DSpace Coleção:
https://repositorio.ifg.edu.br/handle/prefix/100
2026-09-03T17:32:03ZAnálise multivariada de imagens digitais no controle de qualidade da torrefação na presença de adulterantes carbonáceos em amostras de café arábica
https://repositorio.ifg.edu.br/handle/prefix/2328
Título: Análise multivariada de imagens digitais no controle de qualidade da torrefação na presença de adulterantes carbonáceos em amostras de café arábica
Autor(es): Freitas, Sabrina Amaral de
Primeiro Orientador: Costa, Bruno Elias dos Santos
Abstract: This work proposes to monitor the quality of coffee in relation to the type of roasting
and the undue addition of carbonaceous adulterants, which are generally made up of
charred leaves and twigs. The type of roasting and carbonaceous adulterants affect the
color of the coffee powder during the bean processing stage. Digital image analysis
therefore becomes an accessible, economical and efficient alternative to be used as a
resource for acquiring multivariate data based on the RGB color model for the
development of analytical methods, aiming to determine the carbon content present in
coffee samples. To this end, digital images of 101 samples made up of a mixture of
coffee and charcoal in defined proportions (0-100% by mass of charcoal) were
captured using a camera as an imaging device, and the distribution of image pixels
was taken using RGB histograms and organized into a data matrix. The data was
processed by chemometric tools, such as Principal Component Analysis (PCA) and
through a multivariate calibration model based on Principal Component Regression
(PCR) for quantitative predictions of the coal content in the samples. Two ways of
arranging samples in separate containers were evaluated: Petri dish and plastic coffee
cups. The PCA revealed the formation of two sample profiles: One with up to 40%
coal and the other above 60% coal. The PCR calibration models provided satisfactory
fits with R2 values ~0.97 and ~0.95 for samples in Petri dishes and cups, respectively.
The samples arranged in the Petri Dish provided more satisfactory cross-validation
results, with less interference from external lighting and shadows.
Editor: Insitituto Federal de Educação, Ciência e Tecnologia de Goiás
Tipo: Trabalho de Conclusão de Curso2025-02-19T00:00:00Z