Stabilization of cod liver oil with a quaternary combination of α‐tocopherol and synergists: Method of assessment

Abstract

This study aimed to identify the concentrations of a quaternary combination of a-tocopherol (a-TOH, 1200-2000 ppm), ascorbyl palmitate (AP, 100-900 ppm), phosphatidylcholine (PC, 1000-9000 ppm), and L-lysine (1000-9000 ppm) optimum for the protection of cod liver oil against oxidation at 30°C. The control oil contained 1100 ppm a-TOH. The evaluation of antioxidant potency considered the rates of formation of conjugated dienes (CD) and thiobarbituric acid reactive substances (TBARS) and rate of loss of a-TOH between Day 1 and Day 4 of oxidation. The trials were designed and analyzed by RSM. Mathematical models of second order polynomial with good confidence (p 0.05) fitted the formation of TBARS and loss of a-TOH but not the length of the induction period (IP) and the rate of formation of CD. The optimal levels of the four additives (in ppm) were found to be 1200 for a-TOH, 100 for AP, 9000 for PC, and 1000 for L-lysine. Higher concentrations of a-TOH and AP either did not give better protections or resulted in a loss of antioxidant efficacy compared to when these additives were added at lower levels. PC was effective at the wide range of high concentrations while L-lysine was most protective at levels up to 5000 ppm. The rate of formation of TBARS was found to provide a very good model for evaluating the stabilizing effects of additives (R 2 ¼ 0.8187, p-value ¼ 0.012) while the IP and the rate of formation of CD provided unsatisfactory models (p values 0.557 and 0.112, respectively).Practical applications: This paper considers the different ways to use oxidation kinetic data to evaluate the effectiveness of synergistic combinations of antioxidants and synergists in stabilizing fish oils. It finds that the commonly used induction period provides a poor model for assessment while the rate of formation of TBARS during the induction period provides a good model, which is an important methodological consideration.

The Use of Sage Oil Macerates (Salvia officinalis L.) for Oxidative Stabilization of Cod Liver Oil in Bulk Oil Systems

“…Therefore, they are often used in combination with other antioxidants, usually in the form of a three-component composition with ascorbyl palmitate and lecithin [ 6 ] or with ascorbyl palmitate and citric acid [ 7 ]. The combinations of tocopherols, lecithin, and ascorbyl palmitate with rosemary extract [ 6 ] and L-lysine [ 8 ] are also applied. Moen et al [ 9 ] elaborated a mixture of antioxidants based on tocopherols, ascorbyl palmitate, rosemary extract, and green tea catechins for the preservation of omega-3 marine oil concentrates.…”

Pigments for Aquaculture of Salmonids. A Comparative Model Study of Carophyll Pink and Panaferd AX in Cod Liver Oil

“…The stability of cod liver oil is generally improved by antioxidants. Budilarto and Kamal-Eldin [36] found the stability to be improved by a specific blend of α-tocopherol, ascorbyl palmitate, phosphatidylcholine, and l-lysine. They also reported the rate of formation of TBARS to be a good model for evaluating the stabilizing effect of additives [36].…”

“…Budilarto and Kamal-Eldin [36] found the stability to be improved by a specific blend of α-tocopherol, ascorbyl palmitate, phosphatidylcholine, and l-lysine. They also reported the rate of formation of TBARS to be a good model for evaluating the stabilizing effect of additives [36]. Hence, higher TBARS observed in PAN oil after 13 days storage in experiment 1 and 8 days storage in experiment 2 compared to CP oils indicates lower stabilization capacity of PAN as compared to CP.…”

Application of natural antioxidants in the oxidative stabilization of fish oils: A mini‐review

“…For the conservation of marine oil omega‐3 concentrates, Moen et al (2017) developed an antioxidant mix consisting of tocopherols, ascorbyl palmate, rosemary extracts, and green tea catechins. Antioxidant properties were studied also in a 4‐component cod liver oil mix in which α‐tocopherols, ascorbic palmitate, and lecithin (phosphatidylcholine) were combined with L‐lysine, an amino acid (Budilarto & Kamal‐Eldin, 2015). The antioxidant system in question was found to be most effective in retarding oxidation when the components were applied in certain defined concentrations (1200 ppm α‐tocopherols; 100 ppm ascorbyl palmate; 9000 ppm phosphatidylcholine; and 1000 ppm L‐lysine).…”