The ability of N-acetyl-cysteine and glutathione to inhibit the oxidation of corn oil stripped of tocopherols and
refined olive oil was examined.
The oxidative stability of corn oil stripped of tocopherols at 50 oC, 120 oC and 180 oC was evaluated. The absorbances at
234 nm and 270 nm, and p-anisidine value were monitored. N-acetyl-cysteine and glutathione inhibited the oxidation of
oil, N-acetyl-cysteine at a higher degree. In comparison to BHA at 200 mg/L, both thiols at 20-40 mg/L exhibited lower
(50 oC and 120 oC) or similar (180 oC) antioxidant activities. Compounds similar to the two thiols but not containing –SH
group, N-acetyl-serine and oxidized glutathione, exhibited very low or no antioxidant activities. The oxidative stability of
refined olive oil at 20 oC was determined by monitoring the peroxide value. N-acetyl-cysteine and glutathione at 20 mg/L
exhibited antioxidant activities comparable to that of BHA at 200 mg/L.
Present results show the ability of N-acetyl-cysteine and glutathione to inhibit the oxidation of corn oil stripped of tocopherols
and refined olive oil indicating that thiols can inhibit the oxidation of any oil.