Banca de DEFESA: BRUNA RAMOS DE SOUZA GOMES

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : BRUNA RAMOS DE SOUZA GOMES
DATE: 21/03/2025
TIME: 14:00
LOCAL: Em ambiente virtual (Google meet)
TITLE:

DEVELOPMENT OF LOW-COST ANALYTICAL METHODS USING DIGITAL IMAGES FOR FOOD QUALITY CONTROL

KEY WORDS:

Digital images, aspartame, reducing sugars, food security.

PAGES: 100
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Analítica
SPECIALTY: Análise de Traços e Química Ambiental
SUMMARY:

Considering the importance of food safety for the protection of public health, the control and monitoring of chemical substances in food is essential. In this context, this work proposed the development of new analytical methodologies to provide simplicity, speed, and low cost, offering efficient alternatives for food analysis. The thesis is structured in two studies, both based on the combination of colorimetric reactions with smartphones as analytical tools, using the RGB color method from the capture of digital images to quantify analytes. In Study 1, two methods were developed for the quantification of reducing sugars (RS) in milk and dairy products, the first employs direct image acquisition (DIA), while the second captures images after centrifugation (Centrifugation Image Acquisition - CIA) of the solution resulting from the colorimetric reaction between the RS and the reagent. Both methods, based on digital image analysis, did not show statistically significant differences about the AOAC 923.09 reference method, meeting the validation criteria. Thus, it was possible to quantify AR in the concentration range of 10 to 100 mg mL-1 in commercial samples of milk and dairy products. In Study 2, two methods were developed for the quantification of aspartame in lemon-lime beverages and soft drinks. The reference methodology based on UV-Vis analysis was initially optimized by replacing the sample preparation solvent (isopropanol: methanol) with water, making the method more sustainable. This optimization resulted in greater stability of the colorimetric reaction product, with recovery values within acceptable limits (84.41% - 102.43%) according to the adopted validation guide. Subsequently, a method based on the use of digital images was successfully developed for the same purpose, which also showed satisfactory recovery values, ranging from 89.34% to 109.20%. Both methods optimized UV-Vis and digital images, did not show statistically significant differences between them when comparing the concentrations determined in the samples, where values corresponding to the aspartame concentration informed on the packaging labels were found. Thus, this work enabled the development of more accessible methods, with the replacement of toxic solvents and expensive equipment, providing faster, more sustainable, and adequate analyses to guarantee the food safety of AR in milk and dairy products and aspartame in lemon-lime beverages and soft drinks.

COMMITTEE MEMBERS:
Presidente - JANDYSON MACHADO SANTOS
Interno - ANDRE FERNANDO LAVORANTE
Interno - RAMOM RACHIDE NUNES
Externo à Instituição - ANA PAULA SILVEIRA PAIM
Externo à Instituição - VAGNER BEZERRA DOS SANTOS - UFPE