Samaneh Mollaeitavani - Department of Food Science and Technology, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran
Morteza khomeiri - Department of Food Science and Technology, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran
Ali moayedi - Department of Food Science and Technology, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran
alireza sadeghi mahonak - Department of Food Science and Technology, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran

Background and Aim : Conjugated linoleic acid (CLA) are the geometric and spatial isomers of linoleic acid (LA) in which the double bonds are in the conjugated state. Its anti-cancer properties, reduction of body fat and improvement of immune function are its health effects. As a high-consumption dairy product, cheese can provide public access to this micronutrient. In several studies, the strains in yogurt starter have been identified as producing CLA. Sunflower oil with a high percentage of LA is an affordable source of CLA precursor; Therefore, it can be used to increase the CLA content in cheese.Methods : At the first step, a pre-test based on the potential of CLA production by yogurt starter was performed in MRS broth containing extrapur LA by spectrophotometry method and after confirming the production of CLA in MRS broth by GC, it was used as a co-culture in cheese production. CLA production was measured at two oil levels (۱and۲ %), with or without yogurt starter (as co-culture) and ripening length by using the gas chromatography (GC). Results : The results showed that the highest amount of CLA production was related to cheese containing ۲% sunflower oil before reaching the end of the ripening period. Examination of GC data showed that increasing the arrival time reduced the CLA. On the other hand, increasing the oil in cheese has increased the amount of CLA produced.Conclusion : Using food as a pragmatic product to deliver CLA to the body is better than its medicinal form. Therefore, increasing the amount of CLA in cheese by adding oil in its formulation as a high-consumption dairy product can be one of the best ways to deliver this beneficial fatty acid to people.

CLA, Sunflower, yogurt starter, co-culture, cheese