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might be the case with other components changing and usually no blank wells needed to be scanned; thus
the overall fingerprint profile upon sample dilution; maximizing sample testing. Three wells per sample are
alcoholic beverages composed of several hundred sufficient, in our opinion, once a library of data has been
constituents providing a complex matrix for such established for a product to assist in subsequent testing
analyses. The issues with respect to sample dilution of newer or suspect batches of the same beverage.
with beer samples was also discussed elsewhere (12). Carbonated beverages were first degassed. Plates were
Nevertheless, either with or without sample dilution then read in a BMGLABTECH SPECTROStar Nano
it seems the method can be applied to a wide range scanning spectrophotometer in 1 nm increments
of alcoholic beverages and provide solid and reliable from 220 to 1000 nm; path-length correction was set
results as to quality – consistency, brand authentication to “off”. Averaged data from the individual sets were
and potential adulteration of the spirit, liqueur, wine or evaluated and plotted using spreadsheet programs
beer. The method may be used alone or in conjunction (either internal or external to the manufacturers’
with powerful chemometric evaluations of the spectral software). Simple Z-score statistical evaluations were
data to further discriminate different brands or made to look for occasional outlier data from wells
types/styles of beverages (1-4, 7, 9, and 10). Recent measured from within a set. Deviation may be caused
developments in chemometric analyses are, in our by slight imperfections in the plastic micro-plates, if
opinion, expected to play a greater role in this arena the wells are soiled or otherwise contaminated, if the
as more testing of alcoholic beverages takes place. Our correct volume from multi-pipette additions are not
lab in collaboration with a British University team is even across the range of wells or if any air bubbles
looking into the application of chemometrics to further are present after pipetting such low volumes. Only
discriminate samples and map styles. occasionally do we see any such issues. The method
and testing should be amenable to newly trained non-
Experimental Protocols and Systems Assessment laboratory personnel (including beverages sales teams)
Samples of most distilled spirits, 1:10 distilled water- without the need to perform statistical analyses for
diluted sherry samples or beer/malt beverages were routine quality evaluations in the beverage plant or the
loaded as 50 or 100 microliter additions into micro- field. While many instruments on the market are useful
wells (Costar Corning #3635 UV transparent 96-well for such analyses, as described herein, we believe that
plates) avoiding bubbles; typically up to eight wells many benefits are offered through the use of a scanning
per sample were examined in each run to test for any plate-reading instrument. As the preferred instrument
variance in data through optical transmission through in our own facility (used in other studies, 18 and 19)
the base of the plate and within the individual cells we discuss such advantages in more detail elsewhere

Figure 2: Five sherry samples with different aging periods and characteristics.

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