Effect of Oxygen-Reducing Atmospheres on the Safety of Packaged Shelled Brazil Nuts during Storage

Abstract

This work reports the application of oxygen-(O2-) reducing atmosphere methods on stored shelled Brazil nut (Bertholletia excelsa H.B.K.) packs aiming to evaluate the degree of aflatoxin degradation, nuts lipid oxidative stability, fungi control, and hygienic conditions improvement. The methods applied were (a) ozone: O3, (b) carbon dioxide: CO2, and (c) O2 absorber pads with and without vacuum. From all modified atmospheres evaluated, the best performance was obtained with O3, either with or without vacuum. It was the only nut treatment that was able to degrade aflatoxins. None of the spiked (AFLs: 15 μg·kg−1) nut samples O3- treated had aflatoxins detected up to the LC-MS/MS method LOQ (0.36 μg·kg−1 for total AFLs), thus producing safer nuts. Also it kept the fatty acid oxidation indicator—malondialdehyde stable and improved the sensory attributes for consumer acceptance. In addition, the destruction of fungi and yeast was observed since the O3 application (from 1.8 × 104 cfu/g to NG = no growth). All other treatments stabilized and/or inhibited microorganisms' growth only. By adding CO2 gas also played an important role in the nut quality. Regarding cost, gaseous O3 showed to be of low cost for application in the nut packs.

Effectiveness of Ozone Gas Application Methods against Combined Multi-Contaminants in Food

“…In this same study, the CTR levels reduced after O 3 treatment in both concentrations (40 and 60 µmoL/moL) after 180 min of exposure [8]. Regarding nuts, the application of O 3 in Brazil nut in studies of Scussel et al [42] and Giordano et al [43] at rate of 10 and 31.5 mg/l during 1.5 and 5 h obtained 100% of A. flavus, A. parasiticus and AFLs decontamination.…”

“…(a) Doses and contamination levels: the gas application methodology can be efficient, in (a.1) a single or may need multiple O 3 doses; including (a.2) adjustments on its concentration according to the extent/intensity (load/level) of living organisms / toxic compounds to be destroyed, and/or the food group to be treated [42,43,[60][61][62][63]. [7,8,41].…”

Procedimentos para colheita de amostras e análises laboratoriais de micotoxinas presentes em dietas humanas e animais

“…Por outro lado, o uso de IACs tem substituído procedimentos de LLE e SPE para purificação do extrato de amostras alimentares ou biológicas (Scussel et al, 2011). Este processo de purificação das amostras é realizado através da interação de um anticorpo pela(s) micotoxina(s) a ser (em) analisada(s), o que resulta em interferência mínima nas etapas de quantificação subsequentes (Binder, 2007).…”

“…Estes métodos de análise devem preferencialmente ser simples, rápidos, sensíveis, seletivos, confiáveis e de baixo custo (Stroka et al, 2004, Amaral and Machinski Junior, 2006, Scussel et al, 2011.…”

“…Esta metodologia está relacionada com ensaios competitivos ou não competitivos, onde primeiramente ocorre uma reação entre um anticorpo específico e um antígeno (micotoxina alvo). Em seguida, ocorre a revelação e a mensuração através de uma hidrólise enzimática entre o complexo antígeno-enzima e substrato (Turner et al, 2009, Scussel et al, 2011. O ensaio imunoenzimático representa uma alternativa para a análise qualitativa de micotoxinas, não requerendo nenhum equipamento sofisticado para obtenção dos resultados (Preedy, 2014 ser de fácil aplicação, as análises realizadas através deste método fornecem respostas rápidas, representando uma alternativa interessante principalmente para o controle de micotoxinas a nível industrial (Pitt, 2000, Preedy, 2014.…”