Banca de DEFESA: CARLOS MONTEIRO DE LIMA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : CARLOS MONTEIRO DE LIMA
DATE: 31/10/2025
TIME: 14:00
LOCAL: Videoconferência
TITLE:

Development of methodologies and tools for quality control and authentication of beers using UV-Vis spectroscopy, Histogram-Based Fluorescence (HBF), and Chemometrics.

KEY WORDS:

Beer; Authentication; Histogram-based Fluorescence (HBF); Chemometrics; DD-SIMCA; UV-Vis Spectroscopy

PAGES: 162
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Analítica
SPECIALTY: Instrumentação Analítica
SUMMARY:

This thesis presents an innovative, simple, efficient, rapid, and environmentally sound analytical methodology for beer authentication and quality control by introducing a novel approach termed Histogram-based Fluorescence (HBF). The approach integrates ultraviolet-visible (UV-Vis) molecular absorption spectroscopy, HBF, and Chemometrics tools. An AFTM-Led device (Fluorimeter and Turbidimeter Apparatus with LED excitation and digital image detection) was developed, using a blue Light-Emitting Diode (LED) (λ = 450-465 nm) as the radiation source. Twenty-nine beer samples (commercial, craft, and homebrewed) were analyzed under three conditions: undiluted and diluted to 5.0% and 0.5% (v/v). The analyses involved acquiring UV-Vis spectra and digital images, as well as extracting their histograms. These datasets were explored using Principal Component Analysis (PCA) and modeled by one-class DD-SIMCA (Data-Driven Soft Independent Modeling of Class Analogy), with validation by Procrustes Cross-Validation (PCV). Based on UV-Vis data, PCA revealed a clear visual separation of the target class (TB), composed exclusively of Heineken brand samples, with a marked distinction from IPA samples and a consistent grouping of homebrewed beers. Authentication by DD-SIMCA using the same data showed efficiencies greater than 97%, even for diluted samples. Models based on HBF achieved performances comparable to those using UV-Vis data, with the grayscale (GS) color space standing out by correctly classifying 100% of the samples diluted to 5.0%. The methodology, based on both analytical techniques, proved effective for beer authentication. The AFTM-Led device offers significant operational advantages, such as portability and ease of use. This proposal is promising for microbreweries and homebrewers, contributing to standardization and quality control. Procrustes validation demonstrated robustness even with reduced datasets. Furthermore, we propose expanding the use of the AFTM-Led device and HBF to other complex matrices, broadening its potential for various analytical applications.

COMMITTEE MEMBERS:
Presidente - 1714946 - KASSIO MICHELL GOMES DE LIMA
Interna - 2413537 - POLLYANA SOUZA CASTRO
Externo à Instituição - SÓFACLES FIGUEREDO CARREIRO SOARES - UFPB
Externo à Instituição - ADRIANO DE ARAÚJO GOMES - UFRGS
Externo à Instituição - Germano Veras - UFPB