Brix readings equate with superior
nutrient content, and optimal flavor.
Passion series of Kiwi Berries have the highest sugar levels on
record with an average of 28.25 degrees Brix.
The following is the equipment
and test protocol utilized, and results determined by Matthew Kinkade, IGDP in
Plant Biology, Department of Horticulture, Foolad Lab, Penn State University,
University Park, PA in 2009 on our Passion Popper variety that is proprietary
to Kiwi Korners:
The refractometer we have is a
Spectronics Instruments refractometer (cat# 334610). This company has since
been bought out; the same model is available via VWR - it is the "ABBE-3L"
refractometer from Thermo Scientific.
As mentioned in my previous message, I
split the fruits up into two centrifuge tubes, and produced a fine puree by
grinding the samples with an OMNI TH tissue homogenizer (if you have a
larger sample size, a normal household blender would probably work).
I then centrifuged the tubes at 3500
rpm for approximately 20 minutes. This separated the solid matter from the
liquid (a higher centrifuge speed would be ideal, but this was the upper
limit of the rotor we use). I then sampled approximately 200 uL of liquid
from each tube twice (avoiding any solid debris in the tube, as it may
interfere with measurement) and obtained an average reading of 28.25 Brix. I
calibrated the machine prior to use, and made sure that pure water produced
a reading of 0 Brix between each determination.