Technical University of Cluj Napoca, North University Center of Baia Mare, No. 76 Victoriei Street, Baia Mare, Romania.
Technical University of Cluj Napoca, North University Center of Baia Mare, No. 76 Victoriei Street, Baia Mare, Romania.
Ultrason Sonochem. 2022 Sep;89:106155. doi: 10.1016/j.ultsonch.2022.106155. Epub 2022 Sep 5.
This study aimed to evaluate the influence of different power-time ultrasound regimes of pasteurization on the physical, chemical, organoleptic properties, and lipid quality indices of goat curds characterized by a low cholesterol level. Cholesterol was eliminated by a percentage of 92.1 % by treating the raw goat milk with beta-cyclodextrin in the proportion of 0.6 %. Afterward, the goat milk was subjected to the following ultrasound regimes: 320 W for 1 (PA1), 3 (PA3), and 6 min (PA6) and 881 W for 1 (PP1), 3 (PP3), and 6 min (PP6) and then used for the curds production. Due to the ultrasound treatment, the milk suffered a concentration phenomenon, the most accentuated being registered for the PP6 sample. Considering the sensory properties, the most appreciated curd was the one obtained by the PP6 regime which recorded the highest scores for color and taste. Regarding the microbiological aspects, the ability of ultrasounds to inactivate microorganisms is observed and the most accentuated phenomenon is reported in the PP6 case. Thus, in comparison with the control sample, the total number of germs is reduced by a proportion of 91.85 %, the β-glucuronidase-positive Escherichia coli decreased by 93.15 %, while the coagulase-positive staphylococci were completely inactivated for the PP6 curd. The curds obtained for the PA6 and PP6 regimes registered the highest dry matter values as a cause of an accentuated syneresis process. The acidity values were higher for the curds obtained for PA1, PA3, and PA6 regimens due to more pronounced lactose hydrolysis and lower in the cases of PP3 and PP6 regimens compared to the control cheese. Twenty-five saturated, monounsaturated, and polyunsaturated fatty acids were identified in the curd samples and a rise in the unsaturated fatty acids proportion as the intensity of the applied ultrasound regime increased was observed. Also, AI, TI, and H/H lipid quality indices recorded better values as the power and time of the ultrasound action increased.
本研究旨在评估不同功率-时间超声处理对巴氏杀菌后羊奶凝乳的物理、化学、感官特性和脂质质量指数的影响，该羊奶凝乳的胆固醇水平较低。通过在生羊奶中添加 0.6%的β-环糊精，将胆固醇去除 92.1%。然后，羊奶分别采用 320W 处理 1（PA1）、3（PA3）和 6 分钟（PA6）以及 881W 处理 1（PP1）、3（PP3）和 6 分钟（PP6），然后用于凝乳生产。由于超声处理，牛奶发生了浓缩现象，其中 PP6 样品的浓缩现象最为明显。就感官特性而言，最受赞赏的凝乳是 PP6 处理得到的凝乳，其颜色和味道得分最高。就微生物学方面而言，观察到超声能使微生物失活，在 PP6 的情况下，这种现象最为明显。因此，与对照样品相比，总菌数减少了 91.85%，β-葡糖苷酸阳性大肠杆菌减少了 93.15%，而 PP6 凝乳中的凝固酶阳性葡萄球菌完全失活。PA6 和 PP6 处理得到的凝乳的干物质含量最高，这是由于更剧烈的胶凝收缩过程。由于乳糖水解更明显，PA1、PA3 和 PA6 处理得到的凝乳的酸度值更高，而与对照奶酪相比，PP3 和 PP6 处理得到的凝乳的酸度值更低。在凝乳样品中鉴定出 25 种饱和、单不饱和和多不饱和脂肪酸，随着施加的超声处理强度的增加，发现不饱和脂肪酸的比例增加。此外，随着超声作用的功率和时间的增加，AI、TI 和 H/H 脂质质量指数记录到更好的值。
