Nowadays, consumers are interested in cheese produced without chemical additives or high-temperature treatments, among which, protective lactic acid bacteria (LAB) cultures could play a major role. ...In this study, the aims were to isolate, identify and characterize antilisterial LAB from traditionally produced cheese, and utilize suitable LAB in cheese production. Among 200 isolated LAB colonies, isolate PFMI565, with the strongest antilisterial activity, was identified as Enterococcus durans. E. durans PFMI565 was sensitive to clinically important antibiotics (erytromicin, tetracycline, kanamycin, penicillin, vancomycin) and had low acidifying activity in milk. E. durans PFMI565 and the previously isolated bacteriocin producer, Lactococcus lactis subsp. lactis BGBU1–4, were tested for their capability to control Listeria monocytogenes in experimentally contaminated ultrafiltered (UF) cheeses during 35 days of storage at 4 °C. The greatest reductions of L. monocytogenes numbers were achieved in UF cheese made with L. lactis subsp. lactis BGBU1–4 or with the combination of L. lactis subsp. lactis BGBU1–4 and E. durans PFMI565. This study underlines the potential application of E. durans PFMI565 and L. lactis subsp. lactis BGBU1–4 in bio-control of L. monocytogenes in UF cheese.
Two groups of market samples were collected: four samples of whey produced in small scale facilities, and four samples produced in large scale dairy factories. The additional two groups: acid (a) and ...sweet whey(s) were collected in laboratory from cheeses produced from differently heated goat milk (A—65°C/30 min, B—80°C/5 min and C—90°C/5 min). Gross composition (dry matter content, fat content, protein content), pH, protein, mineral composition and microbial counts were determined. Obtained results for laboratory and market whey samples were analyzed by two-way and one-way ANOVA, respectively. Visualization of quantitative relationships within market and laboratory whey samples has been done by principal component analysis (PCA). Comparison of the protein composition of market samples with those from the laboratory suggested that the majority of goat whey from the market originated from milk heated between 65 and 80°C. While heat treatment of milk affected protein composition, coagulation type determined mineral composition of whey. The amount of Ca content was almost four times higher, while the amount of Zn is more than 15 times higher in acid than in sweet goat whey. The lack of influence of heat treatment on the Ca and Mg content in whey has been detected. Such behavior is the opposite of cow milk behavior, in which with the subsequent increase in heating temperature, the amount of soluble Ca and Mg decreases. For all analyzed samples, dry matter content was in agreement with the legally required minimum level (5.5%). Although legal requirements for safety and quality of small scale dairy products are more flexible than that of the large counterparts, there was not a single characteristic that differed significantly between small scale and large scale market goat whey.
A normal-phase high-performance liquid chromatography–evaporative light-scattering detector method employing dichloromethane, methanol, and acetic acid/triethylamine buffer as the mobile phase was ...developed for analysis of polar lipids (PLs). This method was applicable for analysis of PLs from both dairy materials and soy lecithin. All of the PLs of interest such as glycolipids, phospholipids, and sphingomyelin were well separated with a total run time of 22.5 min and without necessitating the removal of neutral lipids beforehand. Peak retention times were stable, and the method was reproducible. In this study, a modified method of using solvents for extraction of PLs from dairy matrices was also investigated. The modified method offered higher extraction efficiency, consumed less time, and in some cases saved solvent use.
Rennet coagulation of goat milk heated to 65 °C/30 min (Gc), 80 °C/5 min (G8) and 90 °C/5 min (G9) was studied. A rheometer equipped with a vane geometry tool was used to measure milk coagulation ...parameters and viscoelastic properties of rennet gels. Yield parameters: curd yield, laboratory curd yield and curd yield efficiency were measured and calculated. Scanning electron microscopy of rennet gels was conducted. Storage moduli (G') of gels at the moment of cutting were 19.9 ± 1.71 Pa (Gc), 11.9 ± 1.96 Pa (G8) and 7.3 ± 1.46 Pa (G9). Aggregation rate and curd firmness decreased with the increase of milk heating temperature, while coagulation time did not change significantly. High heat treatment of goat milk had a significant effect on both laboratory curd yield and curd yield. However, laboratory curd yield (27.7 ± 1.84%) of the G9 treatment was unreasonably high compared to curd yield (15.4 ± 0.60%). The microstructure of G9 was notably different compared to Gc and G8, with a denser and more compact microstructure, smaller paracasein micelles and void spaces in a form of cracks indicating weaker cross links. The findings of this study might serve as the bases for the development of different cheese types produced from high-heat-treated goat milk.
Butter adulteration with margarine continues to be a threat for consumers; therefore, new rapid analytical tools are needed for quality control/quality assurance purposes. In this study, we used ...Raman spectroscopy coupled with partial least squares regression to quantify butter adulteration with margarine. The main difference between Raman spectra of butter and margarine comes from two bands associated to C=C double bond (1656 and 1268 cm
−1
) and the band associated to phospholipids’ choline group (973 cm
−1
). The intensity of these peaks decreases with a decreasing margarine content. The coefficient of determination (
R
2
= 0.994) and root-mean-square error of prediction (RMSEP = 2.754) display very good overall model performance. The sample preparation procedure that we employed was notably simplified compared to previous studies. This confirms that Raman spectroscopy can be effectively applied to quantify butter adulteration with margarine and further indicates that simplification of the analysis procedure is possible. These results could aid the efforts for implementation of this technique in routine rapid quality analysis of butter.
Understanding consumers’ behavior and their handling of high-risk foods at home is essential for reducing the number of foodborne illnesses. This study shows the results of a cross-national analysis ...of consumers’ perception from nine countries, and the identification of customers’ clusters and its characteristics in order to understand customers’ behavior, and to build safe chilled ready-to-eat (RTE) foods prevention strategies. The cluster analysis resulted in two clusters: (1) “Precautious consumers” characterized by the orientation towards pre-packed RTE foods, with consumers mainly coming from Bosnia and Herzegovina, India, Poland, Portugal, Spain, and Turkey. Their attitudes and self-reported practices may be categorized as less risky in terms of food-borne illnesses connected with the consumption of RTE foods; (2) “Unconcerned consumers” preferred cutting and slicing RTE foods freshly at the point of purchase, usually sold at the delicatessen department in a supermarket or at open markets. Those consumers mostly came from Croatia, Serbia and Slovenia and their attitudes and self-reported practices were riskier. These results allow a better understating of what characterizes consumers of RTE foods in different countries.
Cheese has been listed as one of four priority food groups intended for salt reduction reformulation. The present study aimed to investigate the possibility of producing Serbian white brined cheese ...(Homoljski Sir) with half of NaCl, three quarters of NaCl and all NaCl replaced with KCl (Na50, Na25 and Na0, respectively). Basic composition, proteolysis and texture profile parameters were monitored during 60 days of ripening. At the end of ripening, an acceptance test was conducted by untrained consumers (
= 46). According to the cluster analysis based on hedonic scores, three clusters emerged: male consumers (47.8%), agreeable consumers (30.4%) and highly educated female consumers (21.8%). Both partial and a total salt replacement had no effect on the course of proteolytical changes, the texture and basic composition during ripening. Female consumers did not accept any level of salt substitution, while male consumers showed dislike only for the Na0 cheese. Almost 80% of all consumers liked moderately-to-very-much the Na25 cheese variant. It implies that it is worth considering the production of cheese with 50-75% of NaCl replaced with KCl. The addition of natural flavoring and clear labeling of the sodium reduction should accompany the salt replacement strategy.
A high viability of probiotics in food product, with a living cells threshold of 107/cfu/g (colony‐forming units/g) is a challenge to achieve in food production. Spray drying is an efficient and ...economic industrial method for probiotic bacterial preservation and its application in food products. In this study, the survival of free and spray‐dried cells of potential probiotic strain Lactobacillus plantarum 564 after production and during 8 weeks of storage of soft acid coagulated goat cheese was investigated, as well as compositional and sensory quality of cheese. Total bacterial count of spray‐dried Lb. plantarum 564 cells were maintained at the high level of 8.82 log/cfu/g in cheese after 8 weeks of storage, while free‐cell number decreased to 6.9 log/cfu/g. However, the chemical composition, pH values and sensory evaluation between control cheese (C1 sample made with commercial starter culture) and treated cheese samples (C2 and C3, made with the same starter, with the addition of free and spray‐dried Lb. plantarum 564 cells, respectively) did not significantly differ. High viability of potential probiotic bacteria and acceptable sensory properties indicate that spray‐dried Lb. plantarum 564 strain could be successfully used in the production of soft acid coagulated goat cheeses.
The aim of this study was to evaluate the effect of nisin and storage temperature on the microbiological, physico-chemical and sensory properties of processed cheese. Processed cheese samples were ...prepared without and with 12.5 ppm nisin, stored at different temperatures (4, 8 and 20 °C). Research covered microbiological, physico-chemical and sensorial analysis of the samples. In processed cheese samples prepared without nisin, aerobic colony count (ACC) significantly increased over the experimental period, while in nisin supplemented samples no significant increase was determined. At lower storage temperature (4 °C), the effectiveness of nisin was more pronounced. Yeast and moulds (YM) and psychrotrophic colony count (PCC) were below the limit of quantification over the entire experimental period. Also, no significant changes in pH values and textural characteristics (firmness and stickiness) were determined. Sensory analyses confirmed that processed cheese samples became whiter and less yellow, compared to fresh samples. The viscosity of all samples decreased over the experimental period, which was in line with the results of baking stability. The obtained results confirmed the potential of using this type of processed cheese in baking industry.
PDF
