Enzymatic Modification of Granular Potato Starch Using Isoamylase—Investigation of Morphological, Physicochemical, Molecular, and Techno‐Functional Properties

Abstract

Granular potato starch is modified using the debranching enzyme isoamylase. The modification is performed in aqueous suspension (40% w/w) at 35 °C by grading the volume (100, 250, and 400 µL/50 g of starch, 200 U · mL−1) of enzyme solution added. The starch products obtained are comprehensively investigated in terms of morphological (scanning electron microscopy), structural (X‐ray diffraction), thermal (differential scanning calorimetry), techno‐functional (solubility, hot paste viscosity, gel strength), and molecular properties (size exclusion chromatography‐multi angle laser light scattering‐differential refractive index detection). The granular integrity is basically preserved after modification and a molecular degradation predominantly of the amylopectin by debranching is proved. However, a slight reduction of the weight average molar mass of the amylose fraction is found too. In addition, the intended partial molecular degradation of the starch polysaccharides, the effect of the preparation procedure including washing with ethanol and grinding impacts several starch characteristics conspicuously.

Genome-wide identification of BAM (β-amylase) gene family in jujube (Ziziphus jujuba Mill.) and expression in response to abiotic stress

“…Additionally, AT5G11720 is a hydrolase that is involved in carbohydrate metabolism and hydrolyzes O-glycosyl compounds; it is expressed in 23 plant structures during 13 growth stages. In addition, other interacting proteins, such as GBSS1 (Granule-bound starch synthase 1) and SS (starch synthase) are important enzymes regulating the catalytic degradation of starch and other sugars [ 42 – 44 ].…”

Organic Pea Starches – I. Comprehensive Investigation of Morphological and Molecular Properties

“…According to the description of Ulbrich et al, the starch particle surface properties were investigated by means of SEM using a ZEISS Gemini SEM500 NanoVP microscope (Carl Zeiss AG, Oberkochen, Germany) equipped with a wolfram cathode. [ 47 ] The granular starch samples were affixed with double‐faced adhesive tape on the sample carrier and sputtered with gold (Au) with a layer thickness of about 3 nm (SCD 030, Balzers Union, Balzers, Liechtenstein). The micrographs were taken at a magnification of 2000.…”

Physical, Chemical and Biochemical Modification Approaches of Potato (Peel) Constituents for Bio-Based Food Packaging Concepts: A Review

“…The opposite happens during enzymatic debranching of potato starch, where debranching enzymes such as pullulanase [ 194 ] or isoamylase [ 196 ] can be used. Here α-1,6-glycosidic bonds are cleaved and new α-1,4-glycosidic bonds are formed.…”

“…Here α-1,6-glycosidic bonds are cleaved and new α-1,4-glycosidic bonds are formed. As a result, starch polymers become less branched, resulting in a decrease in amylopectin and increase in amylose content [ 196 ]. Accordingly, average molecular weight of the samples gradually decreased with increasing isoamylase concentration and granular damaging occurred, which intensified with increasing enzyme concentration.…”

“…Accordingly, average molecular weight of the samples gradually decreased with increasing isoamylase concentration and granular damaging occurred, which intensified with increasing enzyme concentration. However, B-type crystallinity, thermal properties and solubility were not significantly affected upon isoamylase treatment, but gel strength and viscosity of debranched potato starch pastes decreased [ 196 ].…”