raw or pasteurised milk with two different thermophilic lactic cultures were monitored during ripening. Results showed that at day 1 of manufacture, the moisture content and pH were lower in raw milk cheese than in pasteurised milk cheeses. Levels of water-soluble nitrogen, casein breakdown, free amino groups and free fatty acids were higher in cheese made from raw milk than in that made from pasteurised milk. Textural characteristics, such as hardness, cohesiveness and chewines, increased in all treatments during the first 60 days of ripening due to the reduction in the moisture level during the second stage of salting (dry salting during the first 60 days of ripening). Cheese made from raw milk received the highest texture and flavour scores by panellists.     

Effect of production factors and ripening conditions on the characteristics of Serra cheese

Summary  The individual and interactive effects of four production factors (amount of vegetable rennet, temperature of coagulation, pressing and salting of the fresh cheese) and two ripening factors (temperature and relative humidity) on microbiological, physico-chemical, biochemical, textural and sensory characteristics of Serra cheese were simultaneously studied using a 2vi^6-1 factorial design. Highly significant effects of salting and ripening relative humidity upon the characteristics of the cheese were detected. Addition of salt to the surface of the fresh cheese reduced microbial growth, water activity, moisture and lactic acid contents, proteolysis, lipolysis, aroma and softness of the cheese. Conversely, increase of the relative humidity during ripening increased these charactereristics. Pressing had no statistically significant effect on cheese characteristics.     

Kinetics of Proteolysis of β-Casein During Ripening of Fynbo Cheese Salted with NaCl or NaCl/KCl and Ripened at Different Temperatures

ABSTRACT: The proteolysis of β-casein during ripening of low-fat Fynbo cheese was studied using 1st-order kinetics to improve the knowledge of the p-casein hydrolysis in Fynbo cheeses salted with NaCl or NaCl/KCl and ripened at different temperatures. Effects of ripening temperature, partial replacement of NaCl by KCl during cheese salting, and total salt concentration were evaluated. Central and external zones from cheeses at 1, 5, 10, 20, 30, 60, and 90 ripening days were analyzed by polyacrylamide gel electrophoresis. No significant differences in the kinetic parameters were observed between cheeses salted with NaCl and those salted with a NaCl/KCl brine. Kinetic constants were significantly affected by region within cheese and ripening temperature. Kinetic constant values were in the range of 0.004/d to 0.018/d, and the activation energy of the reaction was approximately 19 kcal/gmol.     

Kinetics of Casein Degradation during Ripening of Fynbo Cheese Salted with NaCl/KCl Brine

First-order kinetics with respect to the α_s1-casein concentration was used to study casein degradation during low-fat Fynbo cheese ripening. Effects of partial NaCl replacement by KCI during cheese salting were studied by statistical treatment of the casein degradation results. Four zones from cheeses at 1, 5, 10, 20, and 30 ripening days were analyzed by a polyacrylamide gel electrophoresis method. Similar kinetic parameters were obtained for a cheese salted with a NaCl/KCl brine and for a control cheese during ripening. Results were more affected by salt concentration than by salt substitution. KCl did not strongly influence kinetics of Fynbo cheese proteolysis.     

Proteolysis in reduced sodium Feta cheese made by partial substitution of NaCl by KCl

Feta cheeses (five trials) of different sodium content were made, using ewes’ milk, from split lots of curd by varying the salting procedure, i.e. dry salting with NaCl (control) or mixtures of NaCl/KCl (3:1 or 1:1, w/w basis) and filling the cans with brine made with NaCl or the above NaCl/KCl mixtures, respectively, in order to study the influence of the partial substitution of NaCl by KCl on the proteolysis during cheese ripening. The extent and characteristics of proteolysis in the cheeses were monitored during aging by using Kjeldahl determination of soluble nitrogen fractions (water-soluble nitrogen, trichloroacetic acid-soluble nitrogen, phosphotungstic acid-soluble nitrogen), the cadmium–ninhydrin method for the determination of total free amino acids (FAA), urea–polyacrylamide gel electrophoresis of cheese proteins followed by densitometric analysis of the α_s1- and β-casein fractions, reverse-phase HPLC analysis of the water-soluble extracts of cheeses, and ion-exchange HPLC analysis of FAA. The results showed that proteolysis was similar in control and experimental cheeses at all sampling ages, indicating that the partial substitution of NaCl by KCl in the manufacture of Feta cheese had no significant effect on the extent and characteristics of proteolysis during cheese aging.     

Effects of salting method and storage time on composition and quality of feta cheese

Feta cheese was manufactured by using five different salting methods (dry salting for one day followed by addition of 6% NaCl brine, dry salting for 1,2 or 3 days followed by addition of 7% NaCl brine and dry salting for 3 days followed by addition of 8% NaCl brine). The effects of salting method and storage time on the composition, physicochemical, organoleptic and rheological properties of feta cheese were studied. It was found that moisture was not affected by salting method or storage time. The salting method but not the storage time had a significant effect on salt content. As the salt content of cheeses increased or the storage time was prolonged the moisture decreased. pH and cheese yield were not influenced by salting method but did decrease with storage time. Protein content was not affected by salting method or storage time, whereas fat content was affected by both factors. Proteolysis, lipolysis, organoleptic and rheological properties of cheeses were not influenced by the salting methods applied. On the other hand, storage time had a significant effect on proteolysis, lipolysis, cheese appearance, fracturability and percentage compression at the yield point. Dry salting of cheese for one day and preservation in 7% NaCl brine was considered as the most appropriate salting method for practical application.     

Biochemical changes in Picón Bejes-Tresviso cheese,a Spanish blue-veined variety,during ripening

The changes in the gross chemical composition, physico-chemical parameters, nitrogen fractions, caseins and their degradation products, and some fat characteristics were studied during the ripening process of 10 batches of Picón Bejes-Tresviso cheese, a traditional blue-veined variety made in the north of Spain. The values of the different compositional and physico-chemical parameters at the end of ripening did not differ very much from those found in other Spanish and European blue-veined cheeses. The total soluble nitrogen and the non-protein nitrogen increased by factors of 5.4 and 8, respectively, at the end of ripening compared to the values found in cheese curd after salting. The final values of all the nitrogen fractions showed that Picón Bejes-Tresviso cheese undergoes extensive and in depth proteolysis. The intense degradation of the caseins during ripening was confirmed when the caseins and their degradation products were quantified using PAGE techniques. The autooxidation of the fat does not seem very important during the ripening of this cheese. Nevertheless, lipolysis was very intense; the acidity index of the fat values (free fatty acid contents) increased by a factor of about 20 during ripening.     

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.