Antioxidant impacts on volatile formation in high-pressure-processed milk.

The effect of antioxidants on volatile formation in milk under high pressure was investigated. Raw milk samples with addition of either butylated hydroxyanisole (BHA), epicatechin, ascorbic acid, beta-carotene, or L-cystine were pressurized under 655 MPa at 75 degrees C for 3, 5, and 10 min. Formation of selected volatile compounds including aldehydes, ketones, and sulfur compounds was studied using headspace solid-phase microextraction and gas chromatography. BHA and epicatechin effectively inhibited the aldehyde formation. Ascorbic acid and beta-carotene also inhibited aldehyde formation but to a much lower extent. L-cystine was capable of inhibiting aldehyde and hydrogen sulfide formation. In general, the inhibition of volatile formation was proportional to the concentration of the added antioxidants. Reducing oxygen contents in milk also decreased aldehyde formation. Results suggested that the inhibition of volatile formation under high pressure could be similar to that under normal-pressure condition.