Evaluation of texture differences among varieties of cooked quinoa.

Texture differences of cooked quinoa were studied among 13 different varieties. Correlations between the texture parameters and seed composition, seed characteristics, cooking quality, flour pasting properties, and flour thermal properties were determined. The results showed that texture of cooked quinoa was significantly differed among varieties. 'Black,' 'Cahuil,' and 'Red Commercial' yielded harder texture, while '49ALC,' '1ESP,' and 'Col.#6197' showed softer texture. '49ALC,' '1ESP,' 'Col.#6197,' and 'QQ63' were more adhesive, while other varieties were not sticky. The texture profile correlated to physical--chemical properties in different ways. Protein content was positively correlated with all the texture profile analysis (TPA) parameters. Seed hardness was positively correlated with TPA hardness, gumminess, and chewiness at P ≤ 0.09. Seed density was negatively correlated with TPA hardness, cohesiveness, gumminess, and chewiness, whereas seed coat proportion was positively correlated with these TPA parameters. Increased cooking time of quinoa was correlated with increased hardness, cohesiveness, gumminess, and chewiness. The water uptake ratio was inversely related to TPA hardness, gumminess, and chewiness. Rapid Visco Analyzer peak viscosity was negatively correlated with the hardness, gumminess, and chewiness (P < 0.07); breakdown was also negatively correlated with those TPA parameters (P < 0.09); final viscosity and setback were negatively correlated with the hardness, cohesiveness, gumminess, and chewiness (P < 0.05); setback was correlated with the adhesiveness as well (r = -0.63, P = 0.02). Onset gelatinization temperature (To ) was significantly positively correlated with all the texture profile parameters, and peak temperature (Tp ) was moderately correlated with cohesiveness, whereas neither conclusion temperature (Tc ) nor enthalpy correlated with the texture of cooked quinoa.