The study on dehydration of frozen saskatoon berries and the need for dried fruits has been strategically identified in the prairies. Our motivation was to find a suitable method for dehydration in order to extend saskatoon berry shelf life for preservation. Microwave, convection and microwave-convection combination drying processes were identified to finish-dry saskatoon berries after osmotic dehydration using sucrose and high fructose corn syrup (HFCS) sugar solutions. Osmotic dehydration removes moisture in small quantities and also introduces solutes into the fruit that acts as a preservative and also reduces the total drying time. <p>Due to the very short harvesting season of saskatoon berries, an accelerated process like microwave combination drying can bring down the moisture to safe storage level, immediately after harvest. Untreated and osmotically dehydrated berries were subjected to convection (control), microwave and microwave-convection combination drying conditions at different product drying temperatures (60, 70 and 80C) until final moisture content was 25% dry basis. A laboratory-scale microwave combination dryer was developed, built with temperature and moisture loss data acquisition systems using LabView 6i software. Thin-layer cross flow dryer was used for convection-only drying and for comparison. <p>Drying kinetics of the drying processes were studied and curve fitting with five empirical equations including Page equation, was carried to determine drying constant, R2 and standard error values. The microwave-combination drying method proved to be the best for drying saskatoon berries. Dehydrated product quality analysis by means of color changes, rehydration ratio measurements and observed structural changes with scanning electron microscope technique were the factors in drying method selection for saskatoon berries.<p> This research was instrumental in the modification and development of a novel drying system for high-moisture agricultural materials. Microwave-convection combination drying at 70oC, yields good results with higher drying rates and better end-product quality.

The study on dehydration of frozen saskatoon berries and the need for dried fruits has been strategically identified in the prairies. Our motivation was to find a suitable method for dehydration in order to extend saskatoon berry shelf life for preservation. Microwave, convection and microwave-convection combination drying processes were identified to finish-dry saskatoon berries after osmotic dehydration using sucrose and high fructose corn syrup (HFCS) sugar solutions. Osmotic dehydration removes moisture in small quantities and also introduces solutes into the fruit that acts as a preservative and also reduces the total drying time. <p>Due to the very short harvesting season of saskatoon berries, an accelerated process like microwave combination drying can bring down the moisture to safe storage level, immediately after harvest. Untreated and osmotically dehydrated berries were subjected to convection (control), microwave and microwave-convection combination drying conditions at different product drying temperatures (60, 70 and 80C) until final moisture content was 25% dry basis. A laboratory-scale microwave combination dryer was developed, built with temperature and moisture loss data acquisition systems using LabView 6i software. Thin-layer cross flow dryer was used for convection-only drying and for comparison. <p>Drying kinetics of the drying processes were studied and curve fitting with five empirical equations including Page equation, was carried to determine drying constant, R2 and standard error values. The microwave-combination drying method proved to be the best for drying saskatoon berries. Dehydrated product quality analysis by means of color changes, rehydration ratio measurements and observed structural changes with scanning electron microscope technique were the factors in drying method selection for saskatoon berries.<p> This research was instrumental in the modification and development of a novel drying system for high-moisture agricultural materials. Microwave-convection combination drying at 70oC, yields good results with higher drying rates and better end-product quality.

Submitted by Samira Ramos (samira.ramos@unifenas.br) on 2018-04-23T21:22:43Z No. of bitstreams: 1 João Paulo Marques.pdf: 1012005 bytes, checksum: 71d82a764900814bb8c03c30f77accce (MD5) / Made available in DSpace on 2018-04-23T21:22:43Z (GMT). No. of bitstreams: 1 João Paulo Marques.pdf: 1012005 bytes, checksum: 71d82a764900814bb8c03c30f77accce (MD5) Previous issue date: 2017-08-11 / Brazilian coffee growers are becoming more and more concerned about the production of high quality coffees, with the purpose of producing special coffees, adding value to the final product. The production of special coffees gains force in the world market pleasing the palate of different consumers. Coffee beans have their intrinsic attributes modified by local characteristics such as altitude, temperature, lightness, rainfall index and relative humidity where the crop is located. Together with the climatic conditions of the place, the method of processing the grains by dry (producing natural coffee), wet (peeled coffees), moist with fermentation (pulped coffee) and wet desmucilador demultipled), confers changes in the quality of the grains produced. The objective of this study was to evaluate the relationship between post-harvest processing and the chemical and sensorial attributes of coffee from three locations in Minas Gerais. The coffees of the different regions presented their own characteristics, which are conferred according to the type of processing to which the grains are submitted in the post-harvest period. The samples of peeled coffees from the three regions studied presented higher scores for the sensorial attributes, compared to samples of natural coffees. The chemical analysis of coffee supports, however does not replace the sensorial analysis aiming at the classification of coffee beverage quality. / Os cafeicultores brasileiros vêm a cada dia mais se preocupando com a produção de cafés com qualidade superior, tendo como propósito a produção de cafés especiais, agregando valor ao produto final. A produção de cafés especiais ganha força no mercado mundial agradando o paladar de diferentes consumidores. Os grãos de café têm os seus atributos intrínsecos modificados pelas características locais como altitude, temperatura, luminosidade, índice pluviométrico e umidade relativa de onde a lavoura se encontra instalada. Juntamente com as condições climáticas do local, o método de processamento dos grãos realizado por via seca (produzindo o café natural), por via úmida (cafés descascados), por via úmida com fermentação (café despolpado) e por via úmida com desmucilador (cafés desmucilados), confere variações na qualidade dos grãos produzidos. Objetivou-se com o presente estudo avaliar a relação entre o processamento de pós-colheita e os atributos químicos e sensoriais de cafés de três locais de Minas Gerais. Os cafés das diferentes regiões apresentaram características próprias, que são conferidas de acordo com o tipo de processamento a que os grãos são submetidos no período de pós-colheita. As amostras de cafés descascados das três regiões estudadas, apresentaram maiores notas para os atributos sensoriais, em relação às amostras de cafés naturais. A análise química do café apoia, entretanto não substitui a análise sensorial visando a classificação da qualidade de bebida do café.

Objetivou-se com este estudo avaliar a potencialidade dos revestimentos comestíveis à base de Fécula de mandioca e pectina com e sem adição de óleo de buriti para aplicação em melancia e melão minimamente processados, visando a extensão da vida de prateleira destes produtos. A qualidade do óleo de buriti adicionado aos revestimentos comestíveis foi comprovada através do parâmetros físico-químicos; densidade: 1021 kgm-3; índice de acidez: 1,59 % em ácido oleico; índice de peróxido: 6,20 meqKg-1 e viscosidade cinemática: 41,3 mm²s-1. A caracterização dos principais ácidos graxos presentes no óleo de buriti foi realizada por métodos espectroscópicos de Ressonância Magnética Nuclear de Prótons (1H-RMN) e Espectroscopia de Infravermelho com Transformada de Fourier (FTIR). O ácido oleico (78%) foi o componente majoritário na composição do óleo de buriti. Os revestimentos comestíveis foram elaborados com 3% de fécula de mandioca ou 3% de pectina, 1% de glicerol ou 1% óleo de buriti, 2,5% de gelatina, 0,5% de ácido cítrico e 0,5% ácido ascórbico, os frutos minimamente processados foram revestidos utilizando a técnica de imersão. Os frutos revestidos foram analisados em relação ao pH, sólidos solúveis totais, acidez titulável e contagem microbiana ao longo de 10 dias de armazenamento. Os pH dos frutos revestidos variaram entre 5,35-5,76 para o melão e (4,52-5,49) para a melancia ao longo do tempo de armazenamento. Os teores de sólidos solúveis totais da melancia (7,6-9,6 °Brix) e do melão (7,2-8,6 °Brix) minimamente processados se mantiveram constantes para todos os revestimentos testados. A acidez titulável da melancia e do melão variou de 0,11 à 0,20 % e de 0,06 a 0,14 % em ácido cítrico, respectivamente. Os revestimentos comestíveis apresentaram eficiente barreira para permeabilidade de vapor, sendo que película à base de fécula proporcionou menor média de perda de massa da melancia (2,32%) e o revestimento fécula/óleo para o melão (3,39%). A população microbiana aeróbica e mesófila foi crescente ao longo do período de armazenamento em todos os revestimentos e no controle em ambos os frutos. Ao final dos 10 dias de armazenamento, a melancia apresentou crescimento de bactérias cerca de 9,0 log UFCmL-1, sendo o mesmo valor na população de bolores e leveduras. Os revestimentos fécula e pectina/óleo proporcionaram menor população de bactérias, aproximadamente 7,8 log UFCmL-1. O melão apresentou maiores valores de população de bactérias em comparação com a melancia no revestimento fécula e controle; 10,1 e 9,7 log UFCmL-1, v respectivamente. A contagem de bolores e leveduras também foi maior nos revestimentos fécula e fécula/óleo, aproximadamente 9,0 log UFCmL-1. Conclui-se que o óleo de buriti neste trabalho não apresentou atividade antimicrobiana nos revestimentos comestíveis presentes nos frutos. Os revestimentos comestíveis fécula e pectina proporcionaram à melancia condições adequadas para o consumo até o oitavo dia após o processamento. Entretanto no melão, apenas o revestimento pectina e pectina/óleo garantiram estabilidade microbiológica ao consumo até o quarto dia de armazenamento. / The objective of this study was to evaluate the potential of cassava starch and pectin-based edible coatings with and without addition of buriti oil for application in minimally processed watermelon and melon, aiming to extend the shelf life of these products. The quality of the buriti oil added to the edible coatings was confirmed by physicochemical parameters; Density: 1021 kgm-3; Acidity index in oleic acid: 1.59%; Peroxide index: 6.20 meqKg-1 and kinematic viscosity: 41.3 mm²s-1. The characterization of the main fatty acids present in the buriti oil was performed by spectroscopic methods of Proton Nuclear Magnetic Resonance (1H-NMR) and Fourier Transform Infrared Spectroscopy (FTIR). Oleic acid (78%) had the major percent composition in the buriti oil. The edible coatings were prepared with the concentration of 3% cassava starch or 3% pectin, 1% glycerol or 1% buriti oil, 2.5% gelatin, 0.5% citric acid and 0.5% ascorbic acid, the minimally processed fruits were coated using the immersion technique. The coated fruits were analyzed for pH, total soluble solids, titratable acidity and microbial counts over 10 days of storage. The pH of the coated fruits varied between 5.35 and 5.76 for melon and 4.52 and 5.49 for watermelon over the storage time, respectively. The total soluble solids contents of minimally processed watermelon (7.6-9.6 ° Brix) and melon (7.2-8.63 ° Brix) remained constant for all evaluated coatings. The titratable acidity of watermelon and melon ranged from 0.11 to 0.20% and from 0.06 to 0.14% in citric acid. The edible coatings presented an efficient barrier for vapor permeability, being the starch-based film provided a lower average loss of watermelon mass (2.32%) and starch/oil coating for melon (3.39%). The aerobic and mesophilic microbial population was increasing over the storage period in all coatings and control in both fruits. At the end of the 10 days of storage, the watermelon had a bacterial growth of about 9 log UFCmL-1, the same value for mold and yeast population. The starch and pectin/oil coatings provided a lower bacterial population of approximately 7.8 log UFCmL-1. The melon presented higher values of bacterial population in comparison with the watermelon in the starch and control coating; 10.15 and 9.7 log UFCmL-1, respectively. The mold and yeast counts were also higher in the starch and oil coatings, approximately 9 log UFCmL-1. It is concluded that the buriti oil in this work didn’t present antimicrobial activity in the edible coatings present in the fruits. The edible coatings starch and pectin provided the watermelon suitable conditions for consumption until the eighth day after processing. However, for the melon, only pectin and pectin/oil coating ensured microbiological stability for consumption up to the fourth day of storage.

Gulf oysters are harvested and consumed year-round, with more than 90% consumed in a raw, unprocessed state. A chief concern of policymakers in recent years is the incidence of Vibrio vulnificus infection following raw seafood consumption. V.vulnificus refers to a halophilic bacterium naturally occurring in brackish coastal waters, which concentrates in filter-feeding oysters. Proposed FDA legislation requiring processing of all raw Gulf oysters sold during warmer summer months threatens the Gulf oyster industry, as little to no research regarding demand for post-harvest processing (PHP) has preceded the potential mandate. This research endeavors to examine the relationship between oyster consumers' fears of V.vulnificus infection and their willingness-to-pay (WTP) for processing of an oyster meal. The psychological model of Protection Motivation Theory (PMT) is employed alongside the economic framework of contingent valuation (CV) to result in an analysis of oyster processing demand with respect to threats and efficacy. A survey administered to 2,172 oyster consumers in six oyster producing states elicits projected consumption and PMT data. Principal Component Analysis is used to reduce the number of PMT variables to a smaller size, resulting in five individual principal components representing the PMT elements of source information, threat appraisal, coping appraisal, maladaptive coping, and protection motivation. Using survey data, the marginal willingness-to-pay (MWTP) for PHP per oyster meal is also calculated, and the five created PMT variables are regressed on this calculation using four separate OLS models. Results indicate significant correlation for four of the five created PMT variables. In addition, a mean MWTP for PHP of $0.31 per oyster meal is determined, contributing to the demand analysis for processing of Gulf oysters. The findings suggest a strong relationship between the fear elements and the demand for processing, and support arguments in favor of further research on specific PHP treatments and the necessity for a valid PMT survey instrument.

Le cacao et le café sont les produits agricoles les plus échangés dans le monde. Ils subissent de nombreuses transformations post-récolte au niveau des pays producteurs (tropicaux) avant d'être exportés. Les procédés de traitements post-récolte diffèrent d'un pays à l'autre voire d'un agriculteur à l'autre. La transformation technologique du cacao en fèves marchandes et des grains de café en café vert nécessite un processus primaire de manutention. Ces pratiques participent et influencent, en général, la qualité marchande et organoleptique des produits destinés à la transformation. Notre hypothèse de travail est que les différents procédés de transformation post-récolte appliqués sur le café et le cacao ont une influence sur la structure des communautés microbiennes. L'objectif principal était de pouvoir mesurer cet effet en réalisant l'analyse globale des communautés microbienne en utilisant un outil de biologie moléculaire, la PCR-DGGE (Amplification par PCR couplée à l'électrophorèse sur gel en gradient dénaturant). Cette technique a été associée au séquençage afin d'identifier les espèces microbiennes majoritaires. Cette étude a montré que les communautés microbiennes associées aux grains de café et aux fèves de cacao varient au cours des différentes étapes pour chaque type de traitement post-récolte appliqué.Notre approche a permis de discriminer les voies de traitements, et l'origine géographique du café Camerounais et Indonésien. Notamment, nous avons montré que l'origine géographique et l'espèce de café utilisée ont un impact sur l'écologie microbienne du café moins important par rapport à celui du procédé. L'application au cacao nous a permis de relier l'analyse globale de l'écologie microbienne (DGGE) à l'analyse des composés volatils (SPME-GC-MS) afin de discriminer les différents traitements post-récolte. Des micro-fermentations ont été réalisées avec des souches microbiennes isolées du cacao (L. fermentum, A. pasteurianus, P. kudriavzevii et P. mashurica) dans le but d‘identifier l'origine des composés volatils détectés sur le cacao fermenté. Notre étude a contribué à montrer que la fermentation combinée à une courte durée de stockage avant fermentation est le procédé qui permet d'obtenir des fèves contenant plus de composés aromatiques désirables sur le cacao. Une analyse statistique a permis de combiner les résultats des deux types d'analyses (écologie microbienne et composés aromatiques) et de créer des relations entre les espèces détectées et les composés volatils présents. Les profils aromatiques identifiés ont permis d'envisager l'utilisation des souches testées comme starters de culture pour la fermentation du cacao. / Cocoa and coffee are the most traded agricultural commodities in the world. They undergo many post-harvest transformations in producing countries (tropical) before being exported. Post-harvest processes differ from one country to another and from one production site to another. The technological transformation of cocoa on commercial beans and of coffee to green coffee requires a primary process handling. These practices play a crucial role in global and organoleptic quality of the products that will be processed. Our work hypothesis isthat different post-harvest processing applied to coffee and cocoa have an influence on the structure of microbial communities. The main objective was to measure this effect by performing a global analysis of microbial ecology using a molecular biology tool (PCR-DGGE, PCR amplification coupled to denaturing gradient gel electrophoresis). This technique allows variations in microbial communities to be detected and the main microbial species to be identified by sequencing.Our approach permitted to discriminate treatments, and the geographical origin of Cameroonian and Indonesian coffees. Notably, we showed that geographical origin and coffee species have a minor impact on the structure of the microbial communities when compared to the type of process used (wet or dry).By applying the approach to cocoa, we could link the global analysis of microbial ecology (PCR-DGGE) to the analysis of volatile compounds (SPME-GC-MS) to discriminate the different post-harvest treatments. Micro-fermentation were carried out with strains isolated from cocoa (L. fermentum, A. pasteurianus, P. kudriavzevii and P. mashurica) in order to identify the origin of the volatile compounds detected in the fermented cocoa. This study contributed to to show that fermentation combined with a short storage duration before fermentation is the best method to obtain cocoa beans with more desirable aromatic compounds. The statistical analysis was used to combine the results of the two types of analyzes (microbial ecology and aromatic compounds) and get relations between the detected microbial species and volatile compounds. The identified aromatic profiles prompted us to consider the use of the tested microbial strains as starter culture for cocoa fermentation.