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Updated: Jan 23, 2026

Rapid High Throughput Amylose Determination in Freeze Dried Potato Tuber Samples
Published on: October 14, 2013
Comparison of molecular structure of oca (Oxalis tuberosa), potato, and maize starches
1School of Chemical Sciences, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand.
Abstract:
Oca (Oxalis tuberosa) is an underutilized species and represents a novel starch source. Composition and structure of starches from tubers of two commercial oca varieties grown in New Zealand were compared to those of normal maize and potato starches. The phosphorus content of oca starch was ∼60% of that of potato starch. The amylose content of oca starch (∼21%) was lower than that of maize and potato starches (concanavalin A precipitation method). The fine structure of oca amylopectin was much more similar to that of potato amylopectin than to that of maize amylopectin. Oca amylopectin had a shorter internal chain length and less fingerprint B-chains than potato amylopectin. The two oca starches were structurally and compositionally similar. Oca starch granules had a volume moment mean size of 34.5 μm and B-type polymorph. Comparative analysis suggested that oca starch has the potential to be developed as a novel starch source.
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