Effect of whey storage on physicochemical properties, microstructure and texture profile of ricotta cheese

The aim of this study is to evaluate the effect of whey storage period (0, 24, 48 and 72 h) on the physicochemical parameters, color, texture and microstructure of fresh ricotta during storage. Sweet whey and acid whey were evaluated based on titratable acidity, pH, fat, cryoscopy, and density, while ricotta was based on yield, fat, protein, ash, acidity, pH, moisture, total solids, color, texture, and microstructure. This was done with analysis of variance in a completely randomized design using Tukey test at 5% probability. Whey pH values increased with storage time. Ricotta made with stored whey had average yield of 5.33%, with decreased fat content and pH, and increased acidity. There were subtle differences in color and texture of ricotta during storage; its hardness and gumminess decreased, resulting in microstructure compression. It is concluded that the production of ricotta with whey stored for up to 72 h makes the product appropriate for consumption.Key words: Byproduct, fat, fresh cheese, ricotta, whey cheese, organoleptic properties

<b>Milk composition and blood metabolic profile from holstein cows at different calving orders and lactation stages

This study aimed to evaluate milk composition and metabolic profile of Holstein cows at different calving orders in the beginning, middle, and end of lactation. One hundred ten Holstein cows were housed in a free stall system receiving the same diet and were grouped according to calving order (first, second, third, and fourth calving) and days in milk (DIM): early (1-90 DIM), middle (91-180 DIM), and end of lactation (over 181 DIM) for comparing milk yield, milk composition, and blood metabolic profile between the calving orders within the same lactation period. These parameters were also evaluated between lactation periods of the cows in different calving orders. The calving order, in any lactation stage, had no influence on milk yield per day and blood biochemical profile of Holstein cows receiving the same diet. However, calving order in all stages of lactation influenced milk composition. The first, second, third, and fourth calving order had no effect on the blood biochemical profile of Holstein cows, in any lactation stage. On the other hand, the different stages of lactation influenced milk yield and milk composition of Holstein cows.

Influence of the type of milking and storage of milk on the chem ical composition, Somatic Cell Count and bacterial count Total

The refrigeration of milk and the usage of mechanical milking are important to obtain milk in accordance with quality standards. In this work we evaluated the influence of the type of milking process and type of storage on the quality of the refrigerated milk. It was obtained 1363 refrigerated milk samples stored in single or collective expansion tanks, from manually or mechanically milked animals. The experiment was carried out in a 2x2 randomized factorial scheme. Two types of expansion tanks (single and collective) and two types of milking (manual and mechanical). The average comparison test and Tukey test was carried out with 95% confidence. The levels of fat, protein, lactose and defatted dry extract, were evaluated according to the type of milking and type of milk storage. The values obtained were higher when compared to the values stabilished by the Ministry of Agriculture, Livestock and Food Supply. The level of milk fat was higher in samples with somatic cell count above 501,000 SC/mL. However, the levels of protein and defatted dry extract were higher in samples with somatic cell count below 500,000 SC/mL. The type of milking and the type of storage have influence on parameters related to milk quality such as levels of fat, protein, lactose and somatic cell count. The milk chemical composition revealed in accordance with the values stabilished by the Brazilian legislation. The total bacterial count did not vary with storage type nor the type of milking