Physicochemical Properties and Trans Fatty Acids Content of Commercial Shortenings Produced in Iran

Shortenings are fats used mainly in the formulation of bakery, confectionery, dairy, and frying products. The aim of this study was to assess the physicochemical properties and trans fatty acid (TFA) content of shortenings produced in Iran.

Samples of 15 shortening brands produced in Iran (summer of 2016) were collected and characterized for their physicochemical properties.

Iranian shortenings contained 0.21-15.54% TFA and 40.08-59.54% saturated fatty acids. The iodine value of Iranian shortenings was between 40.84 and 73.32. Lovibond yellow and red color indices of the samples were 2.1-13.6 and 28-70.4, respectively. The induction period of oxidation at 110°C (IP110) of the samples was between 10.03 and 44.02 h. The slip melting point of the shortenings was between 42.5 and 49.3°C. Solid fat content of Iranian shortenings was 40.6-75.0% at 10°C, 24.2-59.5% at 20°C, 11.4-36.4% at 30°C, 7.8-27.3% at 35°C, and 3.1-17.4% at 40°C. Free fatty acid (FFA) content of shortenings ranged from 0.02 to 0.92%, and peroxide value was between 1.0 and 3.0 meq/kg.

Compared to the national standard for the specification of shortenings, 20.0% of samples had TFA content higher than the standard level (5%). Additionally, 13.3% of samples did not meet the standard limits of lauric acid content, 46.7% had FFA contents above and 53.3% showed IP110 below the standard level. Accordingly, efficient control protocols should be established by the authorities to assure the production of shortenings with the standard properties.