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.
This study aims to determine the effects of the autochthonous probiotic bacteria Lactobacillus plantarum B (currently Lactiplantibacillus plantarum) and Lactococcus lactis subsp. lactis S1 on ...proteolysis during the ripening of Sir iz mišine—a Croatian cheese which ripens in a lambskin sack. Sir iz mišine was produced in four different variants: (1) from raw milk without starter cultures, and from pasteurized milk with added (2) Lactococcus lactis ssp. lactis S1, (3) Lactobacillus plantarum B, or (4) a starter culture consisting of a mixture of Lactococcus lactis ssp. lactis S1 and Lactobacillus plantarum B (1:1). The addition of Lactobacillus plantarum B alone or in combination with Lactococcus lactis subsp. lactis S1 noticeably increased the alpha and beta indices because of the synergistic activity between the enzymes responsible for primary proteolysis and added autochthonous bacteria. Cheese produced from raw milk had the lowest (12.16%) content of WSN%TN. The highest WSN%TN content was found in cheese produced with combined probiotic bacteria (30.40%) and Lactococcus lactis ssp. lactis S1 (29.74%). Cheese with added combined probiotic bacteria had a noticeably higher content of TCA-SN%TN, indicating a synergistic performance among autochthonous probiotic bacteria. In conclusion, autochthonous probiotic bacteria, in addition to having a functional value, can improve the ripening properties of cheese.
The aim of this study was to compare the effectiveness of gas chromatography (GC) and near‐infrared spectroscopy (NIR) spectroscopy in detecting butter adulteration. Butter samples with a known ...percentage of added margarine or pork fat were prepared. Chemometric techniques (principal component analysis and partial least squares regression) were applied on the NIR spectra and GC data, which enabled the qualitative separation of samples depending on the added proportion of adulterant, and the quantitative prediction of the proportion of added adulterant or certain fatty acid content. C12:0; C16:0; C18:0; C16:1; C18:1n9; C18:2n6 showed significant trend changes depending on the adulteration degree. NIR has proven to be a suitable technique for the rapid determination of butter adulteration.
Novelty impact statement
Fast and nondestructive technique as near‐infra red (NIR) spectroscopy can be used in qualitative and quantitative detection of butter originality. Obtained models by chemometrics methods allow prediction of proportion of added adulterant in butter and identify specific fatty acids. NIR may be applied in screening control of the correctness of butter labeling to improve the system of quality control in food fraud.
This study aims to determine the effects of the autochthonous probiotic bacteria Lactobacillus plantarum B (currently Lactiplantibacillus plantarum) and Lactococcus lactis subsp. lactis S1 on ...proteolysis during the ripening of Sir iz mišine—a Croatian cheese which ripens in a lambskin sack. Sir iz mišine was produced in four different variants: (1) from raw milk without starter cultures, and from pasteurized milk with added (2) Lactococcus lactis ssp. lactis S1, (3) Lactobacillus plantarum B, or (4) a starter culture consisting of a mixture of Lactococcus lactis ssp. lactis S1 and Lactobacillus plantarum B (1:1). The addition of Lactobacillus plantarum B alone or in combination with Lactococcus lactis subsp. lactis S1 noticeably increased the alpha and beta indices because of the synergistic activity between the enzymes responsible for primary proteolysis and added autochthonous bacteria. Cheese produced from raw milk had the lowest (12.16%) content of WSN%TN. The highest WSN%TN content was found in cheese produced with combined probiotic bacteria (30.40%) and Lactococcus lactis ssp. lactis S1 (29.74%). Cheese with added combined probiotic bacteria had a noticeably higher content of TCA-SN%TN, indicating a synergistic performance among autochthonous probiotic bacteria. In conclusion, autochthonous probiotic bacteria, in addition to having a functional value, can improve the ripening properties of cheese.
The aim of this study was to introduce a reference method for the detection of cow milk in ewe and goat cheeses (EC 273/08) in order to protect manufacturers and consumers from adulterations and ...imitations, and to ensure alignment with the demands of domestic and EU markets. The method includes isolation of casein from cheese, isoelectric focusing of γ2- and γ3-casein originating from the hydrolysis of β-casein by plasmin, the detection and quantitative determination of γ-casein in cow, ewe and goat cheese by densitometry. Ewe or goat cheese products with a minimum of 1 % of cow milk are considered to be adulterated. For the quantitative determination of cow, ewe and goat milk in cheeses, standard mixtures of cow-ewe and cow-goat milk were made by adding 0; 0.5; 1; 2; 5; 10; 25; 50; 75 and 100 % (v/v) of cow milk. The quantification was performed by determining the peak area ratio of cow γ-casein in comparison to ewe/goat casein in prepared standard cheeses. The calibration curves were calculated based on the relation of the peak area ratio of cow γ-caseins (calculated as the percentage of total γ-caseins) in contrast to the relative content (%) of cow milk in the mixture. The method proved to be adequate for the detection of raw and heat-treated cow milk in fresh and ripened cheeses made from ewe or goat milk, or a mixture of ewe and goat milk.
The aim of this study was to determine the influence of microbial (commercial starter) culture on concentration of total free amino groups (amino acids) in cheeses in different ripening stages. Free ...amino groups were determined by reaction with ninhydrin with cadmium (Cd) in the water soluble cheese extract, and were expressed as the concentration of leucine in cheese dry matter. Changes in concentration of total free amino acids during cheese ripening (0th, 30th, 60th, 90th and 120th day) were monitored. In water soluble extracts of cheese, the presence of free NH2 groups in all ripening stages was detected, which means smaller peptides and amino acids, whose concentration significantly (P<0.01) increased during ripening. Cheeses produced with and without microbial culture resulted in statistically significant differences (P<0.01) in content amino acids free on the 90th and 120th day of ripening. Cd - ninhydrin method was found to be suitable for cheese ripening monitoring, as well as for determination of the differences in mature characteristics of cheeses, depending on the production process.
Istria and Pag curd are specific products that are mostly consumed fresh made in coastal areas and on islands. Curd is a sort of soft cheese. Due to its structure, it is very healthy. It has a high ...nutritional value which is the result of a great amount of proteins that are easy to digest and have a high level of utilization. The aim of this study was to describe the technological process of production, to determine the chemical structure and to suggest the value of standardization on the basis of sensory evaluation. The total of 28 curd samples were physically and chemically analyzed according to standard and accredited scientific methods. Statistical data analysis was carried out by using the procedures of Microsoft Office Excel (2007). According to water content in cheese, Istria and Pag curd belongs to a group of soft cheeses. On average the water content in Istrian curd was 56.62 %, and in Pag curd was 63.03 %. Istrian curd showed higher values of the fat content (28.9 %) and the fat in a dry matter (64.47 %) than Pag curd (23.25 % and 59.65 %). The sensory quality of Istrian curd was not as homogenous as of Pag curd. Based on the research results, it can be concluded that the physical and chemical structure of Istria and Pag curd was uneven, which is understandable if the production terms and conditions and the way of draining the curd are taken into account. The description of technological process of production and the understanding of physical and chemical structure of the curd, represent the significant contribution to the research and knowledge of domestic dairy products, which certainly should not be neglected in our dairy industry. In any case, these products deserve the experts full attention.
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.
Konzumacija sirovog mlijeka iz mljekomata u Republici Hrvatskoj posljednjih godina je povećana. Međutim, njegova zdravstvena sigurnost nije dovoljno istražena i kontrolirana. Cilj rada bio je ...istražiti prikladnost konzumacije sirovog mlijeka iz 28 mljekomata, tijekom jednogodišnjeg razdoblja u 3 županije u RH, na osnovu njegove fizikalno-kemijske i higijenske kvalitete. Također, provedena je simulacija rasta psihrotrofnih bakterija, u cilju određivanja optimalnog vremena pohrane zbog njihovog nepovoljnog utjecaja na kvalitetu mlijeka. Metodama infracrvene spektrometrije i krioskopije, uzorcima sirovog mlijeka (n=320) određen je fizikalno-kemijski sastav, dok je higijenska kvaliteta određena ukupnim brojem bakterija (TBC) i brojem somatskih stanica (SCC). Mikrobiološke analize uključivale su određivanje prisutnosti Enterococcus spp., Pseudomonas spp. te patogenih vrsta. Zadovoljavajuća kvaliteta sirovog mlijeka utvrđena je u 95% (kemijska kvaliteta) i 70% nepatvorenih uzoraka (bez dodane vode). Propisanoj higijenskoj kvaliteti udovoljilo je 36,6% (TBC) i 71,9% (SCC) uzoraka. Prisustvo bakterija iz roda Pseudomonas spp. utvrđena je u 93,4% odnosno 96,9% uzoraka, a bakterija Escherichia coli, Staphylococcus aureus, Lysteria monocytogenes u 32,2%, 27,5% odnosno 3,8% uzoraka. Nalaz Salmonella spp. i Yersinia enterocolitica bio je negativan. Na kraju istraživanja utvrđeno je poboljšanje mikrobiološke kvalitete sirovog mlijeka iz mljekomata. Rezultati ukazuju na potrebu sustavne kontrole te obveznu termičku obradu sirovog mlijeka iz mljekomata prije konzumacije.
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