Hop extract intended for use in beer brewing or elsewhere in the food industry
This method describes how to determine the acid consumption or acid capacity of water.
Water intended for use as an ingredient in the production of beer (brewing liquor) or other foods
Water intended for use as an ingredient in the production of beer (brewing liquor) or other foods
The level of carbonate removal in the water treatment system is monitored using the analysis for the p and m values. The standard values specified in the analysis should not be exceeded.
Boiler water for use in the production of beer and other foods
Analogous to the p and m values obtained in the determination of acid capacity (pH 8.2 and 4.3), this analysis is performed according to W-000.13.031 Acid Consumption (Alkalinity, p-Value and m-Value)/Acid Capacity to pH of 8.2 and/or 4.3 for Water. The alkaline capacity of the boiler water is determined through titration of the sample with 0.1 N sodium hydroxide (instead of hydrochloric acid) to a pH of 4.3 and/or 8.2.
Hydrolytic cleavage of carbohydrates to determine total glucose from the glucose already present and that formed by hydrolysis.
Suitable for all beverages
Carbohydrates are split by acid hydrolysis in the boiling heat under reflux with acid. After neutralization and filtration of the hydrolysis mixture, the glucose content is determined enzymatically after dilution. In this process, glucose is phosphorylated by the enzyme hexokinase (HK) and adenosine 5'-triphosphate (ATP) to glucose 6-phosphate (G-6-P):
\(\text{Glucose + ATP} \space ^{\underrightarrow{\text{HK}}} \space \text{G-6-P + ADP}\)
In the presence of the enzyme glucose-6-phosphate dehydrogenase (G6P-DH), G-6-P is oxidized by nicotinamide adenine dinucleotide phosphate (NADP) to gluconate-6-phosphate. Reduced nicotinamide adenine dinucleotide phosphate (NADPH) is formed:
\(\text{G-6-P + NADP}^+ \space ^{\underrightarrow{\text{G6P-DH}}} \space \text{NADPH + H}^+\)
The amount of NADPH formed during the reaction is equivalent to the amount of glucose. NADPH is determined based upon its absorbance at 334, 340 or 365 nm.
Hops and hop products intended for use in beer brewing or elsewhere in the food industry
Hop constituents are distributed between an aqueous acidic methanolic phase and diethyl ether. Hop bitter substances extracted with ether are subsequently separated according to their different solubility properties in cold methanol and hexane into fractions: total resins, soft resins and hard resins. The soft resins are further separated according to their capacity to form complexes with lead salts into α-acids (conductometer value) and a β-fraction.