Mycotoxin occurrence in breast milk and exposure estimation of lactating mothers using urinary biomarkers in São Paulo, Brazil

In this study, the occurrence of aflatoxins (AFs), fumonisins (FBs), ochratoxin A (OTA), deoxynivalenol (DON), zearalenone (ZEN) and some of their metabolites were assessed in breast milk and urine of lactating women (N = 74) from Pirassununga, São Paulo, Brazil. Exposure estimations through urinary mycotoxin biomarkers was also performed. Samples were collected in four sampling times (May and August 2018, February and July 2019) and analyzed by liquid chromatography coupled to tandem mass spectrometry. Aflatoxin M₁ (AFM₁) was not detected in breast milk. However, two samples (3%) presented FB₁ at 2200 and 3400 ng/L, while 4 samples (5%) had OTA at the median level of 360 ng/L. In urine, AFM₁ and aflatoxin P₁ (AFP₁) were found in 51 and 11% of samples, respectively (median levels: 0.16 and 0.07 ng/mg creatinine, respectively). Urinary DON (median level: 38.59 ng/mg creatinine), OTA (median level: 2.38 ng/mg creatinine) and ZEN (median level: 0.02 ng/mg of creatinine) were quantified in 18, 8 and 10% of the samples, respectively. Mean probable daily intake (PDI) values based on urinary biomarkers were 1.58, 1.09, 5.07, and 0.05 μg/kg body weight/day for AFM₁, DON, OTA, and ZEN, respectively. Although a low mycotoxin occurrence was detected in breast milk, the PDI for the genotoxic AFs was much higher than those reported previously in Brazil, while PDI values obtained for OTA and DON were higher than recommended tolerable daily intakes. These outcomes warrant concern on the exposure of lactating women to these mycotoxins in the studied area.

Dietary exposure assessment and risk characterization of mycotoxins in lactating women: Case study of São Paulo state, Brazil

The exposure and risk characterization of lactating women to aflatoxins (AFs), fumonisins (FBs), ochratoxin A (OTA) and zearalenone (ZEN) due to consumption of different types of food products in Pirassununga, São Paulo, Brazil, was assessed. Lactating women (N = 74) provided samples of foods stored and available at their households between April-August/2018, totaling 184 samples. Mycotoxins were determined in food samples by liquid chromatography-tandem mass spectrometry. According to findings, 20% (n = 36) of all food samples were contaminated with AFs at median concentrations ranging from 9.2 to 18.5 µg/kg, while OTA was detected only in three samples (rice, bread and pasta) at concentrations of 22.3, 23.8 and 48.7 µg/kg, respectively. ZEN was detected in 34 samples (18%) at median levels of 62-195 µg/kg, and FBs at median levels of 58-1546 µg/kg was observed in 22 samples (12%). Moreover, the concentration of AFs, OTA, ZEN and FBs exceeded their respective maximum permitted levels in 11 (6%), 3 (2%), 8 (4%) and 5 (3%) from total samples, respectively. Twenty-eight samples (15%) were contaminated with two or three types of mycotoxins. Corn products contributed for the highest mean probable daily intakes (PDI) of AFs (0.119 ± 0.193 µg/kg body weight (bw)/day), ZEN (0.325 ± 0.097 µg/kg bw/day) and FBs (2.936 ± 1.541 µg/kg bw/day), while wheat-based products contributed for the highest PDI of OTA (0.035 ± 0.028 µg/kg bw/day). The Margin of Exposure (MoE) value for AFs (3.72) demonstrated a high cancer risk (MoE < 10,000), and the Hazard Quotient (HQ) obtained for OTA (24.66), ZEN (4.24) and total FBs (5.01) also resulted in a non-tolerable risk (HQ > 1) via consumption of the investigated food products. Results of this trial indicate high exposure levels of lactating women to dietary mycotoxins in the studied area, which warrant concern about the possible transfer of residual mycotoxins into breast milk.

Voltammetric Detection of Lead Using Chitosan-tripolyphosphate Crosslinked Electrode

This paper discusses about the improvement of electrochemical characteristics of graphite paste electrode chemically modified with chitosan through physical crosslinking of the biopolymer with sodium tripolyphosphate. Biopolymer characterizations were performed by scanning electron microscopy, Fourier transform infrared spectroscopy, cyclic voltammetry and electrochemical impedance spectroscopy. The electrochemical characterization of Pb with graphite paste electrode modified with chitosan crosslinked with sodium tripolyphosphate (GPE-CTS-TPP) showed that the process is quasireversible, controlled by adsorption and involves the transfer of two electrons. Additionally, the physical crosslinking process decreased the electrode resistance as well as improved the electron transfer rate. Once the GPE-CTS-TPP showed enhanced morphological and electrochemical characteristics, it was applied for Pb determination by square wave anodic stripping voltammetry. The method presented appropriate accuracy (recoveries from 95 to 108% and concordance with comparative method between 90 and 107%), high sensitivity (limit of detection and quantification of Pb were 0.73 and 2.44 μg L^-1, respectively) and could be applied to analytical determinations.

Aflatoxin in foodstuffs: Occurrence and recent advances in decontamination

Aflatoxins are highly toxic compounds produced as secondary metabolites by some Aspergillus species, whose occurrence have been reported predominantly in several types of foods of low moisture content, while aflatoxin biotransformation products have been reported mainly in milk and milk products. This review deals with the occurrence of aflatoxins in some of the major food products in the last 5 years including regulatory aspects, and recent advances in detoxification strategies for contaminated foods. Aflatoxin contamination in cereals including corn and peanut is still a public health problem for some populations, especially in African countries. Despite that most of physical and chemical methods for aflatoxin detoxification may affect the nutritional properties of food, or are not safe for human consumption, gamma-radiation and ozone applications have demonstrated great potential for detoxification of aflatoxins in some food matrices. Biological methods based on removal or degradation of aflatoxins by bacterial and yeast have good perspectives, although further studies are needed to clarify the detoxification mechanisms by microorganisms and determine practical aspects of the use of these methods in food products, especially their potential effects on sensory characteristics of foods.

Effects of different sources of Saccharomyces cerevisiae biomass on milk production, composition, and aflatoxin M1 excretion in milk from dairy cows fed aflatoxin B1

The aim of the present study was to evaluate the effect of different sources of Saccharomyces cerevisiae (SC) biomass (20.0 g/d) obtained from sugarcane (cell wall, CW; dried yeast, DY; autolyzed yeast, AY) and the beer industry (partially dehydrated brewery yeast, BY) on milk production, fat and protein percentages, and aflatoxin M₁ (AFM₁) excretion in milk from dairy cows receiving 480 µg aflatoxin B₁ (AFB₁) per day. A completely randomized design was used with 2 lactating cows assigned to each of 10 dietary treatments, as follows: negative controls (no AFB₁ or SC-based biomass), positive controls (AFB₁ alone), DY alone, DY + AFB₁, BY alone, BY + AFB₁, CW alone, CW + AFB₁, AY alone, and AY + AFB₁. The cows in the aflatoxin treatment group received AFB₁ from d 1 to 6, while the SC biomass was administered with the AFB₁ bolus from d 4 to 6. Aflatoxin B₁ or SC-based products did not affect milk production or milk composition during the experimental period. Aflatoxin M₁ was detected in the milk from all aflatoxin treatment group cows, reaching maximum levels at d 3 and varying from 0.52 ± 0.03 to 1.00 ± 0.04 µg/L. At end of the treatment period, CW, AY, DY, and BY removed 78%, 89%, 45%, and 50% of AFM₁ from the milk, respectively, based on the highest level found on d 3. Results indicate a potential application of industrial fermentation by-products, especially CW and AY, as a feed additive in the diets of dairy cows to reduce the excretion of AFM₁ in milk.