Structural Characteristics of Hydroxypropyl Potato Starch Granules Depending on Their Molar Substitution

Abstract

The structural changes of potato starch granules, caused by hydroxy‐propylation, were studied using light microscopy. The starch samples used consisted of a native potato starch, hydroxypropyl potato starches with varying molar substitution (M. S.) and a hydroxypropyl and cross‐linked potato starch. The structural characteristics of the samples were evaluated by comparing the colour intensities of thin sections of samples stained with iodine and Schiff's reagent. The manner of loss of birefringence of samples in 5 M aqueous urea under polarized light was observed as well. The results obtained by three different methods were found to be similar to each other, suggesting that the central region of the potato starch granule is where hydroxy‐propylation mainly takes place or where hydroxypropyl groups are mainly distributed. The results can provide an explanation for the altered pasting properties of hydroxypropyl potato starches depending on their M. S.

Effect of chemical modifications on thermal, rheological and morphological properties of yellow sorghum starch

“…The affected granules appeared as folded structures with their outer side drawn inwards, giving the appearance of a doughnut. The results agreed with those reported by (Kim et al 1992), who suggested that most of the structural changes take place at the relatively less organized central region of the starch granule, i.e., where. the hydroxyproply groups are most densely deposited.…”

Hydroxypropylation of pigeon pea (Cajanus cajan) starch: Preparation, functional characterizations and enzymatic digestibility

“…However traces of degradation were observed on some starch granules after modification. Changes in appearance of starch granules after hydroxypropylation have been reported for potato starches (Kim et al, 1992) and cassava starch (Jyothi et al, 2007). Also, no change in surface and shape characteristics of the granules was reported for canna starches in a previous work (Chuenkamol et al 2007).…”

Modified broken rice starch as fat substitute in sausages

“…Differences were considered to be significant when p < 0.05. a short period of time (MILLER, 1988). Extrusion promotes a high physical modification in granular structure, increasing water absorption and retention (LIMBERGER et al, 2008).…”

“…Modified starches have been proposed as fat substitutes in several foods, such as cheese (SIPAHIOGLU; ALVAREZ; SOLANO-LOPEZ, 1999), beef patties (KHALIL, 2000) and ice-cream (JIMENEZ-FLORES; KLIPFEL; TOBIAS, 1993;AIME et al, 2001). The rheological properties of starch may be improved or adapted to technological needs through physical (extrusion) or chemical (phosphorylation) modification (BRANEN;DAVIDSON;SALMINEN, 1990;KIM;HERMANSON;ERIKSSON, 1992;ELIASSON;GUDMUNDSSON, 1996;SIVAK;PREISS, 1998;ALVES;GROSSMANN;SILVA, 1999;STAHL et al, 2007). Starch phosphates prepared through chemical methods produce clear pastes of high consistency, good freeze/thaw stability, lower gelatinization temperatures and high swelling power and solubility (SIVAK;PREISS, 1998;SITOHY et al, 2000a;STAHL et al, 2007).…”