Role of Endogenous and Exogenous Tocopherols in the Lipid Stability of Marine Oil Systems: A Review

Abstract

In marine organisms primarily intended for human consumption, the quality of the muscle and the extracted oils may be affected by lipid oxidation during storage, even at low temperatures. This has led to a search for alternatives to maintain quality. In this sense, antioxidant compounds have been used to prevent such lipid deterioration. Among the most used compounds are tocopherols, which, due to their natural origin, have become an excellent alternative to prevent or retard lipid oxidation and maintain the quality of marine products. Tocopherols as antioxidants have been studied both exogenously and endogenously. Exogenous tocopherols are often used by incorporating them into plastic packaging films or adding them directly to fish oil. It has been observed that exogenous tocopherols incorporated in low concentrations maintain the quality of both muscle and the extracted oils during food storage. However, it has been reported that tocopherols applied at higher concentrations act as a prooxidant molecule, probably because their reactions with singlet oxygen may generate free radicals and cause the oxidation of polyunsaturated fatty acids in fish oils. However, when tocopherols are included in a fish diet (endogenous tocopherols), the antioxidant effect on the muscle lipids is more effective due to their incorporation into the membrane lipids, which can help extend the shelf life of seafood by reducing the lipid deterioration that occurs due to antioxidant synergy with other phenolic compounds used supplements in fish muscle. This review focuses on the most important studies in this field and highlights the potential of using tocopherols as antioxidants in marine oils.

Cardio-Protective Properties and Health Benefits of Fish Lipid Bioactives; The Effects of Thermal Processing

“…The strong antioxidant properties of vitamin E are associated with the main effects of its presence in fish and fish oils, which is to beneficially protect against lipid peroxidation of the long chain unsaturated fatty acids, and especially being prone to oxidation of n-3 PUFA, EPA, and DHA, in fish and fish oils [ 105 , 176 ]. Incorporation of exogenous tocopherols in extracted fish oils at low concentrations maintain the quality of both muscle and the extracted oils during food storage [ 176 ].…”

The Difference between the Effect of Green Tea Cream and Tocopherol on Decreasing Level of Tyrosinase Enzyme and Amount of Melanin in Rattus norvegicus Exposed to UVB Rays

“…On the other hand, some studies also state that tocopherol may directly inhibit tyrosinase activity in melanogenesis mechanism (Suárez-Jiménez et al, 2016) and even reduce up to 70% pigmentation and reduce 40% tyrosinase activity compared to the control group (Keen & Hassan, 2016). Therefore, we may state that green tea application may inhibit melanin formation.…”

“…This research result is slightly different from the in vitro study on B16 melanoma cell, stating that various analog tocopherols evidently reduce melanin amount and tyrosinase activity significantly (Albakry, Amiyati, & Hasan, 2018). Among the 8 analog tocopherols, that ones with high potential are D-b-tocopherol and D-g tocopherol (Suárez-Jiménez et al, 2016). In this study, the analog tocopherol used is D-α.…”

“…In cell membrane, tocopherol may prevent lipid oxidation, particularly Poly Unsaturated Fatty Acid (PUFA).In mitochondria, tocopherol protects metabolic pathway which will transform energy fuel into ATP. In fat tissue, antioxidant from tocopherol attacks lipid peroxide as the result of lipid and free radicals reaction (Suárez-Jiménez et al, 2016). The concentration of gamma tocopherol in skin is higher than that of alpha tocopherol.…”

Preparation and Thermal Stability of α-Tocopheryl acetate and Strawberry Anthocyanidins Complexed with Starch and β-Cyclodextrin

“…Although α-Tocopherol is found in most oils and fats; oils are richer in α-Tocopherol particularly in canola, corn, soybean and sunflower oils (Choe and Min 2009). Its role is mainly protecting oils from thermal and oxidative degradation; hence it is regularly used to enhance fatty foods during food processing (Suárez-Jiménez et al 2016). However, α-Tocopherol was observed to undergo degradation upon thermal treatment (Vaidya and Choe 2011).…”