- Welcome back to our
virtual Friday field days.
This week, we're gonna do
something a little different
than we could do at a normal field day.
And we are gonna take
you behind the scenes
at the Grains Lab.
Once our samples have been
processed for test weight,
grain moisture and germination,
we bring them back to the grinding room.
We process a lot of different
kinds of grants here.
This is a commercial wheat sample,
commercial rice sample, some hulless oats
and some of our winter
barley malting trial.
We write down the analysis
that need to be performed
and the sample number on the jar.
And then we put them
through the laboratory mill.
We always wanna grind about 300 grams
so that we get a good
representative sub-sample.
We have that marked on the hopper
and then suction pulls it
through the hammer mill,
which is not turned on for this
demonstration or plugged in.
And then it goes through a sieve.
A lot of our machinery is calibrated to
specific grains and specific
little particle sizes.
So we wanna make sure that
we've got a really nice uniform
particle size, which is why
we ask our commercial folks
to send in whole grain
samples that we grind on site.
This is how we measure crude
protein and flour moisture.
We scoop the sample in, we tamp it down in
with this special little press.
And the what the machine is doing
is called near infrared spectroscopy.
And so it's shooting little beams of light
at this sample and then
from how it bounces back,
it can tell us calibrated
for that particular grain,
what the moisture is in the flour
and what the protein level is.
And so for this barley sample,
it's got a 15.1% moisture
content and a 9.1% protein.
You may have seen the
starch in the window,
we do not have it calibrated for starch.
So that's the cell that it's packed into
that Rory is cleaning out right now.
And that little window is where
the light streams come out
and also where they'll
measure when they bounce back
and the machine can determine
the composition from that.
We use the flour moisture
to help us set up our sample
size for our next test,
which is a Falling Number.
You may remember Falling Number from when
Henry talked about why
harvest state trials.
So Falling Number
measures how long it takes a way to disk
to fall through a test tube
as that test tube is being heated
with a mixture of flour and water inside.
This is approximately the
enzymatic activity in the grain.
Grain that is not mature enough,
has a really low Falling
Number that way to disk
basically fall straight through the tube.
Around 250 seconds is your best
and then if the grain is over mature
and it starts to pre germinate,
you'll get a high Falling Number.
So we grind it up, we
weigh out the sample,
we add 25 mils of water,
we shake it up to take
it all in suspension
and then it cooks inside
the Falling Number machine
and gives us our Falling Number.
So this is the test tube
and the way to disk.
And what happens as it's cooking
is it slowly drops through that tube
and when it hits the bottom,
there's a sensor that sees that it's there
and there's your Falling Number.
And Ray is gonna show us
how it's actually done.
We add the 25 mils of water.
We get a nice tight cork
and shake it all up.
If there's flour stuck to the bottom,
it can incorrectly read that as
already having fallen down the bottom.
So we always make sure it's
completely in suspension.
And then we make sure we
scraped down the sides
with the disk and make sure that
all of the flour is in the tube.
The tube goes into a little plastic color
that fits over the top of the machine.
If you drop it in without the color,
you make a big flourly mess
inside your Falling Number machine.
And it grabs a hold of
that plunger on the top
and rapidly shakes it up and
down for the first minute,
while it's a starting to cook.
And this is what it looks
like when it's done.
This is a test tube
that's completely cooked
and the way to disk has
fallen to the bottom.
And that's how we measure
our Falling Number.
So one of the most common
tests that we run in here
is testing for a toxin
produced by a fungus,
which is called deoxynivalenol.
And the FDA limits this toxin
and for human consumption
at one part per million
in the finished food.
So we have to make sure that
we are being really accurate
and precise with this
test since we're measuring
parts per million level.
So we always measure out
exactly 10 grams of flour.
We add that to an Erlenmeyer flask.
We add exactly a 100 milliliters of water.
And like with the Falling Number
we shake it up to make
sure it's in suspension
and not stuck to the bottom and
then we put it on the shaker
for three minutes. Once
it's finished shaking,
we let it settle out for a few minutes
and then we filter out the flour
and what we're measuring is the
filtrate that's left behind.
We combine that with some chemicals,
and this is what we call
a colorimetric test.
So one of the reactions
that's happening in there
with one of the chemicals,
it produces a blue toxin.
If a blue color, if
the DON is not present,
if the DON is present, it
reacts with that one substrate,
then it can't bind to the other molecule
that produces that blue color.
So if you see that blue, you know,
that you don't have very much DON present
and it goes through to a pink color,
which is what you get if you
have a lot of DON present.
We haven't seen much
of this toxin this year
because it's been a nice warm year.
We don't just look at
this ourselves though,
we put it through a machine
that shines light through it
and reads the exact wavelength,
so it can tell us exactly
how blue this is versus pink.
Where the light falls
along that wavelength
and then it correlates that back
to the specific level of the toxin.
So we put it in the
reader and we press start.
There's a couple of ways
that we check ourselves against this,
one is that every time we
run this standard curve
with known amounts of the toxin
and the machine calculates an R squared
and lets us know how close we are.
We also participate in a
proficiency testing program
from the Neogen company where quarterly,
we run samples with a
known amount of the toxin
or an unknown. They know how
much of the toxin is there.
We also test our own research
samples for forges and corn.
These go through a separate mill.
It grinds things finer and we
have it completely enclosed
because it's grinding
a finer particle size,
also because a lot more of these things,
particularly forages contain
things that can be irritants.
We grind these up at the research
farm through a Wiley mill.
So they're already partially
ground when we get them.
And then we put them through this mill
and grind it to a very
fine powdery particle size.
And that's how fine the powder is
when it comes out of the forage mill.
And then we ran them through another NIR,
which is again, using
that near infrared light
to determine the composition
of these samples.
This is a much more generalized one.
You can run corn on it
or forages or silages,
but you don't have to tell
it the specific species.
It uses these cups with glass bottoms.
They're all chipped,
so you can tell if you
have it in the right way
and it moves them around
and scans them with the near
infrared streams of light
and then can tell from the
spectrum that's produced
what the composition is.
So for these, we have to fill this cup up.
It doesn't have to be completely full,
but the bottom has to
be completely covered.
We spread it around a little
and then we tamp it down with this lid
making really sure not
to actually press on it.
Just kind of letting it set down on there
to even things out.
If you compress it, it
changes the readings.
It reads through the
bottom of that glass cup.
We put it in.
We press the button and
then the magic happens.
The lasers are going.
We have to tell it what
the sample number is
and it gives us a pretty
detailed report afterwards
of all the different components
that make up the forage
or the corn sample.
It tells us the dry matter.
It tells us the protein.
It tells us how much digestible
and nondigestible fiber are in it.
It can tell us the chemical composition
as far as individual elements
that we might wanna know what
the nutritional quality is.
And it also tells us how digestible
that particular forage is.
So thanks for joining
us in the Grains Lab.
