Centrifugal
The centrifugal process essentially chops and grinds the fruit and vegetables into tiny particles and dispenses a mixture of juice and microscopic particles. Therefore, they produce a very high yield of drinkable juice. However, this is not technically true juice extraction, and produces a lower quality of “living juice”.
Mastication
The mastication process mimics the natural process we use to chew food. An auger (or sometimes two augers- see below for the difference between single-gear and twin-gear) rotates and gently chews up the food to extract high-quality “living juice”. This difference in juice quality is actually visible- juices are much darker and more flavorful.
Cold-Press
Cold-press juicers run at a low enough RPM (between 70 RPMs and 200 RPMs) that the juice does not get heated up and therefore does not oxidize excessively
Oxidation
Oxidation occurs when juice is heated during the juicing process or exposed to open air for long periods of time. Essential vitamins and nutrients can escape during oxidation. The more a juice oxidizes, the shorter the shelf-life it has.
Single-Auger or Single-Gear
Single-gear juicers use a single auger in the mastication process to extract a “living juice”. There is no difference in the quality of juice that comes from single-gear or twin-gear juicers. Twin-gear juices simply have a higher extraction rate.
Twin-gear
Twin-gear juicers use two gears to extract juice through the mastication process. Since there are two gears doing the work, they are more efficient and therefore produce a higher yield of juice than single-gears. However, the quality of juice from single gear and twin gear juicers is the same.
Living Juice
“Living juice” is a concept that was started by Dr. Norman Walker. According to Walker, when juice heats to 50 degrees Celsius, the enzymes from the fruits and vegetables die. Therefore, living juice is juice that comes from raw fruits or vegetables that has never been heated up to 50 degrees Celsius. This juice lasts longer and contains more vitamins and nutrients than “dead” juice.