What is Oxidation and Why Does it Matter to Juicing?
You might have read in various reviews that a cold pressed juicer will yield more nutrition per glass of juice because it avoids oxidizing the nutrients in your fruits and vegetables. Unlike the fast-spinning metal blades of a centrifugal juicer which heats and kills the nutrients in your produce, the cold pressed method slowly extracts your juice and maintains its nutrients. A lot of fuss is made about oxidation – but what does oxidation really mean? And why is it so important to juice?
Oxidation – What is it?
Oxidation is a term used in chemistry to refer to the loss of electrons by a molecule, atom, or ion. The process is often associated with oxygen molecules (O2 ), which are highly reactive and can form compounds with other molecules easily. In a chemical reaction, oxygen can take electrons from another molecule, thus oxidizing that molecule.
Oxidation is commonly seen when leaving an apple core exposed to air for a long time. An apple left out too long will eventually turn brown. This color change is caused by the oxygen in the air reacting with compounds in the apple (specifically, polyphenol oxidase enzymes and phenolic compounds), which then react with amino acids and proteins to produce the unwanted brown color.
Why Oxidation Matters to Juice
Serious juicers care about the taste of their juice, and about its nutritional content. A cold pressed juicer does better on both accounts because it avoids the oxidation reactions caused by fast moving centrifugal juicers. The fast moving blades do two things: 1) they move quickly thus ‘stirring’ more oxygen into your juice, 2) they heat things up. Heat causes chemical reactions to occur faster, and more oxygen can mean more oxidation reactions. As the blades cut up your produce, the cell walls of your fruits and vegetables are exposed and the nutrients within them can get oxidized. Vitamins A, C, and E are all molecules that can react with and be broken down by oxygen.
Avoiding Oxidizing Your Juice
A cold pressed juicer avoids oxidation by slowly crushing your produce rather than rapidly chopping it up. This minimizes the ability for oxidation reactions to happen – and thus conserves your nutrients for you and your juice. Drinking your juice soon after you’ve made it will also help reduce oxidization and ensure you are drinking the freshest, healthiest juice around!