O Brasil é o país que possui o maior rebanho bovino comercial do mundo, e o balanço de exportações de couro vem demonstrando ascensão no número de metros quadrados de couros exportados. No processo produtivo, a etapa de curtimento é de extrema importância para transformar a pele bovina em couros, tornando-a resistente ao ataque de microorganismos, além de conferir enchimento e garantir maior estabilidade hidrotérmica do material. O crescente apelo ambiental pela utilização de materiais renováveis na indústria levou aos taninos vegetais desempenharem papéis importantes como compostos curtentes na indústria coureira. Os taninos são estruturas fenólicas complexas, existindo uma quantidade considerável de parâmetros químicos que podem ser mensurados através de diversas técnicas analíticas. Por outro lado, para os couros, também existem ensaios empregados no produto final, cujo desempenho pode depender do material curtente utilizado. No presente estudo, foram empregados cinco tipos de taninos de maior uso na indústria coureira para avaliação de parâmetros químicos e posterior associação com propriedades nos couros: tanino de acácia, quebracho, castanheiro, mirabolano e tara. Inicialmente, foi realizada uma revisão bibliográfica, a fim de determinar propriedades químicas de maior relevância a serem mensuradas nos taninos no contexto de sua utilização como agentes curtentes. Nesse sentido, elencaram-se os ensaios de determinação de tanantes totais, não-tanantes, sólidos insolúveis, sólidos solúveis, sólidos totais, fenóis totais e massa molecular média para os taninos. Os parâmetros de percentual de sólidos insolúveis, sólidos solúveis não-tanantes e tanantes totais distinguiram bem os grupos de taninos que atravessaram dos que não atravessaram o couro. Assim, pela análise de insolúveis ser a mais simples e direta delas, recomendar-se-ia o seu uso para definir uma faixa de corte para distinguir o desempenho dos taninos no curtimento. A análise de FTIR-UATR foi útil na caracterização e distinção dos taninos nas famílias dos hidrolisáveis e condensados. Os ensaios de temperatura de retração e distensão da flor nos couros também mostraram associação com o atravessamento dos taninos nas peles durante o curtimento. Por fim, a diferença total de cor após exposição à luz UV também foi avaliada para os couros curtidos com os taninos vegetais, sendo que os taninos hidrolisáveis apresentaram uma menor diferença de cor em relação aos condensados. / Brazil is the country with the largest commercial cattle herd in the world, and the balance of exports of leather has shown a rise in the number of square meters of exported leather. In the production process, the tanning step is extremely important to transform the skin into leather, making it resistant to the attack by microorganisms, as well as providing filling and assuring greater hydrothermal stability of the material. The increasing environmental approach for the use of renewable materials in the industry has led to vegetable tannins an important role as tanning compounds in the leather industry. Tannins are complex phenolic structures and there are a considerable amount of chemical parameters that can be measured through various analytical techniques to characterize them. On the other hand, for hides, there are also tests used in the final product, whose performance may depend on the tanning material used. In the present study, five types of tannins highly used in the tanning industry were used for the evaluation of their chemical parameters and later correlation with properties in hides: Black Wattle (Acacia mearnsii), Quebracho (Schinopsis lorentzii), Chestnut (Castanea sativa), Tara (Caesalpinia spinosa) and myrabolan (Terminalia chebula). Initially, a bibliographical review was carried out to determine the most relevant chemical properties to be measured in the tannins in the context of their use as tanning agents. In this context, the assays for the determination of total tannin polyphenols, non-tannin polyphenols, insoluble solids, soluble solids, total solids, total phenols and average molecular weight for tannins were performed. FTIR-UATR analysis was useful in characterizing and distinguishing tannins in their families of hydrolysates and condensates. The Mann-Whitney-U test showed that the insoluble solids, non-tannin polyphenols, soluble solids and total tannin polyphenols percentage distinguished well the groups of tannins that crossed the hide from those that didn´t. Hence, once the analysis of insoluble solids is the simplest and the most direct of them, it would be recommended to use this parameter to define a cutting range to distinguish the performance of tannins in leather tanning. The shrinkage temperature and distension tests in the leather also showed association with the leather cross-sectional results during tanning baths. Finally, the total color difference after exposure to UV light was also evaluated for the tanned hides with the vegetable tannins, and the hydrolysable tannins presented a smaller color difference or greater light fastness in comparison to the condensates.

Bread waste represents a significant portion of global food waste, necessitating innovative approaches for its valorization. This research project explores the utilization of bread waste through fermentation with Aspergillus oryzae to produce fungal film which could be used for textile applications. While previous studies have examined various applications of food waste, this project specifically targets the textile industry, aiming to mitigate pollution associated with conventional textile manufacturing. The objective of this project was to investigate the feasibility of creating fungal films derived from bread waste. Additionally, to analyze the material's properties through assessments of tensile strength, microscopic analysis, and the identification of an appropriate methodology for this investigation. The biomass suspension was prepared using an ultrafine grinder, and a kitchen blender was subsequently employed to minimize the presence of remaining solids from the grinding process. Additionally, a range of strategies for film casting and wet laying were implemented and evaluated. Wet laying involved combining fungal biomass with tannin to mimic the characteristics of leather. On the other hand, casting utilized pre-treated biomass suspension to assess the formation and quality of the films. As the research progressed and different tannins were used to treat the biomass, a methodology was developed, and glycerol was introduced as a plasticizer. Furthermore, nanocellulose was later incorporated exclusively for the casting of the films to serve as a binder. The films that were produced gave interesting results are observed in casted sheets containing nanocellulose and glycerol-infused biomass (3% BM + 2% Cellulose + 0.13 g Glycerol), exhibiting exceptional tensile strength (35.1 ± 3.42 MPa) and elongation (16.7 ± 5.98%). Wet laid biomass sheets treated with Tara and glycerol display tensile strength (19.9 ± 3.55 MPa) and elongation (6.66 ± 3.02%). These findings signify the potential for developing fungal films from bread waste, necessitating further research to refine methodologies. Overall, this research project paves the way for future advancements in fungal films derived from bread waste. By investigating the use of Aspergillus oryzae and employing wet laying and casting techniques, the project establishes a foundation for sustainable textile production. The successful utilization of bread waste not only addresses the issue of food waste but also contributes to reducing pollution in the textile industry.

Det slängs bröd i svenska matvarubutiker i Sverige samtidigt som läderproduktion är miljöförstörande. För att mildra miljöpåverkan av konventionell lädertillverkning och matsvinn i matvarubutiker odlades filamentös svamp på brödrester för att användas som ett miljövänligt alternativ till animaliskt läder. Detta arbete undersöker ifall en ny typ av läder-liknande material kan förbättras genom att tillsätta växt-tanniner och andra naturliga ämnen till filamentös svampbiomassa vid olika steg i tillverkningsprocessen. Den filamentösa svampen Rhizopus delemar odlades med hydrolyserade brödrester från matvarubutiker som substrat, och fyra olika växt-tanniner tillsattes odlingsmediumen (Tara, Myrobalan, Quebracho, Kastanje). Av de tannin-behandlade biomassorna uppvisade material som behandlats med tara tannin efter skörd av biomassan mest läderliknande mekaniska egenskaper (dragstyrka och förlängning) medan ren, obehandlad biomassa uppvisade högst dragstyrka av alla testade material. Additionen av tanniner ökade töjningsförmågan samtidigt som dragstyrkan minskade hos de resulterande materialen. Behandling med den naturliga tvärbindaren genipin resulterade i ökad dragstyrka och förlängning för flera av materialen. Resultat från HPLC analys av odlingsmediet med tara tannin indikerade även att Rhizopus delemar använde tanninet som substrat. / Bread is thrown away in Swedish grocery stores in Sweden at the same time as leather production is environmentally destructive. In order to mitigate the environmental impact of conventional leather making and to reduce food waste, fungal mycelium was grown on bread waste to be utilized as an eco-friendly leather substitute. This work investigates whether this new type of leather-like material can be improved by adding vegetable tannins and other natural compounds to filamentous fungal biomass at different stages of the production process. The filamentous fungus Rhizopus delemar was grown in shake flasks with hydrolyzed bread as substrate and four different plant tannins were added to the growth mediums. (Tara, Myrobalan, Quebracho, Chestnut). Tara and myrobalan were not inhibitory for growth during the shake flask cultivation, so they were further used in a scaled-up cultivation using 4 L bubble column reactors. However, myrobalan tannin was inhibitory when cultivating in 4 L bubble column reactors. Out of the tannin-treated biomasses, materials treated with tara tannin post cultivation exhibited the highest mechanical properties (tensile strength and elongation), while pure, untreated biomass exhibited the highest tensile strength of all materials tested. Overall, the addition of tannins to the biomasses increased the elongational capacities while lowering the tensile strengths. Treatment with the natural crosslinking-agent genipin resulted in increased average tensile strength and elongation at break for several of the materials tested. Furthermore, HPLC analysis of culture medium containing tara tannin indicated that Rhizopus delemar was able to metabolize the tannin and use it as a substrate.