雅致放射毛霉添加量对牦牛霉菌奶酪品质的影响

研究毛霉添加量对牦牛霉菌奶酪品质的影响,确定最佳添加量及发酵时间。采用单因素实验设计,固定其他工艺参数,研究雅致放射毛霉的不同添加量(质量比:0.2%、0.3%、0.4%),测定成熟过程中奶酪的性能指标(感官评分、质构指标、营养成分、pH、蛋白质与脂肪分解指标)。结果表明:毛霉添加量为0.3%,奶酪品质及感官指标最佳;随着毛霉添加量增加,水分、蛋白质、脂肪含量、pH均呈下降趋势,灰分呈上升趋势。成熟至第6 d时,牦牛霉菌奶酪感官指标最佳;随成熟时间延长,pH4.6醋酸盐缓冲液可溶性氮含量、12%三氯乙酸可溶性氮含量、硫代巴比妥酸值、酸价不断升高。因此,发酵剂添加量0.3%,发酵6 d时,牦牛霉菌奶酪品质最佳。     

牦牛乳硬质乳酪成熟特性的研究

对牦牛乳硬质乳酪成熟特性进行研究。检测其成熟过程中感官指标、质构指标、营养成分、微生物指标、蛋白质与脂肪分解指标的变化,确定其成熟时间。结果表明:牦牛乳硬质乳酪在成熟过程中,质构指标呈先上升后下降的趋势,在(45~60)d范围内感官品质最佳;p H、水分、蛋白质及脂肪含量均呈下降趋势,灰分含量上升;蛋白质水解及脂肪分解反应在成熟过程中一直进行,并在(45~60)d阶段反应较快;微生物方面乳酸菌总数先上升后下降,而细菌总数呈下降趋势。综合考虑牦牛乳硬质乳酪成熟时间为60 d时品质最佳,风味最好,各项指标达到最优值。     

成熟温度对牦牛毛霉菌奶酪成熟过程中品质的影响

文章通过研究不同成熟温度对牦牛毛霉菌奶酪成熟过程的影响,找寻最适应的温度及成熟时间.选取实验材料牦牛毛霉菌奶酪,将其置于不同的成熟温度下(20,25,30℃),选取相应成熟时间节点,测定质构、色泽、蛋白质分解、pH值等.结果 表明,成熟温度为25℃时,牦牛毛霉菌奶酪在第6天时质构达到最佳值,此时感官评分也较高.3组牦牛...     

热激处理菌种对奶酪品质的影响

为研究热激处理（63 ℃、20 min）发酵剂菌种（唾液链球菌嗜热亚种和保加利亚乳杆菌德氏亚种混合菌种）对奶酪成熟过程中品质特性的影响,对两种不同菌种所制作奶酪基本组成及成熟过程中的质构、感官、蛋白降解、风味物质等指标进行了测定。结果表明,热激处理菌种对奶酪基本组成影响不大,但热激处理菌种有利于奶酪成熟过程中蛋白质的降解,进而使奶酪的硬度和咀嚼性显著降低,也促使奶酪在成熟120 d时形成了更多的醛类、酮类、酯类等主要挥发性风味物质,同时奶酪的风味和组织状态的感官评价也较好。     

姜黄素-牛血清白蛋白复合物对牦牛乳干酪品质的影响

本研究旨在探讨牛血清白蛋白构建包封姜黄素的纳米复合物作为提高牦牛乳干酪成熟品质的潜在策略,试验测定了牦牛乳干酪的水分、灰分、粗蛋白、粗脂肪、pH、pH4.6醋酸盐缓冲液可溶性氮、12%三氯乙酸溶液可溶性氮、硫代巴比妥酸反应物、酸价以及感官指标。结果表明:姜黄素-牛血清白蛋白纳米复合物的存在能够显著提升牦牛乳干酪的水分与蛋白质含量（P<0.05）,还能促进乳酸菌的增殖并抑制杂菌生长,有助于牦牛乳干酪中脂肪与蛋白质的分解,形成短链脂肪酸和多肽,呈现较好的独特风味;而复合物添加量过高会减弱益生效果,降低脂肪和蛋白分解效率,同时也引起干酪色泽发黄而降低感官评分。在成熟过程初期,感官评分显著提升（P<0.05）得益于蛋白质水解反应以及脂肪分解反应的发生,但成熟期过长会导致苦味小肽等物质的堆积,形成不良风味,影响感官品质。总体来讲,姜黄素-牛血清白蛋白复合物添加有助于牦牛乳干酪品质的提升,且复合物添加量为4%,成熟时间为60 d时,干酪产品品质最佳。     

钙添加对切达奶酪品质的影响

研究了钙添加(100、200、500 mg/L)对切达奶酪成熟特性及感观品质的影响。测定了切达奶酪在成熟中不可溶钙、pH 4.6-可溶性氮、12%三氯乙酸(TCA)-可溶性氮、质构及挥发性风味物质的变化,对产品进行气味、滋味及质构的感观评价。结果表明:钙添加能显著降低蛋白质水解程度,增大奶酪硬度及弹性,降低切达奶酪苦味。0~200 mg/L钙添加对质构的感官无显著性影响,500 mg/L钙添加能显著降低奶酪粘性和凝聚性,并导致奶酪呈现易碎性和粉质特性。     

不同稳定剂对凝固型牦牛酸奶在冷藏后熟过程中品质及风味的影响

为了探讨黄原胶、果胶和羧甲基纤维素钠(CMC-Na)对牦牛酸奶在后熟过程中品质及风味的变化,实验测定了添加不同稳定剂酸奶的感官、酸度、持水性、质构,并分析了不同后熟时间酸奶的挥发性风味成分。结果表明,不同稳定剂对牦牛酸奶的感官、理化性质及质构的影响不同。添加黄原胶、果胶及CMC-Na对牦牛酸奶的感官、酸度及持水性有显著影响(p<0.05),均在一定程度上提高了酸奶的硬度,但稳定剂添加量过大时会降低酸奶的粘聚性。通过正交实验确定稳定剂最佳复配组合为:果胶0.04%、黄原胶0.02%、CMC-Na 0.03%,此时牦牛酸奶的持水力为71.52%,感官评分为42。对牦牛酸奶中的挥发性风味物质检测发现,醇类是牦牛酸奶中含量最高的物质,其次为酮类、其他类(主要为芳香类),再次为醛类。随冷藏后熟时间的延长,空白组中检出的挥发性风味物质数量变化不大;在冷藏后熟2 d时,果胶组风味的稳定效果最好,其次为CMC-Na,复合稳定剂组效果最差;至冷藏后熟7 d时,与第2 d相比,复合稳定剂组风味的稳定效果最好。     

低钠复合盐对发酵香肠理化特性及风味的影响

以添加58%氯化钠、30%氯化钾、7%氯化钙、5%甘氨酸的低钠复合盐发酵香肠作为实验组,以100%氯化钠为对照组,通过测定理化指标、感官评价、电子舌味觉特征、游离氨基酸含量以及挥发性风味物质等探究低钠复合盐对发酵香肠品质的影响。结果表明：在香肠发酵成熟过程中,香肠pH值、水分含量呈显著下降趋势,钠含量显著增加。实验组pH值显著低于对照组,水分含量显著高于对照组,并且对产品的色泽和质构特性有一定改善作用,实验组在显著降低钠含量的同时,感官评价与对照组无明显差异。根据电子舌分析,实验组的鲜味、丰富度、苦味显著高于对照组。此外,实验组促进了游离氨基酸的释放,并对挥发性风味物质的产生没有负面影响。因此,实验组在减少42%食盐添加量的基础上,保证了发酵香肠良好感官和风味品质。     

促成熟牦牛乳半硬质(切达)干酪成熟特性及挥发性风味物质变化研究

为探究牦牛乳半硬质干酪促成熟特性并确定经促成熟处理后的最佳成熟期,该实验选用经促成熟工艺处理的干酪与未处理干酪进行对比研究成熟期间(20、40、60、80 d)干酪质构与理化性质,并探究促成熟干酪在不同成熟期挥发性风味物质的变化。结果表明,在促成熟条件下牦牛乳半硬质干酪40～60 d硬度、黏性、弹性、凝聚性、咀嚼性变化明显(P<0.05)。理化性质方面水分含量逐渐降低,pH值升高,脂肪含量下降,实验组干酪酸价及过氧化值均上升,且高于对照组,表明促成熟效果好。采用固相微萃取-气相色谱-质谱联用技术检测出促成熟牦牛乳半硬质干酪成熟期间产生66种风味物质,其中主要特征风味物质包括酯类(丁酸丁酯)、酸类(丁酸)、酮类(2-丁酮)、醇类(1-丁醇)。促成熟干酪中酸类、酮类、醇类物质的含量显著增加。综上所述,促成熟干酪在成熟40～60 d质构与营养成分均达较高标准,特征风味物质含量上升,显著缩短成熟时间,为牦牛乳半硬质干酪的快速成熟和市场发展提供了理论依据。     

成熟温度和时间对半硬质干酪成熟特性影响研究

研究成熟温度和时间对半硬质干酪成熟特性的影响。将干酪分别在4、10、16℃条件下成熟,测定其在90d 内品质变化规律。结果表明,在90d 成熟期内,pH 值先下降后升高,最后趋于稳定;pH4.6 可溶性氮含量和12% 三氯乙酸可溶性氮含量逐渐升高;乳酸菌总数逐渐下降。成熟温度对干酪的感官品质、pH 值、蛋白质的降解和乳酸菌总数影响显著。4℃成熟的干酪,在第90 天时,感官品质达到最好;10℃成熟的干酪,在第45天时,感官品质达到最好;16℃成熟的干酪,感官品质较差。根据感官品质和其他参数的变化规律,确定半硬质干酪的最佳成熟温度为10℃,最佳成熟时间为45d。     

Nutritional Evaluation of Accelerated Ripened Cheddar Processed Cheese

Accelerated ripened Cheddar cheese was prepared by blending two parts of shredded curd made from standardized cow's milk with one part of 5.2% NaCl solution and ripening at 30°C for 8 days. On a dry matter basis, protein and fat of accelerated ripened cheese were similar to that of conventionally ripened Cheddar cheese, while lactose and total ash were greater. Similar observation was made for processed cheese samples. No change in vitamin A or in riboflavin but a fourfold increase in folic acid was observed during accelerated ripening. Protein efficiency ratio, net protein utilization and digestibility coefficient by rat tests were slightly but significantly higher for conventionally ripened processed cheese. However, no difference in biological value was observed.     

新疆特色酸凝干酪成熟期间理化特性研究

对新疆特色酸凝干酪成熟50 d内理化特性研究结果表明:干酪成熟过程中水分含量减少,变化差异极显著(P<0.01);pH值在前20 d内下降较快,达到最低值;脂肪含量减少;pH4.6可溶性氮和12%TCA可溶性氮含量有不同程度的上升,且pH4.6可溶性氮比12%TCA可溶性氮含量高;通过SDS-PAGE图谱分析,得知干酪在成熟30 d之后蛋白质降解程度较深;乳糖含量在成熟前期下降较快,后期较慢。     

Edam牦牛干酪成熟过程中品质变化及蛋白质降解

为研究Edam牦牛半硬质干酪成熟机理，分别测定成熟0、20、40、60、80 d Edam牦牛干酪的感官、理化、物性、蛋白质和脂肪分解指标，采用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳和傅里叶变换红外光谱等方法研究酪蛋白降解情况，通过Pearson相关性分析成熟时间与各指标间的相关性。结果表明：随着成熟时间延长，感官评分先下降后上升；水分含量、pH值下降；亮度值（L*）下降，红度值（a*）和黄度值（b*）值上升；硬度、弹性、胶黏性均上升，凝聚性逐渐下降；储能模量和损耗模量升高，损耗角正切值始终小于1；成熟时间与总氮含量、pH 4.6和12%三氯乙酸条件下干酪中可溶性氮含量等呈极显著正相关（P<0.01）；脂肪含量先升高后降低，游离脂肪酸含量和硫代巴比妥酸值逐渐增加。酪蛋白（casein,CN）降解研究结果表明：αs1-CN、αs2-CN、β-CN及κ-CN均随成熟时间延长而不断降解，成熟80 d时大分子蛋白降解明显；成熟过程中β-折叠、α-螺旋逐渐向无规卷曲转化；成熟时间与羰基含量、表面疏水性呈极显著正相关（P<0.01），与总巯基含量呈显著负相关（P<0.05）。     

Effects of ripening conditions on the texture of Gouda cheese

Summary The effects of ripening temperature, type of packaging film and storage period before packaging were related to the degree of proteolysis and the texture of Gouda cheese, so as to determine the optimum ripening conditions. Gouda cheeses from a local plant were subjected to different ripening conditions. A factorial design of 2³× 5 was used, where the three factors selected in two levels were: (1) time of storage before packaging, 4 and 10 days, (2) ripening temperature, 10 and 20 °C and (3) plastic film, BK1 and BK5 (Grace, Quilmes, Argentina). Ripening time was a fourth factor analyzed; sampling times were 15, 25, 35, 49 and 70 days after production. Cheeses traditionally ripened (without packaging) were also analyzed. Water content and pH were determined. Nonprotein nitrogen (soluble in 12% trichloracetic acid (TCA)) was quantified by the Kjeldhal method. Cheese texture was analyzed by compression and relaxation tests which were done by using an Instron Universal Testing Machine (Instron Corp., Canton, MA, USA). The pH and water content of cheeses which ripened at 20 °C were lower than the corresponding ones ripened at 10 °C. Only ripening time and temperature had a significant effect on water content, nonprotein nitrogen concentration and rheological parameters. Results show that texture properties of Gouda cheese ripened in plastic films with low gaseous permeability are similar to those of traditionally ripened Gouda. Texture development was accelerated by increasing the storage temperature.     

Texture,flavor, and sensory quality of buffalo milk Cheddar cheese as influenced by reducing sodium salt content

The adverse health effects of dietary sodium demand the production of cheese with reduced salt content. The study was aimed to assess the effect of reducing the level of sodium chloride on the texture, flavor, and sensory qualities of Cheddar cheese. Cheddar cheese was manufactured from buffalo milk standardized at 4% fat level by adding sodium chloride at 2.5, 2.0, 1.5, 1.0, and 0.5% (wt/wt of the curd obtained). Cheese samples were ripened at 6 to 8°C for 180 d and analyzed for chemical composition after 1 wk; for texture and proteolysis after 1, 60, 120, and 180 d; and for volatile flavor compounds and sensory quality after 180 d of ripening. Decreasing the salt level significantly reduced the salt-in-moisture and pH and increased the moisture-in-nonfat-substances and water activity. Cheese hardness, toughness, and crumbliness decreased but proteolysis increased considerably on reducing the sodium content and during cheese ripening. Lowering the salt levels appreciably enhanced the concentration of volatile compounds associated with flavor but negatively affected the sensory perception. We concluded that salt level in cheese can be successfully reduced to a great extent if proteolysis and development of off-flavors resulted by the growth of starter and nonstarter bacteria can be controlled.     

Physicochemical analysis of full-fat, reduced-fat, and low-fat artisan-style goat cheese

The objective of this study was to examine the physicochemical properties of cheese elaborated via traditional artisan methods using goat milk containing 5, 1.5, or 0.4% fat and ripened for 1, 7, 14, or 28 d. Seventy-two cheeses were produced (2 batches × 3 fat levels × 4 ripening times × triplicate). Proximal composition, pH, texture analysis, and color were recorded in each cheese. Protein and moisture were increased in cheese, and fat and fat in DM were decreased with decreasing fat in milk. Internal and external pH was higher in low-fat and reduced-fat cheese, and pH values decreased during the first 2 wk of ripening but increased slightly on d 28. Cheese fracturability, cohesiveness, masticability, and hardness increased with decreasing fat, whereas elasticity and adhesiveness decreased. Cheese lightness and red and yellow indexes decreased with decreasing fat content; during ripening, lightness decreased further but yellow index increased.     

Physicochemical and sensory evolutions of the lactic goat cheese Picodon in relation to temperature and relative humidity used throughout ripening

To produce a wide variety of cheeses, it is necessary to control the ripening process. To do that, artisanal goat cheeses were ripened to evaluate the effects of temperature (10 and 14°C) and relative humidity (RH; 88 and 98%) on (1) 16 physicochemical characteristics throughout ripening and (2) 19 sensory characteristics at the end of ripening (d 12). Whatever the ripening time, the physicochemical characteristics were strongly dependent on the daily productions, which affected the sensory perception of the cheeses. Both physicochemical and sensory characteristics were strongly reliant on RH, whereas only a few of the characteristics were influenced by temperature changes. On d 12, whatever the ripening temperature, an RH increase from 88% to 98% modified many cheese characteristics (core pH, lactate consumption, underrind thickening, dry matter content, and hardness). As a result of these physicochemical properties, changes in perception were observed: the cheeses ripened under 88% RH were dry and hard compared with those ripened under 98% RH. An RH of 98% led to an acceleration of the ripening process, inducing a slightly ammonia and milky flavor and a sticky and creamy texture in the mouth. However, cheeses ripened under 14°C and 98% RH were also indicative of overripened cheeses: a temperature of 14°C induced an acceleration of the ripening process due to physicochemical modifications compared with a temperature of 10°C. Nevertheless, when the cheeses on d 0 were still very humid and soft, those ripened under 98% RH collapsed and were overripened with a liquid underrind. This study provides a means for achieving a better and more rational control of the ripening process in artisanal lactic goat cheeses.     

雅致放射毛霉在干酪中的应用

雅致放射毛霉(Actinomucorelegans)是酿造腐乳的优良菌株,鉴于其优良发酵特性和蛋白酶解效力,将其引入到传统表面霉菌成熟干酪的发酵成熟过程中,研究该菌种对干酪成熟期间理化特性等各项指标的影响。理化特性研究表明,雅致放射毛霉表面成熟干酪在成熟期间水分含量由59%(W/W)下降到50%;外部和内部的pH都呈上升的趋势,最后达到pH7.0左右;乳酸含量由1.2%(W/W)下降到0.4%;pH4.6 SN(可溶性氮)和12%TCA(三氯乙酸)SN在成熟的30 d内分别由10.1%(W/W)和2.5%增长到了45.2%和27.1%;电泳结果表明,酪蛋白发生强烈水解;毛霉干酪游离脂肪酸含量在成熟末期达到6.54%(W/W);TPA硬度由450 g下降到150 g。毛霉干酪成品的主要成分指标为:水分50%,蛋白质20%(W/W),脂肪20.6%(W/W),盐含量2.1%(W/W),符合NY478-2002软质干酪农业部标准,与Camembert青霉干酪的理化指标相似。