4-Nitrophenyl-β-D-glucopyranoside

The primary quality assessor of wheat grain is the Hagberg Falling Number (FN) method. This is a viscometric test surrogate for α-amylase activity. Despite being used for over sixty years, FN has been increasingly scrutinised due to its low throughput, poor reproducibility and inability to differentiate between the causes of low FN including Pre-harvest Sprouting (PHS) and Late Maturity α-Amylase (LMA). Our study describes initial efforts to analyse a specific wheat flour set tailored for the identification of enzymatic candidates that would allow discrimination between PHS and LMA affected grains. Using the sensitive enzyme-coupled assay substrate R-AMGR3, results suggest that α-glucosidase (exo-α-glucosidase) is a potential enzyme marker candidate to specifically detect sprouted but not LMA-affected grain.

A largely defined series of hydrolytic enzymes active during malting and/or mashing, substantially determine the quality, profitability, and efficiency of the brewing process. These enzymes potentially hydrolyze starch, proteins and cell wall non-starch polysaccharides including β-glucan and arabinoxylan. Commercial malts (94) were assayed for the DP enzymes (limit dextrinase, beta/α-amylase), and NSP hydrolyzing enzymes (β-glucanase, xylanase, arabinofuranosidase, β-glucosidase). The levels of enzyme activity were related to conventional measures of malt quality such as extract, fermentability, protein, KI, DP, friability, wort viscosity, FAN, and β-glucan. These parameters were interrelated with less conventional measures of malt quality including coarse extract and fermentability (modified infusion mash 65 °C), lautering efficiency, the Small-scale Wort ‘I’ Filtration Test (SWIFT), and viscosity. Substantial variation was observed between the malt samples for all enzymes assayed. Australian barley, whether malted in Australia (n = 61) or China (n = 24), was observed to be of comparable quality. A limited set of Canadian barley samples (n = 9) were malted in China and produced malts with somewhat higher levels of extract, AAL, and some enzymes. Remarkably, the level of limit dextrinase was observed to be almost double that from previous investigations. Greater levels of steep water aeration were proposed to explain this dramatic increase. The interrelationships between the enzyme activities and malt quality identified, enable potential selection of novel malt quality parameters that are more predictive of a malt’s brewing performance (efficiency and quality) than current measures to provide a malt quality assessment system based on ‘functional’ malt quality.

This study aimed at developing a complete miniaturized high‐throughput screening workflow for the evaluation of the Cell Wall‐Degrading Enzyme (CWDE) activities produced by any fungal strain directly cultivated on raw feedstock in a submerged manner. In this study, wheat straw was selected as model substrate as it represents an important carbon source but yet poorly valorised to yield high added value products. Fungi were grown in a microbioreactor in a high‐throughput (HT) way to replace the fastidious shaking flask cultivations. Both approaches were compared in order to validate our new methodology. The range of CWDE activities produced from the cultures was assayed using AZO‐died and pNP‐linked substrates in an SBS plate format using a Biomek FXp pipetting platform. As highlighted in this study, it was shown that the CWDE activities gathered from the microbioreactor cultivations were similar or higher to those obtained from shake flasks cultures, with a lower standard deviation on the measured values, making this new method much faster than the traditional one and suitable for HT CWDE production thanks to its pipetting platform compatibility. Also, the results showed that the enzymatic activities measured were the same when doing the assay manually or using the automated method.