RAW QUALITY OF MILK PRODUCED AND STORED IN BULK TANKS IN GOIAS STATE, BRAZIL

Abstract

This research aimed to evaluated the raw milk quality in samples obtained from bulk tanks in the Goiás State. Thirty raw milk  samples of 1000 mL were harvest. It was performed the following analyses: total bacterial count (TBC) by Flow Citometry, search for the presence of residues of antimicrobial agents by the Delvotest® SP kit and investigation for the fraud by adding to milk the following substances: hydrogen peroxide, formaldehyde, sodium bicarbonate and sodium hydroxide. It was not found any residues of antimicrobial agents in all (100%) samples. Physicochemical test also showed the absence of hydrogen peroxide, formaldehyde, sodium bicarbonate and sodium hydroxide in milk. About TBC, it was observed that 30% (9/30) of bulk tanks showed TBC>106 CFU/mL, in 46.67% (14/30) the TBC was between 105 to 106 CFU/mL and 23.33% (7/30) showed TBC <105 CFU/mL. Means observed were TBC of 9.2 X 106, TBC of 4.5 X 105, TBC of 5.1 X 104, respectively. From bulk tanks with TBC>106 CFU/mL, 100% were available for common utilization and had significantly higher values for TBC (P<0.05). Educational standards and training about the hygienic procedures applied to milk obtainment and to milking equipments, a well implemented mastitis control program and correct use of milk cooling system after milking must be adopted in order to provide a better raw milk quality. These measures provide benefits to industry due to the higher income of quality raw material. It also provides benefits for the farmer, since they can receive a better wage from dairy companies that pay higher for better quality products; to the trade because quality products have a longer shelf-life and to consumer, that can have an increase in quality of life.

KEY WORDS: CFU, raw milk,  quality, residues.