Banca de DEFESA: ROSANGELA CAMARA COSTA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : ROSANGELA CAMARA COSTA
DATA : 26/09/2018
HORA: 14:00
LOCAL: Auditório do Química 3
TÍTULO:

ANALYTICAL METHODOLOGIES FOR FRUIT AGROINDUSTRY EMPLOYING NEAR INFRARED AND CHEMOMETRIC

PALAVRAS-CHAVES:

NIR. Chemometrics. Fruits. Jaboticaba fruit. Indian-almonds. Classification. Regression

PÁGINAS: 91
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Química
SUBÁREA: Química Analítica
ESPECIALIDADE: Métodos Óticos de Análise
RESUMO:

The application of methodologies in fruits agroindustry using non-destructive techniques such as near-infrared has great importance due to the rising demand for products in addition to the necessity of technologies that can follow the growth of this field. Also, the use of these techniques implies in reduction of time of analyses, costs with chemical reagents, the need of specialized work and generation of residual components. Therefore, this thesis was developed aiming to contribute to the repertoire of analytical techniques applied in fruits agroindustry using near-infrared (NIR) combined with chemometric treatment. This research was conducted using two types of approaches, one application to classify the fruits and another one to quantify the evaluation parameters of sensory and nutritional quality of fruits. For the classification, jaboticaba fruit [Myrciaria cauliflora (Mart.) O. Berg cv. Açú] were analyzed in three stages of maturation (immature, physiologically mature and mature fruit) using NIR. After that, classification models for these maturation stages were developed applying the PCA-LCA, SPA-LDA and GA-LDA algorithms. The best PCA-LDA model was calculated using four principal components. As for the SPA-LCA, the best adjustment was obtained using 123 variables and the best GA-LDA model was found using 48 variables. Evaluation parameters of these models such as sensitivity and specificity were calculated presenting satisfactory values: 100% of validation for the immature stage, 77% for the intermediate stage and 50% for the mature stage. These results indicate the effectiveness of the technique to evaluate the maturation stage of jaboticaba fruit, indicating its applicability in agroindustry. Concerning the approach of quantification of fruits parameters, the concentrations of anthocyanins and phenolic compounds in Indian-almonds (Terminalia catappa) were determined using NIR. Subsequently, regression models were developed in order to predict these parameters applying PLS and the variables selection using iPLS-PLS and GA-PLS. The best results acquired in order to determine the levels of anthocyanins and phenolic compounds were obtained using GA-PLS for both parameters. The best model for phenolic compounds presented a determination coefficient of prediction (𝑅𝑝2) of 0.82 and an error of prediction (RMSEP) of 11.3 mg GAE g-1 (mg of gallic acid equivalent (GAE) per gram of sample). Regarding the anthocyanins determination, the best model presented a determination coefficient of prediction 𝑅𝑝2 of 0.80 and an error of prediction (RMSEP) of 8.7 mg GAE g-1. In conclusion, the results obtained in this research confirm that NIR allied to chemometric methods present a potential of applicability for fruits agroindustry for both quantitative and qualitative approaches.

MEMBROS DA BANCA:
Externo ao Programa - 1913849 - EDGAR PERIN MORAES
Interno - 1803692 - FABRICIO GAVA MENEZES
Presidente - 1714946 - KASSIO MICHELL GOMES DE LIMA
Externo à Instituição - LUCIANO FARIAS DE ALMEIDA - UFPB
Externo à Instituição - MÁRCIO JOSÉ COELHO DE PONTES - UFPB