Effect of acid treatment on the physicochemical and structural characteristics of starches from different botanical sources

Abstract

Starch and starch derivatives (maltodextrins) are used as encapsulating materials. Starch for use as encapsulating material could be subjected to mild acid treatment. However, the granule size and organization of starch components (AM and AP) play an important role in the acid treatment. The aim of this research was to produce modified starch that might be used as encapsulate material, applying moderate acid-treatment with 3 N sulphuric acid in a ratio 1:5 w/v for 3 h at 608C, in starches from different granule size, evaluating their morphological, physicochemical, and structural features. Acid treatment has an effect in the AM content and the outcome was higher in starch with larger granule size. Bimodal granule size distribution was found in acid-treated rice and maize starches. Erosion and exo-corrosion were observed in acid-treated starches with SEM. The XRD pattern did not change with the acid treatment, the native and acid-treated samples showed similar crystallinity values, except rice starch. The branching degree was higher for modified potato starch, showing higher branching points, modified starches had shorter chains with increased A-chains, and decreased B3þ chains, and the effect was higher in cereal starches; modified starches had a higher degree of retrogradation and they did not show pasting properties. The internal organization given by the granule size is an important parameter in the acid treatment of starches as it affected their physicochemical and structural features, and in the end, their functionality as encapsulate agent.

Changes in physicochemical properties and in vitro digestibility of common buckwheat starch by heat-moisture treatment and annealing

“…Viscosities reduction in Ann was similar to that of HMT-30. The decrement in breakdown viscosity proved that CBS modified by ANN and HMT was stable during continued heating and shearing, which was in conformity with previous studies (Palma-Rodriguez et al, 2012;Zavareze & Dias, 2011).…”

In vitro digestibility, crystallinity, rheological, thermal, particle size and morphological characteristics of pinole, a traditional energy food obtained from toasted ground maize

“…The gelatinization properties of raw and toasted maize flour were analyzed by differential scanning calorimetry (TA Instruments, Q2000, New Castle, DE, USA) previously calibrated with indium following the procedure described by Palma-Rodriguez et al (2012) with slight modifications. A flour sample (3.0 mg dry basis) was weighed in an aluminium pan and deionized water (6.0 L) was added.…”

Ascorbic acid microencapsulation by spray‐drying in native and acid‐modified starches from different botanical sources

“…ModMS microcapsules showed significantly lower surface AA % than the ModRS and ModPS microcapsules (Table 1). These results can be probably be associated with the amylose contents of these starches, which is considerably higher in modified maize starch than in modified potato and rice starches 31. One part of the total AA retained in the microcapsules was localized in the surface.…”

“…Thus, the differences in moisture content could be attributed to the structure of granules and viscosity of starches. Palma‐Rodríguez et al 31 reported that NRS had a more rigid or tight crystalline structure and higher viscosity than acid the acid‐ModS, influencing the rate of drying 33. It should be remarked that a low a w in the microcapsules is desirable for achieving longer shelf‐life.…”

“…L ‐Ascorbic acid A7506 (AA), Na 2 HPO 4 and KH 2 PO 4 were purchased from Sigma–Aldrich de Mexico (Toluca, State of Mexico, Mexico). The morphological characteristics of the three starches were reported previously 31.…”