Feasibility study on the use of attenuated total reflectance mid-infrared spectroscopy for the analysis of malt quality parameters in wort

Abstract

The feasibility of using attenuated total reflectance in combination with mid-infrared (MIR) spectroscopy for the analysis of malt quality parameters in wort, such as free α-amino acid (FAN), apparent attenuation limit (AAL), soluble protein (SP) and viscosity (VIS), was evaluated. The coefficients of determination in cross-validation R 2 CV À Á and the standard error of crossvalidation were 0.81 and 10.3 mg L À1 for FAN, 0.80 and 1.49% for AAL, 0.78 and 0.18% for SP and 0.69 and 0.13 cP for VIS. Good calibration and validation statistics were obtained for AAL. However, for nitrogenous compounds the MIR predictions can only be used as approximate estimates of the true concentrations, for example to rank samples (low, medium, high) in the context of a breeding programme.

Impact of moisture and grinding on yield, physical, chemical and thermal properties of wholegrain flour obtained from hydrothermally treated sorghum grains

“…Final viscosity (FV) is the parameter most commonly used to define the properties of the pasta of a given sample and the particular quality of a product. FV indicates the ability of the material to form a viscous paste or gel after cooking and cooling (Cozzolino et al, 2012). No significant tendency was observed in the values obtained by the treatments and types of mills; values were similar to those obtained by Sun et al (2014).…”

Infrared spectral analysis of sugar profiles of worts from varying grist to liquor ratios using infusion and ramping mash styles

“…Near‐infrared spectroscopy has been used to predict malt and wort quality and beer quality but its use in breeding programmes is where is has the greatest value . While mid infrared technology (IR) has had limited used in plant breeding selection , it has been applied to investigate wort quality and, fermentation and wort sugars . It has also been used to monitor the changes in the barley during malting .…”

The Brewing Industry and the Opportunities for Real-Time Quality Analysis Using Infrared Spectroscopy

“…Near infrared and MIR have been used for calibrations for fermentable sugars [63,67,69,70]. Along with the capacity to measure the fermentable sugars, reports have shown NIR can measure fermentation efficiency or what is called the apparent attenuation limit (AAL) [71]. In addition, there have been a number of reports showing NIR and MIR calibrations specifically for ethanol [57,70,72,73] with specific studies reporting a flow-through FTIR for ethanol measurement [57,72].…”

“…The measure of the soluble protein from the mash does not provide information on active proteins but the measure is based on the amount of nitrogenous compounds (mostly proteins). NIR has been used to build a calibration to predict soluble protein calibration [7,37,45,63,71]. These calibrations were developed with different malt samples and different mashing programs thus showing the robustness of NIR and MIR for samples with high concentrations of nitrogenous material (>4%).…”

“…Most brewers will require the FAN to be above a certain amount which indicates the yeast will have sufficient amino acids. NIR and MIR has been shown to also be suitable for calibrations for FAN [7,63,69,71] and more importantly for individual amino acids [37] with yeast having a preference for certain amino acids. The combination of soluble protein, FAN and amino acid profile would provide brewers with a vast amount of data for decisions on optimizing yeast pitching.…”