Suitable for Congress mash
The amount of soluble nitrogenous substances in Congress wort is determined using spectrophotometry at wavelengths of 215 and 225 nm.
Malt intended for use in beer brewing or elsewhere in the food industry
Using a buffer solution, malt extract is produced, and then under defined conditions the extract is incubated on a specific substrate of PNPβ-G3 (p-nitrophenyl-β-D-maltotrioside) in the presence of highly pure β-glucosidase. The PNPβ-G3 molecule is hydrolyzed through the activity of the β-amylase in the malt to maltose and p-nitrophenyl-β-D-glucose. This is cleaved directly to form D-glucose and p-nitrophenol by the β-glucosidase in the substrate mixture. The formation of p-nitrophenol is proportional to the release of maltose by the activity of β-amylase.
Adding an alkaline solution halts the enzymatic activity and simultaneously induces a color reaction. The absorbance measured at 400 nm is directly dependent upon the activity of β-amylase in the sample.
Malt intended for use in beer brewing or elsewhere in the food industry
Using a buffer solution, malt extract is produced, and then under defined conditions the extract is incubated on a specific substrate of BPNPG7 oligosaccharide (a p-nitropheny-maltoheptaoside blocked at the non-reducing end) in the presence of thermostable α-glucosidase. The α-glucosidase is initially unable to degrade the "blocked" oligosaccharide. Only when the oligosaccharide is hydrolyzed by the activity of the α-amylase (an endoenzyme) from the malt are the resulting fragments vulnerable to the enzyme. Then, they are quantitatively degraded to glucose and free p-nitrophenol by the α-glucosidase, which is present in excess.
Adding a weakly alkaline solution halts the enzymatic activity and simultaneously induces a color reaction. The absorbance measured at 400 nm is proportional to the activity of α-amylase in the sample.
Malt intended for use in beer brewing or elsewhere in the food industry
Using a buffer solution, malt extract is produced, and then under defined conditions the extract is incubated on an azo-barley glucan substrate. The substrate is coupled with an azo dye, which is degraded by the β-glucanase activity to form low-molecular weight fragments. After addition of the precipitating agent, these fragments stay in solution and can be spectrophotometrically determined in the supernatant after centrifugation. The absorbance in the supernatant depends directly upon the activity of the β-glucanase in the analyzed malt.
Malt intended for use in beer brewing or elsewhere in the food industry
The determination of the color of the Congress wort is carried out by measuring the absorbance of the wort at 430 nm and then multiplying the value by a specified factor.
This method describes the spectrophotometric determination of the color of roasted malt beer/extract.
Roasted malt beer/extract intended for use in beer brewing or elsewhere in the food industry.