Ana Maria de Magalhães

Superfícies protetoras na diminuição de danos mecânicos em tomate de mesa

Quality losses of fresh market fruit are often related to mechanical damages that occur from harvest thru final consumer. Those damages normally occur when fruits drop from high heights or collide against not protected surfaces or against other fruits. The main goal of this work was to evaluate in laboratory for impact magnitude and tomato quality different surfaces in three drop heights. For measuring impact magnitude it was used the instrumented sphere and for tomato quality the evaluation was based on internal bruising. Fruit drop tests were done using three protective surfaces that showed different levels of maximum acceleration combined with three different heights. It was concluded that the use of determined protective surfaces rubber plate, under low drop high can decrease internal bruising incidence and impact magnitude on packing lines.

Qualidade dos frutos de tomate de mesa quando submetidos a impacto por ocasião do beneficiamento

ABSTRACT Fresh market tomatoes quality when submitted to impact The cultivation of fresh market tomatoes has been modernizedwith the introduction of packing lines for cleaning, sorting andclassifying. Despite of those technological changes, post harvest lossesare still high, mainly due to the incidence of the mechanical damagesthat occurr in the transfer points and during packing. The main goal ofthis research was to evaluate tomato quality of cv. Debora, subject todropping after being subjected to the cleaning step on a prototypedeveloped in laboratory to simulate a commercial system, relatingquality changes to impact magnitude (G, m/s2). Therefore, fruits weresubject to a 100 rpm rotation and submitted to a fall from three differentheights (10, 20 e 30 cm) and three different surfaces (foam, plasticbox and metallic sheet). The impact magnitude (G, m/s2) was measuredusing an instrumented sphere, 70 mm Techmark, Inc., Lansing, EUA).Fruit quality after impact was evaluated by weight loss (%), internalbruising, and chemical analyses. The use of an instrumented sphereshowed that a foam surface decreases maximum acceleration (G, m/s2) by about 70% for 10 and 20 cm high drops and 47% for 30 cmdrop, compared to a metallic surface. Tomatoes submitted to dropsfrom 30 cm high over metal surface showed increase on 31% oninternal bruising when compared to fruits submitted to drops at thesame height on the covered surface (foam). The highest weight loss(3,46%) was found in fruits submitted to a drop from 30 cm on plasticboxes. No statistical differences were observed between the differenttreatments. Based on the results, it could be concluded that the use ofprotective surfaces significantly decrease internal bruising and weightloss and tomatoes submitted to drops in plastic boxes showed asignificant increase in physical damage, therefore, changes have to bemade at the packaging stage.

Eficácia de limpeza durante o beneficiamento do tomate de mesa

A etapa de limpeza em uma linha de beneficiamento para tomate de mesa e importante, pois e responsavel pela retirada de impurezas externas dos frutos, sem danificalos. O objetivo deste trabalho foi avaliar a eficacia da limpeza e a qualidade dos frutos apos serem submetidos a esse processo, alterando o tipo de cerdas e as rotacoes das escovas utilizadas, tendo como modelo referencial o tomate de mesa Debora. Os ensaios foram realizados em laboratorio, na etapa de limpeza do prototipo UNIMAC1. Primeiramente, identificou-se entre as metodologias, analise com colorimetro e turbidimetro, a mais adequada para avaliar a eficacia de limpeza. Para isto utilizou-se esferas de borracha, de peso similar ao tomate, que foram sujas artificialmente e passaram pela limpeza no prototipo com cerdas de nylon e rotacao de 100 rpm. Em uma segunda etapa, avaliou-se a eficacia de limpeza, utilizando as esferas de borracha, variando-se o tipo de cerda (nylon, sisal, Tereftalato de polietileno - PET e fibra de coco) e a rotacao (40, 80, 120 e 160 rpm) das escovas. E por fim, realizou-se o estudo com o tomate de mesa, analisando a eficacia da limpeza e a qualidade dos frutos (perda de massa, atividade respiratoria, concentracao de etileno e aparencia externa). Observou-se que a analise com o turbidimetro foi a mais precisa na avaliacao da eficacia de limpeza. No ensaio com as esferas, o uso de cerdas mais flexiveis, nylon e sisal, que apresentam um indice de flexibilidade (Gc) de 68,34 e 70,27 N.m-1, respectivamente, combinadas a altas rotacoes tornaram o processo de limpeza mais eficaz. A cerda PET, que e mais rigida, Gc de 135,94 N.m-1, e a rotacao de 40 rpm foram ineficientes, apresentando um indice de limpeza inferior a 50%. Para os frutos de tomate, o tratamento cerdas de nylon a 120 rpm foi o mais eficaz no processo de limpeza, com um indice de limpeza de 91%, ja na rotacao de 160 rpm o indice foi inferior (88%), uma vez que devido a alta velocidade das escovas os frutos pulavam e assim nao eram envoltos pelas cerdas. Os menores indices de limpeza, 75,4 e 78,8% foram obtidos nos tratamentos com fibra de coco a 80 e a 120 rpm, respectivamente. De um modo geral, os frutos limpos apresentaram alta perda de massa, alta atividade respiratoria e um maior incremento na concentracao de etileno apos o processo de limpeza. A limpeza dos frutos nao foi perceptivel na analise sensorial, todavia os tomates que passaram pela limpeza foram os mais aceitos no teste de intencao de compra. Assim concluiuse que a cerda de nylon, por ser mais flexivel, quando combinada a rotacao de 120 rpm, envolveu melhor os frutos, tornando a limpeza mais eficaz. Contudo, tal processo aumentou a perda de massa e a atividade respiratoria logo apos o tratamento. Por outro lado quando combinada a rotacao de 160 rpm, apesar do processo ser mais ineficiente com relacao a limpeza, ocorreu menores alteracoes de qualidade nos frutos. Abstract

Otimização da eficiência de limpeza em equipamento de beneficiamento de tomate de mesa

The post-harvesting cleaning process in fresh market tomatoes production is essential to the consumer acceptance, since the degree of dirtiness of the fruits is directly related to its quality. However, the washing stage of the cleaning process of commercial packinghouse demands an excessive water volume, bringing serious environmental concerns. The objective of this work was to compare the cleaning efficiency in two cleaning systems through the evaluation of different operational conditions of the cleaning process, related with the brush rotation, water flow and fruit standing time under the system. It was compared the conventional system utilized in commercial equipment with a system using commercial sprays. The results showed that the cleaning efficiency was not directly related to the water volume used, but to the water pressure, standing time and brushes rotation. Therefore, the use of commercial sprays can bring benefits to the cleaning efficiency, increasing it up to 13%, and to the environmental, decreasing water consumption.

Caracterização de dois equipamentos de beneficiamento e classificação de tomates para mesa

No Brasil, nos ultimos anos, tem aumentado o beneficiamento e a classificacao de frutas e hortalicas em equipamentos. O objetivo deste trabalho foi caracterizar a etapa de limpeza de dois equipamentos de beneficiamento de tomate de mesa, um nacional e outro importado, instalados na regiao metropolitana de Campinas - SP. A caracterizacao foi realizada quanto ao numero, tipo e velocidade de rotacao das escovas, aplicacao de agua, tempo de permanencia dos frutos e eficiencia de limpeza. O tempo de permanencia foi mensurado com relacao ao tamanho dos frutos, segundo os padroes da CEAGESP. Para mensurar a eficiencia, foi desenvolvido um equipamento composto de um anel deslizante envolvido por um pano branco. As amostragens foram realizadas antes e apos a etapa de limpeza e avaliadas utilizando colorimetro HUNTER Lab. Por meio dos resultados, observaram-se diferencas entre os dois equipamentos, em que o importado apresentou menor numero de escovas, rotacoes mais baixas e maior consumo de agua que o nacional. No equipamento nacional, o tempo de permanencia dependeu do tamanho dos frutos, nao sendo encontrada essa correlacao no equipamento importado, e ambos tiveram a mesma eficiencia de limpeza. Conclui-se que a limpeza esta relacionada a interacao entre os parâmetros estudados, sendo tambem necessario realizar manutencoes nos equipamentos das unidades para a melhoria no funcionamento.

Influência do auxílio mecânico na colheita de tomates

Fresh tomato harvest is traditionally made without harvesting aids. The main goal of this research was to evaluate performance parameters of fresh tomato harvesting aid equipment and compare it to traditional harvest, in the state of Sao Paulo. Therefore, an equipment was developed and the harvest process was evaluated in four different ways: traditional system (harvest system used in Santa Luzia farm, Brotas, SP, Brazil), picker walking with a harvesting aid equipment, picker seated in a harvesting aid equipment and a composition of both systems: two pickers seated and one picker walking in two different velocities ranges. The different systems using harvesting aid showed an average yield by picker more efficient than reference. Harvest system using three pickers showed an increase of 290% on yield average by picker, on the range of 0.5-1.0 fruit per plant, followed by the systems with a walking picker, that increased productivity in 41%, and picker seated harvester, that showed an increase of 35%. These results demonstrate the importance of using a harvesting aid equipment.

Comparison between two methods used for evaluating cleaning effectiveness during fresh market tomato processing.

The cleaning step of a packing line for fresh tomatoes is very important, because it removes surface residues of fruits; however, there are few methods used for evaluating the effectiveness of the cleaning process. The main goal of this work was to evaluate two new methodologies for evaluating the effectiveness of the cleaning process. The methodologies applied were the ones that used colorimeter and turbidimeter. The assays were carried out at the laboratory, in a cleaning step on a prototype developed and named UNIMAC (Harvesting aid equipment for tomatoes). Rubber spheres, with similar tomato weight, were artificially dirtied and submitted to the cleaning step on the prototype, with brushes of nylon bristles and rotation of 100 rpm. The results observed from the colorimeter method showed low accuracy and some limitations. This methodology did not give a representation of the dirt that remained on the spheres and, consequently, the process effectiveness. The turbidimeter method most precisely evaluated the spheres cleaning process, being this method the most effective.