共查询到19条相似文献,搜索用时 375 毫秒
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类Cheddar豆乳干酪工艺参数的优化 总被引:3,自引:0,他引:3
研究了类Cheddar豆乳干酪的生产工艺并对其工艺参数进行了优化,对影响产品质量的主要因素进行了研究。通过正交试验,对发酵剂、豆乳、凝乳酶、CaCl2的最适添加量、凝乳时间和凝乳效果进行了研究和探讨。结果表明,添加豆乳20%、发酵剂3%、凝乳酶0.03%(活力为9 000 u/g)、CaCl20.06%时凝乳效果较好,在质构上与纯牛乳Cheddar干酪无明显差异。 相似文献
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嗜酸乳杆菌发酵生产低脂干酪凝乳工艺的优化 总被引:1,自引:1,他引:0
以脱脂乳为原料,采用嗜酸乳杆菌发酵进行预酸化,对其生产的低脂干酪凝乳工艺条件进行了研究。实验选取凝乳pH、氯化钙添加量、凝乳酶添加量、凝乳温度4个影响因素,以干酪产率、乳清中非脂乳固体物质残留量、嗜酸乳杆菌活菌数为指标,采用L9(34)正交实验进行优化。结果表明,凝乳的最佳工艺参数为凝乳pH6.0,氯化钙添加量0.02%(w/w),凝乳酶添加量0.01%(w/w,酶活20000u/g),凝乳温度35℃,以此条件生产的低脂干酪脂肪含量小于5%,干酪产率29.41%,乳清中非脂乳固体物质残留量5.66%,嗜酸乳杆菌活菌数在109cfu/mL以上。 相似文献
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为了优化牦牛乳酸凝干酪生产工艺,以牦牛乳为原料,在单因素试验的基础上,以模糊数学处理牦牛乳酸凝干酪感官评价结果为响应值,采用响应面试验进行分析,确定干酪的最佳工艺参数。对干酪感官品质的影响因素依次为:发酵剂添加量切割pH值凝乳温度氯化钙添加量。最佳工艺参数为:发酵剂添加量0.10%,凝乳温度55℃,氯化钙添加量0.03%,切割pH值4.4,在此条件下,得到的干酪,组织状态细腻,色泽均匀有光泽,滋气味浓郁,牦牛乳酸凝干酪感官评分为95.632,验证试验干酪感官评分为95.517。试验结果可为牦牛乳酸凝干酪的生产加工提供理论基础和参考依据。 相似文献
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基于十二烷基硫酸钠-聚丙烯酰胺凝胶电泳,液相色谱-串联质谱法研究辣木凝乳酶对酪蛋白的酶切位点和水解特性,并分析该凝乳酶水解产生的酪蛋白糖巨肽和酪蛋白磷酸肽。结果表明,辣木凝乳酶酶切κ-酪蛋白的Arg 93-His 94位点导致凝乳,区别于其他已报道的凝乳酶,具有明显特异性。酶作用下κ-酪蛋白的米氏常数Km=0.49 mg/mL,最大反应速率Vm=45.2 U/min,有效促进酪蛋白胶束的聚集和凝乳。该酶对α-、β-、κ-酪蛋白产生不同程度的水解,对α-酪蛋白的水解速度最快,说明其适用于软质奶酪的加工。以酪蛋白为底物,通过钡-乙醇沉淀法得到酪蛋白磷酸肽(casein phosphopeptides,CPPs),产率为15.87%,得到的CPPs可以使钙沉淀推迟23 min,有利于钙离子被肠道有效吸收。以水牛乳为底物时,乳凝固后析出的乳清中含酪蛋白糖巨肽6.61 mg/mL,糖基化程度477.527 μg/mg。研究为新型植物凝乳酶的研发,及其在奶酪、酪蛋白活性肽等产品的应用提供科学依据。 相似文献
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研究婴儿双歧杆菌的生长促进剂,并对活化菌种进行耐氧驯化培养,探讨婴儿双歧杆菌在搅拌花生酸奶加工中的应用。结果表明:酵母浸出液对婴儿双歧杆菌活化影响最大,酪蛋白胨次之,磷酸氢二钾最小,三者最佳水平组合:酵母浸出液0.4%,酪蛋白胨0.2%,磷酸氢二钾0.1%。菌种被连续活化三代后凝乳时间稳定至3.5h。通过对4种因素婴儿双歧杆菌生长的影响研究发现:鲜牛奶与花生乳配比的影响最大,其次是蔗糖,再次是接种量,最后是葡萄糖。当鲜牛奶与花生乳配比1∶1,蔗糖6%,葡萄糖2%,接种量5%,婴儿双歧杆菌达到最佳生长状态,活菌数达到2.5×109 CFU/mL。 相似文献
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响应面法优化Camembert干酪加工工艺 总被引:1,自引:0,他引:1
在氯化钙添加量、凝乳酶添加量、凝乳温度、排乳时间等单因素实验的基础上,根据Box-Behnken中心组合实验设计原理,采用4因素3水平响应曲面分析法,以凝乳效果为响应值建立二次多项回归模型,并验证模型的有效性。实验结果表明:Camembert干酪最佳制作工艺为氯化钙添加量为0.06%,凝乳酶添加量为0.02%,凝乳温度为32℃,排乳时间为30min。在此条件下,理论凝乳效果得分为89.63,验证值为89.50。 相似文献
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为发掘性能优良的产凝乳酶细菌菌株,开发新型细菌凝乳酶。本文采用酪蛋白培养基从采自青海牧区土壤样品分离筛选产凝乳酶细菌,利用菌株16S rDNA基因序列对菌株进行鉴定并分析其多样性。结果表明,36个样品中分离得到21株产凝乳酶细菌,沉淀圈与菌落直径比值为1.41~5.5;分离菌株在不同培养基上凝乳酶和蛋白水解活性有明显差异,麸皮汁培养基中凝乳酶活性为11.3~1215.6 SU/mL,蛋白水解活力为14.6~59.5U/mL;21株菌中有14株菌属芽孢杆菌属(Bacillus),是产凝乳酶细菌的优势属;多样性指数分析表明,该地区产凝乳酶细菌具有丰富多样性。 相似文献
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R. Anusha Maheshwari Kumari Singh O. S. Bindhu 《European Food Research and Technology》2014,238(6):997-1006
The steady increase in world cheese demand keeps the search for appropriate coagulating enzymes as rennet substitutes in the scientific focus. This work reports the milk-clotting activities of aqueous crude enzyme (CE) from different parts of Calotropis gigantea using skim milk as substrate. CE from latex exhibited high caseinolytic (86.445 ± 1.055 U/ml) as well as milk-clotting activity (450 U/ml) when compared to other parts. Significant milk clotting index (MCI) was presented by crude enzyme of latex followed by stem, flower and leaf in the decreasing order (p < 0.05). CE from all parts showed an optimum activity at 37 °C, pH 5.5 and 10 mM calcium chloride concentration with excellent pH (4.5–6.5) and thermal stability (30–60 °C). Hydrolysis pattern of casein components by CE during 1 h incubation, as assessed by Tricine–SDS-PAGE, and subsequent peak analysis revealed CE from stem to be closely similar to that of rennin. However, extensive casein hydrolysis was observed when incubated with crude latex enzyme. Casein bands of CE and rennin tended to disappear as incubation progressed to 24 h. Proteolytic degradation was found to be advanced and resulted in complete breakdown of casein fractions unravelling the importance of incubation time as a possible essential requisite for controlled and appropriate casein hydrolysis. The study provides evidence of rennin-like activity associated with C. gigantea plant parts which may serve as a promising source of vegetable milk coagulant. 相似文献
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Eight milk-clotting enzyme prepartations were standardized to equal clot time and used to coagulate pasteurized whole milk. Diffuse reflectance profiles were monitored for 60-min using a fiber optic sensor sensitive to infrared light at 950 nm. Modified M. miehei and M. pusillus protease, recombinant chymosin and calf rennet produced similar profiles. Rates of increase in diffuse reflectance were E. parasitica recombinant chymosin > calf rennet > modified M. miehei, M. pusillus var. Lindt > 50:50 blend of calf rennet and bovine pepsin > unmodified M. miehei > pepsin. Monitoring milk coagulation as described may be useful during cheese making and allow setting optimal conditions for milk-clotting enzyme preparations. 相似文献
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Pontual EV Carvalho BE Bezerra RS Coelho LC Napoleão TH Paiva PM 《Food chemistry》2012,135(3):1848-1854
This work reports the detection and characterization of caseinolytic and milk-clotting activities from Moringa oleifera flowers. Proteins extracted from flowers were precipitated with 60% ammonium sulphate. Caseinolytic activity of the precipitated protein fraction (PP) was assessed using azocasein, as well as α(s)-, β- and κ-caseins as substrates. Milk-clotting activity was analysed using skim milk. The effects of heating (30-100°C) and pH (3.0-11.0) on enzyme activities were determined. Highest caseinolytic activity on azocasein was detected after previous incubation of PP at pH 4.0 and after heating at 50°C. Milk-clotting activity, detected only in the presence of CaCl(2), was highest at incubation of PP at pH 3.0 and remained stable up to 50°C. The pre-treatment of milk at 70°C resulted in highest clotting activity. Enzyme assays in presence of protease inhibitors indicated the presence of aspartic, cysteine, serine and metallo proteases. Aspartic proteases appear to be the main enzymes involved in milk-clotting activity. PP promoted extensive cleavage of κ-casein and low level of α(s)- and β-caseins hydrolysis. The milk-clotting activity indicates the application of M. oleifera flowers in dairy industry. 相似文献