F-751 Avocado Operation Manual Rev. 1/25/2023
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Felix Instruments
1554 NE 3rd Ave
Camas, WA 98607, USA
Phone: +1 (360) 833-8835
Fax: +1 (360) 833-1914
www.felixinstruments.com
[email protected]
Incident
Beam
Backscattered light
Illuminated
Region
Figure 2
. Schematic of light scattering
within an object after being struck with
Vis-NIR radiation from a spectrometer.
Incident light is reflected, absorbed, or
transmitted depending on the physical
and chemical composition of the sample
(Diagram adapted from Lu et al., 2017).
The F-751 Quality Meter utilizes a light interactance geometry (Fig. 1 & 2), in
which a halogen lamp directs NIR and visible light into the commodity. As light
Theory of Operation
At Felix Instruments, visible and near-infrared (Vis-NIR) spectroscopy
instrumentation is utilized to collect spectral signature data of various
agricultural and food commodities. This spectral data is then used alongside
data from destructive analytical testing to create predictive models that can
rapidly and non-destructively evaluate external and internal quality traits of
the commodity.
penetrates a sample, photons scatter,
and
the
resulting
reflectance,
transmittance, and interactance spectra
is collected by a fiber optic lens (Lu et al.,
2017 & Cavaco et al., 2020). The resulting
frequency and wavelengths are called a
spectrum, enabling users to identify and
quantify the chemical composition of a
sample. To create regression-based
predictive models from this spectral data,
artificial neural networks (ANN) are
employed during chemometric analysis.
The use of ANN enables users to extract
hidden or unknown relationships in
complex multivariate datasets (Héberger,
2008). Some of the quality traits in
agricultural and food commodities that
are commonly modeled using NIR
spectroscopy and chemometrics include:
dry matter content (DM), total soluble
solids (TSS), titratable acidity (TA), pH, fat
content, water content, phenols, etc.
Figure 1
. Geometrical configuration
of Vis-NIR spectra that may be
acquired in spectroscopic analysis.
Light is split when it strikes an object,
as some photons are absorbed, and
others are reflected (A) reflectance,
(B)
transmittance,
and
(C)
interactance
modes
(Diagram
adapted from Cavaco et al.)
A
B
C
