Banca de DEFESA: ANDREA REBOUÇAS ROCHA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : ANDREA REBOUÇAS ROCHA
DATE: 10/12/2021
TIME: 14:00
LOCAL: On-line
TITLE:

Occurrence of aflatoxins B1, B2, G1 and G2 in beers produced in Brazil and their carcinogenic risk assessment

KEY WORDS:

aflatoxins, beers, imunoafinity, HPLC, risk assessment.

PAGES: 25
BIG AREA: Ciências da Saúde
AREA: Farmácia
SUBÁREA: Bromatologia
SUMMARY:

Introduction: Aflatoxins (AFs) are secondary metabolites produced by filamentous fungi that contaminate various cereals. Such contamination affects beer ingredients and adjuncts used in its processing. Due to AFs high thermostability, they can be transferred from raw material to beer. Exposure to aflatoxins is thus of great concern, as these contaminants have high toxic potential and carcinogenic, teratogenic, and mutagenic effects. Since beer is the most consumed alcoholic beverage in Brazil, the assessment of aflatoxins occurrence and carcinogenic risk arising from such exposure are of paramount importance.

The first chapter of this study presents a literature review on the occurrence of aflatoxins in beer, their transfer from raw material to the beverage, and the methods used for their identification and quantification. The second chapter presents the results of the research on these contaminants in beer, involving the validation of the analytical method, application of the analytical technique to beer samples produced and commercialized in Brazil, and the assessment of carcinogenic risk.

Objectives: The objectives of this study were: (i) to evaluate the occurrence of aflatoxins B₁, B₂, G₁, and G₂ in beers, with and without adjuncts, commercialized in Brazil, and (ii) to carry out the carcinogenic risk assessment arising from the exposure to aflatoxins through consumption of those beers.

Method: Sixty beer samples (30 with adjunct and 30 without adjunct) of the leading industrial brands produced and commercialized in Brazil were analyzed. An analytical method by HPLC with fluorescence detection was standardized. Aflatoxin extraction and purification were performed on immunoaffinity columns. The limit of quantification (LQ) ranged from 10 ng.L^-1 to 30 ng.L^-1, and the mean recoveries were 88.5%, 98.0%, 98.3%, and 110.1% for AFB₁, AFB₂, AFG₁, and AFG₂, respectively. The standardized method showed selectivity, specificity, precision, and accuracy, meeting the requirements established by INMETRO guidelines. The risk assessment was performed by determining the margin of exposure (MOE) in two scenarios: medium consumption and high consumption, for men and women.

Results and discussion: Of the total beer samples (n=60), 88.3% showed the occurrence of at least one of the AFs. The median levels of AFB₁, AFG₁, and AFG₂ were lower than the LD/LQ. AFB₂ had a higher incidence in the analyzed samples than other aflatoxins. There was a significant difference between the content of AFB₂ in the beer groups with and without adjuncts (p=0.003). The median levels of AFB₂ contents were 27.0 and 40.4 ng.L^-1 for the beer group with and without adjunct, respectively. Contrary to our results, previous studies carried out in other countries suggested that the use of adjuncts may contribute to the occurrence of aflatoxins in beer. Furthermore, we identified that, in addition to the need of assessment of the occurrence of aflatoxins in brewing adjuncts, this test should be carried out on barley malt used for beer production in Brazil.

 Regarding the risk assessment, MOE values corresponding to high beer consumption (> 160 mL/day) were 5,303 for beer with adjunct and 3,643 for beer without adjunct. The risk characterization showed that people who drink more than 1.1 L per week might be exposed to carcinogenic effects from AFB₂. The risk is higher for the consumption of beer without an adjunct. These data can thus help the authorities to establish maximum tolerated limits for aflatoxins in beer.

BANKING MEMBERS:
Presidente - 2181841 - JOSE ANTONIO MENEZES FILHO
Interna - 225.961.678-08 - ALINE CAMARÃO TELLES BIASOTO - EMBRAPA
Externa à Instituição - KARIM CRISTINA PIACENTINI