Coagulation properties and cheese yield of ultrafiltrated cow milk

GIMÉNEZ, PAULA; PEROTTI, MARIA CRISTINA; GEORGE, GUILLERMO ANDRÉS; HYNES, ERICA RUT; BERGAMINI, CARINA

Virtual

Simposio; IDF International Cheese Science & Technology Symposium; 2021

IDF International Dairy Federation

Ultrafiltration (UF) of cheesemilkcan be used to standardize the protein level and to optimize the plant capacity. However, this process produce changes in the coagulation properties (CP) of milk and there is no consensus about the rennet dose to use in the UF milk. In the present work, weassess the CP of UF milksusing Optigraph, and to estimate the cheese yield. The influence of three levels of rennet (dose based on the ratio rennet:volume or rennet:protein, and 75% of this last dose) and two levels of calcium (addition or not) was studiedon the UF milks. The milk protein level (%w/w) was increased from 3.29 (control milk) to 4.08, 5.14 and 6.02 (ultrafiltrated milks). In general, a decrease of the rennet coagulation time (RCT) and cutting time (CT) and an increase in the firmness of the curd (FC) was observed with the increase of the protein level in the UF milks at each studied condition. UF milks with a rennet dose on a protein basis and the addition of calciumshowed the lowest values of RCT and CT, and the highest levels of FC, which were very different to the control milk. On the contrary, UF milks with a rennet dose on a volume basis showed more similar CP to the control milk, which could allow a better handling of curd in the vat and save up rennet. Yield cheese increased proportionally to the protein level of the starting milk independently of the rennet dose, while the adjusted yield was in a narrower range with higher values (around 1%) for the more concentrated milk.Our results highlight the significant influence of protein level, rennet dose and calcium in the CP of UF milks; these studies are useful in order to adapt the protocols for the UF cheesemaking.