Ivanova Ivelina, Ivanova Mihaela, Ivanov Galin, Bilgucu Ertugrul
Department of Analytical Chemistry, Technological Faculty, University of Food Technologies, Plovdiv, Bulgaria.
Department of Milk and Dairy Technology, Technological Faculty, University of Food Technologies, Plovdiv, Bulgaria.
J Food Sci Technol. 2021 Sep;58(9):3409-3416. doi: 10.1007/s13197-020-04935-z. Epub 2021 Jan 6.
Comparative studies on physicochemical characteristics of milk with different somatic cells count (SCC) (L-low < 400,000 cells/ml, M-medium between 500,000 and 600,000 cells/ml and H-high > 1,000,000 cells/ml) and obtained cheeses, were conducted. No significant differences between samples were found. The H SCC milk was characterized by the highest total viable count. Higher levels of proteolysis were established in cheeses made from milk with SCC exceeding 500,000 cells/ml. After 10 months of ripening and cold storage the water-soluble nitrogen in total nitrogen (WSN/TN), noncasein nitrogen in total nitrogen (NCN/TN), nonprotein nitrogen in total nitrogen (NPN/TN) and free amino groups values of the sample with the highest SCC reached 28.4 ± 0.8%, 24.8 ± 0.9%, 18.3 ± 0.9% and 83.6 ± 0.3 mg/kg respectively. The biogenic amine concentration in the cheese samples from the L and M batches remained below 10 mg/kg throughout the ripening and cold storage period. The present study established an increase in the biogenic amine content during the ripening period and the cold storage of the cheeses made from milks with high SCC (batch H). The main amines accumulated at the end of the storage period (10th month) were tyramine (31.7 ± 0.3 mg/kg), putrescine (20.5 ± 0.2 mg/kg) and cadaverine (14.6 ± 0.2 mg/kg). Histamine was not found in any of the studied cheese samples.
对不同体细胞数(SCC)的牛奶(L - 低<400,000个细胞/毫升,M - 中500,000至600,000个细胞/毫升,H - 高>1,000,000个细胞/毫升)及其制成的奶酪的理化特性进行了比较研究。未发现样品之间存在显著差异。高SCC牛奶的特征是总活菌数最高。由SCC超过500,000个细胞/毫升的牛奶制成的奶酪中蛋白质水解水平更高。经过10个月的成熟和冷藏后,SCC最高的样品的水溶性氮占总氮的比例(WSN/TN)、非酪蛋白氮占总氮的比例(NCN/TN)、非蛋白质氮占总氮的比例(NPN/TN)和游离氨基的值分别达到28.4±0.8%、24.8±0.9%、18.3±0.9%和83.6±0.3毫克/千克。在整个成熟和冷藏期间,L批次和M批次奶酪样品中的生物胺浓度保持在10毫克/千克以下。本研究发现,在成熟期间以及由高SCC牛奶(H批次)制成的奶酪冷藏期间,生物胺含量会增加。储存期结束(第10个月)时积累的主要胺类是酪胺(31.7±0.3毫克/千克)、腐胺(20.5±0.2毫克/千克)和尸胺(14.6±0.2毫克/千克)。在所研究的任何奶酪样品中均未发现组胺。