Influence of pulsed vacuum osmotic dehydration on mass transfer, color and rheological properties of mango slices

The aim of this work was to study rheological and colour properties and process kinetics of mango slices subject to pulsed vacuum osmotic dehydration. The slices were immersed in osmotic sucrose solutions (45, 55 and 65 ºBrix) at 20 or 30 ºC. At the beginning, a sub-atmospheric pressure was applied or not to the solid-liquid system (50 or 100 mbar of pressure) for 10 minutes followed by an atmospheric pressure operation up to 5 hours. Fruit samples were evaluated after pre-determined times in terms of weight loss, water loss, solids gain, a w, colour and rheological properties (stress and strain at rupture). The concentration and temperature increases lead to a weight and water reduction. Solid gain was favoured by lower concentration and a higher temperature and by the pulsed vacuum application. The sample softening, which is characterized by a reduction of maximum stress at rupture, and the increased stress on strain at rupture ocurred at the great solids updake conditions. The colour parameters did not change during the dehydration process.O presente trabalho teve como objetivo estudar as propriedades reológicas, de cor e a cinética do processo de desidratação osmótica, a pulso de vácuo, de fatias de manga. As fatias de manga foram imersas em soluções hipertônicas de sacarose, nas concentrações de 45, 55 e 65 ºBrix com temperatura controlada (20 e 30 ºC). No início do processo, aplicou-se ou não um pulso de vácuo, utilizando as pressões de 50 e 100 mbar por 10 minutos. As frutas foram desidratadas por 5 horas, sendo avaliadas em diferentes tempos em relação à perda de peso, perda de água, ganho de sólidos, a w, cor e propriedades reológicas (tensão e deformação na ruptura). O aumento da concentração e da temperatura da solução causou um aumento na perda de peso e de água enquanto que a incorporação de solutos foi favorecida em baixas concentrações e altas temperaturas e com a aplicação do pulso de vácuo. O amaciamento do produto, caracterizado pela diminuição da tensão máxima de ruptura, e o aumento da deformação na ruptura da amostra ocorreram nas condições de maior incorporação de solutos. Não houve alteração dos parâmetros de cor das mangas durante o processo de desidratação.5463Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Supercritical fluids and fluid mixtures to obtain high-value compounds from Capsicum peppers

Peppers of the Capsicum genus have a rich nutritional composition and are widely consumed worldwide. Thus, they find numerous applications in the food, pharmaceutical and cosmetic industries. One commercial application is oleoresin production, a nonpolar fraction rich in bioactive compounds, including capsaicinoids and carotenoids. Among the technologies for pepper processing, special attention is given to supercritical fluid technologies, such as supercritical fluid extraction (SFE) with pure solvents and CO2 plus modifiers, and SFE assisted by ultrasound. Supercritical fluid-based processes present advantages over the classical extraction techniques like using less solvents, short extraction times, specificity and scalability. In this review, we present a brief overview of the nutritional aspects of peppers, followed by studies that apply supercritical fluid technologies to produce extracts and concentrate bioactives, besides oleoresin encapsulation. Furthermore, we present related phase equilibrium, cost estimation, and the gaps and needs for the full use of peppers from a sustainable perspective

Measurement and PC-SAFT modeling of solid-liquid equilibrium of deep eutectic solvents of quaternary ammonium chlorides and carboxylic acids

In this study the solid-liquid equilibria (SLE) of 15 binary mixtures composed of one of three different symmetrical quaternary ammonium chlorides and one of five different fatty acids were measured. The experimental data obtained showed extreme negative deviations to ideality causing large melting-temperature depressions (up to 300 K) that are characteristic for deep eutectic systems. The experimental data revealed that cross-interactions between quaternary ammonium salt and fatty acid increase with increasing alkyl chain length of the quaternary ammonium chloride and with increasing chain length of the carboxylic acid. The pronounced decrease of melting temperatures in these deep eutectic systems is mainly caused by strong hydrogen-bonding interactions, and thermodynamic modeling required an approach that takes hydrogen bonding into account. Thus, the measured phase diagrams were modeled with perturbed-chain statistical associating fluid theory based on the classical molecular homonuclear approach. The model showed very good agreement with the experimental data using a semi-predictive modeling approach, in which binary interaction parameters between quaternary ammonium chloride and carboxylic acid correlated with chain length of the components. This supports the experimental findings on the phase behavior and interactions present in these systems and it allows estimating eutectic points of such highly non-ideal mixtures.This work was developed in the scope of the project CICECO e Aveiro Institute of Materials, POCI-01-0145-FEDER-007679 (Ref. FCT UID/CTM/50011/2013) and LSRE-LCM, POCI-01-0145- FEDER-006984jUID/EQU/50020/2013, financed by national funds through the FCT/MEC and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement. M.A.R.M acknowledges FCT for her PhD grant (SFRH/BD/87084/2012). FCT is also acknowledged for funding the project DeepBiorefinery (PTDC/AGRTEC/ 1191/2014). P.V.A.P., G.J.M., M.D.H. and E.A.C.B thank the national funding agencies CNPq (National Council for Scientific and Technological Development) (305870/2014-9, 309780/2014, 406856/2013-3), FAPESP (Research Support Foundation of the State of S~ao Paulo) (2014/21252-0, 2016/08566-1), FAEPEX/UNICAMP (Fund for Research, Teaching, and Extension) (0125/16) and CAPES (Coordination of Improvement of Higher Level Personnel) for financial support and scholarships. E.A.C thanks Erasmusþ program of the European Union for co-funding.info:eu-repo/semantics/publishedVersio

Avaliação tecnica e economica de um processo de desidratação de cebolas pela combinação de prensagem e secagem com ar aquecido

Orientador: Herbert G. WirthDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos e AgricolaResumo: Um novo método da desidratação de cebola foi pesquisado, com o intuito de se atingir insumos energéticos menores que os de secagem convencional, mantendo o compromisso de um produto final de qualidade aceitável. A primeira etapa consistiu em se submeter cebola triturada à prensagem, para retirada mecânica de líquido. Avaliou-se a influência do tempo, pressão e carga de material sob processamento. Verificou-se que um aumento de pressão resultava em aumento do rendimento; o melhor tempo encontrado foi o de 8 min e a carga mais adequada estabelecida foi de 23 kg/m2. Dois produtos foram originados nessa etapa: suco e polpa úmida. O suco foi concentrado em evaporador tipo termo-sifão e o processo ocasionou geração de odor característico, quando se trabalhou a temperaturas não muito próximas das de inativação enzimática. Previu-se, em escala industrial, um evaporador de triplo efeito, com recuperador de aroma. A polpa ou bagaço úmido foi seca em secador de bandejas com movimentação das mesmas em contra-corrente ao ar de secagem, levando a um processo semi-contínuo de operação. A melhor condição de secagem aqui estabelecida foi a de velocidade do ar de 1,0 m/s, temperatura de 55°C e carga de bandejas de 11,2 kg/m2. O tempo requerido para se atingir um teor final de umidade de cerca de 6%, ao se trabalhar nessas condições, foi algo menor que 3 horas. O dimensionamento do processo previu a instalação de uma unidade de produção de 4.000 kh/h, com equipamentos nacionais, que processaria o bulbo durante todo o período de safra, ou seja, 180 dias em 3 turnos/dia. Os custos fixos e variáveis decorrentes podem ser considerados aceitáveis e através da análise de ponderação, constatou-se que o custo de matéria-prima e o de maior influência. O custo da energia elétrica também ê alto e sugerem-se modificações no processo, que podem minorá-lo. A implantação de uma indústria do tipo permite a utilização de 14.500 ton/ano de uma matéria-prima que sempre apresenta excedentes de produção, com a geração de 270 empregosAbstract: An onion dehydration process was sought, with the purpose of decreasing energy consumption as compared with current drying methods and resulting in products of good quality. The first major step consisted in pressing crushed onion, to remove liquid mechanically. The influence of time, pressure and material load was evaluated. An increase in pressure resulted in higher yields; the best time was 8 min and the most appropriate load was 23 kg/m2. The expression produced two fractions: juice and wet pulp. The juice at 10°Bx was concentrated in a natural circulation evaporator and its distinctive odor was generated, during the processing, when working at temperatures not too close to those of enzymatic in activation. The commercial unit was designed with a three effect evaporator with aroma recovery. The pulp with 17% solids was dried in a tray dryer; the trays being moved at intervals counter-currently to the hot air in a semi-continuous operation. The best drying conditions obtained were as follows: air velocity 1 m/s, temperature 55°C and tray load 11,2 kg/m2. Under these working conditions, a final humidity of 6% was attained in about three hours of operation. The process design was based on a plant capacity of 4.000 kg/h, using only equipment fabricated in Brazil. The operating schedule covers 180 days a year, and three shifts a day during the production season. The fixed and variable costs worked out can. be considered acceptable. It was observed that raw material cost is the one of largest influence. The electric energy charges are also high and processes modifications should be evaluated so as to decrease them. This plant would process 14.500 ton/year of a raw material that shows seasonal overproduction, generating 270 jobsMestradoMestre em Engenharia de Alimento

Modelagem, simulação e avaliação energetica e exergetica de secadores a leito deslizante

Orientador: Florencia Cecilia MenegalliTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de AlimentosResumo: Neste trabalho simula-se um secador a leito deslizante com as seguintes configurações de escoamento: contra-corrente, concorrente e misto (contra + concorrente) com reciclo de ar. O modelo matemático baseou-se na integração das equações diferenciais de conservação de calor e massa, considerando-se, para cálculo da umidade do sólido, distribuições de tempo de residência verificadas experimentalmente. a sistema de quatro equações diferenciais ordinárias (E.D.O.) obtido é resolvido numericamente pelo algoritmo de Runge-Kutta de 4ª ordem. Verifica-se o ajuste do modelo à secagem de proteína texturizada de soja e assim, a determinação de algumas propriedades do sólido é apresentada. As equações para cálculo da eficiência térmica do processo e avaliação da destruição de exergia são discutidas. A influência de algumas variáveis de processo, como distribuição de tempo de residência, temperatura do gás de secagem, comprimento do leito e relação vazão de gás/vazão de sólido na eficiência do secador, para as configurações de escoamento anteriormente citadas, foi avaliada. A eficiência energética e exegética das diferentes situações permitiu estabelecer quais as condições de operação mais indicadas para esse tipo de secador quando se trabalha com proteína texturizada de sojaAbstract: This work deals with the modelling and simulation of a moving bed dryer with the following flow configurations: counter-current; concurrent and mixed flow (counter + concurrent) with air recirculation. The mathematical modelling was based on the balance equations of mass and energy conservation, considering, for the partic1e moisture calculation, residence time distributions obtained experimentally. The system of four ordinary differential equations was solved numerically by a Runge-Kutta algorithm of the 4th order. Determination of some of the physic~ properties of the material used, texturized soybean protein, are presented. Equations for ca1culating thermal efficiency and thermodynamic availability ("exergy") are discussed. The influence of the following process variables were evaluated for the above-mentioned flow configuration: residence time distribution, air drying temperature, bed length and gas mass flow rate/solid mass flow rate. The energetic and exergetic performance determined for the different situations allowed for the establishment of the most efficient operating conditions for this type of dryer when used for texturized soybean proteinDoutoradoDoutor em Engenharia de Alimento

Hydrophilic food compounds encapsulation by ionic gelation

Among the several methods for encapsulating active compounds, ionic gelation is an interesting technique, because it can be considered as low cost and does not require specialized equipment, high temperature and organic solvents. However, this method is more adequate for encapsulating hydrophobic materials. The current challenge for hydrophilic compounds is to increase encapsulation efficiency and enhance controlled release properties. This review focuses in some ways to encapsulate hydrophilic materials by ionic gelation. Using polymer filler into particle matrix, coating particles to create a barrier external layer, emulsification and internal ionic gelation or applying inverted solidification are some alternatives reported in the literature to contour the drawback of ionic gelation for hydrophilic compounds15505

Influência das condições de processo na cinética de hidrólise enzimática de carne de frango Influence of process conditions on enzymatic hydrolysis kinetics of chicken meat

A influência da temperatura, pH e razão enzima:substrato na cinética de hidrólise enzimática de carne de frango utilizando a protease Alcalase® 2,4 L foi avaliada neste trabalho. Os experimentos foram conduzidos à temperatura de 43 a 77 °C, razão enzima:substrato de 0,8 a 4,2% p/p e pH de 7,16 a 8,84, de acordo com um planejamento experimental completo, totalizando 17 ensaios. A reação foi monitorada, utilizando-se o método pH-stat para obtenção dos graus de hidrólise em função do tempo de processo. As curvas de hidrólise obtidas apresentaram uma alta taxa inicial de reação, seguida da sua diminuição até alcançar uma fase estacionária. Os resultados experimentais da cinética de reação foram ajustados a um modelo empírico, que consiste na variação do grau de hidrólise em função do logaritmo neperiano do tempo. Esse modelo apresentou um bom ajuste, com coeficientes de determinação superior a 0,96 e desvio relativo médio inferior a 10%. Os parâmetros do modelo foram avaliados através de um planejamento experimental, de modo a verificar a influência das variáveis de reação sobre eles. O aumento da razão enzima:substrato e da temperatura acarretou maiores valores do parâmetro a. O parâmetro b não sofreu influência da variável razão enzima:substrato e o seu valor aumentou com o aumento da temperatura. A variável pH afetou significativamente os parâmetros estudados.<br>The hydrolysis of chicken breast meat by commercial protease Alcalase® 2.4 L was studied in order to evaluate the temperature, renzyme:substrate ratio, and pH influence on enzymatic hydrolysis kinetics. The tests were carried out under different conditions with respect to temperature (43-77 °C), enzyme:substrate ratio (0.8-4.2% w/w, g enzyme/100 g protein), and pH (7.16-8.84) according to factorial 2³ experimental design with the total of 17 tests. The reaction was monitored by the pH-stat method to obtain the degree of hydrolysis values at different intervals of time. The hydrolysis curves were characterized by high initial reaction rates followed by decreases in the reaction rate up to the stationary phase. The results were fitted an exponential model that presented a good fit with high determination coefficient and low average relative error. The variables influence on model parameters was observed by experimental design. An increase in the enzyme:substrate ratio and temperature led to higher parameter a values. The parameter b was not affected by the enzyme:substrate ratio and its value increased with higher temperature. The variable pH affected significantly the parameters a and b

Ascorbic acid microencapsulation by spray chilling: production and characterization

This study reports on the use of spray chilling to synthesize solid lipid microparticles containing ascorbic acid and describes the characterization of the resulting microparticles. Lauric acid (LA)/oleic acid (OA) mixtures at 70/30, 80/20, and 90/10 g:g ratios served as carrier. Different carrier/core (core = aqueous ascorbic acid solution 30 g/100 g) ratios, namely 70/30, 75/25, and 80/20 (g:g), were tested. The synthesized microparticles presented high TE values, which varied from 89% to 98%; differences between experiments were not significant (p > 0.05). EE values were inversely proportional to the amount of LA in the carrier; EE ranged from 58% to 88%. The mean volume moment of particle D[4,3] of the microparticles containing LA concentrations of 70 g/100 g of lipid and 90 g/100 g of lipid ranged from 45 to 67 μm and from 18 to 24 μm, respectively. The core release profile revealed that microparticles containing intermediate concentration of LA in the carrier (80 g/100 g of lipid) retained the ascorbic acid core better. The ratio between the fatty acids used as carrier rather than the ratio between the carrier and the core affected the characteristics of the microparticles the most631353360CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP131425/2012-9PROEX – 2952/20112012/50411-

Membrane Fractionation of Protein Hydrolysates from By-Products: Recovery of Valuable Compounds from Spent Yeasts

Spent brewer&rsquo;s yeast (Saccharomyces sp.), the second most generated by-product from the brewing industry, contains bioactive and nutritional compounds with high added value such as proteins (40&ndash;50%), polysaccharides, fibers and vitamins. Molecules of interest from agro-industrial by-products need to be extracted, separated, concentrated, and/or purified so that a minimum purity level is achieved, allowing its application. Enzymatic hydrolysis has been successfully used in the production of peptides and protein hydrolysates. The obtained hydrolysates require efficient downstream processes such as membrane technology, which is an important tool for the recovery of thermolabile and sensitive compounds from complex mixtures, with low energy consumption and high specificity. The integration of membrane techniques that promote the separation through sieving and charge-based mechanisms is of great interest to improve the purity of the recovered fractions. This review is specifically addressed to the application of membrane technologies for the recovery of peptides from yeast protein hydrolysates. Fundamental concepts and practical aspects relative to the ultrafiltration of agro-industrial protein hydrolysates will be described. Challenges and perspectives involving the recovery of peptides from yeast protein hydrolysates will be presented and thoroughly discussed