Modulation of cream cheese physicochemical and functional properties with ultrafiltration and calcium reduction.

The production of cream cheese from ultrafiltered (UF) milk can reduce acid whey generation but the effect of altered protein and calcium concentration on the physicochemical properties of cream cheese is not well understood. In this study, the effect of skim milk concentration by UF (2.5 and 5 fold) was assessed both with and without calcium reduction using 2% (w/v) cation resin treatment. UF concentration increased the concentration of peptides and free amino acids and led to a more heterogeneous and porous microstructure, resulting in a softer, less viscous and less thermally stable cream cheese. Calcium reduction decreased peptide generation, increased the size of corpuscular structures, decreased porosity and increased thermal stability but did not significantly decrease cheese hardness or viscosity. The study illustrates how protein or calcium concentration, can be used to alter functional properties.

Relationships between cheese-processing conditions and curd and cheese properties to improve the yield of Idiazabal cheese made in small artisan dairies: A multivariate approach.

Very diverse cutting and cooking intensity processes are currently used in small artisan dairies to manufacture Idiazabal cheese. The combination of the technical settings used during cheese manufacturing is known to affect cheese composition and yield, as well as whey losses. However, the information regarding the effect on microstructure and texture of cheese is scarce, especially in commercial productions. Therefore, the effect of moderate- and high-intensity cutting and cooking processes on whey losses, curd-grain characteristics, microstructure and cheese properties, and yield were analyzed. Three trials were monitored in each of 2 different small dairies during the cheesemaking of Idiazabal cheese, which is a semihard cheese made from raw sheep milk. The role and know-how of the cheesemakers are crucial in these productions because they determine the cutting point and handle semi-automatic vats. The 2 dairies studied used the following settings: dairy A used moderate-intensity cutting and cooking conditions, and dairy B used high-intensity cutting and cooking settings. Multiple relationships between cheese-processing conditions and curd, whey, and cheese properties as well as yield were obtained from a partial least square regression analysis. An increased amount of fat and casein losses were generated due to a combination of an excessively firm gel at cutting point together with high-intensity cutting and cooking processes. The microstructural analysis revealed that the porosity of the protein matrix of curd grains after cooking and cheese after pressing was the main feature affected, developing a less porous structure with a more intense process. Moderate-intensity cutting and cooking processes were associated with a higher cheese yield, regardless of the longer pressing process applied. No significant differences were observed in cheese composition. After 1 mo of ripening, however, the cheese was more brittle and adhesive when the high-intensity cutting and cooking process was applied. This could be associated with the composition, characteristics, and size distribution of curd grains due to differences in the compaction degree during pressing. These results could help to modify specific conditions used in cheesemaking, especially improving the process in those small dairies where the role of the cheesemaker is crucial.

Effects of technological settings on yield, curd, whey, and cheese composition during the cheese-making process from raw sheep milk in small rural dairies: Emphasis on cutting and cooking conditions.

The technological conditions of cheese-making affect cheese yield and compound losses in the whey, especially the processes of cutting and cooking. Although significant compositional and functional differences have been reported among animal species, there is a lack of studies on the effects of cheese-making technology on cheese yield and losses for sheep milk. Thus, we examined the cheese-making settings in 8 small rural dairies working with raw sheep milk and their effects on cheese yield and compound losses in whey during the cheese-production season. Actual cheese yield varied in 2 to 3 kg of cheese/100 kg of milk among dairies due to the cheese-making conditions, particularly the duration of cutting and cooking and the final cooking temperature. The combination of the conditions used during cutting and cooking, especially, determined fat losses in the whey. Fat losses were increased with high-speed and short cutting time settings together with high stirring speed and long duration of cooking. Additionally, cheese-makers should adapt the cutting and cooking conditions to the seasonal variations of milk composition, especially during early summer, when fat losses in the whey are higher. Our results suggest that it could be useful to use approximately 10 to 15 min of cutting time and moderate cooking speed and duration. The data reported in this study may assist the improvement of the cheese-making process in small rural dairies using sheep milk, where facilities are limited and the role of the cheese-maker is crucial.

Characterization of curd grain size and shape by 2-dimensional image analysis during the cheesemaking process in artisanal sheep dairies.

The size and shape of curd grains are the most important parameters used by cheesemakers to decide when to end the cutting or stirring processes during cheesemaking. Thus, 2-dimensional image analysis was used to measure the characteristics of curd grains in commercial cheese productions carried out by artisanal sheep dairies. Dairies used different technical settings for cutting and stirring steps, causing differences in the size and shape of curd grains. A linear relationship between total revolutions used for cutting and stirring and curd particle size was established. However, particle size distributions after curd cutting and stirring were highly heterogeneous. Actual cheese yield was correlated with particle size and cutting revolutions, whereas curd grain shape and fat loss were associated with stirring conditions by a multivariate approach. Image analysis of the size and shape of curd grains gives useful information for determining characteristics related to cheese yield and quality and may contribute to improving and controlling the cheesemaking process in small artisanal dairies.