Megaspore germination and initial development of Regnellidium diphyllum Lindman (Pteridophyta, Marsileaceae) sporophytes in the presence of cadmium

Regnellidium diphyllum has its distribution restricted to Southern Brazil and adjoining localities in Uruguay and Argentina. Currently it is on the list of threatened species of Rio Grande do Sul. The conversion of wetlands into agricultural areas or soil contamination by the introduction of waste products and fertilizers may compromise the establishment and survival of this species. Among the pollutants are heavy metals, such as cadmium (Cd). Megaspores were germinated in liquid culture medium, with concentrations 0 (control), 0.39; 0.78; 1.56; 3.12; 6.25; 12.5; 25; 50 and 100 mg L-1 of Cd, starting from a standard solution of Titrisol® at 1000 mg L-1. The increase of Cd in the growth medium to 50 mg L-1 resulted in low germinability (58%), and no germination was observed on 100 mg L-1. In apomictical sporophytes, the growth of primary root and leaf was significantly reduced and no secondary leaf was formed at Cd concentrations of 12.5 and higher than this. The results indicated that R. diphyllum is tolerant to the presence of Cd up to considerably higher concentrations (0.78 mg L-1) than that normally found in unpolluted aquatic ecosystems (0.01 mg L-1), although the sensitivity to higher concentrations might endanger the establishment and permanence of this species in habitats exposed to contamination with this metal.

Comparison of the efficacy of biodegradable and non-biodegradable scintillation liquids on the counting of tritium- and [14C]-labeled compounds

The widespread use of ³H and 14C in research has generated a large volume of waste mixed with scintillation liquid, requiring an effective control and appropriate storage of liquid radioactive waste. In the present study, we compared the efficacy of three commercially available scintillation liquids, Optiphase HiSafe 3, Ultima-Gold™ AB (biodegradable) and Insta-Gel-XF (non-biodegradable), in terms of [14C]-glucose and [³H]-thymidine counting efficiency. We also analyzed the effect of the relative amount of water (1.6 to 50%), radioisotope concentration (0.1 to 100 nCi/ml), pH (2 to 10) and color of the solutions (samples containing 0.1 to 1.0 mg/ml of Trypan blue) on the counting efficiency in the presence of these scintillation liquids. There were few significant differences in the efficiency of 14C and ³H counting obtained with biodegradable or non-biodegradable scintillation liquids. However, there was an 83 and 94% reduction in the efficiency of 14C and ³H counting, respectively, in samples colored with 1 mg/ml Trypan blue, but not with 0.1 mg/ml, independent of the scintillation liquid used. Considering the low cost of biodegradable scintillation cocktails and their efficacy, these results show that traditional hazardous scintillation fluids may be replaced with the new safe biodegradable fluids without impairment of ³H and 14C counting efficiency. The use of biodegradable scintillation cocktails minimizes both human and environmental exposure to hazardous solvents. In addition, some biodegradable scintillation liquids can be 40% less expensive than the traditional hazardous cocktails.

Study of adsorption isotherms of green coconut pulp

Brazil is considered one of the largest producers and consumers of tropical fruits. Green coconut (Cocos nucifera L.) stands out not only for its production and consumption, but also for the high amount of waste produced by coconut water industry and in natura consumption. Therefore, there is a need for utilization of this by-product. This study aims to study the adsorption isotherms of green coconut pulp and determine its isosteric heat of sorption. The adsorption isotherms at temperatures of 30, 40, 50, 60, and 70 °C were analyzed, and they exhibit type III behavior, typical of sugar rich foods. The experimental results of equilibrium moisture content were correlated by models present in the literature. The Guggenheim, Anderson and De Boer (GAB) model proved particularly good overall agreement with the experimental data. The heat of sorption determined from the adsorption isotherms increased with the decrease in moisture content. The heat of sorption is considered as indicative of intermolecular attractive forces between the sorption sites and water vapor, which is an important factor to predict the shelf life of dried products.

Chemical characterization of the flour of peel and seed from two papaya cultivars

Papaya is among the currently most important tropical fruits grown in Brazil and in the world. The fruit is mainly consumed fresh although it offers many industrial products. The processing of this fruit, as well as its fresh consumption, results in large amounts of waste, such as peels and seeds. Papaya consumption is one of the causes of significant loss of food value; therefore, new aspects on the use of its waste as by-products, or in the production of food additives, or even the incorporation of its flour in food have aroused great interest because these are products of high nutritional value, and their use may be economically viable. The objective of this study was to produce and characterize peel and seed flours from two papaya cultivars (Havai and Calimosa) for their chemical constituents focusing on possible use in foods. The proximate and mineral composition, titratable acidity, soluble solids, pH, contents of vitamin C, and phenolic compounds were determined. According to the results obtained, the papaya peel and seed flours had high contents of protein and fiber and therefore can be used as alternative sources of nutrients and can also be added in foods avoiding waste and adding value to the fruit.

Physicochemical and sensory characteristics of snack made with minced Nile tilapia

Nile tilapia is one of the major fish species cultivated worldwide and in Brazil. The tilapia fillet yield is between 30-35%, thus around 70% of waste is generated. A portion of this waste can be used to obtain minced fish, and the resulting product can be used as meat raw material to prepare fish snacks. The aim of this study was to produce fish snacks containing different inclusion levels (20, 30, and 40%) of minced fish obtained from Nile tilapia processing waste and evaluate their physicochemical characteristics and sensory acceptance. Protein content, ash, water activity, and hardness increased with increasing inclusion of minced fish. The scores obtained in the sensory evaluation were: flavor acceptance (from 7.2 to 5.7), texture (from 7.4 to 5.3), overall acceptance (from 7.1 to 5.9), and willingness to purchase (from 4.0 to 3.1). This study demonstrates that the inclusion of 20 to 40% of minced fish of Nile tilapia in snacks is well accepted and improves their nutritional value without affecting the physicochemical properties.

Stability of gluten free sweet biscuit elaborated with rice bran, broken rice and okara

Abstract A challenge to the food sector has been the development of new products incorporating co-products from the food processing industry with minimal impact on their pre-determined structures and adding nutritional quality. In order to add value and develop alternatives for the use of co-products generated during the agroindustrial processing, this work aimed to study the stability of gluten-free sweet biscuits developed with soybean okara, rice bran and broken rice. The formulations were elaborated with increasing percentages of these ingredients and compared with the standard (commercial sweet biscuit) for ten months. The analyses were: weight, diameters (internal and external), thickness, specific volume, instrumental parameters of color, texture, scanning electron microscopy, water activity, proximal composition and isoflavones. The experimental sweet biscuits had characteristics of color, weight, volume and diameters (internal and external) very similar to the commercial, whereas texture, lipids and energy value decreased, and aw, moisture and protein increased during storage. The sweet biscuits showed the same stability when compared to the standard, and the