A Maltose Biosensor for Determining Gelatinized Starch in Processed Cereal Foods

Abstract

Cereal Chem. 81(1):6-9 A reliable method for the quantitative determination of gelatinized starch in processed cereal foods was developed. It consists of an electrochemical biosensor based on amyloglucosidase and glucose oxidase enzymes co-immobilized on a Pt electrode surface, and a third enzyme, a-amylase, added in solution. Analytical parameters such as time, temperature, and enzyme units were optimized. The degree of starch gelatinization was determined in different processed cereal foods using the biosensor method and the results were commensurate to those obtained with the reference method. The biosensor methods showed good accuracy (r 2 = 0.9629; relative error <12%) and comparable precision (RSD <5%). This electrochemical system is rapid, reliable, inexpensive, user-friendly for unskilled operators, and can be a valid alternative to the methods traditionally used for gelatinized starch analysis.

Enzymatic Method for Measuring Starch Gelatinization in Dry Products in Situ

“…Total Starch Measurement. For measuring total starch content, a chemical reagent, such as dimethyl sulfoxide (DMSO), 14 an alkali solution, 15,18,22 or an enzyme preparation, 22,23 is usually used to solubilize starch in a sample as completely as possible immediately before AGS hydrolysis. Among the methods of using an alkali solution (NaOH or KOH), there are variations in alkaline concentrations, from 0.25 M 15 to 2.00 M. 22 Shetty et al 14 stated that the reliability of the method used to determine total starch was one of the three key elements for the accuracy of their enzymatic procedure for determining starch gelatinization.…”

“…The extent of starch gelatinization not only determines the textural and organoleptic properties of processed products but also affects human and animal nutrition through changing enzymatic access to glucosidic linkages and consequent digestibility. Starch gelatinization is characterized by (a) loss of starch granule birefringence, (b) alterations in starch crystalline organization, (c) an increase in viscosity, (d) an increase in dye-binding ability, and (e) an increase in susceptibility to enzyme attack. , On the basis of these principles, many methods have been described to measure starch gelatinization, including polarization microscopy, X-ray diffraction, amylography, , differential scanning calorimetry (DSC), , pulsed nuclear magnetic resonance, absorbance of iodine binding, , and enzymatic susceptibility. ,− …”

“…However, most of these techniques, including some popular enzymatic methods, are applicable only to purified starch. For processed products, starch has to be isolated first, making the method laborious and/or prone to errors. , Others, such as the DSC method and biosensor method, can measure gelatinized starch in situ but require costly instrumentation or special devices that are not easily accessible. Still others, such as dye-binding methods, are found to be less reliable .…”

“…The objective of the present study was to develop an enzymatic method that can determine starch gelatinization in dried products without the need to isolate starch. In developing an enzymatic method for measuring starch gelatinization, except for Marconi et al, all previous researchers ,− , generally focused on three key steps of the methodology: enzymatic hydrolysis of starch to glucose, assay for d -glucose, and expression of starch gelatinization. The present study was able to achieve the objective by focusing on not only the above three steps but also new steps before the enzymatic hydrolysis.…”

Biosensors for Determination of the Most Common Carbohydrates

“…Авторами [36] описується біосенсор з іммобілізованими на його поверхні за допомогою ГА амілоглюкозидазою, ГОД та БСА, за допомогою якого визначали мальтозу, яка утворюється з крохмалю під дією α-амілази. Це дає можливість використовувати такий біосенсор для визначення кількості клейстеризованого крохмалю у зернових харчових продуктах, що слугує китерієм оцінки їхньої якості.…”