CDR Srl with QCL (QuadraChem Laboratories Ltd), the distributor of CDR products in United Kingdom, have requested to Campden BRI the evaluation of new VDKs concentration analysis and determination of yeast vitality, now available on the CDR BeerLab® Analyser.
The instrument was previously evaluated by Campden BRI for the test of pH, bitterness, colour and alcohol and was found to give comparable results to reference methods.
Campden BRI is an international reference laboratory and innovation, research and technology centre for the food and drinks industry.
The study
Five yeast slurry samples and five beer samples were analysed in triplicate for yeast vitality and VDK respectively using the CDR BeerLab® equipment and reference methods.
Further more to establish repeatability of the analyses and allow calibration of the equipment, one sample each of the VDK beer and yeast sample sets was analysed in 10 replicates by the CDR BeerLab® and the Campden BRI methods.
The reference methods used are:
- reference UKAS accredited VDK method (Campden BRI Method AM/008 based on Analytica-EBC, 9.24.2, 1999)
- the yeast acidification power test (APT), one of the most common vitality tests used)
The two CDR BeerLab® analyses were calibrated using the data obtained with the reference methods. The calibrated values were compared to those from the reference methods and the precision/repeatability of the two methods was also compared.
Results
The repeatability data produced by the CDR BeerLab®, as expressed in standard deviations of the eight/ten replicates showed that the CDR BeerLab® VDK and yeast vitality analyses have
good repeatability compared to the reference method.
For yeast vitality the CDR BeerLab® results were similar to those for the yeast acidification power test (APT) (correlation R2 = 0.90). Both methods were equally precise and repeatable.
Comparison of the analysis results of the 5 beer samples for VDK using both, the CDR BeerLab® (calibrated values) and the reference method, showed that the results were similar (correlation R2 = 0.99). Thus the CDR BeerLab® method had good accuracy and is good for analyses requiring distillation and spectrophotometric measurement.
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Conclusions
In summary, the CDR BeerLab® yeast vitality and VDK analyses show a linear correlation with the results obtained by the reference methods and the values obtained were similar (correlation R2 ≥ 0.9).
Campden BRI study using the CDR BeerLab® Analyser showed that:
- The instrument is easy to use
- The user interface is logical and user friendly
- Compared to the acidification power yeast vitality and the reference VDK methods, the CDR BeerLab® methods are much quicker
- The system has a low environmental impact due to minimal waste production and the very low sample and reagent volumes required
