Otimização da extração e obtenção de microcápsulas de compostos bioativos da polpa e resíduo agroindustrial de acerola

• Ano de defesa: 2016
• Autor(a) principal: Rezende, Yara Rafaella Ribeiro Santos
• Orientador(a): Narain, Narendra
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Programa de Pós-Graduação: Pós-Graduação em Ciência e Tecnologia de Alimentos
• Palavras-chave em Português: Acerola; Resíduos; Plantas; Compostos bioativos; Resíduo de acerola; Otimização; Microencapsulação; Atividade antioxidante; Acerola residue
• Palavras-chave em Inglês: Optimization; Microencapsulation; Bioactive compounds; Antioxidant activity
• Área do conhecimento CNPq: CIENCIAS AGRARIAS::CIENCIA E TECNOLOGIA DE ALIMENTOS
• Link de acesso: http://ri.ufs.br/jspui/handle/riufs/16101

Acerola (Malpighia emarginata DC.) is a very popular fruit and cultivated in Brazil, mainly in the Northeast. This fruit contains high concentrations of bioactive compounds which contribute to fruit´s antioxidant capacity. The acerola processing produces a deep red residue, which is usually discarded. These residues in its composition have higher concentrations of bioactive compounds compared with the pulp. The use of residue could increase the commercial value of acerola and profitability of processing. The best forms of application is then extraction microencapsulation, which ensures greater stability and functionality to the product. Studies on optimization for better extraction of bioactive compounds from the pulp and residue of acerola are necessary. In this context, this study aimed to produce a microencapsulated product (by freeze-drying and spray-drying) from the pulp and residue of acerola to maximize the amount of extracted bioactive compounds. To determine the best conditions of extraction, analysis was performed on anthocyanins, carotenoids, ascorbic acid, phenolics, flavonoids and antioxidant activity, in addition to stability tests (hygroscopicity, solubility, moisture and water activity) and microstructure. Preliminary extractions were performed to determine the best method, using residue of acerola as raw material. The extraction conditions were optimized by varying the concentration of ethanol (0 to 99.5%), ratio of solvent:residue (1:1 to 10:1 (v:m)) and extraction time (10 to 60 minutes), using A factorial design 23 (DCCR) with three central points, totalling 17 trials. The optimum condition was determined by Desirability function available in the Statistica software 12.0. Then, the extractions were made to the pulp and the residue using optimized conditions and microencapsulation by lyophilization of the extracts and atomization. The chemical composition showed that the residue of acerola possessed higher contents of anthocyanins and carotenoids. The concentrated extracts obtained by sonication showed higher concentrations of the bioactive compounds analyzed, and hence this was the method chosen to optimize the extraction process. The concentration of ethanol 46.487%, the ratio solvent:residue 8.655:1 (v:m) and the extraction time of 49.295 minutes were determined as optimum conditions. The extraction performed under optimized conditions was not efficient for carotenoid, however, it was satisfactory for phenolic compounds. The acerola extract from residue showed higher concentrations of bioactive compounds, but less antioxidant capacity proven by ABTS, DPPH, FRAP and ORAC methods. The model showed good correlation between the predicted and observed results of 16.92 and 16.58 mg/100g for anthocyanins, 3.35 and 3.97 mg/g for carotenoids, 407.94 and 488.76 mg/100g for ascorbic acid, 1129.79 and 1067.92 mg/100g phenolic compounds and 569.79 and 559.26 mg/100 g for flavonoids, respectively. Extracts subjected to lyophilization in greater efficiency in the retention of carotenoids (52.39%), ascorbic acid (46.67%) and phenolic compounds (69.75%). Furthermore, on an average the lyophilized extracts showed higher yields (9.44%), lower hygroscopicity (8.42%) and higher moisture (6.13%) when compared with atomized extracts. The spray dried particles have spherical shape, whereas the lyophilized powders showed irregular structures.