Application and stability of natural antioxidants in edible oils in order to substitute synthetic additives

Abstract

Antioxidants are components which prevent auto-oxidation of oils and fats by giving their hydrogen to free radicals formed in the initiation and propagation stages of autoxidation. During the past two decades, a lot of researches using natural plants extract in edible oils have been carried out due to the trend to minimize or avoid the use of synthetic food additives. According to the most studies, there are various natural antioxidants which can be extracted from low cost resources, such as most parts of olive plant, green tea, sesame, medicinal plants, etc. One of the most important requirements for a suitable antioxidant in oils and fats is the thermal stability during heat processing. It has been shown that most of natural additives have more antioxidants activity and thermal stability than synthetic ones in different edible oils. In this review, recent advances in the application of natural antioxidants in the food industry will be covered.

Quality Characterization and Oxidative Stability of Camellia Seed Oils Produced with Different Roasting Temperatures

“…A previous study showed that food moisture, atmospheric oxygen, and high temperatures can produce various chemical changes and decrease antioxidant activity, such as via the steam distillation of antioxidants, as well as the oxidation of phenolic compounds and decreases in their pro-oxidative activity due to reaction with fried materials and polymerization 12 . Lipid oxidation is one of the main factors which affects the shelf life of vegetative oils.…”

“…For example, the antioxidant activity of tocopherols makes an oil able to scavenge reactive oxygen species and lipids, while polyphenol additions to edible oil have the effect of mitigating the heat-induced formation of toxicants, mainly by inhibiting oxidative pathways and trapping reactive intermediates 12 . Subjecting an edible oil to high roasting temperature induces moisture reduction and the release of hydrophilic phenolics, while the high polar phase of an oil increases the speed of the degradation process 37 .…”

“…A variety of physicochemical changes occur to oils during lipid degradation, such as the main physical changes of increased viscosity and foaming, as well as color changes and a decreased smoke-point 12,13 . Meanwhile, the main chemical changes consist of increases in the concentration of free fatty acids and polar components and decreases in unsaturated fatty acid content, flavor quality, and nutritive value due to the degradation of minor compounds that affect the organoleptic and nutraceutical properties of the oils 13 .…”

“…As a result of the oxidation of polyunsaturated fatty acids PUFAs , the vitamins in the oil may lose some of their biological properties and may even form toxic products, some of which may be carcinogenic in nature 15 . On the other hand, sufficiently sophisticated processing and antioxidants can improve the oxidative stability of commercial products 12 .…”

Effect of the phytochemicals curcumin, cinnamaldehyde, thymol and carvacrol on the oxidative stability of corn and palm oils at frying temperatures

“…Because of perceived harmful effects of synthetic antioxidants, investigations have focused on the using of natural antioxidants to stabilise the oils. Many studies have proven the effectiveness of natural antioxidants in protection of the oils from lipid oxidation (Rodrigues et al 2012;Inanc and Maskan 2012;Chen et al 2014;Taghvaei and Jafari 2015).…”