Heat Stability of RIKEN E-oil
|Heating conditions||Residual amount|
|Heated at 40°C for 6 month||95.9%|
|Heated at 140°C for 2 hours||No change|
|Heated in rape seed oil at 200°C for 1 hour||97.0%|
|Heated in rape seed oil at 200°C for 3 hours||90.0%|
From Antioxidant Effect to Food Freshness Retention
The formation of peroxides by auto-oxidation of fats and oils occurs by the following mechanism:
|Initiation||RH -> R' + H'|
|Propagation||R´ + O2 -> ROO|
|ROO´ + RH -> R'+ ROOH|
|Termination||R' + R' -> R - R|
|R' + ROO´ -> ROOR|
|ROO´ + ROO´ -> ROOR + O2|
|RH : oxidizable substance R'
: fatty radical
ROO´. : peroxyl radical ROOH : hydroperoxide
In general, edible fats and oils consist of unsaturated fatty
acids. The radicals R' and ROO' play an important role in oxidation of unsaturated
fatty acids which contain double bonds. Oxidation is inhibited if these
radicals are scavenged.
This mechanism of action is the same as that of phenol antioxidants like BHA and BHT. Ascorbic acid (vitamin C) in the figure acts as a synergist and is useful for the reactivation of TOCOPHEROL.
The following substances are also known to act synergistically with Tocopherol; citric acids, EDTA which chelate metals, in particular Cu and Fe, from the reaction system, phospholipids, amino acids, peptides, and melanoidin. To obtain a better effect as an antioxidant it is suggested to use TOCOPHEROL along with a synergist. The amount of TOCOPHEROL and the choice of synergist can be selected according to the application.
TOCOPHEROL scavenges radicals in the following manner:
TOCOPHEROL is recommended to be used as antioxidants for not only edible fats and oils but also for foods containing fats and oils regardless of the amount.
A rancid odor is generated by the oxidation of lipids and it is emitted independently of lipid content. Even a small quantity of lipid contained in foods materials such as grain is known to be oxidized and causes in unfavorable odor. TOCOPHEROL exhibits an antioxidant effect on such lipids.
Lipid peroxides formed by oxidation may become associated with proteins in food and cause an unpleasant mouthful. This problem is, of course, solved by TOCOPHEROL.
Consequently, Tocopherol is not only utilized as antioxidant for fats and oils but also expected to give a freshness retaining effect on foods.