RESUMO

Legumes are abundant sources of proteins, and white common bean proteins play an important role in air-water interface properties. This study aims to investigate the technical-functional properties of white common bean protein isolate (BPI) as a function of pH, protein concentration, and guar gum (GG) presence. BPI physicochemical properties were analyzed in terms of solubility, zeta potential, and mean particle diameter at pH ranging from 2 to 9, in addition to water-holding capacity (WHC), oil-holding capacity (OHC), and thermogravimetric analysis. Protein dispersions were evaluated in terms of dynamic, interfacial, and foam-forming properties. BPI showed higher solubility (>80 %) at pH 2 and above 7. Zeta potential and mean diameter ranged from 15.43 to -34.08 mV and from 129.55 to 139.90 nm, respectively. BPI exhibited WHC and OHC of 1.37 and 4.97 g/g, respectively. Thermograms indicated decomposition temperature (295.81 °C) and mass loss (64.73 %). Flow curves indicated pseudoplastic behavior, with higher η100 values observed in treatments containing guar gum. The behavior was predominantly viscous (tg δ > 1) at lower frequencies, at all pH levels, shifting to predominantly elastic at higher frequencies. Equilibrium surface tension (γeq) ranged from 43.87 to 41.95 mN.m-1 and did not decrease with increasing protein concentration under all pH conditions. All treatments exhibited ϕ < 15°, indicating predominantly elastic surface films. Foaming properties were influenced by higher protein concentration and guar gum addition, and the potential formation of protein-polysaccharide complexes favored the kinetic stability of the system.

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RESUMO

The oil extracted from baru (Dipteryx alata Vog.) seeds is in bioactive compounds and it presents potential to be used in food and cosmetic industries. Therefore, this study aims to provide insights into the stability of baru oil-in-water (O/W) nanoemulsions. For this purpose, the effects of the ionic strength (0, 100 and 200 mM), pH (6, 7 and 8), and storage time (28 days) on the kinetic stability of these colloidal dispersions were evaluated. The nanoemulsions were characterized in terms of interfacial properties, rheology, zeta potential (ζ), average droplet diameter, polydispersity index (PDI), microstructure, and creaming index. In general, for samples, the equilibrium interfacial tension ranged from 1.21 to 3.4 mN.m-1, and the interfacial layer presented an elastic behavior with low dilatational viscoelasticity. Results show that the nanoemulsions present a Newtonian flow behavior, with a viscosity ranging from 1.99 to 2.39 mPa.s. The nanoemulsions presented an average diameter of 237-315 nm with a low polydispersity index (<0.39), and a ζ-potential ranging from 39.4 to 50.3 mV after 28 days of storage at 25 °C. The results obtained for the ζ-potential suggest strong electrostatic repulsions between the droplets, which is an indicative of relative kinetic stability. In fact, macroscopically, all the nanoemulsions were relatively stable after 28 days of storage, except the nanoemulsions added with NaCl. Nanoemulsions produced with baru oil present a great potential to be used in the food, cosmetic, and pharmaceutical industries.

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This article presents a study of the interfacial properties of oil-in-water emulsions containing sugar esters and polysaccharides. Sucrose fatty acid esters were synthesized using immobilized Candida antarctica lipase B. A yield of 53.4% was obtained using 2-methyl-2-butanol and 1:3 M ratio of sucrose:stearic acid. Equilibrium surface tension was 45 mN/m and low critical micellar concentration (CMC) value was obtained (ca. 10 mg/mL), characteristic of non-ionic surfactant. The interfacial properties of mixtures of sucrose esters and polysaccharides, at the oil-water interface were determined using a pendant drop tensiometer. Addition of polysaccharides increased the interfacial tension. Studies of interfacial viscoelasticity showed that the films were predominantly elastic. The presence of polysaccharides in emulsions resulted in flocculated droplets. All the emulsions presented great stability along 28 days with no creaming formation.

RESUMO

The surface properties and foaming of ovalbumin and guar gum aqueous solutions was investigated in the presence of sucrose or sorbitol. All solutions had a broad particle size distribution (395.60 at 1137.50 nm). Higher ovalbumin concentrations had lower equilibrium surface tension and higher absolute values of the zeta potential, regardless the presence of sucrose or sorbitol. Mixtures containing ovalbumin and guar gum resulted in a predominantly elastic character of the air-water interface probably due to the formation of a complex (hydrogen bonding and/or hydrophobic interactions) between ovalbumin and guar gum. Besides, the increase in guar gum concentration enhanced the elasticity of the surface film. Higher concentrations of both polymers were required to provide higher kinetic stability to the system, although the increase in guar gum concentration reduced foam capacity due to the increase in the apparent viscosity. Foams formed in the presence of sucrose or sorbitol showed similar half-lives.

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This study sought to determine the attitude of consumers in the city of Viçosa-MG, Brazil in relation to products containing probiotics using a validated questionnaire. A total of 352 individuals responded to questionnaires which, in addition to the items of attitude, also assessed the health of consumers and acceptance and frequency of consumption of these products. Internal validation utilized the Cronbach coefficient to measure the reliability of the attitude scale. To analyze the profile of these consumers, descriptive statistics was utilized. The results indicated a low consumption of products containing probiotics by respondents. A reliable attitude scale was obtained (alpha = 0.70). In general, the attitude of respondents was positive however it was verified that there is a need to develop more explanatory labels, clearly stating the information allowed by Brazilian legislation, as well as strengthen campaigns to promote the benefits of consuming probiotic to the consumer.

Neste trabalho, buscou-se verificar a atitude de consumidores da cidade de Viçosa-MG em relação a produtos contendo probióticos, por meio de um questionário validado para tal fim. Um total de 352 indivíduos respondeu aos questionários que, além dos itens de atitude, também avaliou questões de saúde dos consumidores, aceitação e frequência de consumo desses produtos. A validação interna valeu-se do coeficiente de Cronbach para medir a confiabilidade da escala de atitude. Para analisar o perfil desses consumidores, foi utilizada a estatística descritiva. Os resultados indicaram baixo consumo de produtos contendo probióticos pelos entrevistados. Foi obtida uma escala de atitude confiável (alfa = 0,70). De uma forma geral, a atitude dos entrevistados foi positiva, porém, verificou-se a necessidade de se desenvolver rótulos mais explicativos, expondo de forma clara as informações permitidas pela legislação brasileira, assim como reforçar as campanhas publicitárias que divulguem os benefícios do consumo de probióticos ao consumidor.

RESUMO

This study sought to determine the attitude of consumers in the city of Viçosa-MG, Brazil in relation to products containing probiotics using a validated questionnaire. A total of 352 individuals responded to questionnaires which, in addition to the items of attitude, also assessed the health of consumers and acceptance and frequency of consumption of these products. Internal validation utilized the Cronbach coefficient to measure the reliability of the attitude scale. To analyze the profile of these consumers, descriptive statistics was utilized. The results indicated a low consumption of products containing probiotics by respondents. A reliable attitude scale was obtained (alpha = 0.70). In general, the attitude of respondents was positive however it was verified that there is a need to develop more explanatory labels, clearly stating the information allowed by Brazilian legislation, as well as strengthen campaigns to promote the benefits of consuming probiotic to the consumer.(AU)

Neste trabalho, buscou-se verificar a atitude de consumidores da cidade de Viçosa-MG em relação a produtos contendo probióticos, por meio de um questionário validado para tal fim. Um total de 352 indivíduos respondeu aos questionários que, além dos itens de atitude, também avaliou questões de saúde dos consumidores, aceitação e frequência de consumo desses produtos. A validação interna valeu-se do coeficiente de Cronbach para medir a confiabilidade da escala de atitude. Para analisar o perfil desses consumidores, foi utilizada a estatística descritiva. Os resultados indicaram baixo consumo de produtos contendo probióticos pelos entrevistados. Foi obtida uma escala de atitude confiável (alfa = 0,70). De uma forma geral, a atitude dos entrevistados foi positiva, porém, verificou-se a necessidade de se desenvolver rótulos mais explicativos, expondo de forma clara as informações permitidas pela legislação brasileira, assim como reforçar as campanhas publicitárias que divulguem os benefícios do consumo de probióticos ao consumidor.(AU)

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