Chapter 1: Introduction
Chapter 2: Theory of the Analytical Procedure
Chapter 3: Kit Content
Chapter 4: Reagent Preparation
Chapter 5: Milling of Samples
Chapter 6: Weighing of Malt Samples & Extraction of Alpha Amylase
Chapter 7: Weighing of Wheat & Barley Flour & Extraction of Alpha Amylase
Chapter 8: Extraction/Dilution of Microbial Enzyme
Chapter 9: Assay Procedure
Chapter 10: Calculations
100 / 200 assays per kit
Prices exclude VAT
Available for shipping
|Content:||100 / 200 assays per kit|
Short term stability: 2-8oC,
Long term stability: See individual component labels
|Stability:||> 2 years under recommended storage conditions|
|Assay Format:||Spectrophotometer, Auto-analyser|
|Limit of Detection:||0.05 U/mL|
|Reproducibility (%):||~ 3%|
|Total Assay Time:||~ 30 min|
|Application examples:||Cereal flours, fermentation broths and other materials.|
|Method recognition:||AACC Method 22-02.01, AOAC Method 2002.01, ICC Standard No. 303, RACI Standard Method and CCFRA (Flour Testing Working Group Method 0018)|
The Ceralpha Method: α-Amylase test kit is suitable for the specific measurement and analysis of α-amylase in cereal grains and fermentation broths (fungal and bacterial).
Browse the complete list of our enzyme activity assay kits.
- Very cost effective
- All reagents stable for > 2 years after preparation
- Very specific
- Simple format
- Mega-Calc™ software tool is available from our website for hassle-free raw data processing
- Standard included
Measurement of available carbohydrates, digestible, and resistant starch in food ingredients and products.
McCleary, B. V., McLoughlin, C., Charmier, L. M. J. & McGeough, P. (2019). Cereal Chemistry, 97(1), 114-137.
Background and objectives: The importance of selectively measuring available and unavailable carbohydrates in the human diet has been recognized for over 100 years. The levels of available carbohydrates in diets can be directly linked to major diseases of the Western world, namely Type II diabetes and obesity. Methodology for measurement of total carbohydrates by difference was introduced in the 1880s, and this forms the basis of carbohydrate determination in the United States. In the United Kingdom, a method to directly measure available carbohydrates was introduced in the 1920s to assist diabetic patients with food selection. The aim of the current work was to develop simple, specific, and reliable methods for available carbohydrates and digestible starch (and resistant starch). The major component of available carbohydrates in most foods is digestible starch. Findings: Simple methods for the measurement of rapidly digested starch, slowly digested starch, total digestible starch, resistant starch, and available carbohydrates have been developed, and the digestibility of phosphate cross‐linked starch has been studied in detail. The resistant starch procedure developed is an update of current procedures and incorporates incubation conditions with pancreatic α‐amylase (PAA) and amyloglucosidase (AMG) that parallel those used AOAC Method 2017.16 for total dietary fiber. Available carbohydrates are measured as glucose, fructose, and galactose, following complete and selective hydrolysis of digestible starch, maltodextrins, maltose, sucrose, and lactose to glucose, fructose, and galactose. Sucrose is hydrolyzed with a specific sucrase enzyme that has no action on fructo‐oligosaccharides (FOS). Conclusions: The currently described “available carbohydrates” method together with the total dietary fiber method (AOAC Method 2017.16) allows the measurement of all carbohydrates in food products, including digestible starch. Significance and novelty: This paper describes a simple and specific method for measurement of available carbohydrates in cereal, food, and feed products. This is the first method that provides the correct measurement of digestible starch and sucrose in the presence of FOS. Such methodology is essential for accurate labeling of food products, allowing consumers to make informed decisions in food selection.Hide Abstract
Prediction of potential malt extract and beer filterability using conventional and novel malt assays.
Cornaggia, C., Evans, D. E., Draga, A., Mangan, D. & McCleary, B. V. (2019). Journal of Institute of Brewing, In Press.
Colourimetric assays were used to measure the activities of six key hydrolases endogenous to barley: β‐glucanase, xylanase, cellulase, α-amylase, beta‐amylase and limit dextrinase. The analysed barley malt samples were previously characterised by 27 conventional malt quality descriptors. Correlations between enzymatic activities and brewing parameters such as extract yield, fermentability, viscosity and filterability were investigated. A single extraction protocol for all six hydrolases was optimised and used for multi‐enzyme analysis using fully automatable assay formats. A regression analysis between malt parameters was undertaken to produce a relationship matrix linking enzyme activities and conventional malt quality descriptors. This regression analysis was used to inform a multi‐linear regression approach to create predictive models for extract yield, apparent attenuation limit, viscosity and filterability using the Small‐scale Wort rapId Filtration Test (SWIFT) and two different mashing protocols – Congress and a modified infusion mash at 65oC (MIM 65oC). It was observed that malt enzyme activities displayed significant correlations with the analysed brewing parameters. Both starch hydrolases and cell wall hydrolase activities together with modification parameters (i.e. Kolbach index) were found to be highly correlated with extract yield and apparent attenuation limit. Interestingly, it was observed that xylanase activity in malts was an important predictor for wort viscosity and filterability. It is envisaged that the automatable measurement of enzyme activity could find use in plant breeding progeny selection and for routine assessment of the functional brewing performance of malt batches. This analytical approach would also contribute to brewing process consistency, product quality and reduced processing times.Hide Abstract
Measurement of Starch: Critical evaluation of current methodology.
McCleary, B. V., Charmier, L. M. J. & McKie, V. A. (2018). Starch‐Stärke, 71(1-2), 1800146.
Most commonly used methods for the measurement of starch in food, feeds and ingredients employ the combined action of α‐amylase and amyloglucosidase to hydrolyse the starch to glucose, followed by glucose determination with a glucose oxidase/peroxidase reagent. Recently, a number of questions have been raised concerning possible complications in starch analytical methods. In this paper, each of these concerns, including starch hydrolysis, isomerisation of maltose to maltulose, effective hydrolysis of maltodextrins by amyloglucosidase, enzyme purity and hydrolysis of sucrose and β‐glucans have been studied in detailed. Results obtained for a range of starch containing samples using AOAC Methods 996.11 and 2014 .10 are compared and a new simpler format for starch measurement is introduced. With this method that employs a thermostable α-amylase (as distinct from a heat stable α-amylase) which is both stable and active at 100°C and pH 5.0, 10 samples can be analysed within 2 h, as compared to the 6 h required with AOAC Method 2014.10.Hide Abstract
Measurement of α-Amylase in Cereal, Food and Fermentation Products.
McCleary, B. V. & Sturgeon, R. (2002). Cereal Foods World, 47, 299-310.
In General, the development of methods for measuring α-amylase is pioneered in the clinical chemistry field and then translated to other industries, such as the cereals and fermentation industries. In many instances, this transfer of technology has been difficult or impossible to achieve due to the presence of interfering enzymes or sugars and to differences in the properties of the enzymes being analysed. This article describes many of the commonly used methods for measuring α-amylase in the cereals, food, and fermentation industries and discusses some of the advantages and limitations of each.Hide Abstract
McCleary, B. V., McNally, M., Monaghan, D. & Mugford, D. C. (2002). Journal of AOAC International, 85(5), 1096-1102.
This study was conducted to evaluate the method performance of a rapid procedure for the measurement of α-amylase activity in flours and microbial enzyme preparations. Samples were milled (if necessary) to pass a 0.5 mm sieve and then extracted with a buffer/salt solution, and the extracts were clarified and diluted. Aliquots of diluted extract (containing α-amylase) were incubated with substrate mixture under defined conditions of pH, temperature, and time. The substrate used was nonreducing end-blocked p-nitrophenyl maltoheptaoside (BPNPG7) in the presence of excess quantities of thermostable α-glucosidase. The blocking group in BPNPG7 prevents hydrolysis of this substrate by exo-acting enzymes such as amyloglucosidase, α-glucosidase, and β-amylase. When the substrate is cleaved by endo-acting α-amylase, the nitrophenyl oligosaccharide is immediately and completely hydrolyzed to p-nitrophenol and free glucose by the excess quantities of α-glucosidase present in the substrate mixture. The reaction is terminated, and the phenolate color developed by the addition of an alkaline solution is measured at 400 nm. Amylase activity is expressed in terms of Ceralpha units; 1 unit is defined as the amount of enzyme required to release 1 µmol p-nitrophenyl (in the presence of excess quantities of α-glucosidase) in 1 min at 40°C. In the present study, 15 laboratories analyzed 16 samples as blind duplicates. The analyzed samples were white wheat flour, white wheat flour to which fungal α-amylase had been added, milled malt, and fungal and bacterial enzyme preparations. Repeatability relative standard deviations ranged from 1.4 to 14.4%, and reproducibility relative standard deviations ranged from 5.0 to 16.7%.Hide Abstract
Analysis of feed enzymes.
McCleary, B. V. (2001). “Enzymes in Farm Animal Nutrition”, (M. Bedford and G. Partridge, Eds.), CAB International, pp. 85-107.
Enzymes are added to animal feed to increase its digestibility, to remove anti-nutritional factors, to improve the availability of components, and for environment reasons (Campbell and Bedford, 1992; Walsh et al., 1993). A wide-variety of carbohydrase, protease, phytase and lipase enzymes find use in animal feeds. In monogastric diets, enzyme activity must be sufficiently high to allow for the relatively short transit time. Also, the enzyme employed must be able to resist unfavourable conditions that may be experienced in feed preparation (e.g. extrusion and pelleting) and that exist in the gastrointestinal tract. Measurement of trace levels of enzymes in animal feed mixtures is difficult. Independent of the enzyme studied, many of the problems experienced are similar; namely, low levels of activity, extraction problems inactivation during feed preparation, non-specific binding to other feed components and inhibition by specific feed-derived inhibitors, e.g. specific xylanase inhibitors in wheat flour (Debyser et al., 1999).Hide Abstract
Sheehan, H. & McCleary, B. V. (1988). Biotechnology Techniques, 2(4), 289-292.
A procedure for the measurement of fungal and bacterial α-amylase in crude culture filtrates and commercial enzyme preparations is described. The procedure employs end-blocked (non-reducing end) p-nitrophenyl maltoheptaoside in the presence of amyloglucosidase and α-glucosidase, and is absolutely specific for α-amylase. The assay procedure is simple, reliable and accurate.Hide Abstract
Measurement of cereal α-Amylase: A new assay procedure.
McCleary, B. V. & Sheehan, H. (1987). Journal of Cereal Science, 6(3), 237-251.
A new procedure for the assay of cereal α-amylase has been developed. The substrate is a defined maltosaccharide with an α-linked nitrophenyl group at the reducing end of the chain, and a chemical blocking group at the non-reducing end. The substrate is completely resistant to attack by β-amylase, glucoamylase and α-glucosidase and thus forms the basis of a highly specific assay for α-amylase. The reaction mixture is composed of the substrate plus excess quantities of α-glucosidase and glucoamylase. Nitrophenyl-maltosaccharides released on action of α-amylase are instantaneously cleaved to glucose plus free p-nitrophenol by the glucoamylase and α-glucosidase, such that the rate of release of p-nitrophenol directly correlates with α-amylase activity. The assay procedure shows an excellent correlation with the Farrand, the Falling Number and the Phadebas α-amylase assay procedures.Hide Abstract