The effect of artificial reduction of the somatic cell count, as a violation of authenticity, on milk quality indicators

The somatic cell count (SCC) in raw milk is an important indicator of health and hygienic quality. Artificial reduction of the SCC (ARSCC) in milk, for the apparent improvement of milk quality for commercial reasons, is an undesirable phenomenon and a violation of authenticity both in the factual sense and legislatively. Analytical methods need to be developed to identify ARSCC as well as to assess the effects that ARSCC may have on milk. The aim of the work was to quantify the effects of ARSCC on cow's milk as a food raw material. The results presented are some of the first on the given problem. Raw bulk tank cow milk was sampled in two experiments, each time for the whole year (2021-2022 and 2023-2024, n = 66 and n = 53, respectively) from herds of Czech Fleckvieh and Holstein cows, 1 : 1. ARSCC in experiment 1 (n = 66) slightly reduced the fat content, in experiment 2 (n = 53) it did not, otherwise the milk indicators with the exception of SCC were almost (1) and completely (2) identical. All samples were negative for the presence of inhibitory substance residues. ARSCC under the specified technological conditions reduced SCC (1) from 772 ± 906 103/ml to 376 ± 630 103/ml, by -51.3% (P < 0.001) and (2) from 592 ± 798 103/ml to 304 ± 468 103/ml, by -48.5% (P < 0.001). Under these circumstances, the milk fermentation ability improved (1) from 28.52 ± 4.72 °SH to 31.0 ± 4.65 °SH, by 8.66% (P < 0.001) and (2) from 32.51 ± 2.61 °SH to 33.80 ± 2.88 °SH, by 3.97% (P < 0.001). Curd firmness was better for SCC ≤ 400 103/ml compared to higher SCC by 5.26% (P < 0.001). Nevertheless, it is not possible, for hygienic and health reasons, to allow such milk for human consumption and it is necessary to find effective identification analytical methods for ARSCC.