Proteolytical, Chemical, Textural and Sensorial Changes During the Ripening of Turkish White Cheese Made of Pasteurized Cows' Milk

Abstract

Turkish White Cheese (TWC), manufactured from pasteurized cows' milk, was ripened over 90 days at 4°C, and proteolytical, chemical, textural, and sensorial changes were investigated. The main compositional characteristics of TWC are low content of total solids (TS) (39.80-41.75 g/100 g of cheese), high content of fat (49.12-49.91 g/100 g of TS) and salt (8.69-9.35 g/100 g of TS). The lactose level, pH values, and titratable acidity of samples were found between 0.74-2.05 g/100 g of TS, 4.39-4.68, and 0.73-1.12 g lactic acid/100 g of cheese, respectively. Changes in nitrogenous fractions, Urea-PAGE electrophoregram and RP-HPLC chromatograms showed that TWC undergoes a slight proteolysis. Textural attributes of TWC were significantly (p < 0.05) affected by the ripening period. The highest overall acceptance scores were found at the 60 days of ripening. Bitterness was identified at the end of the 60 and 90 days of ageing period.

Use of corn oil in the production of Turkish white cheese

“…The oil ratio was determined by pre-experimental study by sensorial evaluation to prevent any oily off-flavour defect in cheese samples. White cheese production was carried out according to Topcu and Saldamli (2006). Briefly, after pasteurization (72°C, 15 sec), milk was cooled to 32°C.…”

“…Water soluble extract (WSE) and trichloroacetic acid soluble nitrogen (TCA-SN) fraction of the cheese sample was prepared as described by Kuchroo and Fox (1982) and Topcu and Saldamli (2006), respectively. The water soluble nitrogen (WSN) and TCA-SN were determined by Kjeldahl method (AOAC 1990).…”

“…The soluble nitrogen in TCA was expressed as a percentage of total nitrogen. Peptide profiles of the WSE were detected by reverse phase-high performance liquid chromatography (RP-HPLC) system, essentially as described by Topcu and Saldamli (2006).…”

“…After cutting, the samples were immediately covered airtightly and allowed to equilibrate to room temperature (20± 2°C) for 30 min prior to testing. The samples were compressed by 33 % from the initial sample's height, using two consecutive compression cycles at a speed of 0.5 mm/s (Romeih et al 2002;Topcu and Saldamli 2006).…”

“…At the beginning of the ripening period, acidification of the milk by lactic acid bacteria occurs rapidly, but later, their action is limited. Because, lactose content of the white cheeses decrease during ripening (Topcu and Saldamli 2006). Proteolysis in cheese leads to an increase in the soluble nitrogen fractions, which is considered as an index of proteolysis (Zhang and Zhao 2010).…”