Process standardization for isolation of quinoa starch and its characterization in comparison with other starches

Abstract

The studies about extraction of quinoa starch are scarce; therefore the process was optimised for its better yield. Starch was then compared with corn and C. album starch for different characteristics. To optimize conventional extraction of quinoa starch various combinations like water steeping and alkaline steeping (alkali concentration 0.20–0.30%) were used. Both methods showed higher starch yield from quinoa flour (32.97–48.45) than quinoa seeds (28.15–43.77). Quinoa flour showed 10.76% higher yield than seed at alkali concentration of 0.25%. The proximate analysis and purity of extracted starch showed the suitability of standard starch extraction process. Granule diameter varied from 0.766 to 4.050 µm for quinoa starch and from 3.78 to 51.94 µm for corn starch. Transmittance (%) was lower for quinoa starch than corn starch. The pasting temperature, breakdown and setback viscosities were lower for quinoa starch. Hardness of starch gel was higher for corn starch (31.98 g) than quinoa starch (26.61 g). Oil binding capacity and bulk density was higher for quinoa starch (159% and 0.69 g/mL) than corn starch (110% and 0.56 g/mL). The results suggest potential application of quinoa starch in food formulations requiring high viscosity and can also be utilized as safe and economic fat replacer and biodegradable materials due to small size which otherwise requires acid catalyzed hydrolysis for reduction of starch granule size.