Seasonal variations in some quality parameters of milk produced in Khorasan Razavi Province, Iran

Abstract In this trial, 60 samples of raw cow’s milk collected during summer and winter in five collective centers from Khorasan Razavi Province of Iran were analyzed for penicillin residues, somatic cell counts (SCC), mesophilic counts (TMC) and adulteration materials. The mean penicillin level (0.57 ± 0.20 μg/L) was much lower than the maximum permitted level (MPL) recommended by the Codex Alimentarius Commission (4 μg/L). However, the mean SCC and TMC (Log 5.71 ± 0.08 cells/mL and Log 6.18 ± 0.11 colony forming units (CFU)/mL, respectively) exceeded their respective MPLs adopted in Iran for grade C milk (Log 5.69 cells/mL and Log 6.0 CFU/mL, respectively), with higher counts (P < 0.05) in the summer. High frequencies of samples containing salt (53-60%), detergents (16-20%) and formalin (7-10%) were observed in milk samples, stressing the need for stringent control measures to improve the quality of milk delivered in the evaluated collection centers.