ABSTRACT The aim of this study was to develop and evaluate the antioxidant characteristics and sensory acceptance of Greek yogurt with added whole sorghum flours (WSF) from genotypes BRS305 (tannin) and BR501 (tannin-free). Five formulations were elaborated: 1) Control (without WSF); 2) 2% BR501; 3) 4% BR501; 4) 2% BRS305 and 5) 4% BRS305 and evaluated for antioxidant capacity, total anthocyanins, total phenols, condensed tannins, sensory acceptance and purchase intention. The 4% BRS305 formulation presented higher antioxidant properties, but lower sensory acceptance. No significant difference was observed for: color, flavor and overall acceptability between the control and 2% BR501; nor for texture and overall acceptability between the control and 4% BR501. Principal component analysis explained that all variables associated with antioxidant properties were positively correlated with the first major component (PC1: 82.7%). The 2% and 4% BR501 formulations were more highly correlated with PC1 (92.7%), as well as the control in relation to sensorial characteristics. The addition of WSF BRS305 improved the antioxidant properties of yogurts and the addition of WSF BR501 did not interfere with the sensory acceptance of the formulations. The similarity of the sensory acceptance of the yogurt containing WSF from the BR 501 genotype to the control, opens perspectives for the insertion of sorghum in human food, using dairy products as suitable matrices, adding potential functionality to this type of product.

RESUMEN El trabajo tuvo como propósito desarrollar y evaluar las características antioxidantes y la aceptación sensorial de yogurt griego con adición de harinas integrales de sorgo (HIS) de los genotipos BRS305 (con taninos) y BR501 (sin taninos). Cinco formulaciones fueron elaboradas: 1) Control (sin HIS); 2) 2% BR501; 3) 4% BR501; 4) 2% BRS305 y 5) 4% BRS305. Las formulaciones fueron evaluadas en función de su actividad antioxidante, antocianinas totales, fenólicos totales, taninos condensados, aceptación sensorial e intención de compra. La formulación 4% BRS305 presentó más propiedades antioxidantes, pero menor aceptación sensorial que las otras formulaciones. No se observó diferencia significativa entre el control y el 2% BR501 para el color, sabor e impresión global, ni tampoco para textura e impresión global en relación al 4% BR501. El análisis de componente principal ha explicado que todas las variables asociadas a las propiedades antioxidantes han sido positivamente correlacionadas con el primer componente principal (PC1: 82,7%). Las formulaciones 2% y 4% BR501 se han correlacionado más con el PC1 (92,7%), así como el control con las características sensoriales. La adición de HIS BRS305 ha mejorado las propiedades antioxidantes de los yogurts y la adición de HIS BR501 no ha interferido en la aceptación sensorial de las formulaciones. La similitud de la aceptación sensorial del yogurt que contiene el HIS del genotipo BR501 con el control, abre perspectivas para la inserción del sorgo en la alimentación humana, utilizando productos lácteos como matrices adecuadas, agregando funcionalidad potencial a este tipo de producto.

Resumo: O objetivo deste trabalho foi avaliar a aceitabilidade de churros sem glúten, feitos com farinha de sorgo com ou sem tanino, assim como a retenção de seus compostos fenólicos e da sua capacidade antioxidante após processamento por cozimento e fritura. Os churros foram desenvolvidos pela substituição da farinha de trigo por farinhas de sorgo das cultivares BRS 305 com tanino (T-churro) ou BR 501 sem tanino (TF-churro). O teor de compostos fenólicos e a atividade antioxidante foram avaliados antes e depois do processamento térmico. Ambos os produtos apresentaram alta aceitabilidade (84,5‒95,5%) para todos os atributos sensoriais avaliados, e nenhuma diferença foi observada quanto à cor, ao aroma e ao sabor. Entretanto, o T-churro teve maior aceitação quanto à textura, à aceitabilidade geral e à intenção de compra. Os churros apresentaram composição centesimal semelhante quanto ao conteúdo de fibra. O teor de fenol foi cerca de três vezes e a atividade antioxidante cerca de 20 vezes maior no T-churro do que no TF-churro. Apesar de ter sido submetido a dois tipos de processamento (cozimento e fritura), o T-churro frito pronto para consumo apresentou mais de 50% de retenção de antocianinas, fenóis e atividade antioxidante, após a fritura. O produto TF-churro apresentou retenção desses compostos acima de 70, 40 e 65%, respectivamente. O teor de tanino do sorgo 'BRS 305' aumenta seu potencial funcional e não afeta negativamente a aceitabilidade dos churros. Sorgos com ou sem taninos têm potencial para a produção de churros sem glúten.

Abstract: The objective of this work was to evaluate the acceptability of gluten-free churros made either with tannin or tannin-free sorghum flour, as well as the retention of their phenolic compounds and antioxidant capacity retention after cooking and frying. The churros were developed by replacing wheat flour with sorghum flour from the sorghum cultivars BRS 305 with tannin (T-churro) or BRS 501 tannin free (TF-churro). The content of phenolic compounds and antioxidant activity were evaluated before and after the thermal processing. Both products had a high acceptability (84.5‒95.5%) for all evaluated sensory attributes, and no difference was observed for color, aroma, and flavor. However, the T-churro showed a higher acceptance for texture, overall acceptability, and purchase intention. The churros had a similar proximate composition for fiber content. The phenol content was about three times and antioxidant activity about 20 times higher for T-churro than for TF-churro. Although subjected to two types of processing (cooking and frying), the fried and ready-to-eat T-churro retained more than 50% of anthocyanins, phenols, and antioxidant activity. The TF-churro product showed a retention of these compounds above 70, 40, and 65%, respectively. The tannin content of 'BRS 305' sorghum increases its functional potential and does not negatively affect the acceptability of the churros. Sorghum either with or without tannins has the potential to be used for the production of gluten-free churros.