Abstract The development potential of byproducts from wastes of grape processing can be a promising alternative due to environmental questions. Moreover, there is the possibility of using this material in the development of products with added value. In this study, the wastes of grape skin (GSk), grape seed (GSe), and defatted grape seed with skin fragments (DGS) from ‘Ives noir’ grape (Vitis labrusca L.), grown under organic farming conditions, had their chemical composition and physical-chemical properties evaluated. Parameters of chemical composition, contents of phenolic compounds, total anthocyanins, flavonoids, and minerals, the antioxidant capacity, and water sorption capacity were evaluated. The wastes of grape were also analyzed by FTIR and TG/DTG. All residues had a high fiber content (54.1 - 74.3 wt.%), the DGS waste had the highest contents of phenolic compounds as flavonoids, and the GSk waste had the highest content of total anthocyanins. Antioxidant capacity values were higher in the ABTS+ method, with no statistical difference. On the other hand, in the DPPH antioxidant assay, the DGS and GSe wastes had higher antioxidant activity; these wastes also had greater thermal stability. The GSk waste had the highest water sorption capacity. The results show that the wastes from grape processing have the potential to be reused in applications with more value added.

Abstract This work aimed to incorporate thyme essential oil into films composed of pectin to provide antimicrobial action to them. The effect of adding essential oil on the films' mechanical, physical-chemical, and barrier properties and their degradability was evaluated. Essential oil addition was possible by using Tween® 20 as an emulsifier, and it was possible to observe antimicrobial activity in the films containing 1.0 wt.% and 2.0 wt.% essential oil. The films containing thyme essential oil were more elastic and thicker but less resistant, with high permeability to water vapor and more hydrophilic relative to other formulations. Scanning electron microscopy analysis showed the presence of heterogeneities in the formulations with essential oil. The films produced using the optimized formulation (30 wt.% glycerol, 1.0 wt.% thyme essential oil, and 0.5 wt.% Tween® 20 relative to pectin mass) degraded entirely after 24 days of exposure to standard soil.

Abstract Whey, a by-product of dairy industry, is a feedstock widely employed in the production of biodegradable films. However, these films present some limitations when considering the performance of synthetic polymers, especially biological transformation by decomposition. This work aimed to evaluate the effects of chitosan addition to whey-based films to improve films physical-chemical properties and resistance to microbial degradation. The results showed that there was an interaction effect between the chitosan concentration and the storage time for the physical-chemical properties of elongation at break and opacity. There was statistical difference among the formulations; however, for the moisture content and film thickness, there was no interaction effect between the formulation and the storage time. The films with 1.5 and 3.0 wt.% chitosan presented a yellowish hue, characteristic of the polysaccharide; this could also be detected by SEM analysis. The films presented an excellent biodegradability, being decomposed in about 8 days. Considering all chitosan contents tested had similar performances, the chitosan content of 0.15 wt.% was the one with the better cost-benefit relation.

ABSTRACT The membrane separation capacity allows the retention of the remaining organic matter that could not be removed by the biological process, increasing the treatment efficiency. The aim of this study was to evaluate the microfiltration (MF) process in a tertiary treatment system for landfill leachate from the Rincão das Flores, Caxias do Sul/RS/Brazil. The microfiltration system of commercial hollow fiber membrane poly(etherimide) was tested in oder to promote leachate treatment. The tests carried out were leachate permeation, concentration factor, determination of fouling and obtention of the values of the resitance to the flux. The resistance due to fouling and flux decline were evaluated to determine the best operating conditions. The potential for fouling was 53% and was evaluated by comparing the pure water permeability before and after the leachate filtration. It was observed that the resistance due to fouling express 32% of the total resistance. The results showed that the MF process allows the elimination of up to 43% of the organic matter measured as chemical oxygen demand (COD) and 63% of that measured as biological oxygen demand (BOD5).