Effects of partial substitution of goat's milk for sheep's milk, cured scalding and dry salting on proteolysis in Urfa cheese

Abstract

The effects of partial substitution of goat's milk for sheep's milk, scalding and dry salting on the proteolysis of Urfa cheese were monitored for 240 days. For this reason, the contents of total nitrogen, water‐soluble nitrogen (WSN), and trichloroacetic acid‐soluble nitrogen (TCA‐SN) were explored as well as the chemical compositions of samples during ripening. Also, RP‐HPLC of pH 4.6‐soluble, 70% ethanol‐insoluble (EtOH‐i), and urea‐PAGE of pH 4.6‐insoluble nitrogen fractions of samples was determined. The results showed that the effects of partial substitution of goat's milk for sheep's milk on WSN and TCA‐SN were significant from sixth to eighth month of the ripening, respectively. Even though the effects of the milk type, dry salting, and scalding on the peptide profile were significant at the beginning of maturation, the peptide profile of cheeses was almost similar at the end of the storage. Furthermore, the proteolysis of Urfa cheese was limited due to dry salting during the ripening. Practical applications The maturation of cheese is a complex biochemical process involving the hydrolysis of fat, breakdown of protein, and metabolism of lactose. Though the biochemical reactions during cheese ripening are not precisely understood, proteolysis is one of the most significant biochemical processes during maturation. It is known that the amino acids resulting from proteolysis are the precursors of flavor components in cheese. Milk itself is a significant source of proteolytic enzymes. And also, the curd scalding temperature and salt content of cheese affect the proteolytic activity during cheese ripening. However, limited proteolysis may be occurred during the cheese maturation due to dry salting and scalding process. Therefore, studies should focus on overcoming this problem. This study can help to overcome the limited proteolysis in the production of cheese. Also, results from the study may contribute to the industrial production of Urfa cheese.

Effects of milk types used in Antep cheese production on some cheese organoleptic quality parameters and brine composition during 5‐month ripening

“…During ripening, salt was transferred from the brine to the cheese, whereas moisture and watersoluble components of the cheese matrix (lactose, mineral substances, and WSN) moved from the cheese blocks to the brine. In the literature, there are similar results supporting this circumstance for different brined ripened cheeses (Antep, Urfa, and Halloumi cheeses) manufactured by scalding (Atasoy et al, 2019;Ayyash & Shah, 2010;Kaya & Öner, 1996).…”

“…It was more obvious that the salt concentrations increased rapidly in the first month of ripening according to the calculations made on a dry basis (Table 2). It was stated in the literature that there was a rapid transition of salt from brine to cheese blocks in the early stages of storage due to the high concentration difference between brine and cheese at the beginning of the ripening period (Atasoy et al., 2019; Kırmacı et al., 2014). Depending on the differentiation of milk mixtures used in Antep cheese production, changes in salt and ash contents were also important ( p < 0.05).…”

“…Atasoy et al. (2019) reported REI values in the range of 6.5%–13% for the 5‐month ripening of Urfa cheese, whereas Mallatou et al. (2004) detected REI values between 8.4% and 14.9% for the 6‐month ripening of Teleme cheese.…”

Preparation and characterization of PLA‐lemon essential oil nanofibrous membranes for the preservation of Mongolian cheese

“…The investigation of nitrogen fractions during storage was important to understand the proteolysis in cheese (Atasoy et al, 2019). Casein was hydrolyzed quickly by microbial proteinases, to form free amino acids and low molecular weight peptides (Sardinas‐Valdes et al, 2021).…”

“…The investigation of nitrogen fractions during storage was important to understand the proteolysis in cheese (Atasoy et al, 2019).…”