Total phenolic compounds content and antioxidant activity in packed and bulk milk in different regions of Tehran, Iran

Abstract

Free radicals and active oxygen species are toxic as they oxidize biomolecules leading to cell death and tissue injury. Lipid oxidation is also a major cause of spoilage in foods. In this survey, antioxidant activity and total phenolic content in milk samples were aimed to investigate. Pasteurized and bulk milk samples were collected from market in Tehran. The total phenolic content was determined based on the Folin-Ciocalteu method. The FRAP (Ferric reducing antioxidant power) assay was used for antioxidant activity. Data were analyzed by SPSS. Brand 9 packed milk had the highest amount of antioxidant power and total phenolic content; 3.820±0.104 μm and 9.001±0.598 μm respectively. Brand 5 packed milk had the lowest amount of antioxidant power and total phenolic; 0.498±0.002 μm and 0.708±0.135 μm respectively. In bulk samples collected from different regions, region 9 had the highest amount of antioxidant capacity and total phenolic content; 8.611±0.002 μm and 8.200±0.760 μm respectively, while the samples from region 22 had the lowest amount of antioxidant capacity and total phenolic content of about 0.218±0.021 μm and 0.395±0.005 μm respectively. Based on the findings, there were significant amounts of antioxidant and total phenolic elements in both types of milk; however, some variations between results were measured. In bulk milk samples, antioxidant activity was higher than branded samples, whereas the total phenolic amounts were less than the branded ones. In the flavored milk samples, the antioxidant activity was higher than unflavored milk samples; however, the total phenolic amounts were lower than in unflavored samples.