Potential of UV and SWIR hyperspectral imaging for determination of levels of phenolic flavour compounds in peated barley malt.

Highlights • Hyperspectral imaging (HSI) used to estimate phenolic flavor concentration in barley malt. • HSI has the advantage of being non-destructive and applicable prior to distillation. • UV HSI faces difficulties during the imaging process. • SWIR HSI can clearly estimate phenol concentration. Abstract In this study, ultra-violet (UV) and short-wave infra-red (SWIR) hyperspectral imaging (HSI) was used to measure the concentration of phenolic flavour compounds on malted barley that are responsible for smoky aroma of Scotch whisky. UV-HSI is a relatively unexplored technique that has the potential to detect specific absorptions of phenols. SWIR-HSI has proven to detect phenols in previous applications. Support Vector Machine Classification and Regression was applied to classify malts with ten different concentration levels of the compounds of interest, and to estimate the concentration respectively. Results reveal that UV-HSI is at its current development stage unsuitable for this task whereas SWIR-HSI is able to produce robust results with a classification accuracy of 99.8% and a squared correlation coefficient of 0.98 with a Root Mean Squared Error of 0.32 ppm for regression. The results indicate that with further testing and development, HSI may potentially be exploited in an industrial production environment. [ABSTRACT FROM AUTHOR]