Search Results (4)

Developing sustainable packaging materials has become a global priority in response to environmental concerns associated with conventional plastics. This study used a wheat flour byproduct (glue flour, GF) and poly(butylene adipate-co-terephthalate) (PBAT) to produce films via blown extrusion, incorporating rosemary extract (RE) at 2% (FRE2) and 4% (FRE4) (w/w). A control film (FCO) was formulated without RE. The physicochemical, thermal, mechanical, and biodegradation properties of the films were evaluated. FCO, FRE2, and FRE4 exhibited tensile strength (TS) values between 8.16 and 9.29 MPa and elongation at break (ELO) above 889%. Incorporating 4% RE decreased luminosity (91.38 to 80.89) and increased opacity (41.14 to 50.95%). A thermogravimetric analysis revealed a main degradation stage between 200 °C and 450 °C, with FRE2 showing the highest residual mass (~15% at 600 °C). Sorption isotherms indicated enhanced hydrophobicity with RE, thereby reducing the monolayer moisture content from 5.23% to 3.03%. Biodegradation tests revealed mass losses of 64%, 58%, and 66% for FCO, FRE2, and FRE4, respectively, after 180 days. These findings demonstrate that incorporating RE into GF/PBAT blends via blown extrusion is a promising strategy for developing biodegradable films with enhanced thermal behavior, mechanical integrity, and water resistance, contributing to the advancement of sustainable packaging materials. Full article

A biodegradable polymer packaging system for ‘Benitaka’ table grapes (Vitis vinifera L.) was developed to inhibit the development of gray mold during refrigerated storage. The system consisted of packages and sachets containing Na₂S₂O₅ to release sulfur dioxide (SO₂), both produced with biodegradable films of starch, glycerol, and poly (adipate co-butylene terephthalate) (PBAT) produced via blown extrusion. The films were characterized in terms of thickness, density, mass loss in water, water vapor permeability, sorption isotherms, and mechanical properties. The table grapes were packed with biodegradable plastic bags containing SO₂-releasing sachets inside. The experimental design was completely randomized, with four repetitions and five treatments: (a) control, without sachet containing Na₂S₂O₅ and SiO₂; (b) 2 g of Na₂S₂O₅ + 2 g of SiO₂; (c) 4 g of Na₂S₂O₅ + 1 g of SiO₂; (d) 4 g of Na₂S₂O₅ + 2 g of SiO₂; and (e) 4 g of Na₂S₂O₅ + 4 g of SiO₂. The bunches were stored in a refrigerated chamber at 1 ± 1 °C and relative humidity above 90%. The treatments were evaluated 30 and 45 days after the beginning of refrigerated storage and 3 days at room temperature. The grapes were evaluated based on the incidence of gray mold, mass loss, stem browning, shattered berries, and berry bleaching. The data were subjected to the analysis of variance, and the means were compared using Tukey’s test at 5%. The biodegradable films had good processability during the production via blown extrusion, with good physical properties to be used in the packaging of grapes and the production of SO₂-releasing sachets. The biodegradable polymer packaging system (biodegradable plastic bags + SO₂-releasing sachets) inhibited the development of gray mold on ‘Benitaka’ table grapes for 45 days at 1 °C, preserving their quality, with low mass loss, few shattered berries, and rachis freshness. Full article

A totally green process based on reactive extrusion was used for the production of cassava starch hydrogels through reaction with two organic crosslinking agents, citric (CA) and tartaric (TA) acids. CA and TA were used at different concentrations (0, 2.5, 5.0, 10.0, 15.0, and 20.0%). Degree of substitution (DS) of hydrogels ranged from 0.023 to 0.365. Fourier transform infrared spectroscopy results showed a new band appearing at 1730 cm⁻¹ associated with ester carbonyl groups. X-ray diffraction indicated that reactive extrusion resulted in the disappearance of diffraction peaks of native starch and samples with lower crystallinity indices ranging from 37% (native starch) to 8–11% in starch hydrogels. Morphology analysis showed that the original granular structure of starch was lost and replaced by a rougher and irregular structure. Water holding capacity values of starch hydrogels obtained by reactive extrusion were superior to those of native starch and the control sample (extruded without the crosslinking agents). Hydrogels obtained with the highest CA or TA concentration (20.0%) resulted in the higher DS and swelling capacities, resulting in samples with 870 and 810% of water retention, respectively. Reactive extrusion was effective in obtaining starch hydrogels by reaction with organic acids. Full article

On March 11, 2020, the World Health Organization (WHO) officially declared the outbreak caused by the new coronavirus (SARS-CoV-2) a pandemic. The rapid spread of the disease surprised the scientific and medical community. Based on the latest reports, news, and scientific articles published, there is no doubt that the coronavirus has overloaded health systems globally. Practical actions against the recent emergence and rapid expansion of the SARS-CoV-2 require the development and use of tools for discovering new molecular anti-SARS-CoV-2 targets. Thus, this review presents bioinformatics and molecular modeling strategies that aim to assist in the discovery of potential anti-SARS-CoV-2 agents. Besides, we reviewed the relationship between SARS-CoV-2 and innate immunity, since understanding the structures involved in this infection can contribute to the development of new therapeutic targets. Bioinformatics is a technology that assists researchers in coping with diseases by investigating genetic sequencing and seeking structural models of potential molecular targets present in SARS-CoV2. The details provided in this review provide future points of consideration in the field of virology and medical sciences that will contribute to clarifying potential therapeutic targets for anti-SARS-CoV-2 and for understanding the molecular mechanisms responsible for the pathogenesis and virulence of SARS-CoV-2. Full article