Physicochemical and technofunctional properties of high Andean native potato starch

Abstract

In the high Andean areas of Peru, a diversity of native potatoes improved at the germplasm level is grown, with higher nutritional and amylose quality, for use mainly in fries. The research aimed to evaluate the rheological behavior, thermal and technofunctional starch extracted from native potato varieties (Solanum tuberosum spp Andigena), cultivated in Andahuaylas, Peru. Native potatoes of the Azul Helada (AH) and Amarilla Reyna (AR) varieties were collected from the district of Champaccocha, Andahuaylas, Peru, and the starch was extracted by hydro extraction. The AH and AR starch in aqueous solution was observed to present dilatant behavior, with a behavior index of n > 1.0; represented by the Power Law and Herschel-Bulkley model, with low retrogradation speed. The starches reported gelatinization temperatures of 61.8 and 66.4 °C and melting of 132.2 and 133.5 °C, thermal degradation with mass losses of up to 89.90 and 86.16 %, 43.56 and 42.09 % of apparent amylose for HA and AR respectively. The solubility, swelling power, water adsorption capacity, oil absorption capacity, emulsifying capacity, and apparent density were higher for HA, with aw around 0.50. The color presented L* values > 95.17, and a whiteness index greater than 94.80. The ζ potential of the starches indicates medium stability, with a granule size of 42.17 and 57.67 nm. They also respond to type B with a degree of crystallinity of 58.95 and 43.12 % and a crystal size of 6.55 and 6.01 nm for AH and AR respectively. The native high Andean potato AH and AR are potential sources for starch extraction, with good techno-functional properties.

Keywords

• Native potato
• Starch
• Retrogradation
• Amylose
• Rheological behavior
• Thermal behavior