A flexible, low-cost energy-harvesting device based on the magnetoelectric (ME) effect was designed using Fe 64 Co 17 Si 7 B 12 as amorphous magnetostrictive ribbons and polyvinylidene fluoride (PVDF) as the piezoelectric element. A 3 cm-long sandwich-type laminated composite was fabricated by gluing the ribbons to the PVDF with an epoxy resin. A voltage multiplier circuit was designed to produce enough voltage to charge a battery. The power output and power density obtained were 6.4 μW and 1.5 mW cm −3 , respectively, at optimum load resistance and measured at the magnetomechanical resonance of the laminate. The effect of the length of the ME laminate on power output was also studied: the power output exhibited decays proportionally with the length of the ME laminate. Nevertheless, good performance was obtained for a 0.5 cm-long device working at 337 KHz within the low radio frequency (LRF) range.

Agricultural, forestry, and food industries produce large amounts of lignocellulosic wastes every year. Land disposal of these residues without proper treatment leads to environmental pollution and negative health effects. The recent advances in valorization of agro-industrial wastes by the production of lignocellulolytic enzymes under solid-state fermentation (SSF) are reviewed. SSF is a promising technology to produce lignocellulolytic enzymes. However, the large-scale feasibility is the main challenge of SSF being the control of operational parameters and adequate reactor design the first locks. The current and future trends of SSF bioreactors for lignocellulolytic enzyme production are summarized. SSF allows the production of lignocellulolytic enzymes with high stability at different temperatures and pH, improving their applicability in different industrial settings.

The nutritional value of Mediterranean wastes was improved and other value-added products such as lignocellulolytic enzymes were produced in the same process, which could facilitate the efficient reuse of these wastes. © 2018 Society of Chemical Industry.

BACKGROUND: Vegetable oils are yearly produced in large amounts generating solid by-products, the oilseed cake (OC). OCs are lignocellulosic materials that have been used for animal feed with some limitations due to high fibre content from the plant cell walls. Biotechnological processes can help to overcome these limitations and contribute to up-grading such by-products, enhancing their nutritional value as feed ingredients.RESULTS: All fungal species were able to decrease neutral detergent fibre and acid detergent fibre in all by-products. Additionally, relevant enzymes were produced by the three fungi studied resulting in an improved antioxidant capacity of all fermented OCs. Aspergillus niger led to the highest activity of cellulase (109 U g −1 ), xylanase (692 U g −1 ) and protease (157 U g −1 ) per dry OC matter and to the recovery of an extract rich in antioxidants, with the highest scavenging potential of free radicals and superoxide anion, iron chelation ability and reducing power. Rhyzopus oryzae produced the highest activity of ⊎-glucosidase (503 U g −1 ) and led to the highest liberation of total phenolic content (TPC). Principal components analysis showed that extracts with high antioxidant potential were obtained in solid-state fermentation (SSF) with high enzymatic activity. A positive correlation was established between the action of ⊎-glucosidase and TPC.CONCLUSION: Within the same bioprocess it was possible to improve the nutritional value of OCs and to obtain relevant bioactive compounds such as lignocellulosic enzymes and phenolic compounds with antioxidant potential, resulting in a significant improvement of already valuable by-products with commercial interest for animal feed.

Oilseed cakes (OC) are natural sources of lignocellulosic biomass, produced every year in large amounts. In addition to their main applications as animal feed, plant or soil fertilizer, and compost, they present enormous potential for being used in biotechnological processes for the obtainment and extraction of valuable bioactive compounds. This work evaluated the effect of solid-state fermentation on the bioactive properties of extracts obtained from the bioprocessing of OC and evaluated the effect of solvents on the recovery of compounds with higher bioactive potential. A general decrease of EC50 values was observed for fermented extracts obtained using a mixture of water/methanol (1:1) as extraction solvent. A decrease in the minimum inhibitory concentration was observed for fermented water extracts compared to non-fermented. Additionally, growth inhibition of Listeria monocytogenes was observed when using aqueous methanolic fermented extracts. These extracts also exhibited a higher percentage of growth reduction against phytopathogenic fungi, and some extracts exhibited increased protection against genotoxic agents such as camptothecin and bisphenol A. It was demonstrated that bioprocessing of OC through SSF is an effective approach to obtaining valuable compounds with bioactive properties for use in the food, pharmaceutical or cosmetic industries.

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Sunflower (SFC), rapeseed (RSC), and soybean cakes (SBC) are examples of oilseed cakes (OC) used in animal feed. Bioprocessing of these OC by solid‐state fermentation (SSF) aims to boost OC applications in feed and other industries by reducing antinutritional factors and releasing enzymes and antioxidants. A simplex centroid design was performed to optimize the substrate composition of SFC, RSC and SBC mixtures that maximize lignocellulolytic enzymes production by SSF with Aspergillus niger and consequently improve the nutritional properties of OC. Enzyme production by SSF of OC mixtures exceeded the activity values obtained using a single oilseed cake. A mixture composed of 50% (w/w) RSC and SBC was found to be the optimum substrate. The scale‐up from flasks to tray‐type bioreactors demonstrated SSF reproducibility, leading to the production of 299 U g−1 cellulase, 1476 U g−1 xylanase, 191 U g−1 β‐glucosidase and 220 U g−1 protease. The obtained enzymatic extract also presented antioxidant activity (around 50 μmol Trolox equivalents/g). This study demonstrated that bioprocessing of OC mixtures through SSF is an effective approach to obtain value‐added products with applications as feed or feed additives and to increase the liberation of bioactive compounds with applications in the feed, food, cosmetic and pharmaceutical industries. © 2022 Society of Chemical Industry and John Wiley & Sons, Ltd.

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