Francisco de Assis Cardoso Almeida

Desidratação da polpa de tamarindo pelo método de camada de espuma

The foam-mat drying process was studied for the tamarind pulp at 50, 60, 70 and 80oC and the temperature effect on the tamarind powder were evaluated as regards to ascorbic acid content, total titratable acidity and colour, expressed by luminosity (L*) and hue (ho). For the representation of the drying process three models for thin-layer were applied and the criterion of evaluation used were the coefficient of determination (R2) and root mean square error (DQM). According to the results the temperature is a determinant parameter in the drying process, and the Midilli and Kucuk model was the best one to represent the behavior of the drying curves. The best results for ascorbic acid content, titritable acidity and colour were obtained at the temperatures of 60 and 70 oC.

Thermodynamic properties of water sorption of jackfruit (Artocarpus heterophyllus Lam.) as a function of moisture content

The Jackfruit tree is one of the most significant trees in tropical home gardens and perhaps the most widespread and useful tree in the important genus Artocarpus. The fruit is susceptible to mechanical and biological damage in the mature state, and some people find the aroma of the fruit objectionable, particularly in confined spaces. The dehydration process could be an alternative for the exploitation of this product, and the relationship between moisture content and water activity provides useful information for its processing and storage. The aim of this study was to determine the thermodynamic properties of the water sorption of jackfruit (Artocarpus heterophyllus Lam.) as a function of moisture content. Desorption isotherms of the different parts of the jackfruit (pulp, peduncle, mesocarp, peel, and seed) were determined at four different temperatures (313.15, 323.15, 333.15, and 343.15 K) in a water activity range of 0.02-0.753 using the static gravimetric method. Theoretical and empirical models were used to model the desorption isotherms. An analytical solution of the Clausius-Clapeyron equation was proposed to calculate the isosteric heat of sorption, the differential entropy, and Gibbs free energy using the Guggenhein-Anderson-de Boer and Oswin models considering the effect of temperature on the hygroscopic equilibrium.

Controle do caruncho Callosobruchus maculatus (Fabr., 1775) (Coleóptera: Bruchidae) utilizando extratos de Piper nigrum L. (Piperaceae) pelo método de vapor

Considerando os prejuizos causados pelo inseto-praga Callosobruchus maculatus (Fabr., 1775) ao feijao Vigna unguiculata Walp. armazenado, com o presente trabalho objetivou-se avaliar a eficacia de extratos de Piper nigrum L. na mortalidade de adultos daquela especie. O delineamento estatistico utilizado foi inteiramente ao acaso com quatro repeticoes e arranjo fatorial 3 x 5, constituido por tres concentracoes do extrato e cinco periodos de exposicoes dos extratos (5, 10, 15, 20 e 25 minutos). Utilizaram-se frutos secos triturados de P. nigrum para extracao em percolador com solvente alcool etilico (70, 50 e 30%). Os extratos foram aplicados na forma de vapor, por meio de um compressor adaptado, para dentro de recipiente contendo 100 insetos. Os resultados permitiram concluir que a mortalidade dos insetos aumenta com o aumento do periodo de exposicao aos extratos, e que todas as concentracoes se mostraram eficientes, embora, em termos de valores absolutos, o extrato com 70% de alcool etilico foi o mais eficaz.

Modelos matemáticos para ajuste das isotermas de dessorção da polpa de banana da variedade prata

The present work had for objective to study desorption isotherms of the pulp of banana in the mature and semigreen stadium (Musa acuminata) of the Silver variety, at temperatures of 20; 30 and 40 oC for static gravimetrical method in the band water activity from 0.48 to 0.81. The experimental curves that were fitted for no-linear regression, for models of BET, GAB, Halsey and Oswin, choosen the best, by means of the value of the determination coefficient (R2) and relative average error (E). Models had presented minor relative error (E) and the biggest determination coefficient (R2) that respectively were of Oswin and GAB. The GAB was picked out to be triparametric, which lets a better adjustment of curves up to water activities to 0.9.

Efeito da temperatura sobre a germinação de três espécies de Pinus cultivadas no Brasil

The Pinus species present a high level of resistance to forest fires, being considered as active pyrofit plants. For this reason a question is raised: Did the seed behavior of these species develop exclusively due to fire disturbances or by other causes that have influenced this process?, Still, did these species develop similar adaptable answers? To answer these questions, seeds of three species of Pinus species were exposed to different thermal intensities and time of exposition, in order to simulate responses to the different fire regimes, evaluating the effects of high temperatures on the seeds, as well as the effect of ashes, as the most notable element of the micro-environment in which the plants should grow later. The used plant material was acquired from IPEF (Researches and Forest Studies Institute) - Piracicaba, SP. To evaluate seed responses to the temperatures, an entirely randomized statistical design with factorial arrangement was used. In the absence of thermal treatments, the seeds presented high germination rates and strong reduction in temperatures equal or superior to 70 oC, suggesting that they are not really active pyrofit plants. The germination values obtained with temperature equal to 50 oC differed statistically from the control, and when the temperature values were equal or superior to 110 oC, an important germination reduction occurred in all treatments. The simultaneous evaluation for heat and ashes showed the existence of an interaction between the factors, with total inhibition of germination in some treatments.

Mechanical behavior of pumpkin fruits subjected to compression during maturation

During handling operations, many problems that reduce the quality of vegetables may occur. Mechanical injuries are the leading cause of postharvest losses for the pumpkin, and can take place at any point of the production chain. This study aimed at evaluating the pumpkin fruits behavior, during their ripening stages, on the values ??of maximum compression force for fixed deformations, and determining the proportional deformability modulus of the fruits under compression at the repose position . Fruits were harvested at 15, 30 , 40 , 50 and 60 days after flowering and uniaxially compressed between two parallel plates . The results allowed to conclude that both the required compression force and the proportional deformability modulus increased during the maturation course, reaching a maximum force of 1,778 N and a maximum deformation modulus of 164 MPa, after 30 days. After this period, both the maximum force and the modulus values ??decreased, reaching 1,514.8 N of maximum force and a modulus of 132.09 MPa, after 60 days of ripening . Over the course of a longer maturation time, the fruit firmness increased, therefore requiring an increase in the maximum load to achieve greater deformation. The ideal period for harvest and transport of ‘Jacarezinho’ pumpkin fruits was set from 30 to 40 days after anthesis.

Viabilidade de sementes de feijão macassar tratadas com extrato vegetal e acondicionadas em dois tipos de embalagens

The objective of this work was to study the loss of seed viability of two varieties of Vigna unguiculata , conditioned in paper and metallic packaging, and stored without temperature and relative air humidity control. After seed harvest, in fields prepared for this purpose, the seeds were manually processed, treated, conditioned and stored; every two months, their physiological quality was evaluated using a germination test. The data analysis was carried out using an entirely randomized design, in a 2 x 2 x 2 x 6 factorial scheme with four repetitions; the quantitative factors were disclosed by the regression in the analysis of variance. Based on the results, the viability of the Vigna unguiculata bean seeds was affected by the treatments and storage condition: after 360 days, the germination rate decreased from 99.37 to 41.68%; the ‘Emepa’ variety was higher than the ‘Corujinha’ by 63.47%, and the Piper nigrum extract proved efficient in the viability maintenance of these seeds.

Physiological Seed Quality of Melon as Affected by Fruit Ripeness

ABSTRACT In order to obtain melon (Cucumis melo L.) seed of high physiological quality, the ideal harvesting time needs to be considered, which could be determined by fruit ripening stage. Seed viability of melon, cv. ‘Rock Cantaloup’, was evaluated based on ripening stage. A completely randomized experiment with fruit harvested at ripening stages based on color appearance and presence, or not, of epidermal reticulation, were classified as follows: I, green fruit with nonreticulated epidermis; II, green fruit with reticulated epidermis; III, yellow fruit and reticulated epidermis, and IV, 10 days after yellow fruit and reticulated epidermis. Seed were taken from fruit and evaluated based on moisture percentage, weight of 1000 seed, percentage germination and number of seed that germinated first, seedling formation, seedling growth rate, seedling length, fresh weight, dry weight, and aging speed. Physiological quality of melon seed increased as ripening advanced. Seed obtained from yellow fruit with reticulated epidermis at stage IV were best in all criteria. The best melon seed for germination and quality standards are from well-ripened fruit. However, seed from less mature fruit are still viable for use in melon cultivation.

COMPORTAMENTO DA ACIDEZ EM MANGA IN NATURA ARMAZENADA EM ATMOSFERA CONTROLADA

O objetivo do estudo foi verificar o comportamento da acidez em mangas ( Mangifera indica L.), da variedade Haden, armazenadas nas atmosferas modificadas: sem embalagem (SE), plastico perfurado (PP) e filme plastico (FP) nas temperaturas de 5 e 10 °C e temperatura ambiente (±26 °C) de Campina Grande, PB. Cinquenta e quatro mangas foram selecionadas aleatoriamente (de acordo com a coloracao da casca) para composicao dos tratamentos e acondicionados em bandejas de tereftalato, e descritos como segue: nao revestidos com filme plastico (SE); revestidos externamente com filme plastico nao perfurado (FP) e revestidos externamente com plastico perfurado (PP). Em seguida as mangas foram armazenadas em condicoes ambientais de Campina Grande, PB (±26 °C) e em câmaras frias nas temperaturas de 5 e 10 °C. No decorrer do armazenamento efetuaram-se analises de acidez em periodos de 7 dias, de acordo com a metodologia descrita por Cecchi (2003). As mangas acondicionadas em embalagem de filme plastico (FP) a 5 oC conservaram o maior teor de acidez. Os teores de acidez sofreram variacoes, sendo revelado o maior teor no 1o dia de armazenagem a temperatura de 5 °C, enquanto o menor teor foi verificado a temperatura ambiente de ±26 °C a partir do 28° dia de acondicionamento. Os resultados obtidos indicam a temperatura e a atmosfera interferem no teor de acidez.