Abstract This research aimed to evaluate the influence of adding cupuassu (Theobroma grandiflorum) and pitaya (Hylocereus polyrhizus) pulps on the physicochemical and sensory properties of milk bread. We prepared four formulations: control (no fruit added), and three formulations where milk was partially replaced for different proportions of pulps. The following percentages were used: cupuassu pulp (32.37 to 41.61%), pitaya pulp (4.62 to 13.87%), and milk (5.60 to 31.52%). The nutritional composition, instrumental color analysis, and acceptability of the bread were assessed. The addition of fruit pulp into the bread reduced up to 41.44% the lipid content, 40.20% of proteins, and 10.27% of caloric value. The colorimetric analysis showed that the increase in pitaya pulp and decrease in cupuassu pulp reduced the lightness (L*) and the coordinate b*, and increased the coordinate a*. The principal components analysis showed that the most accepted bread formulations were those with 18.14% and 20.74% cupuassu pulp, and 7.78% and 5.18% pitaya pulp. Thus, cupuassu and pitaya pulp can be added into bread formulations as alternative to add nutritional value and contribute to the innovation of bakery products.

Abstract This research aimed to evaluate the influence of tropical fruit peel flours on the breading and quality of chicken nuggets. The treatments consisted of nuggets breaded with four different flour formulations: breadcrumbs, pineapple, bacuri, and peach palm peel. The nuggets were subjected to moisture analysis, fixed mineral residue, lipids, proteins, carbohydrates, caloric value, total carotenoids, instrumental color, and sensory analysis. The breaded nugget with peach palm flour had higher lipid, protein, and carotenoid content, which were 11.21%, 17.73%, and 7.60 mg/100g, respectively. The color of the products differed, as the lightness of the nuggets breaded with breadcrumbs and peach palm peel was higher with 58.46 and 54.89. Principal component analysis showed that the most accepted nuggets formulations were those with peach palm peel flour and breadcrumbs. Pineapple, bacuri, and peach palm fruit peel flours are rich sources of carotenoids. Therefore, its use as meat breading can increase the nutritional value of chicken nuggets. Fruit peel flours can be used to prepare healthier and more nutritious meat-based products, while reducing the generation of agro-industrial residues.

A catalyst comprised of SnO2 impregnated on ZnO nanowires, which presented remarkable ability to catalyze fatty acid esterification/transesterification reactions, is reported. For optimization of reaction conditions, artificially acidified soybean oil with 10 wt.% oleic acid was used as a model feed. The optimized conditions were: 150 °C, 6 h, 5 g of oil, catalyst concentration of 5%, and methanol:oil molar ratio of 15:1. The catalyst achieved 92% of total fatty acid methyl esters (FAME) content and was used five times without the necessity of catalyst washing from one reaction to the other. Then, such conditions were applied to produce biodiesel from the oil extracted from Scenedesmus sp. microalgae; the system reached 72% of FAME content, without any previous refining or degumming process of the oil. Rietveld refinement, X-ray diffraction, elemental mapping in scanning transmission electron microscopy, X-ray photoelectron spectroscopy, and pyridine-desorption Fourier-transform infrared spectroscopy were used to characterize the material.

Resumo O objetivo deste estudo foi a elaboração e a caracterização reológica de um iogurte sabor bacuri com reduzido teor de gordura. Foram elaborados três iogurtes a partir dos tipos de leite UHT integral, semidesnatado e desnatado. As análises reológicas foram realizadas em quatro diferentes temperaturas (5 °C, 15 °C, 30 °C e 45 °C) e os dados experimentais foram ajustados ao modelo de Ostwald-de-Waelle. A relação entre temperatura e viscosidade aparente foi descrita por uma equação tipo Arrhenius. Os valores de tensão de cisalhamento e viscosidade aparente dos iogurtes diminuíram com o aumento da temperatura, bem como com a redução do teor de gordura. O modelo utilizado mostrou-se adequado para descrever o comportamento reológico dos iogurtes, segundo os parâmetros estatísticos avaliados. Os baixos valores obtidos para o índice de comportamento indicaram um comportamento característico de fluidos pseudoplásticos (n<1). A equação tipo Arrhenius descreveu de modo satisfatório o efeito da temperatura sobre a viscosidade aparente. Os valores da energia de ativação (Eat) foram de 2,66 kcal g mol-1, 3,81 kcal g mol-1 e 3,93 kcal g mol-1, respectivamente, para as amostras de iogurte integral, semidesnatado e desnatado. Na caracterização físico-química, os teores de gordura se mostraram próximos para os iogurtes desnatado e semidesnatado, não havendo diferença significativa. O iogurte semidesnatado e o desnatado podem ser considerados com reduzido teor de gordura, pois sofreram uma diminuição no teor de lipídios de 75% e 79,1%, respectivamente.

Abstract This work aimed to evaluate the preparation and rheological characterization of a bacuri yogurt with reduced-fat content. Three types of yogurts from UHT whole milk, semi-skimmed and skimmed were elaborated. The rheological analyses were performed in four different temperatures (5 °C, 15 °C, 30 °C and 45 °C) and the experimental data were adjusted for Power Law model. The relation of temperature with apparent viscosity was described by Arrhenius equation. The values of yield stress and apparent viscosity for yogurts decreased with increasing temperature as well as with fat content. The model used was adequate to describe the rheological behavior of the yogurts according to the statistics parameters evaluated. The low values obtained for the behavior index indicated a characteristic behavior of pseudoplastic fluids (n<1). The Arrhenius equation described properly the effect of temperature in apparent viscosity. The values of activation energy were 2.66 kcal g mol-1, 3.81 kcal g mol-1 and 3.93 kcal g mol-1, with respect to the samples of whole yogurt, semi-skimmed and skimmed, respectively. Regarding the physicochemical characterization, the fat levels were similar for the skimmed and semi-skimmed yogurts, demonstrating no significant difference. The semi-skimmed and skimmed yogurts were considered light or with reduced-fat content, thus determining a decrease in values of 75% and 79.1%, respectively.

Abstract Tucupi, a fermented product obtained from cassava (Manihot esculenta Crantz) is widely employed in the cuisine of the Northern region of Brazil, however, its industrial application is incipient. This study used tucupi to prepare a creamy paste, which underwent sensory and rheological evaluation. Paste formulations with 5 to 20% concentrated tucupi were obtained. An acceptance test was used to assess the product’s acceptability regarding the attributes of color, aroma, flavor, texture, and overall impression. A purchase intention test of the product was also applied. The product’s rheology was studied at 25, 40, and 60 °C and the activation energy (Ea) was estimated. The internal preference mapping indicated that the paste formulation with 5% and 10% tucupi were the most accepted by the judge, but only the 10% tucupi paste was characterized. Proportions greater than 15% tucupi influenced negatively in the flavor and texture of the product. Purchase intention test showed that 99% of the judges demonstrated interest in purchasing the product. The product presented 72.7% moisture, 10.4% lipids, 0.5% proteins, 2.1% ashes, 14.3% carbohydrates, and 7.4 μg/g β-carotene. According to the rheological assays, the paste presented characteristics of a pseudoplastic fluid. The Herschel-Bulkley model proved efficient to predict the flow curves for the product in the temperature range tested, for which Ea was estimated at 7.49 kJ/mol.

O objetivo deste trabalho foi determinar o comportamento reológico do suco de abacaxi- pérola natural e tratado com enzimas pectinolíticas. As condições de tratamento enzimático foram otimizadas através de um planejamento experimental do tipo fatorial completo 2k, com três repetições do ponto central. Na avaliação do comportamento reológico foram utilizadas duas amostras submetidas a peneiramento (N e D), analisadas em quatro diferentes temperaturas (10; 25; 50 e 65 °C). As análises reológicas foram realizadas utilizando um viscosímetro de cilindros concêntricos Brookfield e os dados experimentais foram ajustados ao modelo de Mizrahi-Berk. A relação entre temperatura e viscosidade aparente foi descrita por uma equação tipo Arrhenius. A otimização da atividade enzimática indicou, através da análise de variância e da metodologia de superfície de resposta, que as variáveis temperatura e tempo de tratamento exerceram efeito estatisticamente significativo (p<0,05) sobre a concentração de pectina presente na amostra. O modelo utilizado mostrou-se adequado para descrever o comportamento reológico dos sucos de acordo com os parâmetros R², χ² e Bf. Os baixos valores obtidos para o índice de comportamento indicaram um comportamento pseudoplástico (n<1). A temperatura exerceu influência sobre a tensão de cisalhamento e a viscosidade aparente dos sucos analisados, sendo os menores valores observados nas amostras analisadas a 65 °C. A equação tipo Arrhenius descreveu de modo satisfatório o efeito da temperatura sobre a viscosidade aparente. Os valores da energia de ativação (Eat) foram de 4,54 Kcal.g.mol-1 e 4,89 Kcal.g.mol-1, respectivamente, para as amostras do suco de abacaxi natural e despectinizado, aumentando com o tratamento enzimático. A atividade enzimática proporcionou uma redução nos valores dos parâmetros de comportamento reológico das amostras, bem como na viscosidade aparente, em todas as temperaturas utilizadas, sendo o maior percentual de redução observado a 65 °C (41,66%).

The objective this study was determinate the rheological behavior of pineapple juice natural and treated with pectinolytic enzymes. Tests for optimization of enzyme activity used in treatment were realized using a complete factorial planning 2k, with three repetitions of center point and two independent variables (temperature and time of treatment). In evaluation of rheological behavior of pineapple juice, were utilized two samples submitted to sieving (N and D), analyzed in four different temperatures (10, 25, 50 e 65 °C). The rheological analyses were realized using a Brookfield concentric cylinders viscometer and the relationship in the temperature and apparent viscosity was described by an equation type Arrhenius. The experimental data were adjusted by the Mizrahi-Berk model. The optimization tests indicated by ANOVA and response surface methodology that the variables temperature and time of treatment have statistically significant effect (p<0,05) on concentration of pectin present in the samples. The enzymatic treatment was carried with an enzyme concentration of 150 mg.L-1, temperature at 50 °C and treatment time of 80 minutes. The model used was adequate to describe the rheological behavior of the juices according to the parameters R², χ² e Bf. The reduced values of the behavior index (0.61-0.83 for natural juice and 0.57-0.72 for despectinized juice) indicated the pseudoplastic behavior (n<1). The temperature influenced the yield stress and apparent viscosity of the juices analyzed, where the minors values were observed in samples treated at 65 °C, 2.4 mPa.s and 1.4 mPa.s, respectively, for the natural and despectinized samples. The equation of Arrhenius described satisfactorily the effect of temperature in the apparent viscosity. The activation energy values (Eat) was of 4.54 Kcal.g.mol-1 and 4.89 Kcal.g.mol-1, respectively, for the natural and despectinized samples of pineapple juice, increasing with enzymatic treatment. The enzymatic treatment decreased the values of rheological behavior parameters for samples of pineapple juice, and the apparent viscosity for all temperatures used, where the largest percentage reduction was observed at 65 °C (41.66%).