Abstract Dioscorea trifida tuber contains starch, vitamins, minerals and bioactive compounds. It is perishable, requiring dehydration treatment to increase shelf life. This study aimed to investigate the mass transfer parameters and thermodynamic properties of Dioscorea trifida using Refractance Window (RW) drying (70, 80, and 90 °C). It was observed that the dehydration process occurred in a short time (40 min). The moisture diffusivity and the mass transfer coefficient were determined using the Dincer and Dost model. The diffusivity coefficients ranged from 2.62 × 10-6 at 6.13 × 10-6 m2 s-1, the mass transfer coefficient ranged from 3.46 × 10-4 at 4.04 × 10-4 m s-1 and the estimated of activation energy was 44.091 kJ mol-1. In the Dioscorea trifida Refractance Window drying, the enthalpy and entropy are positive and negative, respectively, decreasing with increasing temperature and thus indicating that the process is endothermic. Gibbs free energy increases with increasing temperature, indicating that the process does not occur spontaneously.

Abstract Microbiological safety of fish is a concern of consumers, industries and regulatory agencies worldwide. Among the pathogenic microorganisms, Salmonella spp. is one of the main agents of foodborne diseases and should be absent in animal products. Rapid and accurate identification of pathogens in the supply chain is important for both quality assurance and tracking infectious agents within the chain. In this context, this study aimed to evaluate the equivalence of two rapid detection tests, as alternative methods to the conventional Salmonella detection method, as well as to verify the microbiological quality parameters of two commercially important fish species in the Amazon biome. The plate count of aerobic bacteria ranged from 7.76 x 104 to 8.71 x 107 CFU.g-1 for mesophiles and 1.70 x 106 to 4.27 x 108 CFU.g-1 for psychrotrophic whereas the maximum for this group of microorganisms in fresh fish is 106 CFU.g-1. Regarding the Staphylococcus count, the two species presented variations between 1.35 x 104 to 1.51 x 105 CFU.g-1. This represents unsatisfactory conditions of handling, storage and conservation of fish species. The immunoenzymatic and molecular methods have been shown to be reliable, fast and effective in the detection of Salmonella and for its high index of agreement with the conventional detection method. We also emphasize the convenience of multiplex PCR application due to the high sensitivity, specificity, speed and accuracy of Salmonella detection.

Abstract The Mammee apple (Mammea americana L.) is a widely grown fruit, popular in tropical areas, which is mainly consumed fresh. Refractance Window (RW) drying is used to produce food films, flakes, and powders, and may be an alternative to commercially used dry food production methods. The aim of this study was to obtain a dehydrated product from the pulp of mammee apple using RW. The dehydrated product presented a homogeneous microstructure and good mechanical (TS = 1.15 Mpa, %E = 13.93) and technological properties (hygroscopicity = 21.46 g.100 g-1, water solubility index = 32.73 ± 0.67 g.100 g-1). RW drying was found to be a viable and low-cost method for edible film production, generating products with adequate technological characteristics and high nutritional value. Its dehydrated products can be consumed directly or used as ingredients in the development of food products.

Abstract Tucupi, which is widely enjoyed in the North region of Brazil, is a fermented liquid derived from cassava (Manihot esculenta Crantz) and has been taken abroad for its exotic characteristics. This study aimed to assess the rheological behavior of tucupi with 30, 35, and 40% solids and concentrated at 50, 70, and 90 °C. The rheological data were obtained at 25, 40, 60, and 80 °C with increasing and decreasing shear rates. Rheology at 25 °C indicated that the partial gelification of starch during concentration causes a decrease in the product’s viscosity and, if the concentration is carried out at a temperature that favors total starch gelification, the product’s viscosity increases. Concentrated tucupi behaved as a pseudoplastic fluid, but at 60 and 80 °C with increasing shear rates, the product behaved as a dilatant fluid. Hysteresis were observed in flow curves starting at 40 °C, which characterizes concentrated tucupi as a rheopectic fluid. The Ostwald-de Waele model predicted the product’s flow curves and an Arrhenius-like equation described the dependence of temperature on apparent viscosity for the rheological data obtained with increasing shear rates. The product’s activation energy (E a) values ranged from 16.86 to 25.23 kJ/mol as a function of concentration.

Abstract Peach palm flours prepared from the landraces microcarpa (MIF), mesocarpa (MEF), and macrocarpa (MAF) were assessed for their functional and morphological characteristics. The flours had moisture contents in accordance with the current legislation, considerable lipid (≥3.95%) and carbohydrate (≥66.68%) contents, and potential as an energy source (≥300 kcal/100 g). MEF and MAF can be considered rich in dietary fibers since their fiber contents were above 6 g/100 g, which contributes to the nutritional enrichment of products prepared with those flours. The assessment of the technological properties, WAC (≥255%) and OAC (≥65%) showed the peach palm flours can be used as raw material in different products such as breads, cakes, meat products, and breaded foods, thus adding energy, nutritional, and economic value. It is worth pointing out that peach palm is gluten free, hence it is an option for the development of new products targeted at consumers with celiac disease.

Abstract By the analytical model proposed by Dincer and Dost, the mass transfer parameters (moisture transfer coefficient and moisture diffusivity) of shrimp samples were determined. Three sets of drying experiments were performed with three samples of shrimp: without boiling (WB), boiled in salt solution (SB) and boiled in salt solution and subjected to liquid smoking process (SBS). The experiments were performed under controlled conditions of drying air at temperature of 60°C and velocity of 1.5 m/s. Experimental dimensionless moisture content data were used to calculate the drying coefficients and lag factors, which were then incorporated into the analytical model for slab and cylinder shapes. The results showed an adequate fit between the experimental data and the values predicted from the correlation. The boiling is the most recommended pretreatment, because provided a shorter drying time, with high values of moisture transfer coefficient and moisture diffusivity.

Abstract In this study, the spouted bed drying technique was used to obtain powder from shrimp wastes, with high quality for subsequent extraction of astaxanthin using vegetable oil, as alternative to organic solvents. Shrimp waste paste was dried in three inlet air temperatures (70, 80 and 90 °C), and air velocity used in the experiments was 100% over minimum spouting velocity. The minimum spouting, the velocities were 1.23, 1.33 and 1.39 m/s, for temperatures of 90, 100 and 110 °C respectively. The powder obtained in this work shows properties comparable to of the commercial products, indicating that the spouted bed is an alternative technique to obtain powdered products with quality good, at low cost and suitable for subsequent extraction of astaxanthin. The extractions of astaxanthin from shrimp waste were performed using palm olein at three different temperatures (50, 60, and 70 °C). At these conditions, maximum extraction of astaxanthin was 29.814µg/g of dried waste. The extraction kinetics were modeled using a simplified mass transfer kinetic model which showed a good agreement (0.9685<r2<0.9912), between the experimental and calculated data.

Este estudo avaliou a composição química da farinha de banana verde sem casca e com casca, obtido por secagem em leito de jorro, com o objetivo de agregar valor nutricional a produtos alimentícios. As bananas foram cortados e trituradas para a obteção de uma pasta, sendo esta alimentada no secador leito de jorro (12 cm de altura e T = 80 º C), a fim de obter uma farinha. As farinhas obtidas foram submetidas a análise da umidade, proteína, cinzas, Carboidratos totais, amido total, amido resistente, e fibras. As farinhas de banana verde, principalmente com casca, são boas fontes de fibras e amido resistente, com uma média de 21,91g/100g e 68,02g/100g respectivamente. O teor médio de proteína encontrado foi para 4,76g/100g, sendo classificada como uma proteína de baixo valor biológico, tendo a lisina como o primeiro aminoácido limitante. Os resultados mostraram que a farinha de banana verde com casca obtida por secagem em leito de jorro pode ser uma ferramenta valiosa para agregação de valor nutricional aos produtos, a fim de aumentar a sua fracção não digerível.

This study evaluated the chemical composition of peeled and unpeeled green banana Cavendish (AAA) flour obtained by drying in spouted bed, aiming at adding nutritional value to food products. The bananas were sliced and crushed to obtain a paste and fed to the spouted bed dryer (12 cm height and T = 80 ºC) in order to obtain flour. The flours obtained were subjected to analysis of moisture, protein, ash, carbohydrates, total starch, resistant starch, fiber. The green banana flours, mainly unpeeled, are good sources of fiber and resistant starch with an average of 21.91g/100g and 68.02g/100g respectively. The protein content was found in an average of 4.76g/100g, being classified as a low biological value protein with lysine as the first limiting amino acid. The results showed that unpeeled green banana flour obtained by spouted bed drying can be a valuable tool to add nutritional value to products in order to increase their non-digestible fraction.

Neste trabalho, foi determinado o comportamento reológico do suco misto obtido a partir de uma mistura de frutas tropicais, mediante um viscosímetro de cilindros concêntricos, no intervalo de temperatura de 10 ºC a 60 ºC. Os modelos Lei da Potência e Mizrahi-Berk foram ajustados aos dados experimentais. Os modelos mostraram-se adequados para descrever o comportamento reológico do suco misto, de acordo com os parâmetros estatísticos de ajuste. O produto apresentou índice de comportamento menor do que 1 (um), caracterizando a pseudoplasticidade do suco. Os índices de comportamento de consistência decresceram com o aumento da temperatura. O efeito da temperatura no comportamento reológico do suco foi descrito por uma equação análoga à de Arrhenius e discutida em termos de energia de ativação (Ea). Os valores de Ea variaram de 4,27 a 4, 66 kcal.gmol-1, com o aumento da taxa de deformação.

The rheological properties of a juice blend obtained from a tropical fruit mix were determined in this work using a rotational viscosimeter at temperatures from 10 ºC to 60 ºC. The Power law and Mizrahi-Berk models were fitted to the experimental data. All the models were considered adequate to describe the rheological properties of the juice blend according to the fitted statistical parameters. The behaviour index of the product was below 1.0, indicating the pseudoplasticity of the juice. The behaviour indexes for consistency were found to decrease with increase in temperature. The effect of temperature on the rheological behaviour of the juice was described by an Arrhenius type equation and discussed in terms of the activation energy (Ea). The values for Ea varied from 4.27 to 4.66 kcal.gmol-1 with increases in shear rate.

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%).

Foram caracterizadas a casca, a polpa e a parte fibrosa do buriti (Mauritia flexuosa) e avaliados os seus comportamentos higroscópicos, visando estabelecer condições de secagem e de armazenamento para os produtos. Foram obtidas isotermas de adsorção e dessorção de umidade a 25 °C, determinado o valor da monocamada e avaliada a aplicabilidade dos modelos: Halsey, Handerson, Kuhn, Mizrahi, Oswin, Smith, BET e GAB, na predição das isotermas. A polpa foi classificada como rica em óleo de alta qualidade e juntamente com a casca e a parte fibrosa como ricas em fibra alimentar. As isotermas dos produtos foram classificadas como do tipo II e suas estabilidades microbiológicas a 25 °C asseguradas quando apresentarem umidade inferior a 8,5, 7,3 e 11,0 gH2O.100 g-1de base seca, respectivamente. Segundo a avaliação, os produtos serão mais bem conservados, se acondicionados em embalagens com baixa permeabilidade ao vapor de água, e os valores da monocamada indicaram que a casca, a polpa e a parte fibrosa não devem ser secas a umidades inferiores a 5,9, 5,0 e 6,4 gH2O.100 g-1b.s., respectivamente. O modelo de GAB foi o que melhor descreveu as isotermas dos produtos.

The objective of this study was to perform an analysis of the characterization of buriti fruit (Mauritia flexuosa). Each part of the fruit (peel, pulp, and fibrous part) was analyzed and their hygroscopic behavior was evaluated to establish the drying and storage conditions. Adsorption and desorption isotherms were obtained at 25 °C to the monolayer value was estimated, and the application of the Halsey, Handerson, Kuhn, Mizrahi, Oswin, Smith, BET, and GAB models was evaluated to the prediction of the isotherms. The fruit pulp was classified as rich in high quality oil, and like the peel and the fibrous part, it was also considered as rich in dietary fiber. The isotherms of the fruit parts were classified as type II, and their microbiological stability (a w < 0.6) can be maintained at 25 °C if the moisture content is lower than 8.5, 7.3, and 11.0 g H2O.100 g-1 of dry matter (d.m.), respectively. The hygroscopic behavior showed that in order to ensure stability, the fruit parts should be packaged with low water vapor permeability. The monolayer demonstrated that the peel, pulp, and the fibrous part cannot be dried under moisture content lower than 5.9, 5.0, and 6.4 g H2O.100 g-1 d.m., respectively. GAB was the most adequate model to describe their isotherms.

O buriti e o patauá são duas palmeiras endêmicas da região Amazônica. As polpas destes frutos são tradicionalmente consumidas pela população local, mas ainda não ganharam os mercados nacional e internacional. A composição nutricional em ácidos graxos e tocoferol foi determinada com metodologias analíticas modernas de cromatografia gasosa (CG) e cromatografia líquida de alta eficiência (CLAE) baseadas nos padrões da AOCS (AMERICAN..., 2002) e AOAC (ASSOCIATION..., 1997), respectivamente. As duas polpas se mostraram bastante energéticas, com uma alta concentração em ácidos graxos, respectivamente 38,4% e 29,1% em massa seca (MS), em proteínas, 7,8% e 7,4% MS e em fibras dietéticas, 46% e 44,7%. A polpa de buriti pode ser considerada uma ótima fonte de vitamina E devido ao seu alto teor de tocoferol (1169 µg.g-1 MS). O perfil de ácidos graxos encontrados para a polpa de patauá foi muito semelhante ao de azeite de oliva.

Buriti and patawa are two endemic palm trees from the Amazon region. Their pulps are traditionally consumed by the local population, but are underused and lesser known worldwide. Nutritional composition, fatty acid and tocopherol contents of the two palm pulps were determined by modern analytical methods: Gas Chromatography (CG) and High Performance Liquid Chromatography (HPLC), based on the standards of AOCS (AMERICAN..., 2002) and AOAC (ASSOCIATION..., 1997), respectively. Buriti and patawa fruit pulps are highly nutritive, with respectively, high fat content (38.4% and 29.1% of dry matter (DM)), protein content (7.6% and 7.4% of DM) and dietary fibers (46% and 44.7% of DM). Buriti pulp can be considered healthy food due its high content of vitamin E (1169 µg.g-1 DM). Patawa pulp is highly oleaginous and its fatty acid composition is very similar to the ones of healthy oils, such as olive oil.