| Abstract | Cilj rada bio je istražiti održivost fermentiranih mliječnih proizvoda od pasteriziranog (jogurt i
voćni jogurt) i nepasteriziranog mlijeka (kiselo vrhnje) u uvjetima pohrane u hladnjaku na
različitim temperaturnim uvjetima (+4 °C i +12 °C). Svi su proizvodi proizvedeni u OPG-u, od
mlijeka koje se dobiva iz vlastite proizvodnje. Provedene su senzorička, fizikalno-kemijska (pH),
te mikrobiološka pretraga (Salmonella spp., Listeria monocytogenes, kvasci i plijesni).
Proizvodi su uzorkovani 1., 3., 7. i 14. dan pohrane. U senzoričkoj pretrazi voćnog jogurta,
jogurta i kiselog vrhnja prvog dana pohrane nisu utvrđena značajnija odstupanja u ocjenjivanim
parametrima pa su miris i okus bili svojstveni vrsti proizvoda a konzistencija gusta, tekuća.
Praćenjem pH utvrđeno je da su vrijednosti u jogurtu (4,49-4,47; 4,49-4,43) i voćnom jogurtu
(4,39-4.40; 4,39-4,37) ostale gotovo identične na obje temperature pohrane dok su vrijednosti u
kiselom vrhnju rasle na +4 °C (4,61-4,75), a na +12 °C je mjerenje zaustavljeno zbog kvarenja
posljednjeg dana. U mikrobiološkoj pretrazi baterije Salmonella spp. i L. monocytogenes nisu
utvrđene. Enterobakterije u voćnom jogurtu i jogurtu nisu utvrđene od trećeg dana pohrane na
obje temperature, dok je u kiselom vrhnju njihov broj rastao do 2,1x105 CFU/mL na temperaturi
od +4 °C. Mikrobiološkom pretragom porast kvasaca u vrhnju utvrđen je već od prvog, a u
jogurtu od trećeg dana pokusa. U obje vrste uzoraka na +4 °C utvrđene su vrste Torulaspora
quercuum, Pichia fermentans, Galactomyces candidus (Geotrichum), dok su na +12 °C utvrđeni
još i Candida intermedia, Galactomyces geotrichum, te plijesan Aspergillus sp. Navedeni nalaz
sugerira kako su uzorci kontaminirani tijekom proizvodnje, te im je time narušena održivost, ali i
sigurnost. |
| Abstract (english) | The aim of this study was to investigate the viability of fermented dairy products from
pasteurised (yoghurt and fruit yogurt) and unpasteurised milk (sour cream) at different storage
conditions (+4 °C and +12 °C). All products are produced at the family farm, from milk obtained
from their own production. Sensory, physio-chemical (pH), and microbiological testing for
Salmonella spp., Listeria monocytogenes, and yeasts and moulds were performed. Products were
sampled on the 1st, 3rd, 7th and 14th day of storage. The sensory examination of fruit yogurt,
yoghurt and sour cream did not reveal significant deviations in the evaluated parameters during
storage, so the smell and taste were characteristic for the type of the product, and consistency
was thick, liquid. Monitoring of pH showed that the values in yogurt remained almost identical
at both storage temperatures (4.49-4.47; 4.49-4.43), and fruit yogurt (4,39-4.40; 4,39-4,37),
while the values in sour cream increased to + 4 °C (4.61-4.75), and at +12 °C the measurement
was stopped due to spoilage on the last day. Salmonella spp. and L. monocytogenes were not
detected in the microbiological examination. Enterobacteria in fruit yogurt and yogurt were not
detected from the third day of storage at both temperatures, while in sour cream their number
increased to 2.1x105 CFU/mL at a temperature of +4 °C. Microbiological examination showed
yeast growth in cream from the 1st day, and in yogurt from the 3rd day of the experiment. In both
types of samples at + 4 °C yeasts Torulaspora quercuum, Pichia fermentans, Galactomyces
candidus (Geotrichum) were found. Additionaly at +12 °C Candida intermedia, Galactomyces
geotrichum and the mold Aspergillus sp. were determined. This finding suggests that the samples
were contaminated during production, and thus their sustainability and safety were impaired. |
