The effects of b-glucan on corn tortilla texture were evaluated. Barley flour (9.7% b-glucan) was substituted at 2.5, 5 and 10% for dry masa flour in corn tortillas. Texture was evaluated after 4 hr and up to 7 d storage at 4°C. Substitution of 2.5-10% barley flour significantly improved tortilla texture. Combined effects of barley flour (0-2.5%), maltogenic amylase (0-1650MAU) and carboxymethylcellulose (0-0.5%) were evaluated using surface response methodology. Barley flour increased rollability, pliability, energy dissipated and reduced rupture force and final stiffness. Overall, maltogenic amylase decreased rupture force and Young's modulus but decreased rupture distance, rollability and pliability at levels above 825 MAU. CMC improved rollability, pliability, and rupture distance. The best response was found using barley flour and CMC with 825 MAU, where rollability, pliability, rupture distance and energy dissipated increased while rupture force, Young's modulus and final stiffness decreased. A 70% barley b-glucan concentrate combined with amylase (550 MAU) or CMC (0-0.5%) was evaluated in corn tortillas. Amylase combined with b-glucan did not improve texture. Tortillas with b-glucan and CMC had significantly improved pliability, rollability, final stiffness and energy dissipated. Texture measurements analysis showed that depending on the stage of storage, objective and subjective methods correlate differently. Subjective and objective measurements of texture were not correlated at 4 hr storage. At the end of storage, pliability had significant correlations with stress relaxation measurements, but rollability had higher correlation coefficients with extensibility measurements. Pliability had higher R2 and lower coefficients of variation compared to rollability. Sensory evaluation was conducted using reheated 14-day-old tortillas of control, 825 MAU with 0.25% CMC, 0.12% b-glucans, 0.18% b-glucan with 0.375% CMC, and 0.24% b-glucan with 0.25% CMC. All tortillas had similar appearance, flexibility, gumminess, flavor and overall quality. Softness and chewiness of treatments with 0.12% b-glucan or 0.24% b-glucan with 0.25% CMC were similar to control. Other tortillas were significantly tougher and chewier. b-glucan may be the active ingredient in barley flour that modifies firming of corn tortillas during storage. Barley flour is inexpensive and effectively improves texture of corn tortillas.

Although less common in human food, studies have reported the beneficial effects of b-glucans present in the soluble portion of barley dietary fiber, such as implications in serum cholesterol and blood glucose reduction, besides anticarcinogenic properties. Barley is not commonly used in bakery products, however, partial replacement of wheat flour with barley can result in the development of acceptable and functional products, coming as alternative of bread enrichment. This study aimed to evaluate the technological viability of the incorporation of barley, in the form of flour, on the quality parameters of bread to make a choice of food with potential health benefits to the consumer. Barley flour (BF), whole barley flour (WBF), and breads produced with these flours were characterized as for chemical composition and physical properties. Flours were also analyzed for the granulometry and rheological properties, while the loaves were evaluated as for the quality parameters and sensory analysis. The addition of barley flour in bread did not interfere in nutrient composition and resulted in a favorable increase in fiber levels and dough water capacity absorption. Levels of substitution of up to 30% of barley flour and 10% of whole barley flour did not affect bread softness. As far as barley substitution level increased, texture increase and bread volume decrease were observed. Thirty porcent substitution level of BF and WBF showed desirable bread quality and all breads produced were accepted by consumers, indicating possibility of being produced and subsequently comercialized. / Embora pouco utilizada na alimentação humana, estudos têm relatado os efeitos benéficos das betaglucanas presentes na porção solúvel da fibra alimentar da cevada, tais como implicações sobre o colesterol sérico e redução da glicose sanguínea, além de propriedades anticarcinogênicas. A cevada não é comumente usada em produtos de panificação, entretanto, substituição parcial de trigo com a farinha de cevada pode resultar no desenvolvimento de produtos aceitáveis e funcionais, surgindo como uma alternativa para o enriquecimento de pães. Este trabalho teve como objetivo avaliar a viabilidade tecnológica da incorporação da cevada, sob a forma de farinha, sobre os parâmetros de qualidade do pão de forma a fim de disponibilizar uma opção de alimento com possíveis benefícios à saúde do consumidor. As farinhas de cevada (FC) e de cevada integral (FCI), e os pães elaborados com estas farinhas, foram caracterizados quanto à composição química e propriedades físicas. As farinhas foram ainda analisadas quanto à granulometria e as propriedades reológicas, enquanto os pães foram avaliados quanto aos parâmetros de qualidade e análise sensorial. A adição de farinha de cevada no pão de forma não prejudicou a composição de nutrientes e resultou em um aumento favorável nos teores de fibras e da capacidade de absorção de água na massa. Níveis de substituição de até 30% de farinha de cevada e 10% de farinha de cevada integral não afetaram a maciez dos pães. À medida que aumentaram os níveis de substituição de trigo por cevada, observou-se aumento na firmeza e diminuição do volume dos pães. Níveis de substituição de até 30% de FC e FCI produziram pães com qualidade desejável e todos os pães elaborados foram aceitos pelos consumidores, indicando possibilidade de serem produzidos e posteriormente comercializados.