添加茶油胶对植物油基酸奶品质特性的影响

以脱脂牛乳和茶油为主要原料,经发酵工艺制成茶油基酸奶。以全乳脂酸奶和脱脂酸奶为对照,研究酸奶的理化、质构、流变性及感官品质等特性并进行相关性分析。结果表明,添加茶油胶能明显改善酸奶的凝乳品质。当茶油胶添加量为3.4%时,酸奶的酸度最高（104 °T）,其硬度、黏稠度、表观黏度等指标均优于对照样品;其感官评分最高（93.99分）,表明其良好的品质和感官接受度,以茶油为原料开发植物油基酸奶具有可行性。     

4种植物油制备调配型发酵乳品质对比研究

以全脂发酵乳和脱脂发酵乳为对照,对以4种植物油(葵花籽油、大豆油、油茶籽油、花生油)代替乳脂肪制备的发酵乳的品质进行比对研究,利用模糊数学综合评价法得到感官评分。结果表明:植物油的添加延长了发酵乳的凝乳时间,不同程度地提高了发酵乳的酸度、表观黏度、硬度和黏稠度等理化指标,改善了发酵乳的凝乳品质;以葵花籽油发酵乳的品质为最佳,其感官评价分值最高,表现出良好的应用价值和公众接受度。     

马铃薯山药复合大豆酸乳的制备及贮藏品质研究

以大豆为主要原料,添加马铃薯浆和山药浆,接种乳酸菌发酵制成蛋白保健酸乳。通过单因素试验,研究马铃薯浆、山药浆与 乳液配比对酸奶贮藏品质的影响。 结果表明,原料最适宜配比为马铃薯浆∶山药浆∶乳液=3∶15∶82（V/V）,以此制备的酸乳其贮藏品质 优于其他酸乳样品,其贮藏1 d感官评分为91.37分,贮藏3 d感官评分为90.65分,稳定性良好;酸乳色泽均匀,口感柔滑细腻,具有发酵 豆乳的纯正风味并与马铃薯、山药香味和谐。     

酸浆果保健酸乳的质地及理化性质研究

以蛋白质含量、脂肪含量、pH值、持水力、流变学特性和质构特性为主要测定指标,通过单因素试验,研究了酸浆果浆添加量 对酸乳理化及感官性质的影响。结果表明,酸浆果浆添加量的变化对酸乳的理化及感官性质有明显影响;酸浆果浆添加量为10%的 酸乳样品在5组样品中感官评分最高（94.7分）,各项理化指标均符合发酵乳国家标准;酸乳样品的黏聚性和胶着性分别与硬度具有 显著相关性（P＜0.05）;所酿造的酸浆果保健酸奶呈现均匀的橙黄色,组织细腻,具有酸浆果特有的香味,酸甜爽口。     

柳松菇抽提物对乳酸菌发酵性状的影响

将柳松菇抽提物添加到脱脂乳中，以嗜热链球菌和嗜酸乳杆菌为发酵剂制成发酵乳，考察柳松菇抽提物对发酵乳的凝乳时间、凝乳效果、在发酵及贮存过程中乳酸菌的生长、滴定酸度、pH值、黏度及感官性状等的影响。结果表明，5％的添加量能明显促进乳酸菌在乳中的生长，提高产酸速率，缩短凝乳时间，增强凝乳效果，改善发酵乳品质。     

不同改性淀粉对冷冻酸乳冰淇淋品质的影响

通过添加不同改性淀粉制备冷冻酸乳冰淇淋,分别研究不同改性淀粉及添加量在冷冻处理前对酸乳样品的硬度和黏度的影响,以及在冷冻处理后对冷冻酸乳冰淇淋样品冻融稳定性和感官品质的影响。结果显示,随着改性淀粉添加量在0～1.2 g/100 g范围增加,酸乳样品的硬度和黏度均呈现不同程度的增加,并且全部冷冻酸乳冰淇淋样品的乳析指数均呈现不同程度的下降,其中添加辛烯基琥珀酸酐（OSA）酯化淀粉微粒的样品,其硬度和黏度的增幅最大,分别为67.64%和93.43%,并且表现出最佳的冻融稳定性,其乳析指数下降幅度最大,为52.28%。当OSA酯化淀粉微粒添加量为0.8 g/100 g时,其感官品评综合得分最高,为90.54分,表明此种改性淀粉在提高冷冻酸乳冰淇淋品质上具有良好的应用效果。     

模糊数学评价与响应面结合优化番石榴酸乳发酵工艺

为优化番石榴酸乳的感官品质,以番石榴、牛乳为主要原料,采用响应面优化设计结合模糊数学评价对番石榴酸乳的制作工艺进行优化。结果表明,当番石榴果浆添加量20%、砂糖添加量8%、发酵温度42 ℃、发酵时间9 h、后熟时间20 h时,番石榴酸乳的乳清析出率0.67%,感官评分92.53分,由响应面优化设计得到的番石榴酸乳,其乳清析出率和感官评价结果与模糊数学评价结果相符,模糊数学评价可以作为番石榴酸乳感官品质评价指标;工艺条件对番石榴酸乳成品的乳清析出率和感官品质均呈极显著影响（P＜0.01）。优化后的番石榴酸乳表面光洁呈淡红色,颜色均匀、美观,口感清爽、润滑,风味特异,是一种极具开发价值的功能性乳制品。     

酶法制备天然牛奶香精的工艺条件与应用研究

奶油酶解增香的研究主要是以奶油或无水奶油为原料,利用不同来源的脂肪酶对乳脂肪进行适当酶解,通过控制酶解程度得到具有不同香气特征的酶解产物。本文在奶油酶解工艺单因素研究与特征风味组分研究的基础上,对酶解奶油产物进行风味修饰得到自制天然牛奶香精,并对其与市售商品天然牛奶香精、合成牛奶香精样品在复原乳中的感官品质进行比较评定。研究结果表明添加相同比例的商品天然牛奶香精和自制天然牛奶香精的脱脂复原乳样品的感官评定结果没有差异,即自制天然牛奶香精与商品天然牛奶香精在脱脂复原乳中的感官品质基本相同。此外,感官评价结果还表明添加有合成牛奶香精的复原乳样品中奶香味过于冲鼻且留香持久性较差,感官品质相对一般。     

响应面法优化米酒奶酪的发酵工艺

以纯牛奶、脱脂乳粉和糯米为主原料,将米酒加入牛奶使其凝固制得奶酪,并添加白砂糖调节口感。首先通过Arima法测定米酒中的凝乳酶活性,再以感官指标进行评分,通过Box-Behnken试验研究米酒添加量、脱脂乳粉添加量和白砂糖添加量对米酒奶酪品质的影响,并通过响应面法优化米酒奶酪的试验工艺条件,最终得到米酒奶酪的最佳工艺条件为:米酒添加量16%、脱脂乳粉添加量9%、糖添加量5%。米酒奶酪不但营养丰富,口感优良,而且具有一定的保健功能。     

火麻仁油凝固型酸奶的品质研究

为了获得风味良好的火麻仁油酸奶,本文以脱脂酸奶和全脂酸奶为对照,以火麻仁油和脱脂乳粉配成复合乳,经微射流处理后,发酵制备出以火麻仁油替代乳脂的凝固型火麻仁油酸奶,进一步研究了其流变学性质、微观结构、挥发性风味成分以及感官评价。结果表明微射流处理能获得质地均一的火麻仁油酸奶。当火麻仁油用量在3.0%时,火麻仁油酸奶的持水力、流变学性质及网络结构均与全乳脂酸奶接近,但挥发性香气成分及感官评价差异比较大,其中酸奶的特征性香气成分3-羟基-2-丁酮和2,3-丁二酮的含量比全乳脂酸奶低,并含有火麻仁油的特征性成分石竹烯、D-柠檬烯和β-月桂烯等;当火麻仁油的含量为1.5%时,火麻仁油酸奶的酸度值为97oT、持水力为85%、屈服应力τ0为15 Pa、表观粘度η50为0.54 Pa·s,总体可接收度与全乳脂酸奶没有显著性差异(p0.05)。可见,1.5%的火麻仁油酸奶总体可接受度高,具有良好的应用前景。     

凝固型咖啡酸奶的研制

以全脂乳粉、脱脂乳粉、咖啡为主要原料,添加蔗糖,以安琪酵母8型菌为发酵剂,酸奶感官品质评分和酸奶黏度的综合评分为考察指标,采用正交试验方法对凝固型咖啡酸奶配方进行优化,得到最佳的发酵咖啡酸奶的工艺与配方。结果表明,在发酵温度为42 ℃条件下发酵6 h,脂肪含量3.4%,咖啡添加量1.0%,蔗糖添加量6%,8菌型发酵剂添加量0.1%,发酵后在4 ℃条件下冷藏24 h,获得的发酵酸奶的感官品质评分为89分,黏度为5 640 mPa·s,产品组织状态均匀,口感细腻,略带有咖啡香味,感官评价最佳。最佳发酵条件下的酸度为88 °T,pH值为4.24,乳酸菌活菌数为1.25×108 CFU/mL,符合GB 19302—2010对酸奶品质的规定。     

芦荟山药酸奶的研制

芦荟山药酸奶是以库拉索芦荟、新鲜山药和脱脂奶粉为原料,用保加利亚乳杆菌和嗜热链球菌以1:1混合作为发酵剂进行乳酸发酵,制得的一种集芦荟、山药和酸奶于一体的新型保健乳品。通过单因素和正交试验对芦荟山药酸奶的配方和发酵工艺条件进行了优化。研究表明,芦荟山药酸奶的最佳发酵工艺条件为:乳酸菌接种量4%,发酵温度42℃,主酵时间5h;最佳配方为:粉水比为1:9,其中粉由山药粉和脱脂奶粉以4:6配比而成,白砂糖7%,芦荟汁10%,稳定剂为黄原胶0.20%、CMC-Na0.16%和海藻酸钠0.25%三者混合而成。在此工艺条件下制备的芦荟山药酸奶具有感官品质佳、稳定性好和营养丰富等特点。     

绿豆桂圆果肉酸奶的研制

根据搅拌型酸奶的制造原理,以辉山自营牧场的优质鲜牛奶为原料,适量添加白砂糖、脱脂乳粉、稳定剂,经乳酸茵发酵后加入绿豆沙和桂圆果内,研制出具有绿豆桂圆的保健功能、营养丰富的酸奶制品.     

搅拌型桑椹酸乳的研制

以桑椹汁和乳粉为主要原料,研制了一种复合型发酵酸乳。从产品感官质量和稳定性入手,应用正交试验法,确定了合理的配方和适宜的发酵工艺条件。结果表明,桑椹酸乳的主要原料的最佳配比为:乳粉与水质量之比为1∶8,桑椹汁添加量7.5%,复合稳定剂为0.15%淀粉+0.03%果胶+0.06%CMC-Na+0.15%海藻酸钠,最佳的发酵工艺条件为:接种量5%,发酵温度42℃,发酵时间2.5h。     

In vitro studies of adsorption of milk proteins onto tooth enamel

The aim of this investigation was to study in vitro adsorption of milk proteins onto tooth enamel. In vitro “milk protein pellicles” were formed on enamel specimens incubated in fluid milk products: skimmed milk (pH 6.7), acidified skimmed milk (pH 4.2), yoghurt and neutralized yoghurt (pH 6.7). The enamel specimens were used as such or pre-incubated in saliva. The “milk pellicles” were desorbed from enamel surfaces, and proteins separated by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Proteins were identified by their pattern of migration in SDS-PAGE or by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) fingerprinting. Neutral “milk protein pellicles” (skimmed milk and neutralized yoghurt) mainly consisted of caseins. At pH values close to their isoelectric point, caseins remained unabsorbed, and lactoferrin and bovine serum albumin were the most abundant protein species in the acidified “skimmed milk pellicle”. Virtually no proteins in yoghurt were able to adsorb onto enamel. Pre-incubation of enamel specimens in saliva did not inhibit or affect “milk pellicle” formation indicating that in vivo adsorption of milk proteins may occur on tooth surfaces in the oral cavity and have implications in oral hygiene.     

Production and evaluation of some physicochemical parameters of peanut milk yoghurt

The peanut milk for yoghurt production was prepared by fortifying peanut milk (∼12 g/100 g total solids) with 4 g/100 g skimmed milk powder. The final product was subjected to physicochemical analysis using cow milk yoghurt (CMY) as a control throughout the study. Peanut milk yoghurt (PMY) had higher protein content, fat, water holding capacity and lower susceptibility to Syneresis than CMY. PMY had lower lactose level (1.73 g/100 ml) compared to CMY (4.93 g/100 ml). Generally both PMY and CMY had high mineral composition and contained high amounts of essential amino acids. PMY also contained a higher proportion of unsaturated fatty acids than saturated fatty acids as compared to CMY. Therefore, in terms of fatty acid composition, PMY could be considered to be more health promoting than CMY. Sensory evaluation revealed that though PMY had better sensory texture scores than CMY, its sensory appearance, flavor and overall acceptability scores were lower than those of CMY.     

鲜白莲发酵乳酸饮料加工工艺

以鲜白莲、脱脂乳为主要原料,运用正交试验法对鲜白莲发酵乳酸饮料的加工工艺进行研究,结果表明饮料的最佳配方为:莲子乳60%,脱脂乳20%,蔗糖7%,感官评分为89;复合乳化稳定剂最适配比为单甘酯0.05%,蔗糖酯0.10%,黄原胶0.05%,海藻胶0.05%,卡拉胶0.10%。     

The effect of commonly used dairy processing techniques and unit operations on the equol content of dairy products

Since a large portion of the milk consumed by human is processed, the aim of this study was to determine possible changes in equol content upon processing milk. Individual milks with different levels of equol content were collected from the morning milking to make skimmed milk and cream, as well as pasteurised and sterilised full fat milks. Pasteurised milk was further processed into yoghurt, kefir, cottage cheese and whey. Yoghurt and kefir were also produced from sterilised milk. Equol content was not affected by either pasteurisation or sterilisation. Compared with raw milk, a higher concentration of equol was measured in skimmed milk, but equol content in cream was lower. The concentration of equol remained unchanged after yoghurt production but was reduced by more than 50% after kefir production. The equol content in whey was low compared with that of raw milk, while it increased sharply in cottage cheese.