Rapid Analysis of Whole Malt Using Near Infrared Reflectance Spectroscopy

Abstract

Near infrared (NIR) reflectance spectroscopy has been evaluated for the analysis of whole malt. Good agreement has been obtained between NIR and reference methods for moisture and total nitrogen. A correlation coefficient (r) of 0-974 and a standard error of prediction (SEP) of 0-13% was obtained for the moisture measurement. Similarly the correlation between methods for total nitrogen analysis was 0-964 with a SEP of 0049%. In addition, NIR spectroscopy can be used to predict wort composition from scans on whole malt, without the need for mashing. Hot Water Extract (r 0951, SEP 2-1 17kg), total carbohydrates (r 0-946, SEP 007%), fermentable sugars (r 0-903, SEP 0-11%), total soluble nitrogen (r 0-900, SEP 0027%), free amino nitrogen (r 0-857, SEP 10mg/100ml| andfermentability (r 0-884, SEP 0-90%) can be measured using this technique. Since no sample preparation is required, NIR spectroscopy provides a rapid method for simultaneous measurement of all these parameters in under two minutes.

Applications of near Infrared Spectroscopy in Quality Screening of Early-Generation Material in Cereal Breeding Programmes

“…NIR analysis has also been achieved for whole barley 64,65 and malt. 66 While these applications ( Table 2) have been used for many years in the selection of lines for malting quality, improvements in accuracy have continually been sought. For example, Fox et al 67 developed improved calibrations for barley and malt protein by using wavelengths selected from the spectra of hordeins.…”

How to use the NIR spectroscopy in a brewery laboratory.

“…Mnoho prací se věnuje stanovení dusíkatých látek a vlhkosti v ječmeni a sladu [6,7,8,9]. Popsána byla i korelace NIR spekter s některými dalšími znaky sladu jako jsou friabilita, homogenita, celkový dusík, rozpustný dusík, volný aminodusík, viskozita a barva sladiny [2,10,11]. Úspěšně lze ze spekter předpovídat zkvasitelnost a dosažitelné prokvašení sladin a mladin [12,13,14,15].…”

“…Many works deal with the determination of nitrogen compounds and water content in barley and malt [6,7,8,9]. The correlation of the NIR spectra with some other malt indicators such as friability, homogeneity, total nitrogen content, soluble nitrogen, free amino nitrogen, viscosity and colour of wort [2,10,11]. Fermentability as well as maximum degree of fermentation of worts and hopped worts can be successfully predicted from the spectra [12,13,14,15].…”