干酪成熟过程发酵剂的作用及快速成熟的研究进展

干酪的成熟过程,是在添加酶及各种微生物的协同作用下完成的.干酪中的微生物作用也包括人为添加发酵剂的作用.本文综述了干酪生产过程中发酵剂的使用和成熟过程所起的作用,主要有酸化、改善质构、形成风味物质.此外,本文也讨论了干酪的成熟机制,综述了目前用于促进干酪成熟所使用的一些方法和技术以及对它们的最新研究进展.     

溶菌酶处理发酵剂加速干酪成熟的研究

以pH、蛋白质降解、脂肪酸含量变化及干酪的感官特征为指标,研究了溶菌酶处理发酵剂对干酪成熟的影响。结果表明:实验组干酪的pH在整个成熟期处于对照组1(添加2%发酵剂)干酪和对照组2(添加2.5%发酵剂)的pH之间,表明通过溶菌酶处理发酵剂可明显抑制干酪成熟期间的产酸量;添加溶菌酶处理发酵剂可加速干酪中蛋白质分解和乳脂肪的降解;感官评价结果表明,添加溶菌酶处理发酵剂可提高干酪风味,在相同的成熟时间实验组干酪的质地也较对照组好。      

溶菌酶处理发酵剂加速干酪成熟的研究

以pH、蛋白质降解、脂肪酸含量变化及干酪的感官特征为指标,研究了溶菌酶处理发酵剂对干酪成熟的影响。结果表明:实验组干酪的pH在整个成熟期处于对照组1(添加2%发酵剂)干酪和对照组2(添加2.5%发酵剂)的pH之间,表明通过溶菌酶处理发酵剂可明显抑制干酪成熟期间的产酸量;添加溶菌酶处理发酵剂可加速干酪中蛋白质分解和乳脂肪的降解;感官评价结果表明,添加溶菌酶处理发酵剂可提高干酪风味,在相同的成熟时间实验组干酪的质地也较对照组好。     

辅助发酵剂加速Provolone干酪成熟的研究

将瑞士乳杆菌6024作为辅助发酵剂添加到Provolone干酪中,加速Provolone干酪成熟,研究了其对干酪游离氨基酸、游离脂肪酸、质构特性、电镜、风味物质的影响。结果表明,瑞士乳杆菌6024作为辅助发酵剂对干酪中游离脂肪酸质量分数没有显著影响,但能显著增加干酪游离氨基酸质量分数,60 d时达到对照组90 d时的质量分数,此时干酪的质构特性、微观结构、风味物质与对照组90 d时差异不显著。由此可知,瑞士乳杆菌6024作为辅助发酵剂可加速Provolone干酪的成熟,缩短成熟时间。     

发酵剂对牦牛乳硬质干酪成熟过程中生物胺的影响

乳酸菌产生物胺的能力具有菌株特异性,因此,为了探究不同种类发酵剂对牦牛乳硬质干酪中生物胺形成的影响,该试验利用高效液相色谱对3种不同发酵剂制作的硬质干酪成熟过程中生物胺进行了测定和分析。结果表明,嗜热和嗜温发酵剂牦牛乳硬质干酪中检测出2-苯乙胺、腐胺、尸胺、组胺和酪胺,混合发酵剂干酪中检测出腐胺、2-苯乙胺、尸胺和酪胺。各生物胺之间呈现正相关性。3种不同发酵剂干酪在1～6个月成熟过程中,其各生物胺整体呈现增加趋势,嗜热、嗜温和混合发酵剂干酪中总生物胺最高含量分别为(448.3±9.6)、(456.8±58.4)、(293±24.5)mg/kg。组胺和酪胺是2种毒性相对高的生物胺,嗜热发酵剂干酪中组胺和嗜温发酵剂干酪中酪胺最高,其最高含量分别为(20.8±7.9)、(92.9±6.7)mg/kg,混合发酵干酪中未检测出组胺,酪胺含量次之,3种不同发酵剂干酪中组胺、酪胺含量均低于推荐安全剂量50 mg/kg和100 mg/kg。这为合理选择发酵剂和控制干酪中生物胺形成提供了依据。     

发酵剂添加量和成熟时间对牦牛乳硬质干酪脂肪氧化的影响

为研究发酵剂添加量和成熟时间对牦牛乳硬质干酪中脂肪氧化的影响,试验以添加不同发酵剂质量分数(1%、2%、3%)制得的牦牛乳硬质干酪为材料,对其90 d成熟期内的氧化指标和理化指标进行测定。结果表明:发酵剂添加量和成熟时间对牦牛乳硬质干酪的理化指标和脂肪氧化程度均有显著性影响(P <0. 05),且随发酵剂添加量的增加,干酪中酸度值(acidity value,ADV)、过氧化值(peroxide value,POV)、羰基价(carbonyl value,CV)、硫代巴比妥酸值(thiobarbituric acid value,TBA)增加;随成熟时间的延长,ADV、CV、TBA值增加,POV值先增加后降低。发酵剂添加量为3%时,能够显著增大干酪中脂肪的氧化程度(P <0. 05),同时随成熟时间的延长,脂肪氧化持续进行并且氧化程度也在不断加深。该研究将发酵剂添加量和成熟时间相结合,探讨牦牛乳硬质干酪中脂肪氧化的变化规律,以期从脂肪的氧化机制调控干酪的品质,为实现工业化生产提供理论依据。     

干酪成熟过程中的微生物变化

干酪的成熟过程，是在添加酶及各种微生物的协同作用下完成的。干酪中的微生物，不仅有我们人为添加的发酵微生物，而且还含有残活在巴氏杀菌原料乳中的以及在制造和成熟过程中污染的微生物。在这些微生物的共同作用下，参与干酪成熟过程中的物理、化学以及感官性能的变化     

Cheddar干酪附属发酵剂筛选及其应用

为了筛选能够促进Cheddar干酪成熟,从泡菜、腐乳及不同产地的Cheddar中筛选具有高肽酶活力和自溶度的乳杆菌作为Ched-dar干酪附属发酵剂,并应用于Cheddar干酪的制作中.结果表明,从美国Cheddar干酪中筛选出1株Lactobacillus plantarum OD具有较高的肽酶活力和自溶度,运用于Cheddar千酪的制作中能显著提高其游离氨基酸浓度,改善其风味,有利于加快干酪的成熟.     

干酪成熟过程的微生物变化

干酪的成熟过程，是在添加酶及各种微生物的协同作用下完成的。干酪中的微生物，不仅有我们人为添加的发酵微生物，而且还含有残活在巴氏杀菌原料乳中的以及在制造和成熟过程中污染的微生物。在这些微生物的共同作用下，参与干酪成熟过程中的物理，化学以及感官性能的变化。     

干酪中非发酵剂乳酸菌

非发酵剂乳酸菌是干酪中主要的次生菌群，不属于发酵微生物，通常不能很好的在牛奶中生长，不能产酸，但对干酪的风味形成有很重要作用。本文概述了非发酵剂乳酸菌的一些特征，包括不同原料制成的干酪中非发酵剂乳酸菌的来源、生长能源的利用、自身存在的蛋白分解系统对干酪风味形成影响及作为一种提高干酪品质的附属发酵剂的应用展望。     

提高成熟温度加快Mozzarella干酪成熟的研究

制作2批Mozzarella干酪A和B，分别在4℃(A)和7℃(B)下成熟，观察其在成熟期间的变化及测定可溶性N的含量等指标，可知在7℃下成熟的干酪在制作后30d的蛋白水解性、功能特性等和4℃下成熟50d的干酪无显著差异，而和7℃下成熟50d的干酪有显著差异。说明成熟温度显著影响干酪的蛋白水解性。在7℃下贮藏的Mozzarella干酪成熟30d可达到4℃下贮存50d的成熟度，即将成熟温度从4℃提高到7℃，可将成熟期缩短20d左右。     

Influence of starters on chemical, biochemical, and sensory changes in Turkish White-brined cheese during ripening

Turkish White-brined cheese was manufactured using Lactococcus strains (Lactococcus lactis ssp. lactis NCDO763 plus L. lactis ssp. cremoris SK11 and L. lactis ssp. lactis UC317 plus L. lactis ssp. cremoris HP) or without a starter culture, and ripened for 90 d. It was found that the use of starters significantly influenced the physical, chemical, biochemical, and sensory properties of the cheeses. Chemical composition, pH, and sensory properties of cheeses made with starter were not affected by the different starter bacteria. The levels of soluble nitrogen fractions and urea-PAGE of the pH 4.6-insoluble fractions were found to be significantly different at various stages of ripening. Urea-PAGE patterns of the pH 4.6-insoluble fractions of the cheeses showed that considerable degradation of α_s1-casein occurred and that β-casein was more resistant to hydrolysis. The use of a starter culture significantly influenced the levels of 12% trichloroacetic acid-soluble nitrogen, 5% phosphotungstic acid-soluble nitrogen, free amino acids, total free fatty acids, and the peptide profiles (reverse phase-HPLC) of 70% (vol/vol) ethanol-soluble and insoluble fractions of the pH 4.6-soluble fraction of the cheeses. The levels of peptides in the cheeses increased during the ripening period. Principal component and hierarchical cluster analyses of electrophoretic and chromatographic results indicated that the cheeses were significantly different in terms of their peptide profiles and they were grouped based on the use and type of starter and stage of ripening. Levels of free amino acid in the cheeses differed; Leu, Glu, Phe, Lys, and Val were the most abundant amino acids. Nitrogen fractions, total free amino acids, total free fatty acids, and the levels of peptides resolved by reverse phase-HPLC increased during ripening. No significant differences were found between the sensory properties of cheeses made using a starter, but the cheese made without starter received lower scores than the cheeses made using a starter. It was found that the cheese made with strains NCDO763 plus SK11 had the best quality during ripening. It was concluded that the use of different starter bacteria caused significant differences in the quality of the cheese, and that each starter culture contributed to proteolysis to a different degree.     

酶法促熟干酪的研究进展

干酪促熟常用的方法有酶法；修饰发酵剂细胞；提高成熟温度；悬浮液系统法等．其中的酶法促熟干酪研究较为系统。论述了酶法促熟干酪中常用的酶类及其作用，并对其应用前景作以展望。     

切达干酪加速成熟方法及其研究现状

概述了对切达干酪的加速成熟的现状与研究方法,通过提高温度、添加促熟酶、修饰发酵剂细胞、高压处理等方法缩短切达干酪的成熟时间,提高经济效益。     

干酪快速成熟的研究进展

综述了国内外干酪快速成熟的研究状况,探讨了脂质体微胶囊中性蛋白酶用于加快干酪成熟的可行性。     

蓝纹干酪成熟期间氨基酸的变化研究

采用HITACHIL—8800型氨基酸自动分析仪测定分析了自制蓝纹干酪成熟过程中的氨基酸组分与含量变化。成熟30～60d期间,所有氨基酸含量都呈现上升趋势,成熟90d时,门冬氨酸、谷氨酸、缬氨酸、蛋氨酸、亮氨酸、苯丙氨酸、精氨酸、脯氨酸几种氨基酸由于转化成其他物质含量有所降低。门冬氨酸降低0.07%,谷氨酸降低0.32%,缬氨酸降低0.09%,蛋氨酸降低0.14%,亮氨酸降低0.22%,苯丙氨酸降低0.02%,精氨酸降低0.07%,脯氨酸降低0.32%。成熟90d时,含量较高的是谷氨酸,亮氨酸,脯氨酸,赖氨酸、酪氨酸。     

干酪促熟附属发酵剂的研究进展

干酪成熟时间较长且费用较高,干酪促熟成为降低生产成本的有效途径之一。干酪促熟常用的方法有酶法、修饰发酵剂细胞、提高成熟温度、高压处理等,但均存在一定的不足,限制了其在干酪工业中的应用。非发酵剂乳酸菌可促进干酪风味的形成并加速成熟．已成为干酪促熟方法的研究热点之一。介绍了干酪生产及成熟过程中微生物的作用,特别介绍了干酪附属发酵剂发展的原由并综述了其在干酪成熟过程中研究进展。     

Comprehensive analysis of proteolysis during 8 months of ripening of high-cooked Old Saare cheese

We applied capillary electrophoresis, liquid chromatography coupled with tandem mass-spectrometry (MS/MS), and ultra-performance liquid chromatography to determine the composition of water-insoluble and water-soluble proteinaceous fractions of the cheese and to study in detail the degradation of caseins during 8 mo of ripening of Estonian high-temperature cooked hard cheese Old Saare. The application of high-resolution and high-accuracy MS/MS enabled identification of more than 3,000 small peptides, representing a fairly full casein peptidome containing peptides of 4 to 25 AA in length: 1,049 from β-casein (CN), 944 from α_S1-CN, 813 from α_S2-CN, and 234 from κ-CN. The majority of β-CN- and α_S1-CN-derived peptides originated from the N-terminal parts of the molecule, f6-93 and f1-124, respectively; peptides from α_S2-CN arose predominantly from the C-terminal end f100-162. At the beginning of ripening, we found a relatively high amount of peptides originating from the glycomacropeptide part of κ-CN, whereas peptides from para-κ-CN prevailed during the later stages of ripening of the cheese. The cleavage patterns of β-CN, α_S2-CN, as well as α_S1-CN, showed that primary proteolysis was started mainly by plasmin, although a low proteolytic activity of chymosin was also evident. Based on the analysis of cleavage sites, we observed a significant participation of proteolytic enzymes, including amino- and carboxypeptidases, of both mesophilic and thermophilic starter bacteria in further hydrolysis of oligopeptides during the ripening. Several new phosphopeptides were detected in the result of MS/MS data analysis. The profiles of the estimated concentrations of phosphopeptides revealed that those originating from β-CN and α_S1-CN accumulated during cheese maturation. In contrast, we did not notice any generation of phosphopeptides from the highly phosphorylated part of α_S2-CN, f25-80, presumably due to the inaccessibility of this region to the action of plasmin and chymosin. The analysis of cleavage sites and the combination of principal component and clustering analyses provided a characterization of the complex dynamics of formation and degradation of peptides during cheese maturation. We made an attempt to obtain a comprehensive picture of proteolysis during Old Saare cheese ripening on the basis of the detailed peptidomic data, including also the less abundant peptides determined by MS/MS, and complemented by the data on intact caseins and free AA and reported the results in the paper.