Survival of <i>Lactobacillus acidophilus </i>in Fruit-Flavored Greek Yogurt Acid Whey

Greek yogurt has become much more popular within the last 15 to 20 years. The by-product of Greek yogurt manufacture is acid whey. Although acid whey has been considered a waste product, researchers are exploring various uses of this whey. Since the health benefits of consuming probiotics are widely known, one may propose adding probiotics to acid whey to form a probiotic beverage. Typically, probiotic bacteria do not thrive in acidic conditions. It would be beneficial to determine if the probiotic Lactobacillus acidophilus can survive in these acidic conditions. The objectives were to determine the growth of L. acidophilus in acid whey resulting from manufacturing Greek yogurt and to study any changes in apparent viscosity, pH, and titratable acidity over 4 weeks of refrigerated storage. Plain yogurt was manufactured, and whey was separated from plain yogurt to yield Greek yogurt and acid whey. Acid whey was batch pasteurized, cooled, sweetened, flavored with pineapple flavoring, inoculated with L. acidophilus, and stored at 4°C for 4 weeks. The log L. acidophilus counts progressively decreased from 7.84 immediately after manufacture to 2.06 at week 4. There were no significant changes in pH and titratable acidity of the pineapple-flavored probiotic acid whey over 4 weeks of storage, indicating product stability over shelf life. Viscosity changed over the storage time with minimum values at week 2 and maximum values at week 4. Although the counts declined over 4 weeks of storage, some L. acidophilus survived in the pineapple-flavored acid whey.

奇亚籽希腊式酸奶的工艺优化研究

目的优化奇亚籽希腊式酸奶的配方和工艺,并考察其抗氧化性。方法以纯牛奶为主要原料,奇亚籽、混合发酵剂、乳清蛋白和白砂糖为辅料制作希腊式酸奶,以感官评分为评价指标,通过单因素试验和正交试验方法研究奇亚籽希腊式酸奶的最佳配方和工艺。结果奇亚籽添加量、混合发酵剂添加量、乳清蛋白添加量、白砂糖添加量、发酵温度和发酵时间因素均对奇亚籽希腊式酸奶的感官品质产生明显影响。其最佳配方和工艺为:以纯牛奶质量为基础,奇亚籽添加量4%、混合发酵剂添加量0.3%、乳清蛋白添加量4%、白砂糖添加量9%、发酵温度42℃、发酵时间6 h。在此条件下,奇亚籽希腊式酸奶的蛋白质含量5.37 g/100 g,pH为4.56,DPPH自由基清除率为44.68%。结论适量添加奇亚籽可改善希腊式酸奶的感官品质,并提高其营养价值,所制奇亚籽希腊式酸奶具有一定的抗氧化效果。

响应面法优化褐色希腊式酸奶的生产工艺

以牛奶、乳清蛋白和葡萄糖为原料,研究了褐色希腊式酸奶的生产工艺。在单因素试验的基础上,采用响应面法研究了乳清蛋白添加量、接种量、发酵温度对褐色希腊式酸奶品质的影响,建立了二次回归模型,确定了最佳工艺条件:乳清蛋白添加量1.2%,接种量5%,发酵时间6 h,此时酸奶呈现黄褐色,焦糖风味突出,口感细腻浓稠,感官评分86分,与模型预测值基本相符。

百合希腊式酸奶的研制及其抗氧化活性研究

以百合、乳清蛋白和稀奶油为主要研究对象,利用单因素试验和正交实验优化百合希腊式酸奶的最佳配方。利用Fenton反应法、邻苯三酚自氧化法和1,1-二苯基-2-三硝基苯肼(DPPH)比色法测定百合希腊式酸奶对羟基自由基(·OH)、超氧阴离子(O2-)和DPPH的清除能力。结果表明,百合希腊式酸奶的最佳配方为百合浆添加量7%,乳清蛋白添加量1.2%,稀奶油添加量8%,发酵剂接种量0.500%。抗氧化实验表明10 g百合希腊式酸奶对·OH、O2-和DPPH的清除率分别为51.33%,29.36%和12.41%,显著高于对照组(P<0.05),可见百合的添加显著提高了产品的抗氧化活性。

希腊式酸羊奶的研制

以新鲜羊奶为主要原料,添加羊乳清粉,研究了希腊式酸羊奶的工艺条件。通过单因素试验和正交试验,以感官评分及酸度为评价指标,确定希腊式酸羊奶的最佳发酵工艺条件。结果表明,希腊式酸羊奶的最佳发酵工艺条件为羊乳清粉添加量1.0%,接种量6%,发酵温度42℃,发酵时间8 h。在此最佳条件下,感官评分达到87分,酸度为97°T。希腊式酸羊奶质地均匀,口感细腻浓郁,酸甜适中,发酵乳香味明显,羊膻味不明显,其理化及微生物指标均符合相关国家标准。

希腊酸奶工艺及乳清利用研究进展

随着消费升级的驱动,消费者对优质天然营养食品的摄取日益重视,这也为酸奶市场带来新一轮契机。希腊酸奶由于其丰富的营养和细腻浓密的口感进入了大家的视线。本文将从希腊酸奶的发展现状、生产工艺、副产品乳清的利用等方面进行阐述,以期对希腊酸奶的研制开发提供一定的理论基础。

希腊式酸奶的研制

研制希腊式酸奶,确定希腊式酸奶的最佳配方为鲜牛奶40%、白砂糖8%、脱脂奶粉:WPC为80:20、酪蛋白酸钠2‰、菌种为YO-MIXTM495;同时确定了制作希腊式酸奶的最佳水合条件为50℃、60min,发酵终点pH值控制在4.65。

希腊式酸奶加工中HACCP体系的建立

本文依据HACCP体系的基本原则,对希腊式酸奶加工过程进行危害分析(HA),并确定了加工中的关键控制点(CCP),同时制定了相应的控制限值和监控措施,以期通过这些措施提高希腊式酸奶生产管理水平和产品的质量水平。