Effect of buffalo milk on the yield and composition of buffalo feta cheese at various processing parameters

Microstructural and rheological behavior of buffalo milk chocolates

The development of products with buffalo milk has increased due to its peculiar characteristics, such as taste and high content of total solids, which has attracted consumers and the food industry.In this context, the objective was to develop and evaluate the microstructural properties of chocolates with different concentrations of buffalo milk powder (0%, 5%, 10%, 15% and 20%) through polymorphism, microscopy and rheological studies. For the polymorphism, the X-ray diffraction technique (XRD) was performed, while the crystal morphology was observed by scanning electron microscopy (SEM). The addition of levels of more than 10% buffalo milk caused notable changes in XRD diffractograms, demonstrating the appearance of different polymorphic forms. Microscopy analysis revealed changes in the structure of the matrix with an increase in the concentration of buffalo milk, presenting more continuous surfaces, associated with milk proteins, which have emulsifying capacity. The Herschel-Bulkley model adequately described the flow behavior of the formulations. There was an increase in all rheological properties (yield stress, viscosity, thixotropy and loss tangent (tang δ)) in chocolates with higher concentrations of milk. For that, the composition of the milk influences the degree of structuring of the chocolate. Considering this technological information, it is important to highlight that the production of buffalo milk chocolates shows potential for technological innovation.

Compositional and Functional Characteristics of Feta-Type Cheese Made from Micellar Casein Concentrate

Micellar casein concentrate (MCC) is a high protein ingredient (obtained by microfiltration of skim milk) with an elevated level of casein as a percentage of total protein (TP) compared to skim milk. It can be used as an ingredient in cheese making. Feta-type cheese is a brined soft cheese with a salty taste and acid flavor. We theorize that Feta-type cheese can be produced from MCC instead of milk, which can improve the efficiency of manufacture and allow for the removal of whey proteins before manufacturing Feta-type cheese. The objectives of this study were to develop a process of producing Feta-type cheese from MCC and to determine the optimum protein content in MCC to make Feta-type cheese. MCC solutions with 3% (MCC-3), 6% (MCC-6), and 9% (MCC-9) protein were prepared and standardized by mixing water, MCC powder, milk permeate, and cream to produce a solution with 14.7% total solids (TS) and 3.3% fat. Thermophilic cultures were added at a rate of 0.4% to MCC solutions and incubated at 35 °C for 3 h to get a pH of 6.1. Subsequently, calcium chloride and rennet were added to set the curd in 20 min at 35 °C. The curd was then cut into cubes, drained for 20 h followed by brining in 23% sodium chloride solutions for 24 h. Compositional analysis of MCC solutions and cheese was carried out. The yield, color, textural, and rheological measurements of Feta-type cheese were evaluated. Feta-type cheese was also made from whole milk as a control. This experiment was repeated three times. The yield and adjusted yield of Feta-type cheese increased from 19.0 to 54.8 and 21.4 to 56.5, respectively, with increasing the protein content in MCC from 3% to 9%. However, increasing the protein content in MCC did not show significant differences in the hardness (9.2-9.7 kg) of Feta-type cheese. The color of Feta-type cheese was less white with increasing the protein content in MCC. While the yellowish and greenish colors were high in Feta-type cheese made from MCC with 3% and 6% protein, no visible differences were found in the overall cheese color. The rheological characteristics were improved in Feta-type cheese made from MCC with 6% protein. We conclude that MCC with different levels of protein can be utilized in the manufacture of Feta-type cheese.

Evaluation of concentration process of bovine, goat and buffalo whey proteins by ultrafiltration

In this research, the protein concentration, the permeate flux, and the predominant fouling mechanisms were investigated during ultrafiltration of different whey samples. The research was carried out at different values of transmembrane pressure and temperature using an experimental design, and a protein concentration of approximately 37 g L-1 was obtained for the bovine whey powder solution, at 60 kPa and 40 °C. The maximum flux observed was 8.9 and 7.9 kg m-2 h-1, respectively, for the bovine whey powder solution and bovine whey, at 50 kPa and 30 °C. Although goat and buffalo whey presented lower permeate flux, probably due to high solutes and calcium contents, protein concentrates of around 40 g L-1 were obtained using the ultrafiltration process. This demonstrates the potential of ultrafiltration to obtain non-bovine protein concentrates. The best fit, verified by Ho and Zydney model, suggests that the fouling for all analyzed whey occurs due to pore blocking and subsequent deposit on the membrane surface.

Comparative exploration of free fatty acids in donkey colostrum and mature milk based on a metabolomics approach

Donkey milk is an ideal substitute for human milk owing to its similar composition. Nevertheless, changes in the composition and related metabolic pathways of free fatty acids (FFA) in donkey milk between colostrum and mature milk have not been studied well. In this study, metabolomic methods based on gas chromatography tandem time-of-flight mass spectrometry (GC-TOF-MS) were used to explore and compare FFA in donkey colostrum (DC) and mature milk (DMM). A total of 24 FFA were characterized and quantified in DC and in DMM. Of these, 11 FFA differed significantly between DC and DMM, and there were 6 key differential metabolic pathways. These results demonstrated that the composition of FFA in donkey milk changed with lactation stage. The interactions and metabolic pathways were further analyzed to explore the mechanisms that altered the milk composition during lactation. Our results provide insights into the changes in milk of the nonruminant mammals during lactation. The results provide practical information for the development of donkey milk products and a foundation for future research on specific milk nutrients.

Goat cheese yield and recovery of fat, protein, and total solids in curd are affected by milk coagulation properties

The aims of the present research were to quantify the effects of each coagulation trait, traditional milk coagulation properties [MCP: rennet coagulation time (RCT), curd-firming time (k₂₀), and curd firmness at 30 min (a₃₀)], and modeled curd-firming over time (CF_t) parameters [estimated rennet coagulation time (RCT_eq), curd-firming instant rate constant (k_CF), and potential curd firmness (CF_P)] directly on the following: (1) recovery of 3 milk components in the curd (%REC), (2) 3 measures of cheese yield (%CY), and (3) 3 daily cheese yield traits (dCY) from goat milk. Cheese-making traits were analyzed using 2 mixed different models, the first to test MCP and the second to test CF_t parameters. Pearson correlations were also calculated. Significant and favorable relationships (negative for time intervals and positive for CF measures) were found between the traditional MCP and the CF_t parameters and %REC and %CY traits. The effects of milk fat and protein contents were particularly important on all cheese-making traits, with the only exception being the effect of fat content on water retention in cheese (%CY_WATER). We found an optimum value of milk k₂₀, associated with the highest recovery of components and cheese yield in solids (%CY_SOLIDS). In addition, a lower level of curd water retention and an increased fresh curd yield (%CY_CURD) were associated with greater recovery of fat. The collection of all available information during the process of milk coagulation and curd-firming allowed us to discover the effect of RCT_eq on %REC traits and %CY_SOLIDS, which had not previously been revealed for traditional RCT. Moreover, higher k_CF values were associated with increased %CY_CURD and %CY_SOLIDS. Given that CF_t parameters showed a high level of independence from one another, these can also be easily used and characterized in future applications at the industry level. Information provided by traditional and modeled coagulation properties could efficiently support the goat dairy industry and lay the foundations for a quality payment scheme for goat milk.