Conjugated linoleic acid in cheese: A review of the factors affecting its presence

Abstract

Several health benefits of conjugated linoleic acid (CLA) have been documented. The present work is aimed to review data on the various factors affecting the CLA content in cheese of studies accomplished in the last decade and also indicating the factors that increase the CLA levels. The CLA content in cheese depends on CLA levels present in milk, since the lipids with the CLA are transferred from milk into the cheese. Feed types rich in α-linolenic and linoleic acids such as pasture grass, plant oils, cereals rich in oil, or fish oils can affect the CLA level in milk. In contrast to findings of previous reviews made in previous decade, which stated that the CLA levels in cheese were stable during ripening time, the present review reveals that certain lactic acid bacteria, that is, probiotic Lactiplantibacillus plantarum, Lactobacillus acidophilus, or Lacticaseibacillus casei, as well as Bifidobacterium lactis can increase the CLA levels in cheese by converting linoleic acid during ripening time. These bacteria starters increased the CLA levels by 1.19, 1.6, and 6.6 times as much as the control in Ovine model, Miniature, and Cheddar cheese, respectively. Lipid oxidation due to factors like fluorescent light or aerobic conditions can decrease the CLA levels during storage.