Optimum Control of
Asparagine is one of the most common natural amino acids. A re- action between asparagine and reducing sugars or reactive car- bonyls produces acrylamide, a suspected carcinogen which forms
in certain foods when they are heated to sufficient temperatures. Formation
of acrylamide is a con-
cern in the processing of
fried and roasted
processed foods, such
as potato chips or fries,
baked cereals and
roasted coffee beans.
The potential for acry-
lamide formation directly
correlates with the con-
tent of asparagine and
reducing sugars in the
food, and the formation
process can be con-
trolled if the levels of the
precursors are known.
For such detection, a
quick and reliable enzymatic method has been
developed for acrylamide control in raw
and processed foods,
employing the automated Thermo Scientific
Arena analyzer, which
utilizes discrete cell technology to enable the simultaneous analysis of several different parameters from the same sample. Separate analytical methods, like the determination of asparagine and sugars, glucose and fructose,
can be run simultaneously from a single sample, significantly reducing
analysis time. Its automated features ensure walk-away analysis delivering
improved efficiency and time and cost savings by providing the operator
flexibility to work on other tasks. The special micro-volume cuvette design
enables small reagent volumes making the system economical to use. Enzyme reaction with its substrate is highly specific, so measurements can be
done in low levels with high reproducibility.
Applications of this analyzer are based on photometric measurements
and the wavelength range covers filter configurations from 340 nm to 880
nm. The method developed for the analysis of asparagine is a three-reagent reduction reaction, consisting of a nicotinamide adenine dinu-cleotide phosphate (NADPH) in 2-oxoglutarate buffer, glutamate
dehydrogenase, and asparaginase. Measurement is done at 340 nm.
The analyzer handles all the steps of the analysis and each individual reaction is isolated and temperature-stabilized. The reaction takes place in
micro-volume cuvettes that are automatically deposited to a waste bin
after use. Sample pretreatment is minimal; generally centrifugation or filtration is adequate to prepare the samples. With potatoes, for example, juice
is extracted by a separator and Carrez clarification is performed to stabilize
the juice and to stop microbiological activity. The samples are then ready
for analysis. The sample matrix effects can
be eliminated by using the instrument’s
several blanking possibilities. Automatic
dilutions help to manage different concentration levels with no additional effort.
During the reaction, the incubator of
the analyzer maintains the specified temperature of 37 °C, ensuring a high level of
control in the enzymatic reaction. The reaction temperature is freely adjustable up
to 50 °C. Since the cuvettes are disposable, there is no need for extra cleanouts
or rinsing of the system to avoid carryover
or contamination. Microliter-volume samples reduce waste and operating costs.
Compared with manual methods, the analyzer uses 10–15 times less reagent, which
is especially important when working with
Thermo Scientific Arena reagent kits
are available for D-glucose and D-fructose
as well as sucrose, ammonia, glycerol,
ethanol, acetic acid, lactic acid and malic
acid determinations. All of the kit components are ready-to-use liquids, eliminating
the need for reagent preparation. An analyzer can have 35 or 45 reagents simultaneously on-board and application
parameters allow up to four reagent additions in each test.
A wide selection of system applications are available not only for asparagine
and reducing sugars but also for different
acids. For example, fermentation
processes are easily controlled with the
analyzer. Its open concept allows customers to set up their own applications
with method parameters freely designed
by the user.
Since the analyzer requires minimal
daily and weekly maintenance, it maximizes uptime. There is no need for external water or drainage connections and the
system’s small footprint facilitates installation in any laboratory. Available in four different models, it fulfills different capacity
needs in different size laboratories. All four
analyzers have the same graphical user interface which is intuitive and simple to
use. Analyzers can be connected to the
laboratory information system (LIMS) for
automatic request querying and/or automatic result reporting.
These analyzers are easy-to-use automated systems for product analysis and
quality control, offering flexibility, speed,
accuracy and precision measurements.
Samples, reagents and consumables can
be loaded at any time without interrupting
the analysis. Once loaded, the analyzer
can run without the assistance of the