Variations in Conjugated Linoleic Acid (CLA) Content of Processed Cheese by Lactation Time, Feeding Regimen, and Ripening

Abstract

Dairy products are major sources of conjugated linoleic acid (CLA); thus, an increase in CLA content can improve the quality value of dairy products. The objective of this work was to determine the effects of lactation time, feeding regimen, and ripening period on the level of CLA in processed cheese. CLA content in milk varied with the period of lactation; high in spring (April and May, about 6.8 mg CLA/g fat) and relatively low in mid summer and winter (about 4.3 mg CLA/g fat). The effects of dietary regimen and ripening period were determined in milk, which was obtained from March to May. After aging for 4 months, the cheese made from milk obtained from cows fed on pasture contained relatively higher levels of CLA compared to cheese made from milk obtained from cows fed indoors (8.12 mg CLA/g fat vs 6.76 mg CLA/g fat), but there was no difference in 7 month-aged cheeses. In both pasture and indoor feeding, 7 month-aged cheeses showed higher CLA content than 4 month-aged cheeses. The contents of stearic acid (C18:0) and linolenic acid (C18:3) were significantly higher in cheese from pasture fed cows compared to those in cows fed indoors. These findings should be helpful for the efficient production of functional dairy products with high CLA contents.

Conjugated linoleic acid contents in cheeses of different compositions during six months of ripenin

“…The seasonal difference (summer and winter) in milk fat due to the dietary regimen of animals elicits variations in the CLA contents in the cheese, due to the changes in the rumen microflora, which is strongly affected by the animal's diet. This was shown in the work by Kim et al (2009), who found higher values at Sheep Goat mg CLA/g cheese the beginning of the Korean summer, with 7.1 mg CLA/g of fat, and the lowest ones in January, with 3.9 mg CLA/g of fat.…”

“…Various authors have suggested that fresh grass promotes the synthesis of CLA through a greater activity of Δ9-desaturase in the udder (Khanal & Olson 2004;Nudda 2005;Meluchová et al 2008;Kim et al 2009). Moreover, the high concentrations of soluble fibre and fermentable sugars in fresh grass can create an environment in the gastrointestinal tract of ruminants, without lowering the pH, that is favourable for the growth of the bacteria responsible for synthesising CLA and the production of vaccenic acid (Dhiman et al 1999).…”

Fatty acids composition and trans isomers in cheeses and cheese-like products

“…The results of some studies indicate that e.g. the industrial technological processing, the time of ripening, or the applied additions may promote an increase of CLA participation in fatty acids composition of some types of cheeses (Bzducha--Wróbel and Obiedziński, 2009;Kim et al, 2009;Lin, 2000;Murtaza et al, 2014). The carried out studies proved that the CLA contents in the examined commercial and farmer cheeses showed no meaningful differences (Table 2).…”

Fatty acid composition and CLA content in goat milk and cheese samples from Umbrian market

“…However, considering the CLA % content, an increase was observed from milk (0.4 %) to fresh (0.6 %) to semi-hard cheese (0.8 %). Previously, it has been reported that long-ripened cheeses contain more CLA than others [28]. The high CLA level in semi-hard cheese could be due either to the ripening period or the use of bacteria as starters.…”