Effect of stabilization of crude whale oil with tertiary butylhydroquinone and other antioxidants upon keeping quality of resultant deodorized oil. A feasibility study

Crude whale oil was stored under accelerated conditions for 146 days alone and in the presence of added antioxidants: 0.02% butylated hydroxyanisole, 3,5‐di‐t‐butyl‐4‐hydroxyanisole, propyl gallate, tertiary butylhydroquinone, TBHQ + 0.01% citric acid, and 0.01% citric acid. Inverse relationships were noted between peroxide values and oxidative stabilities and also between secondary oxidation products, measured by anisidine value, and oxidative stabilities at termination of the storage of antoxidant‐treated crudes. Tertiary butylhydroquinone was most effective, followed by butylated hydroxyanisole,3,5‐di‐t‐butyl‐4‐hydroxyanisole, and propyl gallate, in decreasing order, with respect to retardment of oxidative deterioration of stored crude whale oil. All antioxidant‐treated crudes were alkali refined and steam deodorized. Stability times of deodorized oils from crudes treated with butylated hydroxyanisole,3,5‐di‐t‐butyl‐4‐hydroxyanisole, propyl gallate and citric acid ranged from 13.5–18 days at 30 C. Deodorized oils from tertiary butylhydroquinone‐and tertiary butylhydroquinone‐citric acid‐treated crudes gave much longer stability times against oxidative deterioration at 30 C, viz. 49.5 and 56 days, respectively. The major factor that contributed to the improvement in oxidative stability and caused continued effectiveness of tertiary butylhydroquinone even after deodorization was the carry‐through of the antioxidant and its oxidation products from the crude into the deodorized oil. If tertiary butylhydroquinone‐stabilized crude oils are deodorized, the residual antioxidant and its oxidation products should be determined quantitatively by adequate analytical methods and be included as part of the food‐approved antioxidants in processed edible oils.