Resumo

ASSAD-BUSTILLOS, Melissa; RAMIREZ-GILLY, Mariana; TECANTE, Alberto  e  CHAIRES-MARTINEZ, Leandro. Physicochemical, functional, thermal and rheological characterization of starch from huauzontle seeds (Chenopodium berlandieri spp. nuttalliae). Agrociencia [online]. 2014, vol.48, n.8, pp.789-803. ISSN 2521-9766.

Huauzontle seeds (Chenopodium berlandieri spp. nuttalliae) are produced in the central part of Mexico but their use is limited to seedling process. Thus, in order to diversify their applications it is necessary to study their components such as proteins and starch. Therefore, the objective of this study was to extract and characterize the starch contained in the seeds of huauzontle by means of chemical and physical techniques. Analysis of the results showed 50 % extraction yield, 72.5 % starch purity, 5.32 % moisture, 1.09 % ash, 0.083 % fat, 11.4 % total nitrogen, and 4.13 % crude fiber. The amylose content was 10.5 %, which suggests that huauzontle starch gels could have a low tendency to retrograde. Swelling and solubility were similar to reported values for corn, lower than potato and higher than quinoa starches. The peak temperature of gelatinization was 68 °C. Pastes with 4 and 8 % (w/v) starch exhibited solid-like behavior attributable to amylose gelation with clear differences in dynamic moduli values and dependence with angular frequency when starch concentration increased. Non-Newtonian, shear-thinning behaviors with some degree of thixotropy that disappeared upon continuous shearing were observed. Laser diffraction data and SEM observations revealed association of very small (0.5-1.0 μm) starch granules into larger particles.

Palavras-chave : Chenopodium berlandieri; rheology; starch; viscoelasticity; microscopic structure.

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