A new study of the kinetics of curd production in the process of cheese manufacture

Abstract

We studied the role played by temperature and rennet concentration in the coagulation process for cheese manufacture and the evaluation of their kinetics. We concluded that temperature is the main factor that determines the kinetics. The rennet concentration was unimportant probably due to the fast action of the enzyme chymosin. The Dynamic light scattering technique allowed measuring the aggregate's size and their formation kinetics. The volume fraction of solids was determined from viscosity measurements, showing profiles that are in agreement with the size profiles. The results indicate that the formation of the aggregates for rennet cheese is strongly dependent on temperature and rennet concentration. The results revealed that at 35·5 °C the volume fraction of solids has the maximum slope, indicating that at this temperature the curd is formed rapidly. The optimal temperature throughout the process was established. Second-order kinetics were obtained for the process. We observed a quadratic dependence between the rennet volume and the volume fraction of solids (curd), thereby indicating that the kinetics of the curd production should be of order two.

Influence of protein concentration and coagulation temperature on rennet-induced gelation characteristics and curd microstructure

“…These results agree with those of Mellema et al (2002), who proposed that gel strength is increased because of rear-rangement of the protein network, which increases at higher temperature. Muñoz et al (2017) also observed rapid formation of bigger aggregates in gels prepared at 40°C compared with gels prepared at 30°C.…”

“…In renneted milk systems, individual casein micelles flocculate after loss of the hydrophilic domain from κ-casein, leading to the formation of casein aggregates and eventually a 3-dimensional protein network, the gel or coagulum (Horne and Banks, 2004;Muñoz et al, 2017). On reaching a suitable firmness, the gel is cut (Govindasamy-Lucey et al, 2011), which then facilitates whey expulsion from the curd.…”

“…On reaching a suitable firmness, the gel is cut (Govindasamy-Lucey et al, 2011), which then facilitates whey expulsion from the curd. It is well established that increased protein levels (Guinee et al, 2006;Sandra et al, 2011) in milk or higher coagulation temperature (Hussain et al, 2012;Muñoz et al, 2017) increase gel firmness and gel-firming rate (Guinee et al, 1996b;Waungana et al, 1998;Upreti et al, 2011). Guinee et al (1994) reported that increasing protein to >5% caused difficulty in curd cutting using an existing cutting program because of excessive gel strength.…”

“…Lowering the temperature by 3 to 4°C standardizes the coagulation and cutting properties in the case of increased protein concentration (Guinee et al, 1994(Guinee et al, , 1996aGovindasamy-Lucey et al, 2011). Similarly, other factors (e.g., pH and CaCl 2 addition) are critically important for the development of the gel (Nájera et al, 2003;Mishra et al, 2005;Muñoz et al, 2017). Thus, improved understanding of the interactive effects of altering coagulation temperature on the rennet coagulation characteristics and curd cutting properties for milk with increased protein content through use of LCR UF is required.…”