Adimilson Bosco Chitarra

Efeito da aplicação do cloreto de cálcio nos frutos da manga 'Tommy Atkins' tratados hidrotermicamente

The aim of this work was to study the effects of the application of calcium chloride associated with hydrothermal treatment on post-harvest preservation of mango fruit (Mangifera indica L.). The Ca absorption by mango peel and flesh was investigated using the same conditions usually employed for the fruit exportation to the american market. It was verified that the association of heat treatment to Ca application was viable. There was a positive correlation between the amount of Ca applied and the amount of this element presented in the peel, although low penetration toward the flesh was observed. It was demonstrated that Ca reduces anthracnose symptoms. It was also verified, by observing the external appearance of the fruits, that the best results were obtained when 4% of calcium chloride was used, although such concentration did not guarantee the required quality for the fruit exportation. The calcium chloride application was not effective to increase the shelf-life of the fruits.

Qualidade do abacaxi cv Smooth Cayenne minimamente processado

The aim of this work was to evaluate the quality and shelf life of pineapple minimally processed, stored at 8oC and 85% R.H., influenced by the kind of cutting, sanitization with sodium hipochlorite and packaging. It was analyzed the following parameters: the total titrable acidity, the total soluble solids, pH, the appearance, molds and yeasts, total and fecal coliforms. The conclusions were: a) the kind of cutting had not influenced the chemical and physical-chemical characteristics of fruit during storage; b) low pH associated with sanitization and the use of good manufacturing practices (GMPs) reduced bacterial growth; c) the sanitization with sodium hipochlorite was not effective against moulds and yeasts; d) the product had a shelf life of 6 days according to the conditions offered.

Atividade de enzimas pectinametilesterase e poligalacturonase durante o amadurecimento de tomates do grupo multilocular

ABSTRACT Activity of the enzymes pectinmetylesterase andpolygalacturonase during the ripening of tomatoes of themultilocular group The activity of the enzymes pectinametylesterase (PME) andpolygalacturonase (PG) was measured in tomato fruits of themultilocular group at various maturation stages, to obtain thecorrelation to changes in texture, pectin and lycopene. Fruits wereharvested at the mature-green stage and ripened in a room with 85-90% relative humidity and 20”C–2 room temperature. Throughoutstorage, samples were taken to assess enzymes activity of PME andPG at the maturation stages: mature green, breaker, ripe and red-ripe. The other variables were surveyed only after the red-ripe stageof fruits. Among the evaluated genotypes, three hybrids H3: F 1 (BPX308B hv x Stevens), H8: F 1 (BPX 308B hv x Piedmont) and H1: F 1 (BPX 308B hv x BPX-127H) stood out with best characteristics fornatural consumption when compared to control, showing the leastenzymes activities of PME and PG which led to a decrease indepolymerization and solubilization of pectin, causing an increasedtexture. In addition, larger pulp thickness and smaller numbers oflocules of these hybrids also contributed to the texture increase,improving shelf life and fruit quality. The low activity of the enzymePG did not affect the development of color, an important trait foracceptance of the fruit by consumers. The hybrid H1: F

Quality of fresh-cut crisphead lettuce stored under refrigeration and two packaging systems

Minimal processing usually causes quality loss, reduces shelf-life, and promotes sensory attributes alterations. The occurrence of browning in the midrib of fresh-cut lettuce is commonly observed and is associated with cell tissue disrupture, putting in contact enzymes and their respective substrates. Chemical, physical, and biochemical quality of fresh-cut crisphead lettuce stored under refrigeration and two different packaging systems were evaluated in the present work. Lettuce cv. Veronica was harvested in commercial fields in Brasilia, Brazil, and was minimally processed as whole leaves and 5 mm strips. Fresh-cut lettuce was then packed into polypropylene and low density polyethylene plastic films and was stored at 5oC during 14 days. Every two days processed material was evaluated for titratable acidity, color (L*a*b*) and polyphenoloxidase and peroxidase enzymes activity. Lettuce processed as whole leaves showed higher brightness (L*) when compared to the material sliced at 5 mm, for both the packaging systems studied. Both polyphenoloxidase and peroxidase activities were higher for fresh-cut lettuce sliced at 5 mm when compared to whole leaves. Lettuce processed as 5 mm strips had the highest enzymatic browning, lowest brightness and organic acid content for both the packaging systems studied.

Qualidade de palmito pupunha minimamente processado: aplicação de antioxidantes

Objetivou-se, neste trabalho, a avaliacao de antioxidantes na prevencao do escurecimento e na manutencao da qualidade de palmito pupunha minimamente processado armazenado a 5o C (± 1o C e 90% ± 5% UR). Os palmitos foram adquiridos no municipio de Coqueiral (MG), lavados em agua corrente e detergente neutro, sanificados com hipoclorito de sodio 200 mg L-1 por 15 min, processados em rodelas de 1 cm de espessura, sanificados com hipoclorito de sodio 100 mg L-1 por 10 min e submetidos aos seguintes tratamentos: controle, cisteina 0,5%, acido citrico 0,5% e cisteina 0,5% + acido citrico 0,5%. Posteriormente, foram acondicionados em embalagens rigidas de polipropileno, armazenados por 12 dias a 5o C (± 1o C e 90% ± 5% UR). O delineamento experimental foi inteiramente causalizado em fatorial 4x7 (4 tratamentos e 7 tempos de armazenamento) com 3 repeticoes. O palmito sem tratamento apresentou vida util de oito dias. O tratamento com cisteina 0,5% foi o que melhor manteve a qualidade de palmito pupunha (Bactris gasipaes Kunth) minimamente processado, caracterizando um produto com menores valores e menos oscilacoes de a* e b*, manutencao da firmeza e da acidez titulavel ao longo do armazenamento, reducao da atividade da peroxidase e manutencao da qualidade do produto durante o periodo avaliado.

Transformações bioquímicas de abacaxi minimamente processado armazenado sob atmosfera modificada

Pineapples minimally processed were, stored eight days (5oC and 85% RH) under passive and active atmosphere (MA). Neutral sugars, cellulose, hemicellulose, and total polyuronide analysis in cell wall were done. Two different active MA were tested: 5% of O2 + 5% of CO2 (MA1) and 2% of O2 + 10% of CO2 (MA2) and one passive MA (Control); during eight days of storage. Pineapples minimally processed stored under active modified atmosphere showed degradation of cell wall and less solubilization of hemicelluloses, besides being more effective in control of ethanol production and formation of off flavours. Pineapples minimally processed stored under modified atmosphere, showed life average of 6 days under refrigeration at 5oC.

Alterações sensoriais em alface hidropônica cv. Regina minimamente processada e armazenada sob refrigeração

The maintenance of the sensorial quality of minimally processed fruits and vegetables is becoming a fundamental factor due to the increasing demand for these products. The consumer looks for a fresh product with healthy appearance and good color characteristics, as well as other desirable attributes in its appearance. Some sensorial characteristics were evaluated in minimally processed hydroponic lettuce, cv. Regina conditioned in thermally sealed plastic bags and stored at 2oC and 10oC. For both storage temperatures, there was no significant product modification regarding the analyzed quality aspects like color, freshness, browning, rotten aspect and cooked flavor up to the third day of the experiment. At 2oC the lettuce presented a shelf life of 7 days without compromising its main sensorial characteristics as color, freshness and browning. For the product stored at 10oC the shelf life was up to 3 days.

Modificações dos componentes de parede celular do melão tipo Galia durante a maturação

O presente estudo caracterizou quantitativa e qualitativamente as mudancas nos componentes de parede celular do melao tipo Galia, hibrido Nun 1380, associadas ao processo de maturacao. Os frutos foram avaliados em cinco estadios de maturacao (I-V). O material de parede celular e suas fracoes foram determinados por gravimetria. Determinou-se o conteudo de acucares neutros na fracao hemicelulosica e no residuo celulosico, o teor de acidos uronicos e o grau de esterificacao na fracao de substâncias pecticas, e o teor de calcio total e ligado. A fracao de substâncias pecticas foi submetida a cromatografia de filtracao em gel e os acucares neutros da fracao hemicelulosica foram analisados por cromatografia a gas. O conteudo do material de parede celular (MPC) mostrou pouca variacao durante a maturacao. O conteudo de acidos uronicos da fracao pectica e o conteudo de acucares neutros na fracao hemicelulosica (ramnose, arabinose e glicose) apresentaram tendencia de reducao com o avanco da maturacao do fruto. Praticamente nao houve variacao para o grau de esterificacao (% de esterificacao) da fracao de substâncias pecticas e para o teor de calcio ligado. Houve reducao no teor de celulose durante a maturacao. A cromatografia em gel nao revelou tendencia de despolimerizacao das substâncias pecticas.

Conservação pós-colheita de espigas de milho verde minimamente processado sob diferentes temperaturas

Objetivou-se, neste trabalho, avaliar o efeito de tres temperaturas (5oC, 8oC e 11oC), na qualidade de hibridos de milho verde (Zea maiz L.) com endosperma normal, minimamente processado, durante oito dias de armazenamento, com avaliacoes a cada dois dias. Foram utilizadas espigas de dois hibridos, sendo um comercial da Sementes Agroceres (Ag 1051) e outro do programa de melhoramento da Embrapa Milho e Sorgo (Embrapa HT1). A temperatura de 5oC foi a que melhor preservou a qualidade das espigas dos hibridos de milho verde estudados, por proporcionar perda de massa reduzida e manutencao dos teores de solidos soluveis, frutose e glicose. O hibrido Ag 1051 apresentou menor perda de massa, maiores valores de umidade e maior teor de frutose. O Embrapa HT1 apresentou maiores valores iniciais e finais para os teores de solidos soluveis e maior valor para a coloracao b*. O valor L*, que indica quaoclaro e escuro e produto, tambem diminuiu ao longo do armazenamento, indicando escurecimento das espigas ao longo do armazenamento.

Atividade respiratória e evolução de etileno em alface crespa minimamente processada armazenada sob duas temperaturas

O processamento minimo de hortalicas envolve operacoes que ocasionam diversas alteracoes metabolicas no tecido processado, como elevacao da atividade respiratoria e evolucao de etileno. A respiracao e um processo complexo pelo qual reacoes quimicas oxidam compostos orgânicos a dioxido de carbono e agua para producao de energia. O aumento na evolucao de etileno e, tambem, de extrema importância e pode ser observado em hortalicas submetidas ao processamento minimo. No presente trabalho, estudaram-se efeitos fisiologicos desencadeados pelo processamento minimo de alface (Lactuca sativa L.), visando conhecer a melhor temperatura de armazenamento bem como o estresse causado pelo processamento minimo afeta o produto. Verificou-se que, logo apos o processamento minimo, as taxas respiratorias eram estatisticamente diferentes para os materiais processados a 5 e 10 mm e folha inteira, tanto na temperatura de 5 oC quanto a 10 oC. Verificou-se que o armazenamento a 5 oC reduziu de forma mais rapida o metabolismo respiratorio quando se comparou com o armazenamento a 10 oC. O perfil das curvas de atividade respiratoria e evolucao de etileno da alface processada a 10 mm foi o mesmo para as duas temperaturas estudadas, diferindo apenas nos valores, que foram mais altos, conforme esperado, para a temperatura de 10 oC. No armazenamento a temperatura de 5 oC, pode-se observar a reducao da evolucao de etileno para o material processado a 10 mm, mas nao para o processado a 5 mm, nas duas primeiras horas apos o processamento minimo. A melhor temperatura para o armazenamento da alface minimamente processada foi de 5 oC e o produto processado como folha inteira apresentou menor taxa respiratoria e elevacao de etileno.