Ochratoxin A in Spanish retail ground roasted coffee: Occurrence and assessment of the exposure in Catalonia

Comprehensive Insights into Ochratoxin A: Occurrence, Analysis, and Control Strategies

Ochratoxin A (OTA) is a toxic mycotoxin produced by some mold species from genera Penicillium and Aspergillus. OTA has been detected in cereals, cereal-derived products, dried fruits, wine, grape juice, beer, tea, coffee, cocoa, nuts, spices, licorice, processed meat, cheese, and other foods. OTA can induce a wide range of health effects attributable to its toxicological properties, including teratogenicity, immunotoxicity, carcinogenicity, genotoxicity, neurotoxicity, and hepatotoxicity. OTA is not only toxic to humans but also harmful to livestock like cows, goats, and poultry. This is why the European Union and various countries regulate the maximum permitted levels of OTA in foods. This review intends to summarize all the main aspects concerning OTA, starting from the chemical structure and fungi that produce it, its presence in food, its toxicity, and methods of analysis, as well as control strategies, including both fungal development and methods of inactivation of the molecule. Finally, the review provides some ideas for future approaches aimed at reducing the OTA levels in foods.

A Novel Electrochemiluminescence Immunosensor Based on Resonance Energy Transfer between g-CN and NU-1000(Zr) for Ultrasensitive Detection of Ochratoxin A in Coffee

In this study, an electrochemiluminescence (ECL) immunosensor based on nanobody heptamer and resonance energy transfer (RET) between g-C₃N₄ (g-CN) and NU-1000(Zr) was proposed for ultrasensitive ochratoxin A (OTA) detection. First, OTA heptamer fusion protein was prepared by fusing OTA-specific nanometric (Nb28) with a c-terminal fragment of C4 binding protein (C4bpα) (Nb28-C4bpα). Then, Nb28-C4bpα heptamer with the high affinity used as a molecular recognition probe, of which plenty of binding sites were provided for OTA-Apt-NU-1000(Zr) nanocomposites, thereby improving the immunosensors' sensitivity. In addition, the quantitative analysis of OTA can be achieved by using the signal quenching effect of NU-1000(Zr) on g-CN. As the concentration of OTA increases, the amount of OTA-Apt-NU-1000(Zr) fixed on the electrode surface decreases. RET between g-CN and NU-1000(Zr) is weakened leading to the increase of ECL signal. Thus, OTA content is indirectly proportional to ECL intensity. Based on the above principle, an ultra-sensitive and specific ECL immunosensor for OTA detection was constructed by using heptamer technology and RET between two nanomaterials, with a range from 0.1 pg/mL to 500 ng/mL, and the detection limit of only 33 fg/mL. The prepared ECL-RET immunosensor showed good performance and can be successfully used for the determination of OTA content in real coffee samples, suggesting that the nanobody polymerization strategy and the RET effect between NU-1000(Zr) and g-CN can provide an alternative for improving the sensitivity of important mycotoxin detection.

Estimasi Risiko Okratoksin A dari Konsumsi Kopi Bubuk di Indonesia

Ochratoxin A (OTA) is a nephrotoxic and carcinogenic mycotoxin that can be found in coffee. This study aimed to obtain the processing steps commonly applied by coffee shops in Indonesia, calculate the level of OTA in coffee bean and ground coffee, and the risk estimate of OTA exposure from ground coffee in Indonesia. The processing steps were determined through an online survey while the level of OTA in coffee was calculated from available references. The consumption level of ground coffee was determined from the Indonesia total diet study report and the exposure assessment was carried out by deterministic approach. The risk estimates were expressed as % risk towards provisional tolerable weekly intake (PTWI) and margin of exposure (MOE). Based on the survey of coffee shops (n=20), ground coffee is commonly processed using dry method consisting of cherries sorting, sun drying, roasting and grinding. Ground coffee was the most common coffee consumed by adults. Based on references from countries with climate similar to Indonesia, the level of OTA in coffee bean ranged from 0.033 to 168 μg/kg with an average of 12.25 μg/kg and 0.018-55 μg/kg in ground coffee averaging at 5.60 μg/kg. The individual exposure to OTA from drinking coffee is 0.014-0.744 ng/kg bw/day. The risk estimates shows that risk of ochratoxin A from ground coffee consumption is low, with risk percentage of <100 % provisional tolerable weekly intake (PTWI) and a MOE of higher than 10000 for all age groups. The study suggested that adults (19-55 years) have higher exposure and risk than the other age groups.

Assessment of ochratoxin A exposure risk from the consumption of coffee beans in Phnom Penh, Cambodia

This survey aimed to determine OTA contamination in roasted coffee samples commercialised in Phnom Penh, Cambodia and to assess the potential health risk from OTA exposure. Forty locally grown and imported coffee samples were collected and analysed. Analytical validation methods were fully performed. In 3 of 40 samples (7.5%), the results showed detectable levels of OTA, ranging from 0.19 to 1.12 µg kg^-1, with an overall average of 0.26 µg kg^-1 and an average over the LOQ (n = 3) at 0.81 µg kg^-1. OTA estimated daily intake (EDI) of both values were 0.05 (overall average) and 0.17 ng/kg bw/day (the worst-case scenario) with the calculated risk of OTA exposure expressed as a Hazard Quotient at 0.003 and 0.01, respectively. This result could imply a low health risk to Cambodian coffee consumers.

Ochratoxin A and 2'R-Ochratoxin A in Selected Foodstuffs and Dietary Risk Assessment

The aim of this study was to estimate the contamination of grain coffee, roasted coffee, instant coffee, and cocoa purchased in local markets with ochratoxin A (OTA) and its isomerization product 2'R-ochratoxin A (2'R-OTA), and to assess risk of dietary exposure to the mycotoxins. OTA and 2'R-OTA content was determined using the HPLC chromatography with immunoaffinity columns dedicated to OTA. OTA levels found in all the tested samples were below the maximum limits specified in the European Commission Regulation EC 1881/2006. Average OTA concentrations calculated for positive samples of grain coffee/roasted coffee/instant coffee/cocoa were 0.94/0.79/3.00/0.95 µg/kg, with the concentration ranges: 0.57-1.97/0.44-2.29/0.40-5.15/0.48-1.97 µg/kg, respectively. Average 2'R-OTA concentrations calculated for positive samples of roasted coffee/instant coffee were 0.90/1.48 µg/kg, with concentration ranges: 0.40-1.26/1.00-2.12 µg/kg, respectively. In turn, diastereomer was not found in any of the tested cocoa samples. Daily intake of both mycotoxins with coffee/cocoa would be below the TDI value even if the consumed coffee/cocoa were contaminated with OTA/2'R-OTA at the highest levels found in this study. Up to now only a few papers on both OTA and 2'R-OTA in roasted food products are available in the literature, and this is the first study in Poland.

The Occurrence and Contamination Level of Ochratoxin A in Plant and Animal-Derived Food Commodities

Ochratoxin A (OTA) is a highly toxic mycotoxin and poses great threat to human health. Due to its serious toxicity and widespread contamination, great efforts have been made to evaluate its human exposure. This review focuses on the OTA occurrence and contamination level in nine plant and animal derived food commodities: cereal, wine, coffee, beer, cocoa, dried fruit, spice, meat, and milk. The occurrence and contamination level varied greatly in food commodities and were affected by many factors, including spices, geography, climate, and storage conditions. Therefore, risk monitoring must be routinely implemented to ensure minimal OTA intake and food safety.

A signal-on electrochemical aptasensor based on silanized cellulose nanofibers for rapid point-of-use detection of ochratoxin A

An innovative ultrasensitive electrochemical aptamer-based sensor was developed for ochratoxin A (OTA) detection in cold brew coffee through revolutionary combination of nanofibers, electrochemical method, and aptamer technologies. The assembly of the aptasensor was based on the activation of silanized cellulose nanofibrous membranes as a supporting matrix for methylene blue (MB) redox probe-labeled aptamer tethering. Cellulose nanofibrous membranes were regenerated by deacetylating electrospun cellulose acetate nanofibrous membranes with deacetylation efficacy of 97%, followed by silanization of the nanofiber surfaces by using (3-aminopropyl)triethoxysilane (APTES). A replacement of conventionally casted membranes by the nanofibrous membranes increased the active surface area on the working electrode of a screen-printed three-electrode sensor by more than two times, consequently enhancing the fabricated aptasensor performance. The developed aptasensor demonstrated high sensitivity and specificity toward OTA in a range 0.002-2 ng mL^-1, with a detection limit of 0.81 pg mL^-1. Moreover, the assembled aptamer-based sensor successfully detected OTA in cold brew coffee samples without any pretreatment. The aptasensor exhibited good reusability and stability over long storage time. Graphical abstract.

Occurrence of Ochratoxin A in Coffee: Threads and Solutions—A Mini-Review

Ochratoxin A (OTA) is a widespread bioactive extrolite from secondary metabolism of fungi which presence in foods like coffee is of public health concern, particularly for heavy drinkers. Coffee is one of the most consumed and appreciated non-alcoholic beverage in the world. Its production from the plantation to the coffee cup involves several steps that would determine the final concentration of OTA in the beverage. This review gives an overview of OTA contamination in roasted coffee beans in different countries and mitigation strategies for OTA reduction.

Ochratoxin A Concentrations in a Variety of Grain-Based and Non-Grain-Based Foods on the Canadian Retail Market from 2009 to 2014

The extent of ochratoxin A (OTA) contamination of domestically produced foods sold across Canada was determined from 2009 to 2014 with sampling and testing occurring each fiscal year. Cereal-based, fruit-based, and soy-based food samples (n = 6,857) were analyzed. Almost half of the samples (3,200; 47%) did not contain detectable concentrations of OTA. The remaining 3,657 samples contained OTA at 0.040 to 631 ng/g. Wheat, oats, milled products of other grains (such as rye and buckwheat), and to a lesser extent corn products and their derived foods were the most significant potential sources of OTA exposure for the Canadian population. Wine, grape juice, soy products, beer, dairy-based infant formula, and licorice candy were not significant contributors to OTA consumption. Spices had the highest OTA concentrations; but because so little is ingested, these foods are not considered to be a significant source of OTA. In contrast, infant formulas and cereals can be important dietary sources of OTA. Infant cereals containing oats and infant formulas containing soy had detectable concentrations of OTA, some of which exceeded the proposed Canadian guidelines. The prevalence and concentrations of OTA in major crops (wheat, corn, and oats) varied widely across years. Because these foods were purchased at retail stores, no information was available on the OTA concentrations in the raw materials, the storage conditions before purchase of the samples, or the origin of the ingredients (may include blends of raw materials from different years and/or different geographical regions of Canada); therefore, impact of these factors could not be assessed. Overall, 2.3% of the samples exceeded the proposed Canadian OTA regulatory limits and 2.7% exceeded the current European Union (EU) OTA regulatory limits. These results are consistent with a Health Canada exposure assessment published in 2010, despite the inclusion of a wider range of products and confirm the safety of foods widely available across Canada.

A mycotoxin-dedicated total diet study in the Netherlands in 2013: Part II – occurrence

The occurrence of 59 natural toxins was determined in 88 composite food and drink samples of a mycotoxin-dedicated total diet study performed in the Netherlands in 2013. Composite food samples were prepared by pooling foods from a food category (as consumed, e.g. peeled, cooked, etc.) according to their consumption by population groups in the Netherlands. A multi-targeted method based on QuEChERs extraction, dilute and shoot and analysis by liquid chromatography-tandem mass spectrometry was applied to the 88 composite samples. Dedicated methods with lower detection limits for patulin, aflatoxins and trichothecenes were also applied to specific food types. Thirty samples (34%) were positive for one or more mycotoxins. Patulin, aflatoxin M1, zearalenone and plant toxins, with the exception of scopolamine in liquorice, were not detected in any of the composite samples. Aflatoxin B1 was only detected, but not at quantifiable levels, in the composites that contained peanuts. Fumonisin B1 was only found at 18 μg/kg in breakfast cereals consumed by the population group of 7-69 years, whereas ochratoxin A occurred at low levels around 1 μg/kg in liquorice, legumes and coffee. Grains and grain-based food composites were positive for ergot alkaloids, enniatins B and B1 and deoxynivalenol (DON). The levels of DON in the positive samples were lower compared to other studies, with the exception of breakfast cereals for infants with a DON concentration of 116 μg/kg. This specific composite sample may have contained an ingredient with a concentration exceeding the maximum legal limit of 200 μg/kg. Alternaria toxins (alternariol and alternariol methyl ether) were detected at levels ranging from 1.0 to 8.9 μg/kg in a number of composite samples, including tomato products, nuts, cereal products, chocolate and wine. Mycophenolic acid and roquefortine C cooccurred in mould-ripened cheese composites, while mycophenolic acid also was found in dried fruit and liquorice composite samples.

Blood, breast milk and urine: potential biomarkers of exposure and estimated daily intake of ochratoxin A: a review

The purposes of this review are to study potential biomarkers of exposure for ochratoxin A (OTA) in biological fluids (blood, urine and breast milk) for the period 2005-14, calculate the estimated daily intake (EDI) of OTA by using database consumption for the Spanish population, and, finally, to correlate OTA levels detected in blood and EDI values calculated from food products. The values of OTA detected in potential biomarkers of exposure for blood, breast milk and urine ranged from 0.15 to 18.0, from 0.002 to 13.1, and from 0.013 to 0.2 ng ml(-1), respectively. The calculated EDI for OTA in plasma ranged from 0.15 to 26 ng kg(-1) bw day(-1), higher than that obtained in urine (0.017-0.4 ng kg(-1) bw day(-1)). All these values are correlated with the range of EDI for OTA calculated from food products: 0.0001-25.2 ng kg(-1) bw day(-1).

Analysis of mycotoxins in coffee and risk assessment in Spanish adolescents and adults

Mycotoxins are toxic compounds produced by fungal secondary metabolism that cause toxicological effects. Coffee is a highly popular beverage that is susceptible to contamination by mycotoxigenic fungi. The aim of the present study was to determine the presence of the following 21 mycotoxins in coffee using liquid chromatography tandem mass spectrometry (LC-MS/MS-IT): aflatoxin B1, B2, G1 and G2; ochratoxin A; nivalenol; deoxynivalenol; 3-acetyldeoxynivalenol; 15-acetyldeoxynivalenol; diacetoxyscirpenol; neosolaniol; T-2 and HT-2 toxin; sterigmatocystin; enniatin A, A1, B, and B1; beauvericin; and fumonisin B1 and B2. We aimed to determine differences by coffee process (coffee maker, electrical machine, soluble and traditional Turkish process) and to calculate the estimated daily intake (EDI) and risk assessment of mycotoxins from coffee consumption using deterministic approach at various scenarios of food consumption in Spanish adolescents and adults. The results demonstrate that all studied mycotoxins were detected in samples with mean concentrations ranging from 0.69 µg/kg to 282.89 µg/kg. Eleven percent of samples did not show contamination with legislated mycotoxins. Only 15-acetyldeoxynivalenol, deoxynivalenol, neosolaniol, fumonisin B1, and ochratoxin A exhibited significant differences between methods of coffee brewing. The results show that coffee intake does not represent a potential risk for consumers with respect to individual mycotoxin contamination.

Ochratoxin A Dietary Exposure of Ten Population Groups in the Czech Republic: Comparison with Data over the World

Ochratoxin A is a nephrotoxic and renal carcinogenic mycotoxin and is a common contaminant of various food commodities. Eighty six kinds of foodstuffs (1032 food samples) were collected in 2011–2013. High-performance liquid chromatography with fluorescence detection was used for ochratoxin A determination. Limit of quantification of the method varied between 0.01–0.2 μg/kg depending on the food matrices. The most exposed population is children aged 4–6 years old. Globally for this group, the maximum ochratoxin A dietary exposure for “average consumer” was estimated at 3.3 ng/kg bw/day (lower bound, considering the analytical values below the limit of quantification as 0) and 3.9 ng/kg bw/day (middle bound, considering the analytical values below the limit of quantification as 1/2 limit of quantification). Important sources of exposure for this latter group include grain-based products, confectionery, meat products and fruit juice. The dietary intake for “high consumers” in the group 4–6 years old was estimated from grains and grain-based products at 19.8 ng/kg bw/day (middle bound), from tea at 12.0 ng/kg bw/day (middle bound) and from confectionery at 6.5 ng/kg bw/day (middle bound). For men aged 18–59 years old beer was the main contributor with an intake of 2.60 ng/kg bw/day (“high consumers”, middle bound). Tea and grain-based products were identified to be the main contributors for dietary exposure in women aged 18–59 years old. Coffee and wine were identified as a higher contributor of the OTA intake in the population group of women aged 18–59 years old compared to the other population groups.

Public health risk associated with the co-occurrence of mycotoxins in spices consumed in Sri Lanka

A quantitative risk assessment of mycotoxins due to the consumption of chilli (Capsicum annum L.) and black pepper (Piper nigrum L.) was performed in Sri Lanka. A food frequency questionnaire was administered in order to collect the data on consumption of spices by households in the Northern and Southern region (n = 249). The mean chilli consumption in the North was significantly higher (p < 0.001) compared to the South. Mean exposure to aflatoxin B1 (AFB1) in the North (3.49 ng/kg BW/day) and South (2.13 ng/kg BW/day) have exceeded the tolerable daily intake due to chilli consumption at the lower bound scenario, while exposure to OTA was small. Dietary exposure to other mycotoxins, fumonisin B1, fumonisin B2, sterigmatocystin and citrinin due to spices were estimated. Margin of exposure estimations at the mean exposure to AFB1 were remarkably lower due to chilli (45-78) than for pepper (2315–10,857). Moreover, the hepato cellular carcinoma (HCC) risk associated with the mean AFB1 exposure through chilli at the lower bound was 0.046 and 0.028 HCC cases/year/100,000 based on the North and South consumption, respectively. AFB1 exposure via chilli should be considered as a great public health concern in Sri Lanka due to both high mycotoxin concentration and high consumption.

Transfer of ochratoxin A into tea and coffee beverages

Ochratoxin A (OTA) is nephrotoxic, hepatotoxic, immunotoxic, neurotoxic, reprotoxic, teratogenic, and carcinogenic (group 2B), being characterized by species and sex differences in sensitivity. Despite the fact that OTA is in some aspects a controversial topic, OTA is the most powerful renal carcinogen. The aim of this study was to make a small survey concerning OTA content in black tea, fruit tea, and ground roasted coffee, and to assess OTA transfer into beverages. OTA content was measured using a validated and accredited HPLC-FLD method with a limit of quantification (LOQ) of 0.35 ng/g. The OTA amount ranged from LOQ up to 250 ng/g in black tea and up to 104 ng/g in fruit tea. Black tea and fruit tea, naturally contaminated, were used to prepare tea infusions. The transfer from black tea to the infusion was 34.8% ± 1.3% and from fruit tea 4.1% ± 0.2%. Ground roasted coffee naturally contaminated at 0.92 ng/g was used to prepare seven kinds of coffee beverages. Depending on the type of process used, OTA transfer into coffee ranged from 22.3% to 66.1%. OTA intakes from fruit and black tea or coffee represent a non-negligible human source.

Comparison of clean-up methods for ochratoxin A on wine, beer, roasted coffee and chili commercialized in Italy

The most common technique used to detect ochratoxin A (OTA) in food matrices is based on extraction, clean-up, and chromatography detection. Different clean-up cartridges, such as immunoaffinity columns (IAC), molecular imprinting polymers (MIP), Mycosep™ 229, Mycospin™, and Oasis^® HLB (Hydrophilic Lipophilic balance) as solid phase extraction were tested to optimize the purification for red wine, beer, roasted coffee and chili. Recovery, reproducibility, reproducibility, limit of detection (LOD) and limit of quantification (LOQ) were calculated for each clean-up method. IAC demonstrated to be suitable for OTA analysis in wine and beer with recovery rate >90%, as well as Mycosep™ for wine and chili. On the contrary, MIP columns were the most appropriate to clean up coffee. A total of 120 samples (30 wines, 30 beers, 30 roasted coffee, 30 chili) marketed in Italy were analyzed, by applying the developed clean-up methods. Twenty-seven out of 120 samples analyzed (22.7%: two wines, five beers, eight coffees, and 12 chili) resulted positive to OTA. A higher incidence of OTA was found in chili (40.0%) more than wine (6.6%), beers (16.6%) and coffee (26.6%). Moreover, OTA concentration in chili was the highest detected, reaching 47.8 µg/kg. Furthermore, three samples (2.5%), two wines and one chili, exceeded the European threshold.