Analysis for determining the content of added vitamin B6 using HPLC
This analysis is suitable for NAB, juice, beverage bases and vitamin powder.
Vitamin B6 is separated by ion-pair RP-HPLC, detected using UV absorption and quantified through comparison with external standards. If necessary, the identity of the substances can be confirmed via spectra comparison.
Determination of vitamin B1 (thiamine) and B2 (riboflavin) in mash, wort and beer
Suitable for all types of wort and beer
HPLC methods have been successfully used for the analysis of vitamin content in non-alcoholic beverages. However, for the most part, these methods cannot be employed with a wort or beer matrix due to the vitamin concentrations present.
The reagent kit for the determination of vitamins B1 and B2 in blood from Chromsystems GmbH in Munich, Germany was used for the analysis. This company specializes in the manufacture of reagent kits for clinical applications. The kits are easy to use and do not require much additional equipment; a simple isocratic HPLC system is sufficient. In cooperation with the company, this kit was modified to accommodate a different sample matrix (mash, wort and beer).
Hops and hop products intended for use in beer brewing or elsewhere in the food industry
A reliable sampling method for whole hops and hop products is a prerequisite for obtaining suitable material for analysis. The effort involved in collecting the sample depends upon how uniform the hop product is.
Analysis for determining the amount of added vitamin B6 by means of the microbiological microtiter plate test
This analysis is suitable for NAB, juice and other foods.
The VitaFast® microbiological assay for vitamin B6 (pyridoxine) is carried out on microtiter plates and is suitable for the determination of total amount of vitamin B6 in foods and beverages.
Vitamin B6 is added as pyridoxine hydrochloride or as pyridoxine-5-phosphate. Since the phosphorylated vitamin B6 form is not recognized by the microbes in the kit, the beverage is treated with acid phosphatase to determine the amount of supplemental vitamin B6; if necessary, the beverage is diluted with sterile water from the test kit.
The sample must be digested through enzymatic hydrolysis in order to measure the total content of vitamin B6 (naturally occurring and added).
The diluted sample and the vitamin B6 assay medium are added to the wells of the microtiter plate, which are coated with Saccharomyces cerevisiae. Saccharomyces cerevisiae requires vitamin B6 to grow. After an addition of vitamin B6, the microorganism exhibits growth until the vitamin is completely utilized. The plates are incubated at 30 °C for 44–48 h.
The growth of Saccharomyces cerevisiae is dependent upon the concentration of vitamin B6 and is determined through measuring the turbidity. These results are compared with those obtained from a series of standard concentrations. The measurement is performed with a microtiter plate photometer at 610–630 nm (alternatively at 540–550 nm).
Analysis for determining the amount of added vitamin B2 by means of the microbiological microtiter plate test
This analysis is suitable for NAB, juice and other foods.
The VitaFast® microbiological assay for vitamin B2 (riboflavin) is carried out on microtiter plates and is suitable for the determination of total amount of vitamin B2 in foods and beverages.
The beverage is first treated enzymatically and subsequently extracted hot; if necessary, the beverage is diluted with sterile water from the test kit.
The sample must be digested through enzymatic hydrolysis in order to measure the total content of vitamin B2 (naturally occurring and added).
The diluted sample and the vitamin B2 assay medium are added to the wells of the microtiter plate, which are coated with Lactobacillus rhamnosus. Lactobacillus rhamnosus requires vitamin B2 to grow. After an addition of vitamin B2, the microorganism exhibits growth until the vitamin is completely utilized. The plates are incubated at 37 °C for 44–48 h.
The growth of Lactobacillus rhamnosus is dependent upon the concentration of vitamin B2 and is determined through measuring the turbidity. These results are compared with those obtained from a series of standard concentrations. The measurement is performed with a microtiter plate photometer at 610–630 nm (alternatively at 540–550 nm).
Analysis for determining the amount of added vitamin B1 by means of the microbiologial microtiter plate test
This analysis is suitable for NAB, juice and other foods.
The VitaFast® microbiological assay for vitamin B1 (thiamine) is carried out on microtiter plates and is suitable for the determination of total amount of vitamin B1 in foods and beverages.
The beverage is sterile-filtered and diluted with sterile water for the determination of added vitamin B1.
The sample must be digested through enzymatic hydrolysis in order to measure the total content of vitamin B1 (naturally occurring and added).
The diluted sample and the vitamin B1 assay medium are added to the wells of the microtiter plate, which are coated with Lactobacillus fermentum. Lactobacillus fermentum requires vitamin B1 to grow. After an addition of vitamin B1, the microorganism exhibits growth until the vitamin is completely utilized. The plates are incubated at 37 °C for 44–48 h.
The growth of Lactobacillus fermentum is dependent upon the concentration of vitamin B1 and is determined through through measuring the turbidity. These results are compared with those obtained from a series of standard concentrations. The measurement is performed with a microtiter plate photometer at 610–630 nm (alternatively at 540–550 nm).