Background:

Controversy exists regarding the use of blenders in preparing raw foods. Because of the vortexing action of a blender and extensive mixing with air, it is believed by many to cause a loss of sensitive nutrients and enzymes. The hypothesis that blenders cause loss of enzyme activity was put to the test.

Methods:

Carrots, apples, oranges, and kale were processed in three different blenders and 4 different juicers to compare the enzymatic activity of the “beverages” from these appliances. In the blenders an equal amount of water was added to the blender before processing the carrots, apples, and oranges. The kale was made with a 1:3 dilution to assist blending.

Calculation:

Enzyme activity was measured for 6 enzymes: acid phosphatase, alpha-mannosidase, N-acetyl beta-D-glucosaminidase, leucine amino peptidase, beta-gluosidase and beta-galactosidase. Enzymatic activity was compared after taking the dilution of the produce into account. Activities in units/L were normalized on a scale of 100% by scaling each enzyme to the highest reported activity level (which became 100%). Then the normalized activities for each enzyme were averaged together to give a summary activity score. These graphs for carrots, apples, oranges, and kale are shown on the page.

Average Enzyme Content: Carrot Juice

Carrots were processed in three different blenders and 4 different juicers to compare the enzymatic activity of the “beverages” from these appliances. In the blenders an equal amount of water was added to the blender before processing.
  • Blender 1
  • Blender 2
  • Blender 3
  • Vertical Auger 1
  • Vertical Auger 2
  • Centrifugal Juicer
  • Vertical Auger 3
  • Pasteurized
  • 88.4%
  • 90.4%
  • 91.6%
  • 83.4%
  • 88.6%
  • 81.7%
  • 84.2%
  • 0
  • 0
  • 5
  • 10
  • 15
  • 20
  • 25
  • 30
  • 35
  • 40
  • 45
  • 50
  • 55
  • 60
  • 65
  • 70
  • 75
  • 80
  • 85
  • 90
  • 95
  • 100

Average Enzyme Content: Apple Juice

Apples are processed in three different blenders and 4 different juicers to compare the enzymatic activity of the “beverages” from these appliances. In the blenders an equal amount of water was added to the blender before processing the apples.
  • Blender 1
  • Blender 2
  • Blender 3
  • Vertical Auger 1
  • Vertical Auger 2
  • Centrifugal Juicer
  • Vertical Auger 3
  • Pasteurized
  • 64.7%
  • 75.3%
  • 91.6%
  • 55.7%
  • 49.9%
  • 15.6%
  • 43.7%
  • 6.1%
  • 0
  • 5
  • 10
  • 15
  • 20
  • 25
  • 30
  • 35
  • 40
  • 45
  • 50
  • 55
  • 60
  • 65
  • 70
  • 75
  • 80
  • 85
  • 90
  • 95
  • 100

Average Enzyme Content: Orange Juice

Oranges are processed in three different blenders and 4 different juicers to compare the enzymatic activity of the “beverages” from these appliances. In the blenders an equal amount of water was added to the blender before processing the oranges.
  • Blender 1
  • Blender 2
  • Blender 3
  • Vertical Auger 1
  • Vertical Auger 2
  • Centrifugal Juicer
  • Vertical Auger 3
  • Pasteurized
  • 77.4%
  • 86.3%
  • 93.4%
  • 45.2%
  • 43.1%
  • 54.4%
  • 39.6%
  • 1.2%
  • 0
  • 5
  • 10
  • 15
  • 20
  • 25
  • 30
  • 35
  • 40
  • 45
  • 50
  • 55
  • 60
  • 65
  • 70
  • 75
  • 80
  • 85
  • 90
  • 95
  • 100

Average Enzyme Content: Kale Juice

Kale were processed in three different blenders and 4 different juicers to compare the enzymatic activity of the “beverages” from these appliances. The kale was made with a 1:3 dilution to assist blending.
  • Blender 1
  • Blender 2
  • Blender 3
  • Vertical Auger 1
  • Vertical Auger 2
  • Centrifugal Juicer
  • Vertical Auger 3
  • Pasteurized
  • 86.3%
  • 86.8%
  • 86.5%
  • 57.1%
  • 68.6%
  • 64.6%
  • 62.2%
  • 0
  • 0
  • 5
  • 10
  • 15
  • 20
  • 25
  • 30
  • 35
  • 40
  • 45
  • 50
  • 55
  • 60
  • 65
  • 70
  • 75
  • 80
  • 85
  • 90
  • 95
  • 100

Results:

In the carrots, the juicers and blenders produced about the same enzyme activity in the resulting beverage. In the apples, oranges, and kale the blenders consistently delivered more enzymes than the juicers. This means that when you put a pound of produce into a juicer or blender, you will get more enzymes out of the blended beverage. The main loss in the juicer is the enzymes that remain in the pulp, which is not consumed.

However, it should be noted that it is up to the user to make a palatable beverage using a blender. A mix of water and apple or water and orange is not very palatable. It is much easier to make a palatable, full-flavored juice with a juicer. A blender makes good smoothies, but very poor tasting, watery juices.

Conclusion:

Extensive blending does not destroy enzymatic activity of fresh produce. Should you juice your kale or blend it? You will get more nutrition from the blended kale, as long as you can drink the result. However, if you want to eat a lot of kale, you should consider making a green juice with it.

Research performed by:

Dr. Michael Donaldson ( Ph.D. )Research Director

An invaluable asset to the science behind the Hallelujah Diet, Dr. Donaldson is a chemical engineering graduate of Cornell University and now Research Director of the Hallelujah Diet.
View Bio