What's the secret to vitamin E's preservative properties?

一、Key secret: Antioxidant and anti-corrosion, preventing spoilage at the source.

1.Targeted scavenging of free radicals to terminate oxidation chain reactions

• Vitamin E is a fat-soluble antioxidant that preferentially captures free radicals in oxidation reactions and converts itself into stable tocopherol radicals, thus interrupting the diffusion of the oxidation chain reaction.

2. Protect easily oxidized ingredients and extend the product's shelf life.

• In skincare products：It protects squalane, vegetable oils, and other oils from rancidity, while reducing the oxidative loss of active ingredients, extending the product's shelf life by 30%-50%.
• In food / health products：It protects the unsaturated fatty acids in nut oils and fish oils, preventing the formation of harmful substances such as peroxides, and maintaining the flavor and nutritional stability of the products.

二、Key advantages: Natural properties + synergistic effects

1. Natural source

• Compared to chemical preservatives (such as parabens), Vitamin E has an allergy rate of less than 0.5%, is non-irritating, and is suitable for products for sensitive skin, pregnant women, and natural foods.；
• Precisely matching the current consumer trends of "rejecting artificial preservatives" and "clean labeling" has become a core advantage of natural formulas.

2. Synergistic effects reduce reliance on single preservatives

• Combined with chemical preservatives：The amount of chemical preservatives such as phenoxyethanol can be reduced from 1% to 0.5%, reducing irritation and broadening the spectrum of preservatives.
• Combined with natural preservatives：Combined with tea polyphenols, rosemary extract, and vitamin C, it forms a dual antioxidant system of "fat-soluble + water-soluble", which can inhibit oxidation and mildly inhibit bacterial growth, making it suitable for pure natural formulas (such as skin care products without chemical preservatives).

三、The preservative effect of vitamin E depends on the compatibility of raw materials and processes.

1.Raw material purity: α-tocopherol content is the core factor.

• Food-grade/cosmetic-grade Vitamin E raw materials must have an α-tocopherol content of ≥96% and an antioxidant activity (ORAC value) of 18000 μmol TE/100g.
• If the α-tocopherol content is below 80% (such as industrial-grade vitamin E), the preservative effect will decrease by more than 50%, and it may contain heavy metals and solvent residues, affecting the safety of downstream products.

2. Extraction process: Low-temperature purification is the guarantee of activity.

• The mainstream method uses "molecular distillation" (vacuum degree < 1 Pa, temperature 50-60℃), which can separate impurities and retain α-tocopherol activity, with an extraction rate of over 90%.
• Avoid high-temperature refining (such as distillation at >120℃), otherwise α-tocopherol will be converted into inactive tocopherol quinone, completely losing its preservative effect.

3. Dosage form selection: Lipid-soluble / Water-soluble, selected as needed.

• Fat-soluble Vitamin E (natural type): Suitable for use in oil-based products such as face creams, essential oils, and nut butters. It can dissolve directly and work evenly.；
• Water-soluble Vitamin E (modified with polyethylene glycol): Suitable for water-based products such as toners, serums, and beverages, preventing uneven preservation due to stratification.

四、Avoiding the limitations of vitamin E as a preservative

1. Not used alone for high moisture products：Vitamin E can only inhibit oxidation, but cannot kill bacteria or mold. Water-based products need to be combined with other preservatives.
2. Control the amount added：Adding too much (>2%) can easily cause the product to become sticky and yellow, without providing any additional preservative benefits;
3. Avoid strong light exposure：Vitamin E is easily oxidized by ultraviolet light, so downstream products need to be packaged in light-proof packaging (brown bottles, aluminum foil bags).

The core of Vitamin E's preservative properties lies in its natural antioxidant and synergistic effects. The secret to Vitamin E's preservative function is essentially to block the oxidative degradation chain through the strong antioxidant properties of α-tocopherol, while its natural, gentle, and multifunctional advantages align with the trend towards clean labeling.