Available Carbohydrates Assay Kit

Background: The level of available carbohydrates in our diet is directly linked to two major diseases; obesity and Type II diabetes. Despite this, to date there is no method available to allow direct and accurate measurement of available carbohydrates in human and animal foods. Objective: The aim of this research was to develop a method that would allow simple and accurate measurement of available carbohydrates, defined as non-resistant starch, maltodextrins, maltose, isomaltose, sucrose, lactose, glucose, fructose and galactose. Method: Non-resistant (digestible) starch is hydrolysed to glucose and maltose by pancreatic α-amylase and amyloglucosidase at pH 6.0 with shaking or stirring at 37°C for 4 h. Sucrose, lactose, maltose and isomaltose are completely hydrolyzed by specific enzymes to their constituent monosaccharides, which are then measured using pure enzymes in a single reaction cuvette. Results: A method has been developed that allows the accurate measurement of available carbohydrates in all cereal, vegetable, fruit, food, and feed products, including dairy products. Conclusions: A single-laboratory validation was performed on a wide range of food and feed products. The inter-day repeatability (%RSDr) was <3.58% (w/w) across a range of samples containing 44.1 to 88.9% available carbohydrates. The LOD and LOQ obtained were 0.054% (w/w) and 0.179% (w/w), respectively. The method is all inclusive, specific, robust and simple to use. Highlights: A unique method has been developed for the direct measurement of available carbohydrates, entailing separate measurement of glucose, fructose and galactose; information of value in determining the glycemic index of foods.

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.

A Potato (Solanum tuberosum L.) is a major staple food consumed worldwide. Potato peel is an important constituent that is generally discarded and considered agricultural waste before processing or cooking. The present investigation is an attempt to utilize different contents of potato peels (PP) with potato flesh (PF) of processing cultivar (Kufri Chipsona 3) and table cultivar (Kufri Jyoti), which affect starch nutritional profile, glycemic response, and pasting properties. The combination of PP at different concentrations of 5, 10, and 15%, respectively, to PF showed a significant reduction (P < 0.05) in starch hydrolysis index (SHI), glycemic index (GI), and glycemic load (GL). Similarly, there was also a significant increase in the resistant starch content of the PP + PF combination. The maximum change in the predicted glycemic response was observed in the PP with 15%. A higher reduction in the in vitro glycemic response was observed in the Kufri Chipsona 3 as compared to Kufri Jyoti. The pasting properties of also showed significant changes with the addition of PP to the PF flour, which might be due to the change in intrinsic properties such as amylose and amylopectin content. The current investigation will help to provide an understanding of the use of PP in the processing industries to prepare low-GI food products.

Seventeen pigmented maize cultivated in different locations of India were collected and evaluated for their nutritional, anti-nutritional and starch profile. A wide variation was observed in all the parameters evaluated. Protein and total dietary fiber content varied between 7.18 to 10.85 g/100g and 8.76 to 14.04 g/100g, respectively. Among the water-soluble vitamins, B₂ varied from 0.071 to 0.134; B_3, 1.50 to 2.79; B_5, 0.17 to 0.70 and B₆, 0.141 to 0.245 mg/100g; while total tocopherol and tocotrienol varied 1417 to 2246 µg/100g and 18.57 to 30.01 µg/100g, respectively. The resistant starch, total starch and amylose varied significantly and observed between 0.49 to 4.78 %, 61.33 to 69.65 % and 10.91 to 32.01 %, respectively. Among the minerals, Fe and Zn were observed between 1.51 to 5.01 and 2.25 to 5.51 mg/100g, respectively. Total polyunsaturated and total monounsaturated fatty acids were observed up to 45.72 and 55.54 %, respectively. Amongst the anti-nutrients, phytate was detected the lowest in Laal makki, whereas total and soluble oxalates were the lowest in Kashmiri red maize.

Though potato is popular among masses as a carbohydrate rich source of energy, bioaccessibility studies of potato carbohydrates are never carried out. We investigated effect of cooking on glycemic index (GI) and in-vitro bioaccessibility in potato varieties Kufri Chipsona-3 and Lady Rosetta. Samples were analysed in raw, boiled, microwaved and fried form. On average, starch content significantly reduced by 40%, 64% and 2%; amylose by 14%, 17% and 34% after boiling, microwaving and frying, respectively. Total soluble sugars increased concomitantly by 9% and 25% in boiled and microwaved tubers and reduced by 10% in fried tubers. GI of boiled, microwaved and fried tubers of both the varieties was high i.e above 70. Starch content of both the varieties decreased during in-vitro digestion and was least in intestinal phase. Among the cooking methods, frying was better as reducing sugars remained low throughout oral, gastric and intestinal phases in both the varieties. Raw tubers of both varieties released maximum concentration of sugars during gastric phase. Whereas, boiled, microwaved and fried tubers of both the varieties released maximum concentration of sugars during intestinal phase. This study indicated that cooking method has significant effect on starch breakdown and release of sugars in the body.