FOOD. Science. Technology. Quality

Food. SCIENCE. Technology. Quality

Food. Science. TECHNOLOGY. Quality

Food. Science. Technology. QUALITY

Authors

N. INOUCHI, K. NISHI, S. TANAKA, T. ASAI, Y. KAWASE, Y. HAT A, Y. KONISHI, S. YUE, H. FUWA

Title

Characterization of small granular sized starches - amaranthus and quinoa starches

Abstract

Starch granules were prepared from mature grains of 9 samples of Amaranthus and 4 samples of Chenopodium quinoa. By the ordinary GPC of Pseudomonas isoamylase-debranched starch materials the amylose content of amaranth starches was in a range of 0-28 %. Thus we confirmed that there were normal, low-amylose, and waxy-types of amaranth starches. The amylose content of quinoa starches was 25-27 %. The ratio of short chains to long chains of amylopectin of these starches was in a range of 2.2-3.3 and somewhat lower than or similar to that of the normal maize starch. Isoamylase-debranched materials were separated by HPLC with differential refractometer (RI) and low-angle laser light scattering photometer (LALLS) as detectors in one hand, and by high performance anion exchange chromatography with pulsed amperometric detector (HPAEC-PAD) in other hand. We found that amylopectins of amaranth and quinoa had increased amounts of long B chains and decreased amounts of short chains as compared with the waxy maize amylopectin, however, they had increased amounts of short chains with degree of polymerization (DP) from 6 to 12. Amaranth starches had slightly higher temperatures of gelatinization (To, Tp, and To) and smaller heats of gelatinization (ΔΗ) by diferential scaning calorimetry (DSC) comparing with the normal maize starch. Quinoa starch showed lower To, Tp, and Tc and smaller ΔΗ. Amaranth and quinoa starch granules were digested by amylases faster than those of the norami maize.

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