Experiment planned and executed by Ari Sexner, juice business consultant.
You can download the full lab report here.
In the first part of this series, Cold-Pressed VS Centrifugal – Part 1: Real Nutritional Data, we tested the nutrient content of juice made on both a centrifuge and a cold-press and found that the cold-pressed juice contained about 15% higher nutrient content.
For Part 2, we have created a green juice recipe on both types of machines, and tested nutrients every day for 3 days to compare how they deteriorate over time.
For this test, we made a green juice blend consisting of:
- Green Apple
We had the lab test for Vitamin A, Vitamin C, and Iron. Iron did not show up in either of the samples, so we excluded it from the rest of this article.
For the juice equipment, we used:
Cold-Press – Goodnature Countertop CT7 with Sammic CKE-8 for grinding
Centrifugal – Nutrifaster N450
We made the juice and bottled it, packed in cold packs to keep it at 45 degrees, and overnighted it to the lab. There were 3 samples of each type of juice, so that the lab could test one sample each day, without disturbing the other samples that are kept at 41 degrees.
On day one, this sample shows almost identical amounts of Vitamin A, but much higher Vitamin C in the cold press sample.
At 48 hours we see, surprisingly, about a 3% rise in the Vitamin A in cold-pressed, and a 35% decrease in the centrifugal.
Vitamin C stayed in the same in the cold-pressed, and dropped 20% in the centrifugal.
At 72 hours Vitamin A dropped off by about 12% in the cold-pressed juice, and 46% in the centrifugal sample.
Vitamin C remained the same in both samples.
Results Table and Charts:
These lab tests show that this sample of cold-pressed juice did indeed hold up better over time compared to the centrifugal sample. We believe this is due to the following reasons:
- Centrifugal juice is highly oxidized due to the method of extraction.
- Centrifugal juice contains more solids / pulp and therefore breaks down faster than juice made on a press.