分析物意义: 大麦和燕麦的主要细胞壁多糖
Megazyme检测试剂盒优点:反应迅速、试剂稳定, 只有酶检测试剂盒可用。 AOAC方法 995.16; AACC 方法 32-23
AACC Method 32-23.01, AOAC Method 995.16, EBC Methods 3.11.1, 4.16.1 and 8.11.1, ICC Standard No. 166 and RACI standard method for the measurement of 1,3:1,4-ß-D-glucan in cereal grains, milling fractions, wort and beer. Recommended/Standard procedure of the Association of Official Analytical Chemists (AOAC), American Association of Cereal Chemists (AACC), Royal Australian Chemical Institute (RACI), European Brewing Convention (EBC), and International Association for Cereal Science and Technology (ICC). Content:100 assays per kit
Colourimetric method for the determination of β-Glucan in
cereal grains, feed, foodstuffs, beverages and other materials
Principle:
(lichenase)
(1) β-Glucan + H2O → β-gluco-oligosaccharides
(β-glucosidase)
(2) β-Gluco-oligosaccharides + H2O → D-glucose
(glucose oxidase)
(3) D-Glucose + H2O + O2 → D-gluconate + H2O2
(peroxidase)
(4) 2H2O2 + p-hydroxybenzoic acid + 4-aminoantipyrine →
quinoneimine + 4H2O
Kit size: 100 assays
Method: Spectrophotometric at 510 nm
Total assay time: ~ 100 min
Detection limit: 0.5-100% of sample weight
Application examples:
Oats, barley, malt, wort, beer, food and other materials
Method recognition:
AOAC (Method 995.16), AACC (Method 32-23.01), EBC (Methods
3.10.1, 4.16.1 and 8.13.1), ICC (Standard No. 166), RACI (Standard
Method) and CODEX (Type II Method)
Advantages
- Very cost effective
- All reagents stable for > 2 years as supplied
- Only enzymatic kit available
- Very specific
- Simple format
- Mega-Calc™ software tool is available from our website for hassle-free raw data processing
- Standard included
FAQ解答
Q1. Should the pH of the sample be adjusted even for samples in acidic media?
The pH of the assay solution after the sample is added should be the same as that of the assay buffer that is supplied with the kit.
Low sample volumes (e.g. 0.1 mL) are not likely to affect the pH of the assay solution and therefore may not require pH adjustment.
Samples above 0.1 mL are more likely to affect the pH of the assay solution and therefore the pH of these samples should be adjusted as described in the data booklet, prior to addition to the assay.
Q2. There is an issue with the performance of the kit; the results are not as expected.
If you suspect that the Megazyme test kit is not performing as expected such that expected results are not obtained please do the following:
- Ensure that you have tested the standard sample that is supplied with the Megazyme test kit.
- Send the results of the kit standard, blank samples and the results obtained for your sample, in the relevant MegaCalc spreadsheet (if available) to Megazyme (cs@megazyme.com). Where available the relevant MegaCalc spreadsheet can be downloaded from where the product appears on the Megazyme website.
- State the kit lot number being used (this is found on the outside of the kit box).
- State which assay format was used (refer to the relevant page in the kit booklet if necessary).
- State exact details of any modifications to the standard procedure that is provided by Megazyme.
- State the sample type and describe the sample preparation steps if applicable.
Q3. We have measured the molecular weight of beta-glucan originating from barley ordered from your company. Can you please tell us which method have you used for measuring molecular weight?
The MW’s were determined by Multiangle laser light scattering technique.
Q4. I have purchased barley beta-glucan (lot 30108) and carob galactomannan low viscosity (lot 30702) and would like to know what else there might be in these substrates.
Barley beta-glucan lot 30108 would contain about 3-4% arabinoxylan (this was produced in 1993). Material supplied post 1995 contains < 0.5% arabinoxylan. Carob galactomannan is quite pure (> 96%).
Q5. Although not specified on the beta-glucan data sheet, is the ratio of 1-3 to 1-4 bonds measured? If so, what is the ratio and would you expect it to remain standardised over a number of different batches?
The content of 1,3 bonds in barley beta-glucan is about 32% (from literature). We would not expect this to change much (if at all) over different batches.
Q6. Both substrates; barley beta-glucan and wheat arabinoxylan, are standardised to a specific viscosity, e.g. 23-24 cSt. Are the substrates adjusted to give this viscosity?
The substrates are enzymically treated to yield the required viscosity (20 ~ 30 cSt). Modification of the viscosity of beta-glucan is required for IOB viscometric malt beta-glucanase test (which works well).
Q7. We are setting up reducing-sugar assays for both beta-glucanase and xylanase from different fungal origins. Which barley beta-glucan do you recommend for the glucanase assay.
For glucanase assay we recommend the medium viscosity beta-glucan. We now offer low, medium and high viscosity wheat arabinoxylans, and we think that the low viscosity material will be best (easiest) to use in the reducing-sugar assay.