Search

The spatial variability of soils under a same management system is differentiated, as expressed in the properties. The spatial variability of aggregate stability of a eutrophic Red Latosol (ERL) and a dystrophic Red Latosol (DRL) under sugarcane was characterized. Samples were collected in a regular 10 m grid, in the layers 0.0-0.2 and 0.2-0.4 m, with 100 points per area, and the following properties were determined: geometric mean diameter (GMD) of aggregates, mean weight diameter (MWD) of aggregates, percent of aggregates in the > 2.0 mm class and organic matter (OM) content. The eutrophic Red Latosol (ERL) had a higher aggregate stability thn the dystrophic Red Latosol (DRL), which may be attributed to the higher clay and OM content and the gibbsitic mineralogy of this soil class. The differentiated evolution of the studied Oxisols explains the wider range and lower variation coefficient and variability, for all properties studied in the eutrophic Red Latosol.Solos submetidos ao mesmo sistema de manejo manifestam variabilidade espacial diferenciada de seus atributos. A variabilidade espacial da estabilidade de agregados foi caracterizada em um Latossolo Vermelho distrófico e Latossolo Vermelho eutroférrico, sob cultivo de cana-de-açúcar. Foram realizadas amostragens de terra nos pontos de interseção de uma malha de 10 x 10 linhas, espaçadas de 10 m, totalizando 100 pontos de amostragem por área, coletadas nas camadas de 0,0-0,2 e 0,2-0,4 m de profundidade, para determinação de diâmetro médio geométrico (DMG), diâmetro médio ponderado (DMP), agregados na classe >2,0 mm e teor de matéria orgânica do solo. O Latossolo Vermelho eutroférrico apresenta maior estabilidade de agregados quando comparado com o Latossolo Vermelho distrófico, condizente com o maior teor de argila, matéria orgânica e mineralogia gibbsítica. A evolução diferenciada dos Latossolos estudados explica os maiores alcances, o menor coeficiente de variação (CV) e a menor variabilidade, observados no Latossolo Vermelho eutroférrico para todos os atributos estudados.

This study evaluates the effect of a low-cost biodegradable coating formulated with potato starch, rice starch, cassava starch, and gelatin on the postharvest quality of ‘Tommy Atkins’ mango. The experimental design was completely randomized, arranged in a 7x6 factorial scheme with four replications per treatment. The data were subjected to analysis of variance using the Tukey test at 5% probability. After coating, the fruits were stored under ambient conditions (25 ± 3 ºC and 65 ± 5% RH) for 10 days, with analysis every two days. The variables analyzed were: fruit firmness, weight loss, total soluble solids, total titratable acidity, total soluble solids/titratable acidity ratio, delta absorbance (DA) index, colorimetric analysis of the peel and pulp, and ascorbic acid content. The application of biodegradable coatings did not extend the shelf life of ‘Tommy Atkins’ mango during storage.

This research evaluates the effect of osmotic dehydration (OD) as a pretreatment of convective drying in mango pieces (Tommy Atkins) using whole cane sugar solutions in concentrations between 30 and 65 °Brix, and temperatures between 50 and 80 °C in a central composite rotatable design. The effect on effective diffusivity, water loss, sugar gain, color index (CIE-L*a*b*), water activity, sensory perception (color, texture and flavor), and consumption probability were measured. Effective diffusivity was influenced only by temperature of solution, presenting a maximum of 1.4E-4 cm2s-1. Water loss in OD registered a maximum of 40%. Color perception was affected by both variables. The consumption probability was influenced by the conditions evaluated with a maximum value of 80%. It was found the optimal conditions of OD in 65°Brix and 79 °C.

The importance of the selection and classification processes in the industry of agricultural products and the increase in the production of fruits make necessary the development and implementation of new techniques to efficiently perform these tasks. Techniques such as NIR spectroscopy have proved to have potential to accomplish this purpose. The aim of this research was to evaluate the performance of near infrared spectroscopy as a classification tool for agraz (Vaccinium meridionale Swartz), according to its state of maturity. In order to obtain the classification models, the PCA and SIMCA methods were used. Results were obtained close to 100% accuracy in the classification for maturity stages 4 and 5 and between 81 and 90% for maturity stage 3. The NIR spectroscopy appears as a suitable technique for the classification of fruits of agraz according to their state of maturity.

This study was to evaluate the post-harvest conservation of "Paluma" guavas coated with cassava starch and pectin. The selected and disinfected fruit samples were coated with cassava starch or pectin at concentrations of 0 (control), 2, 4 and 6%. Then, fruits were stored at room temperature (25 ± 1.0°C) for 12 days. Every three days, evaluations of mass loss, length, diameter, color of peel and pulp, pulp firmness, total soluble solids, pH and vitamin C content were held. The experiment was completely randomized in a 4 x 5 factorial design with four concentrations of the solutions and five storage periods with three replications. The results showed that cassava starch and pectin-based coatings can be an alternative for maintaining the post-harvest quality of "Paluma" guavas. Concentrations of 4 and 6% of both types of coating provided good results regarding the retention of some attributes. The cassava starch kept the fruits brighter compared to fruits coated with pectin.