Studies on physicochemical changes and volatile organic compounds released during storage of raw cow milk

Abstract

This study aims to determine the changes in physicochemical properties along with the concentration of volatile organic compounds during storage of raw cow milk were discussed until spoilage. The physicochemical properties taken to study the raw milk quality are temperature, humidity, milk pH, milk acidity and concentration of volatile organic compounds. The raw milk sample was tested simultaneously for both the concentration of volatile organic compounds and other physicochemical parameters such as temperature, relative humidity, milk pH and acidity. The experiment was conducted for 10 hours regularly for 5 days. The result reveals that there is an increase in the concentration of total volatile organic acids from 139.50 ± 1.1180 μg/L to 482.25 ± 1.4790 μg/L. The increase in the concentration of volatile organic acids might be due to the metabolic activity of microorganisms such as Lactic acid bacteria, which is responsible for the decrease and increase of pH and acidity of the raw milk respectively. Hence, the concentration of total volatile organic compounds were correlated with milk pH and acidity. In which, the milk pH shows better correlation with the total volatile organic compounds with.