Teor de antocianinas totais em frutos intactos de açaí (euterpe oleracea MART.) e palmiteiro-juçara (euterpe edulis MART.) usando espectroscopia na região do infravermelho próximo e calibração multivariada
In this study was evaluated near-infrared reflectance spectroscopy (NIR), and multivariate calibration potential as a rapid method to determinate anthocyanin content in intact fruit (açaí and palmitero-juçara). It’s important to develop new methods to determinate quality parameters in foods, mostly...
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| Format: | doctoral thesis |
| Status: | Published version |
| Publication Date: | 2014 |
| Country: | Brasil |
| Institution: | Universidade Federal do Rio Grande do Norte (UFRN) |
| Repository: | Repositório Institucional da UFRN |
| Language: | Portuguese |
| OAI Identifier: | oai:repositorio.ufrn.br:123456789/20559 |
| Online Access: | https://repositorio.ufrn.br/jspui/handle/123456789/20559 |
| Access Level: | Open access |
| Keyword: | Açaí Juçara NIR PLS Método não destrutivo Calibração multivariada CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA |
| Summary: | In this study was evaluated near-infrared reflectance spectroscopy (NIR), and multivariate calibration potential as a rapid method to determinate anthocyanin content in intact fruit (açaí and palmitero-juçara). It’s important to develop new methods to determinate quality parameters in foods, mostly the use of quick techniques, non-invasive and which have reliable methods. The NIR spectroscopy fills these requirements and these have shown as an alternative to conventional quality control analysis in several foods, including, fruit. Currently, analytical methods have been reported to determinate anthocyanin in fruits. However, the NIR spectroscopy is cited rarely to determinate anthocyanin content in açaí and palmitero-juçara. This study could contribute to research that already have performed. Several multivariate calibration techniques, including partial least squares (PLS), interval partial least squares (iPLS), genetic algorithm (AG), successive projections algorithm (SPA), were compared and validated by establishing figures of merit. In this job, 139 fruits were used, 69 were acai and 70 were palmiteiro juçara. The potential anthocyanin sources has been quantified using differential pH method, as a reference method. Soon after, the near-infrared diffuse reflectance spectra have been measured, and finally the chemometrics models have been built. Suitable results were obtained with the PLS model (four latent variables and 5- point smoothing) with a detection limit of 6.2 g kg-1, limit of quantification of 20.7 g kg-1, accuracy estimated as root mean square error of prediction of 4.8 g kg-1, mean selectivity of 0.79 g kg-1, sensitivity of 5.04 x10-3 g kg-1, precision of 27,8 g kg-1, and signal-to-noise ratio of 1.04 x10-3 g kg-1. These results suggest NIR spectroscopy and multivariate calibration can effectively be used to determine anthocyanin content in intact açaí and palmitero-juçara fruit. |
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