The investigation of suitability of raw milk consumption from vending machines in Croatia

The consumption of raw milk from vending machine in Croatia has increased in recent years. However, its health safety is insufficiently investigated and controlled. The objective of this study was to investigate the suitability of raw milk consumption, from 28 vending machines from 3 counties in Croatia during one-year research period, based on the physicochemical and hygiene quality. Also, the simulation of psychrothrophic bacteria growth has been conducted in order to determine its optimal storage time because of their unfavorable effect on the milk quality. The physicochemical composition of milk samples (n=320) was determined by the infrared spectrometry (chemical composition) and cryoscopic method (freezing point), while hygiene quality was estimated with a total bacterial count (TBC) and a somatic cell count (SCC). Microbiological analyses included determining the presence of Enterococcus spp., Pseudomonas spp. and the pathogenic species. Satisfactory quality of raw milk was established in 95% (chemical quality) and 70% unadulterated samples (without added water). The prescribed hygiene quality was met by 36.6% (TBC) and 71.9% (SCC) samples. Of total 320 samples, the presence of bacteria in genus Enterococcus spp. and Pseudomonas spp. was confirmed in 93.4% and 96.9% samples, respectively, and bacteria Escherichia coli, Staphylococcus aureus, Lysteria monocytogenes was confirmed in 32.2%, 27.5% and 3.8% samples. The finding of Salmonella spp. and Yersinia enterocolitica was negative. At the end of the study improvement of the microbiological quality of raw milk from vending machines was established. The results indicate the need for systematic control and obligate thermal treatment of raw milk before consumption.