04:11 Reagent Preparation
07:54 Enzyme Digestion: Method 1 - Analysing ~ 0.5 g of sample
09:21 Method 1 (A) – Addition of PAA + AMG solution
09:50 Method 1 (B) - Addition of PAA + AMG suspension
10:23 Enzyme Digestion: Method 2 - Analysing ~ 0.1 g of sample
11:34 Method 2 (A) – Addition of PAA + AMG solution
12:03 Method 2 (B) - Addition of PAA + AMG suspension
12:33 Preparation of Stopping Reagents
13:12 Determination of Digestible Starch
18:27 Determination of Resistant Starch
40 assays of each per kit
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Available for shipping
|Content:||40 assays of each per kit|
Short term stability: 2-8oC,
Long term stability: See individual component labels
|Stability:||> 2 years under recommended storage conditions|
|Analyte:||Digestible Starch, Resistant Starch, Total Starch|
|Linear Range:||5 to 100 µg of D-glucose per assay|
|Limit of Detection:||2 g/100 g|
|Reaction Time (min):||~ 360 min|
|Application examples:||Plant materials, starch samples and other materials.|
See our full range of starch and dietary fiber assay kits.
The Digestible and Resistant Starch Assay Kit (K-DSTRS) method is based on the research of Englyst et al. (Ref) with some modifications. Digestion is performed using saturating levels of pancreatic α-amylase (PAA) and amyloglucosidase (AMG), but in stirred containers rather than shaken tubes, to simplify sample removal.
In line with Englyst definitions:
Rapidly digestible starch (RDS) is that starch which is digested within 20 min.
Slowly digestible starch (SDS) is that starch which is digested between 20 and 120 min.
A new term, ‘Total digestible starch (TDS)’ is introduced (and measured) to cover all starch that is digested within 4 h (the average time of residence of food in the human small intestine).
Resistant starch (RS) then, is that starch which is not digested within 4 h.
The incubation conditions parallel those used in AOAC Method 2017.16, a new, rapid integrated procedure for the measurement of total dietary fiber (Megazyme method K-RINTDF). This method is physiologically based and designed to fit the definition of DF announced by Codex Alimentarius in 2009.
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