Valorização da casca de híbridos de Corymbiacitriodora x Corymbia torelliana como fonte de obtenção de bioprodutos
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Data
2024-09-19
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Universidade Federal de Viçosa
Resumo
A preocupação ambiental e crescente busca por sustentabilidade vêm incentivando o mercado florestal a utilizar de maneira mais efetiva toda sua matéria prima. Com isso recentes estudos para obtenção de produtos químicos verdes, advindos de matéria prima renovável tem ganhado grande destaque. O objetivo deste trabalho foi avaliar o potencial tânico e caracterizar quimicamente a casca de um híbrido de Corymbia citriodora x Corymbia torelliana visando a valorização deste subproduto da indústria florestal como fonte para a obtenção de bioprodutos. A casca foi triturada em moinho martelo e seca em estufa em temperatura de 40ºC até atingir um teor de umidade, base seca, menor que 15% e posteriormente caracterizadas quimicamente. A técnica de FT-IR foi utilizada para identificar os principais grupos funcionais. Os compostos fenólicos presentes no extrato foram avaliados por meio de LC/MS. Os taninos foram extraídos a partir de uma relação solvente/casca de 20:1 (m/m), em banho maria. Foram avaliadas a adição de 3 percentagens do sal sulfito de sódio (2%, 4% e 6% (m/m)) adicionados à solução aquosa. Além disso foram avaliados três tempos de residência (90,120 e 180 min) e três temperaturas (60, 75 e 90ºC) de reação. Após as extrações foram determinados o teor de sólidos dissolvidos, índice de Stiasny, rendimento em sólidos totais e substâncias tânicas e não tânicas. De acordo com os resultados as cascas de Corymbia citriodora x Corymbia torelliana são compostas, principalmente, por extrativos totais (8,86%), carboidratos (53,20%), suberina (10,03%), urônicos (3,72%), lignina total (24,80%) e cinzas (3,65%). De acordo com a composição química elementar as cascas possuem 47,75% de carbono, 5,52% de hidrogênio, 0,19% de nitrogênio, 0,07% de enxofre e 42,82% de oxigênio. Os principais compostos fenólicos obtidos foram os Ácidos Vanílico (58,13 mg.mL-1) e Protocatecuico (15,86 mg.mL-1). A análise de Py- GC/MS obteve como principais compostos presentes na casca CO2, ácido acético e levoglucosana. A extração de melhor resultado para obtenção de substâncias tânicas, foi realizada na temperatura de 90ºC, por 180min com adição de sulfito de sódio a 2% (m/m), onde a média obtida foi de 9,25%. A partir do presente estudo foi possível concluir que a casca de híbridos de C. citriodora x C.torelliana é uma ótima fonte para obtenção de produtos químicos de valor agregado, podendo ser empregados em diversos setores da indústria, exceto para obtenção de produtos tânicos devido ao baixo teor de sólidos totais, que foram inferiores a 1,5% e Índice de Stiasny, não ultrapassando 30%. Palavras-chave: sustentabilidade; biprodutos; índice de stiasny; py-gc/ms; lc/ms; ft-ir.
Environmental concerns and the growing search for sustainability have been encouraging the forestry market to use all its raw materials more effectively. As a result, recent studies to obtain green chemical products from renewable raw materials have gained great prominence. The objective of this study was to evaluate the tannin potential and chemically characterize the bark of a hybrid of Corymbia citriodora x Corymbia torelliana, aiming at the valorization of this byproduct of the forestry industry as a source for obtaining bioproducts. The bark was crushed in a hammer mill and dried in an oven at 40ºC until reaching a moisture content, on a dry basis, of less than 15% and subsequently chemically characterized. The FT-IR technique was used to identify the main functional groups. The phenolic compounds present in the extract were evaluated by means of LC/MS. The tannins were extracted from a solvent/bark ratio of 20:1 (m/m), in a water bath. The addition of three percentages of sodium sulfite salt (2%, 4% and 6% (m/m)) added to the aqueous solution were evaluated. In addition, three residence times (90, 120 and 180 min) and three reaction temperatures (60, 75 and 90ºC) were evaluated. After the extractions, the dissolved solids content, Stiasny index, yield of total solids and tannic and non-tannic substances were determined. According to the results, the barks of Corymbia citriodora x Corymbia torelliana are composed mainly of total extractives (8.86%), carbohydrates (53.20%), suberin (10.03%), uronic (3.72%), total lignin (24.80%) and ash (3.65%). According to the elementary chemical composition, the barks have 47.75% carbon, 5.52% hydrogen, 0.19% nitrogen, 0.07% sulfur and 42.82% oxygen. The main phenolic compounds obtained were vanillic (58.13 mg.mL- 1) and protocatechuic (15.86 mg.mL-1) acids. The Py-GC/MS analysis obtained the main compounds present in the bark as CO2, acetic acid and levoglucosan. The extraction with the best result to obtain tannic substances was carried out at a temperature of 90ºC, for 180min with the addition of sodium sulfite at 2% (m/m), where the average obtained was 9.25%. From the present study it was possible to conclude that the bark of C. citriodora x C.torelliana hybrids is an excellent source for obtaining value-added chemical products, which can be used in several sectors of the industry, except for obtaining tannic products due to the low content of total solids, which were less than 1.5% and Stiasny Index, not exceeding 30%. Keywords: sustainability; bioproducts; stiasny index; py-gc/ms; lc/ms; ft-ir.
Environmental concerns and the growing search for sustainability have been encouraging the forestry market to use all its raw materials more effectively. As a result, recent studies to obtain green chemical products from renewable raw materials have gained great prominence. The objective of this study was to evaluate the tannin potential and chemically characterize the bark of a hybrid of Corymbia citriodora x Corymbia torelliana, aiming at the valorization of this byproduct of the forestry industry as a source for obtaining bioproducts. The bark was crushed in a hammer mill and dried in an oven at 40ºC until reaching a moisture content, on a dry basis, of less than 15% and subsequently chemically characterized. The FT-IR technique was used to identify the main functional groups. The phenolic compounds present in the extract were evaluated by means of LC/MS. The tannins were extracted from a solvent/bark ratio of 20:1 (m/m), in a water bath. The addition of three percentages of sodium sulfite salt (2%, 4% and 6% (m/m)) added to the aqueous solution were evaluated. In addition, three residence times (90, 120 and 180 min) and three reaction temperatures (60, 75 and 90ºC) were evaluated. After the extractions, the dissolved solids content, Stiasny index, yield of total solids and tannic and non-tannic substances were determined. According to the results, the barks of Corymbia citriodora x Corymbia torelliana are composed mainly of total extractives (8.86%), carbohydrates (53.20%), suberin (10.03%), uronic (3.72%), total lignin (24.80%) and ash (3.65%). According to the elementary chemical composition, the barks have 47.75% carbon, 5.52% hydrogen, 0.19% nitrogen, 0.07% sulfur and 42.82% oxygen. The main phenolic compounds obtained were vanillic (58.13 mg.mL- 1) and protocatechuic (15.86 mg.mL-1) acids. The Py-GC/MS analysis obtained the main compounds present in the bark as CO2, acetic acid and levoglucosan. The extraction with the best result to obtain tannic substances was carried out at a temperature of 90ºC, for 180min with the addition of sodium sulfite at 2% (m/m), where the average obtained was 9.25%. From the present study it was possible to conclude that the bark of C. citriodora x C.torelliana hybrids is an excellent source for obtaining value-added chemical products, which can be used in several sectors of the industry, except for obtaining tannic products due to the low content of total solids, which were less than 1.5% and Stiasny Index, not exceeding 30%. Keywords: sustainability; bioproducts; stiasny index; py-gc/ms; lc/ms; ft-ir.
Descrição
Palavras-chave
Cascas, Produtos vegetais, Produtos biológicos, Sustentabilidade, Pirólise, Cromatografia a líquido, Espectrometria de massa, Espectroscopia de infravermelho
Citação
BARBOSA, Verônica Oliveira de Paula. Valorização da casca de híbridos de Corymbiacitriodora x Corymbia torelliana como fonte de obtenção de bioprodutos. 2024. 86 f. Dissertação (Mestrado em Ciência Florestal) - Universidade Federal de Viçosa, Viçosa. 2024.