Sônia Cachoeira Stertz

Segurança alimentar de hortaliças orgânicas: aspectos sanitários e nutricionais

The search for organic foods is expressive worldwide due to the population awareness about the health risks resulting from the presence of chemical residues in food. Several studies suggest that some practices of organic farming, such as the use of animal manure and rules prohibiting the use of conventional pesticides, can increase the microbiological and parasitic risks. Hence, these foods would not be suitable for human consumption. In this context, the present research aimed at determining the sanitary quality of organic vegetables through the evaluation of microbiological contamination by total and fecal and coliforms, Salmonella sp., and parasitological contamination. Moreover, samples of organic lettuce, carrots, and tomatoes from the Metropolitan Region of Curitiba, Parana, were submitted to physicochemical evaluation to assess their nutritional quality. Thermotolerant coliforms, or fecal coliforms, were detected in 40% of the lettuce and in 25% of the carrot samples. It was observed that 25% of the carrot and 20% of lettuce samples presented Salmonella sp., whereas the tomato samples did not present thermotolerant coliforms or Salmonella sp. The major parasites identified in the lettuce samples were acarus, Entamoeba sp., eggs of Ancylostoma sp., and insects. Entamoeba sp., eggs of Ancylostoma sp. and Toxocara sp. were identified in the organic carrot samples, while the tomato samples did not present any parasitological contamination. The data suggest that the organic lettuce and carrot samples might have been contaminated somehow by the soil, water, domestic animals, or non-suitable fertilizers.

Structural, physico-chemical, thermal and pasting properties of potato (Solanum tuberosum L.) flour

In this work, two varieties of potato flour (Ágata and IAPAR Cristina) were studied by simultaneous thermogravimetry–differential thermal analysis (TG–DTA), differential scanning calorimetry (DSC), rapid viscoamylographic analysis (RVA), and microscopy (NC-AFM) that were compared with conventional physico-chemical analysis, according different granulometry of each flour. Flours of IAPAR Cristina showed higher levels of starch, fiber, and phosphate and it showed higher thermal stability (TG–DTA), as well as higher pasting temperature and viscosity (RVA), and lower enthalpy of gelatinization (DSC) in the two granulometries. Flours of Agata showed higher gelatinization enthalpy (DSC) and lower pasting temperature (RVA). Atomic force microscopy—non contact method (NC-AFM), was important to check for protrusions and pores of the flour surfaces. The differences between cultivars can be attributed mainly to the genotypes and growth conditions of the tubers, which can modify the flour properties.

Atividade antioxidante e teor de fenólicos totais em hortaliças orgânicas e convencionais

Considering that consumers are becoming more conscious of their health and more concerned with environmental conditions, there has been an increasing demand for organic foods. The aim of this study was to compare the antioxidant activity and determine the total phenolic content of organic and conventional cultivations of lettuce, arugula, and chicory grown in the same vegetable garden. The antioxidant activity of the methanol extracts of these leaf vegetables wasdetermined using DPPH free radical scavenging assay. The total phenolic content in the extracts was determined spectrometrically according to the Folin-Ciocalteu method and calculated as equivalent of gallic acid. The antioxidant activity against the DPPH free radical was: organic arugula> organic chicory > organic lettuce > conventional arugula > conventional chicory > conventional lettuce. The total phenolic content was higher in the organic vegetables. The results of this study suggest that the organic vegetable can be a good dietary source of natural antioxidant and phenolic compounds; therefore, their consumption must be encouraged.

Comparative morphological analysis of cherry tomato fruits from three cropping systems

Attempts to meet produces market demand are not always followed by research reports showing the impact of novel, intensive cropping systems on the environment, human and animal health, and eventual chemical and structural changes of plants. This work carries a comparative evaluation of the morphology and anatomy of cherry tomato fruits obtained from organic, conventional and hydroponic cropping systems. Fruits were collected at the free market in the greater Curitiba, Parana, Brazil. For each culture method, 50 fruits their weight, diameter and volume measured. For the anatomical analysis, samples of the pericarp of ten fruits were excised and embedded in glycol methacrylate; 6-mm cuts were then obtained, stained with toluidine blue, and mounted on permanent glass slides. The anatomical analysis and illustrations were performed in Olympus and Zeiss photonic microscope. Samples obtained from the organic cropping system presented the highest mass, diameter, volume and density. The pericarp of fruits, obtained from the conventional cropping system presented larger but less abundant cells in comparison to the pericarp of the hydroponic and organic-produced fruits.

Growth kinetics of Rhizopus formosa MUCL 28422 on raw cassava flour in solid state fermentation

Solid state fermentations were carried out using a strain of Rhizopus formosa MUCL 28422 for its ability to grow on raw cassava. Optimal substrate composition, as estimated by surface response design experiments, was 10% each of cassava bagasse and soybean flour and 80% cassava flour. Optimal fermentation conditions were: temperature 32 °C, initial pH and moisture of the substrate 6.5 and 64%, respectively, and inoculum size 106-spores g−1 dry matter. These conditions were employed for studying the kinetics of the biotransformation of cassava flour using Oxygen Uptake Rate (OUR) and Carbon dioxide Evolution Rate (CER) during the process. The respiratory quotient was ∼1, corresponding to an aerobic process in the first 24–26 h. Sporulation started after 26 h of fermentation when the respiratory quotient showed a trend to increase up to ∼6. Biomass estimation, based on oxygen consumption (Yx/o) gave a value of 0.531 g biomass g−1 O2 consumed and the maintenance coefficient (m) was of the order of 0.068 g O2 consumed g−1 biomass h−1. The corresponding value for the specific growth rate (µ) was 0.16 h−1. © 1999 Society of Chemical Industry

CARACTERIZAÇÃO QUÍMICA DO COGUMELO AGARICUS BLASEI MURRIL

CHEMICAL CARACTERIZATION OF AGARICUS BLASEI MURRIL MUSHROOM The mushroom is important by propertieds nutritional and functional. It was determined the chemical composition of drought sample of mushroom blasei Murril, from Pilar city, Sao Paulo, in agreement with Association of Official Analytical Chemists (AOAC) methodology. The results in drought base were compared with dates obtained from producers and literature. The Agaricus blasei Murril presented high tenor of protein (31,34%), Fe (6,03 mg/100g), Zn (10,58 mg/100g), Cu (4,23 mg/100g), K (2,16 g/100g) and P (0,56 g/100g), Both with very organic importance, and considered essentials nutrients to human health. It presented high nourishing fiber tenor (20,59%), responsible for benefit effects, such as reduction of blood cholesterol and reduction of blood glucose. The high tenors of protein and nourishing fiber found, can justify their inclusion in our nourishment. Keywords: Quality Control, Sum Mushroom, Dietary Fiber.

VIABILIDADE DA PRODUÇÃO DE PÃO, UTILIZANDO FARINHA MISTA DE TRIGO E MANDIOCA EM DIFERENTES PROPORÇÕES

Breadmaking tests were conduced to evaluate the possibility of wheat flour substitution by cassava flour in proportions ranging from 10 to 40%. After baking, all breads were sensorially evaluated and the results were statistically analised. Breads produced with 10 to 20% of cassava flour in substitution of wheat flour resulted on soft texture and well aceptable products.