ABSTRACT This study describes the development of mixed flour added of maca for gluten-free bread (GFB) employing a Simplex Centroid Design. Four pseudo-components were evaluated in order to improve the GFB specific volume and texture profile analysis: maca (MC; 0.25 to 0.75), potato starch (PS; 0.25 to 0.75), sweet manioc flour (SEM; 0 to 0.25), and sour manioc flour (SOM; 0 to 0.25). The best GFB formulation – by desirability results - was evaluated regarding physio-chemical, microbiological aspects, and sensory acceptance. The responses specific volume and hardness were adjusted with a special cubic model (R2= 0.973 and 0.913), while cohesiveness, springiness and chewiness was adjusted with a linear model. The significant contribution of maca into GFB dough was evident in the models, and the desirability results indicated an appropriate mixed flour composed by MC (0.25), PS (0.5), and SEM (0.25). The GFB elaborated with this mixed flour generated a product well accepted (acceptability index higher than 73.9%) for attributes of aroma, colour, texture, flavour, and overall acceptance. The values of physio-chemical parameters obtained in the present article was in the range described for GFB in the literature. In addition, the processing method applied allowed for obtaining a GFB that was microbiologically stable.

RESUMEN Este estudio describe el desarrollo de la harina mezclada (MF) agregada de maca para la elaboración de pan sin gluten (GFB) empleando un Diseño Centroide Simplex. Se evaluaron cuatro pseudo-componentes para mejorar el volumen específico y el perfil de textura de GFB: maca (MC; 0,25 a 0,75), almidón de patata (PS; 0,25 a 0,75), harina de yuca dulce (SEM; 0 a 0,25), y harina de yuca agrio (SOM; 0 a 0,25). La mejor formulación de GFB - por la deseabilidad - se evaluó en relación con los aspectos fisicoquímicos, microbiológicos, y sensoriales. El volumen específico y la dureza se ajustaron a un modelo cúbico especial (R2= 0,975 y 0,913). La cohesión, elasticidad y masticabilidad se ajustaron a un modelo lineal. La contribución de la maca a la masa de GFB fue evidente en los modelos, y los resultados indican una MF apropiada compuesta por MC (0,25), PS (0.5) y SEM (0,25). El GFB elaborado con esta MF genera un producto aceptado (índice de aceptabilidad mayor que 73,9%) para aroma, color, textura, sabor y aceptación general. Los parámetros físico-químicos obtenidos estaban en el rango descrito para GFB en la literatura y GFB se mostró microbiológicamente estable.

Abstract The gluten is a protein associated with a numerous food allergy cases. As the gluten-related disorders relates is increasing, the demand for gluten-free breads (GFB) has been also increasing. The aim of this study was to obtain a GFB with increased nutritional aspects and sensorially accepted. A Central Composite Rotatable Design (CCRD) 23 was employed in order to choose the ideal proportions of partially defatted chia flour (PDCF) (1.23 to 24.77%), hydroxypropylmethylcellulose gum (HPMC) (0.00 to 2.51%), and Xanthan gum (XG) (0.00 to 2.51%) in a mixed flour used in GFB. The responses evaluated in GFB were: total lipids, protein, ash, carbohydrate, and omega-3 content, specific volume, L*, a*, and b*. The sensory acceptance was also evaluated. PDCF was the variable with higher effects in nutritional aspects; in high levels PDFC increase the protein, ash, and omega-3 content and decrease carbohydrate content of GFB. Although PDCF addition in the higher proportions negatively influenced the color parameters - decrease L* and increase a* - the mixed flour with 20% of PDCF, 0.51% of HMPC and 0.51% of XG added to GFB, was the most accepted for overall acceptance.