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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Teor de antocianinas totais em frutos intactos de a?a? (euterpe oleracea MART.) e palmiteiro-ju?ara (euterpe edulis MART.) usando espectroscopia na regi?o do infravermelho pr?ximo e calibra??o multivariada

In?cio, Maria Raquel Cavalcanti 12 December 2014 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-05-30T22:35:17Z No. of bitstreams: 1 MariaRaquelCavalcantiInacio_TESE.pdf: 2176193 bytes, checksum: 1c0288ef05b8770739a332aeef0364e1 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-06-01T21:19:57Z (GMT) No. of bitstreams: 1 MariaRaquelCavalcantiInacio_TESE.pdf: 2176193 bytes, checksum: 1c0288ef05b8770739a332aeef0364e1 (MD5) / Made available in DSpace on 2016-06-01T21:19:57Z (GMT). No. of bitstreams: 1 MariaRaquelCavalcantiInacio_TESE.pdf: 2176193 bytes, checksum: 1c0288ef05b8770739a332aeef0364e1 (MD5) Previous issue date: 2014-12-12 / Neste estudo, foram avaliadas a espectroscopia de reflect?ncia do infravermelho pr?ximo (NIR) e o potencial da calibra??o multivariada como um m?todo r?pido para determinar o teor total de antocianinas em frutos intactos de a?a? e palmiteiro ju?ara. Diversas t?cnicas de calibra??o multivariadas, incluindo regress?o por m?nimos quadrados parciais (PLS), M?nimos Quadrados Parciais por Intervalo (iPLS), algoritmo gen?tico (AG), algoritmo das proje??es sucessivas (APS),foram comparadas e validadas pelo c?lculo das figuras de m?rito. Resultados adequados foram obtidos com o modelo PLS (4 vari?veis latentes e suaviza??o em janela com 5 pontos) com limite de detec??o de 6,2 g.kg-1, limite de quantifica??o de 20,7 g.kg-1, precis?o estimada como raiz quadrada da m?dia do erro da previs?o (RMSEP) de 4,8 g.kg-1, seletividade de 0,79 g.kg-1, sensibilidade de 5,04 x 10-3 g kg-1, precis?o de 27,8 g.kg-1 e a raz?o sinal-ru?do foi de 1,04 x 10-3 g.kg-1. Estes resultados sugerem que a espectroscopia NIR e a calibra??o multivariada podem ser efetivamente usadas para determinar o teor de antocianinas em frutos intactos de a?a? e palmiteiro ju?ara. / 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 (a?a? and palmitero-ju?ara). 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 a?a? and palmitero-ju?ara. 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 ju?ara. 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 a?a? and palmitero-ju?ara fruit.

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