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Food antioxidants are a core topic of food science due mainly to the consumption of ultra-processed foods, which cannot be overlooked, and represent an importance to modern society. At the same time, natural food antioxidants are gaining attention in studies due to its food safety aspects, that commonly affect food choices. Based on this, the present study aimed to explore the cognitive evaluation of food antioxidants by consumers using the qualitative consumer technique Word Association. Two stimuli were given. Respondents were first asked to write down the first four words that came to mind; descriptions, associated thoughts, or feelings when reading "Food Antioxidants". Secondly the word Natural was added and the stimulus was "Natural Food Antioxidants". The Word Association technique has been shown to be an important tool for cognitive evaluation of the perception of food antioxidants, and the dimensions, Health, Food Safety, Preservatives, Source and Preference which arose and differentiated the stimuli. The results revealed some prior knowledge about issues related to food antioxidants, natural or not. Additionally, showed a clear potential use for natural food antioxidants by the food industry, judging by consumer perception that primarily related cognitively to positive aspects of healthy and food safety.

ObstractThe aim of this work was to study the relationship of chain size of partially hydrolyzed PVA blended with starch in properties of biodegradable sheets produced by thermoplastic extrusion. It was also studied the effect of extrusion temperature profile to determine the better PVA chain size and temperature profile to produce biodegradable sheets through a factorial design. The processability and the mechanical, thermal, optical, and microstructural properties of the biodegradable sheets were adequate, indicating that PVA/cassava starch blends have potential to replace conventional non-biodegradable polymers. Tensile strength and Young's modulus ranges from 1.0 to 2.6 and 3.0 to 6.9 MPa respectively, the elongation at break ranges from 42 to 421%. It was not possible to state a conclusive relationship between PVA molecular weight and the materials properties, but in general, PVA with medium molecular weight and high extrusion temperature profile promote an increase of mechanical properties of the sheets.

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SbstractThe aim of the work was to study the mechanical properties of extruded starch/polyvinyl alcohol (PVA)/glycerol biodegradable blends using multivariate analysis. The blends were produced as cylindrical strands by extrusion using PVAs with different hydrolysis degrees and viscosities, at two extrusion temperature profiles (90/170/170/170/170 °C and 90/170/200/200/200 °C) and three conditioning relative humidities of the samples (33, 53, and 75%). The mechanical properties showed a great variability according to PVA type, as well as the extrusion temperature profile and the conditioning relative humidity; the tensile strength ranged from 0.42 to 5.40 MPa, elongation at break ranged from 10 to 404% and Young's modulus ranged from 0.93 to 13.81 MPa. The multivariate analysis was a useful methodology to study the mechanical properties behavior of starch/PVA/glycerol blends, and it can be used as an exploratory technique to select of the more suitable PVA type and extrusion temperature to produce biodegradable materials.

Biodegradable active films incorporated with lyophilized extract of Baccharis dracunculifolia, source plant of Brazilian green propolis, were prepared by casting method. The extraction conditions of the bioactive compounds were optimized to generate a lyophilized product that was added to the starch: poly(vinyl alcohol) (1:1 w/w) film at concentrations of 0%, 1.0%, and 1.5% (w/w). The addition of B. dracunculifolia extracts promotes a reduction in the mechanical properties and an increase in the opacity of the active biodegradable films, directly related to the B. dracunculifolia contend added. For the migration tests in the films, using different food simulants solvents, the antioxidant activity (DPPH) and the TPC were performed, and ranged from 71.64 to 215.06 μmol Trolox and from 14.57 to 40.95 mg GAE (Gallic acid equivalent), per gram of film, respectively. The active biodegradable films were efficient against the pathogenic microorganisms Escherichia coli and Salmonella enterica subsp. enterica. The HPLC analysis showed that the major components in B. dracunculifolia extract were catechin, followed by ferulic acid. According to the characteristics presented, B. dracunculifolia lyophilized extract is a promising product for incorporation in food or pharmaceutical formulas, or as an active food packaging, due to its antioxidant and bactericidal activities.

The use of low‐cost natural fibers is an interesting alternative to both improve the mechanical properties and reduce the cost of biodegradable materials. Oat fibers are studied as reinforcer or filler in starch/PVA biodegradable materials produced by an injection molding process, using native and cationic cassava starches. The formulations contain 45 wt% of starch + fiber, 25 wt% of PVA, and 30 wt% of glycerol, and the oat fiber proportions are 0, 2.5, 5.0, 7.5, and 10.0 wt%. All materials have good processability, and the tensile strength, Young's modulus, and elongation at break range from 4.7 to 5.5 MPa, 7.1–12.4 MPa, and 180–260%, respectively. The type of starch (native or cationic) does not influence the biodegradable material properties. The oat fiber presents a good dispersion and compatibility with the polymeric matrix, acting mainly as a filler, reducing the material costs.