Comparative study on the chemical and microbiological properties of goat milk pasteurization through serial and circulation systems of ultraviolet method

Abstract

The aim of research was to evaluate goat milk pasteurization with exposure of ultraviolet rays serial and circulation systems. The chemical properties parameters measured covering fat content, non-fat dry material content, protein content, and lactose content as well as microbiology testing of Total Plate Count method. Discharge of milk flow was obtained 4.32 ± 0.71 cc/sec. Time needed to fully fill the UV reactor with 230 ml volume was 53.24 second. In serial system showed that chemical properties were not significantly different with 0.5 percent significance level. In the circulation system, with flow rate speed 10 cc/sec with the dosage of 1.56 J/ square cm shows that the treatment 2, 4 and 6 of circulation in the treatment of protein content gave different effect from the control. Other treatments were not different from the control. The treatment with three reactors that arranged in serial was the best treatment with inactivation of microorganism and the dosages of the reactor 1, 2 and, 3 of 0.11; 0.25; 0.51 log cycle and 1.81 J/square cm; 3.62 J/ square cm; 5.43 J/ square cm respectively. D value was 313.49 sec with speed rate and treatment time of 4.32±0.71 cc/sec and 159.72 sec respectively.