Using Molecular Fine Structure to Identify Optimal Methods of Extracting Starch

Abstract

Obtaining relations between starch genetics/environment, its molecular structure, and its properties requires that the extraction of starch does not extract more small than large molecules and does minimal damage to molecular structure. There is no single study examining a range of techniques with more than one starch type and with clearly defined criteria for optimal extraction. Here two very different substrates are considered: rice and chickpeas. Eight different techniques are used, and the criteria for optimal extraction are that there should be the greatest number of longer chains (quantified by the average size of the debranched starch) and of larger molecules (quantified by the average size of the whole-undebranchedmolecules), these being the most susceptible to degradation and loss during extraction. Size-exclusion chromatography is used to obtain the requisite structural data. The optimal method of extraction from rice is found by using 0.45% sodium metabisulfite at 4°C for 0.5 h with protease addition, while that for chickpea starch extraction is by using 0.45% sodium bisulfite for 6 h and washing the starch repeatedly with water. The methodology for determining optimal methods can be readily used for other starch sources.

Optimal Extraction Methods for High Amylose Maize Starch Studied by Size-Exclusion Chromatography (SEC) and Small-Angle X-ray Scattering (SAXS)

“…Therefore, at the same temperature (room temperature), the molecular structure of starch extracted by NaOH is severely damaged, which showed the lowest ACL of Ap1, Ap2, and AM. A higher degradation degree of amylose molecules occurred when using NaOH as the extracting reagent, which makes this one the worst reagent, agreeing well with other reports …”

Starch Molecular Structural Features and Volatile Compounds Affecting the Sensory Properties of Polished Australian Wild Rice

“…The extraction of starch from the rice grains was carried out following a previously described method [ 13 ]. Briefly, rices were ground into flour by a cryo-grinder (MM400, Netsch, Germany, 10 s at a time for 6 times at 20 s −1 ) before being filtered with a 75-µm sieve.…”

The importance of glycogen molecular structure for blood glucose control

“…An important consideration is how the extent of structural damage can be assessed. For starch, another complex branched glucose polymer with the same chemical bonds as glycogen, it has been noted (Zhao et al, 2020) that two criteria for minimal structural damage are that there be more large molecules and more long chains, as both of these structural features are the most likely to be damaged. If the objective is to characterize molecular structure, then extraction yield is unimportant, as long as the extraction procedure is not biased in the range of molecular structural features, e.g., more small molecules than large are extracted.…”