Abstract:

Using the Schaal accelerated oxidation test, this study was conducted to investigate the effects of differentcombinations of natural antioxidants with synthetic antioxidants on the stability the shelf-life of linseed oil by examiningthe changes in its acid value and peroxide value. The results showed that under the condition of accelerated oxidation at 100 ℃, acombination of 0.04% oleaginous rosemary, 0.018% butyl hydroxy anisd and 0.018% propyl gallate was found to have thebest antioxidant activity. Comparisons of the changes in acid value of linseed oil before and after alkali refining revealedthat adding 0.30 or 0.35 g of sodium hydroxide (NaOH) to 2 g of linseed oil and allowing them to react for 4 hours reducedits acid value by about 80% and significantly prolonged its shelf-life. According to Arrhenius empirical formula, under thecondition of accelerated oxidation at 60 ℃, the shelf-life of linseed oil treated with the optimal combination of natural andsynthetic antioxidants could be extended to as long as 352 days.

Key words: linseed oil, antioxidant, alkali refining, shelf-life