An analytical approach to reveal the addition of heat-denatured whey proteins in lab-scale cheese making

A simple analytical procedure for the detection of self-aggregated heat-denatured whey proteins (HDWP) in model cheeses was developed. The principle of the approach lies in the solubilization of the cheese matrix by a sodium citrate solution (0.2 M, pH 7.0) resulting in the dissociation of the casein micelles and the insolubilization of HDWP aggregates, which are collected in the pellet after a centrifugation step. The reliability of the procedure was tested in lab-scale cheeses from peroxidase-positive pasteurized milk with different protein-based ingredients (microparticulated whey protein concentrate, milk protein concentrate, whey protein isolate and Ricotta cheese) at concentrations ranging from 0.2 to 1.2% protein (w/v on cheese milk). A linear relationship between the amount of the HDWP added to cheese milk and that recovered from model cheeses was observed. Heat-damage indicators, furosine and lysinoalanine, showed levels in the experimental cheese samples not related with added HDWP, but represented a source of information on the ingredients other than liquid milk. Overall, in the model cheeses, the proposed method was an easy-to-apply and reliable tool for the evaluation of the presence of HDWP-based products. Further investigation is required for the application to real cheeses and for the evaluation of possible interferences from proteolysis during ripening.     

Poultry marketing controls – Inter-laboratory validation of a method to detect previously frozen chicken breasts by determination of HADH activity

EU poultry marketing legislation requires that poultry be marketed either as fresh (chilled) poultry or as frozen (or quick-frozen) poultry. It is not permitted to market poultry which has been previously frozen as if it were fresh. A robust analytical method that is capable of distinguishing between fresh and previously frozen poultry is therefore required for the enforcement of the legislation. A method to detect whether poultry and other meats have been previously frozen was developed and validated by an earlier collaborative study in 1997. The method is based on measuring the HADH activity of intracellular juice pressed from the test samples. The ratio of the HADH activity of sub-samples tested before and after laboratory freezing is compared to a reference cut-off limit, to determine whether the sample has previously been frozen. In a subsequent study in 2010, improvements were made to the analytical procedure and a revised cut-off limit for chicken of 0.5 was determined. The aim of the current study was to validate the improved analytical procedure and the revised cut-off value for chicken via a collaborative trial with 12 European NRLs and 12 UK OCLs. Each laboratory was asked to analyse 24 chicken breast samples and to use the results to determine their thermal history (chilled or previously frozen) according to the SOP provided. All samples were supplied as chilled blind samples. The results of the study showed inter-laboratory variation between the results obtained for chilled and for previously frozen chicken breasts, however despite this, almost all of the samples were correctly identified and reported in terms of their thermal history. Although some reduction in the analytical variability of the method would be beneficial, the results confirmed the suitability of the method and the revised cut-off limit of 0.5 for the official control of marketing of chicken breasts within the EU.     

Presence of mycotoxins in animal milk: A review

Mycotoxins can cause toxicity when ingested by humans and animals. Although the rumen is supposed to be a barrier against mycotoxins, some studies demonstrate that carry-over of mycotoxins to milk is possible. Different studies have found mycotoxin levels in animal milk, mainly related to contaminated feed for ruminants. Aflatoxin M1 is the most studied mycotoxin in milk and levels exceeding the EU maximum level for this mycotoxin in this matrix (0.050 μg/kg) have been found. Maximum levels in milk for other mycotoxins have not been established; however ochratoxin A, aflatoxins G1, G2, B1, B2 and M2, fumonisin B1, cyclopiazonic acid, zearalenone and its metabolites and deepoxy-deoxynivalenol have also been found in milk samples. Taking into account that multi-exposure to mycotoxins is the most likely scenario and co-occurrence of mycotoxins could affect their toxicological effects in humans and animals, there is a need to determine the co-occurrence of mycotoxins in milk.     

A survey on the milk chemical and microbiological quality in dairy donkey farms located in NorthWestern Italy

There is a growing interest in donkey's milk as food for sensitive consumers, such as infants with cow's milk protein allergy and elderly people. The aim of this study was to carry out a survey on the dairy donkeys farming in Piedmont, Italy. The research was conducted in order to analyze the farm characteristics as well as the chemical and microbiological quality of milk. All the farms were small-sized, family-run, and, in most cases, animals were farmed semi-extensively. The donkey milk from Piedmont farms was characterized by a protein content around 1.5 g/100 mL and a fat content lower than 0.1 g/100 mL. Lysozyme activity was considerably higher than that reported in raw cow milk. The milk microbiological profile greatly differed among the farms. Milk sampled in the farm that performed hand milking showed total viable counts significantly lower than milk collected in the farms equipped with automatic milking. Samples were tested for several pathogens and negative results were observed, except for the detection of Bacillus cereus in one sample. The survey provided useful data for the laying down of recent regional regulation for the production and commercialization of donkey's milk. The results of the survey indicate that further research is needed in order to define the best management and nutritional strategies for the improvement of the quali-quantitative production of dairy donkeys.     

Occurrence of aflatoxin M1 in pasteurized and UHT milks in China in 2014–2015

This survey was performed to assess the safety of milk in China, specifically by assessing the presence of aflatoxin M1 (AFM1) residues in pasteurized and ultra high temperature (UHT) milk. In 2014–2015, 193 samples of UHT milk were collected from different cities in China. In 2015, 38 samples of pasteurized milk were collected from different cities in China. AFM1 was detected using an enzyme-linked immunosorbent assay (ELISA). AFM1 positivity was defined as a concentration exceeding the detection limit of the assay (0.005 μg/kg). Other cut-offs that were used were the legal AFM1 limits in the European Union (EU) and China (0.05 and 0.5 μg/kg, respectively). In 2014 and 2015, 88.6% and 59.6% of UHT milk samples were AFM1-positive, respectively. The pasteurized milk samples were less frequently AFM1-positive (47.4%). In 11.9% of the 2014–2015 UHT milk samples, the AFM1 levels exceeded the EU limit. This is lower than the frequency we recorded in 2010 (20.3%). None of the pasteurized milk samples exceeded the EU limit in 2015. The UHT milk samples from the north of China were less likely to be contaminated than the samples from the south in both 2014 and 2015. None of the samples exceeded the Chinese legal limit.     

Authentication of Iberian dry-cured ham: New approaches by polymorphic fingerprint and ultrahigh resolution mass spectrometry

Foods with high added value, such as Iberian dry-cured products, are susceptible to fraud. Many attempts have been made to differentiate the commercial/quality categories of Iberian dry-cured hams by analytical determinations. However, as discrimination by such means is not fully reliable, legislation to prevent fraudulent practice is based on administrative controls and certification. Here, new analytical approaches based on ultrahigh resolution mass spectrometry (UHRMS) and crystallographic techniques applied to the lipid fraction, in combination with chemometrics, are studied. The results of the triacylglycerol profile determined by UHRMS and the fingerprint provided by the thermograms obtained by differential scanning calorimetry offer the promise of analytic discrimination of Iberian dry-cured ham categories. In addition, these determinations, in combination with chemometrics, may prove extremely useful to authenticate many foods containing high to moderate amounts of lipids.     

Occurrence and estimation of aflatoxin M1 exposure in milk in Serbia

The occurrence of AFM1 was investigated in 150 cow's, 10 goat's, 5 donkey's, 10 breasts milk and 1 infant formula samples. Analyses were done using Enzyme Linked Immunosorbent Assay (ELISA) method. AFM1 was detected in 98.7% of analyzed cow's milk samples in concentrations ranged from 0.01 to 1.2 μg/kg. Further, even 129 (86.0%) cow's milk samples contained AFM1 in concentration greater than maximum residue levels (MRL) of 0.05 μg/kg defined by European Union (EU) Regulation. Analysis of other types of milk showed that AFM1 was detected in 80.0% goat's, 60.0% donkey's and 60.0% of breasts milk samples.Although Serbian Regulation for MRL of AFM1 in milk has been changed and harmonized with EU Regulation in 2011, occurrence of AFM1 in milk in Serbia during 2013 resulted in Regulation changes, and MRL were changed from 0.05 to 0.5 μg/kg.On the basis of the obtained concentrations of the AFM1 in cow's milk, collected information about average milk intake and mean body weight (bw) for different age's categories, mean ingestion of AFM1 in ng/kg per bw per day were estimated. Obtained results showed that all age's categories, especially children, are exposed with high risk related to presence of AFM1 in milk.There are only a few published data about occurrence of AFM1 in milk in Serbia and none about intake assessment for AFM1.     

Thermal treatments and their effects on the fumonisin B1 level in rice

The objective of this study was to evaluate the effects of dry and hydrothermal treatment on FB₁ level in polished, parboiled and whole grain rice collected in Brazilian market. The effect of thermal treatment on FB₁ level was carry out by applying conventional cooking, autoclaving and dry heat treatment. Conventional hydrothermal treatment (cooking) reduced the initial natural contamination by 80%. However, no significant reduction was obtained by autoclaving. Dry heat treatment produced the reduction (70%), at temperatures range from 150 to 200 °C.     

Uncovering a challenging case of adulterated commercial saffron

The analytical approach presented uncovers the type of adulteration of a commercial product labeled as “saffron”, sold packed in powder form in a major consuming country. Simple colorimetric and spectrometric tests included in the ISO 3632 trade standard indicated only that it was not “pure saffron”. The TLC and HPLC methods recommended in the same standard for the detection of artificial colorants were not applicable due to limited sample amount available. Since it could not be precluded that substances other than artificial colorants have been used, deeper investigation through metabolic fingerprinting was necessary to uncover chemical composition of the sample. The multistep workflow that exploited chromatographic (HPLC) and spectroscopic (UV–Vis, mid-infrared (FT-IR), and nuclear magnetic resonance (NMR)) data from in-house databases uncovered a “tailor-made” case of 100% substitution of saffron by a mixture of exogenous chemical compounds in such a way that the commercial product would approximately mimic not only the appearance of saffron but also its UV–Vis spectrum and specific absorbance values. The findings indicated a sophisticated practice, including total substitution of saffron constituents by tartrazine and sunset yellow along with propane-1,2-diol, propan-2-ol and acylglycerols, probably as emulsifier agents. Interestingly, the perpetrators avoided the use of toxic compounds. To our knowledge such a type of fraud has not been elucidated so far.     

A survey on the occurrence of aflatoxin M1 in raw milk produced in Adana province of Turkey

During 2012, a total of 176 samples of raw milk obtained from dairy plants of Adana province of Turkey were analysed for the presence of aflatoxin M₁ (AFM₁). Aflatoxin M₁ analysis was carried out by centrifugation, liquid–liquid extraction, immunoaffinity column clean-up and high performance liquid chromatography with fluorescence detection (HPLC-FD). The limits of detection (LOD) and quantification (LOQ) of the analytical method were 0.021 μg kg⁻¹ and 0.025 μg kg⁻¹. Accuracy of the method obtained from bias ranged from 2.94 to 8.70. Aflatoxin M₁ was detected in 53 out of 176 samples analysed (30.1%). The ranges for positive samples were 0.042–0.552, 0.033–1.01, 0.047–0.150 and 0.025–0.102 μg kg⁻¹ in autumn, winter, spring and summer seasons, respectively. Thirty samples of raw milk (17%) were above the legal limits of Turkey and EU regulations.     

Bioaccessibility and changes on cylindrospermopsin concentration in edible mussels with storage and processing time

The alkaloid cylindrospermopsin has been recognized of increased concern due to the global expansion of its main producer, Cylindrospermopsis raciborskii. Previous studies have shown that bivalves can accumulate high levels of cylindrospermopsin. Based on the potential for human health risks, a provisional tolerable daily intake of 0.03 μg/kg-body weight has been recommended. However, the human exposure assessment has been based on the cylindrospermopsin concentration in raw food items. Thus, this study aimed to assess the changes on cylindrospermopsin concentration in edible mussels with storage and processing time as well as cylindrospermopsin bioaccessibility. Mussels, (Mytilus galloprovincialis) fed cylindrospermopsin-producing C. raciborskii, were subjected to the treatments and then analyzed by LC-MS/MS. Mussels stored frozen allowed a significantly higher recovery of cylindrospermopsin (52.5% in 48 h and 57.7% in one week). The cooking treatments did not produce significant differences in cylindrospermopsin concentration in the mussel matrices (flesh), however, cylindrospermopsin was found in the cooking water, suggesting that heat processing can be used to reduce the availability of cylindrospermopsin. The in vitro digestion considerably decreased the cylindrospermopsin availability in uncooked and steamed mussels, highlighting the importance in integrating the bioaccessibility of cylindrospermopsinin in the human health risk assessment.     

Using phytosterol as a target compound to identify edible animal fats adulterated with cooked oil

Incidents of edible oil adulteration have increased all over the world, and improving analytical methods that are capable of identifying adulterated oils has become more important. In this study, we developed an analytical method that uses 4 target compounds belong to phytosterol family to identify lard that has been adulterated with cooked oils. For this, we used five kinds of animal fat, including lard, tallow, duck fat, goose fat, and chicken fat, to estimate the matrix effect, and lard samples were used to verify this analytical method. Specifically, samples inspected by sanitation authorities in a 2014 lard adulteration incident in Taiwan were saponified, and phytosterols were extracted and analyzed by a liquid chromatography-tandem mass spectrometer (LC/MS/MS) equipped with an atmospheric pressure chemical ionization (APCI) source. Parameters for sample extraction, including temperature, concentration of alkaline solution, and duration of saponification, were optimized. Our proposed method was then validated for linearity, matrix effect, precision, accuracy, limit of detection (LOD), and limit of quantitation (LOQ). After using our proposed method to analyze 28 lard samples, we determined that the phytosterol contents of inspected lard obtained from companies that had been found guilty in the 2014 lard adulteration incident were ranged from 19.5 to 205.3 μg/g in campesterol and 17.3–408.8 μg/g in β-sitosterol, and were at most 270-fold higher than that of homemade lard, commercial lard, and inspected lard (ranged from 4.5 to 29.6 μg/g in campesterol and 1.5–44.2 μg/g in β-sitosterol) obtained from companies that had not been found guilty in the 2014 adulteration incident. Therefore, our proposed method should be useful to discriminate between adulterated and unadulterated animal fats.     

Development and validation of an LC–MS/MS/MS method for the quantification of fluoroquinolones in several matrices from treated turkeys

The study presents a sensitive and reliable confirmatory method for the extraction, identification, quantification of five fluoroquinolones (FQ) namely enrofloxacin, ciprofloxacin, difloxacin, sarafloxacin and flumequine, in plasma, liver, kidney, muscle, skin + fat, lung and intestinal content from turkeys.For the extraction and matrix clean-up of FQ residues from all biological matrices, the Quick Easy Cheap Effective Rugged Safe (QuEChERS) methodology was adopted; only for plasma samples acetonitrile was used.The analyses were performed by liquid chromatography with mass spectrometry detection (LC–MS). LC separation was performed on a C18 Kinetex column (100 × 2.1 mm, 2.6 μm, Phenomenex, CA, USA) with gradient elution using ammonium acetate solution (10 mM, pH 2.5) and methanol containing 0.1% formic acid. Mass spectrometric identification was done using an LTQ XL ion trap (Thermo Fisher Scientific, CA, USA), with a heated electrospray ionization probe, in positive ion mode.The method was validated according to the European Legislation (decision 2002/657/EC) and EMA guideline (EMA/CVMP/VICH/463202/2009); selectivity, linearity response, trueness (in terms of recovery), precision (within-day repeatability and within-laboratory reproducibility), limit of detection, limit of quantification, decision limits, detection capability, absolute recovery and robustness were evaluated using turkey blank matrices. All data were within the required limits established for confirmatory methods except for flumequine which presented a recovery value slightly higher than 110% in muscle and intestinal content. For all FQs, all the extraction rates were greater than 70% and limits of quantification ranged from 1.2 μg kg⁻¹ to 118.8 μg kg⁻¹.This fast and robust method was suitable for the identification and quantification of FQ residues in tissues, plasma and intestinal content as confirmed by data obtained from incurred samples of turkeys treated at farm for therapeutic purposes.     

Determination of water-soluble vitamins in energy and sport drinks by micellar electrokinetic capillary chromatography

A method for the determination of water-soluble vitamins in several energy and sport drinks by micellar electrokinetic chromatography (MEKC) has been developed in this work. The separation of vitamins was studied in terms of background electrolyte composition (borate content, pH, surfactant type and content) and in other MEKC parameters. A study of the possible compounds found in the vitamin-enriched drinks that could interfere in vitamin determination was also performed, and a modified procedure with enhanced resolution was developed. The proposed method was successfully applied to the analysis of water-soluble vitamins in a variety of energy and sport drinks and also in fruit nectars. The method implies minimal sample preparation and reagent consumption, being environmentally sustainable. Thus, the proposed methodology could be useful for quality control purposes in the soft drink industry.     

Determination of melamine in infant formulas by fluorescence quenching based on the functionalized Au nanoclusters

An environmentally benign and cost-effective assay was developed for the fast determination of melamine (MA) with tiopronin-stabilized gold nanoclusters (TPN-AuNCs) as a fluorophore. The TPN-protected gold nanoclusters which exhibit strong fluorescence emission were prepared by a simple one-vessel procedure. Upon addition of melamine to TPN-AuNCs, a dramatic decrease in their fluorescence intensity was observed, attributing to the electrostatic attraction between the MA and the surface of the TPN-AuNCs which induces the aggregation of TPN-AuNCs. Parameters affecting the detection of MA were investigated including pH, amount of TPN-AuNCs, temperature as well as reaction time. Under the optimized experimental conditions, trace amounts of MA could be analyzed based on the reduction in the fluorescence intensity of TPN-AuNCs. A linear relationship was established at concentrations ranging from 0.09 μM to 100 μM. The detection limit at 32 nM was achieved for this method. The developed method has been successfully applied to the determination of MA in several spiked infant formulas samples purchased from a local supermarket. Excellent recoveries at 92.0–102.2% and precision (RSD: 1.14–2.80%) were attained, respectively, which confirmed the great potential of tiopronin-stabilized gold nanoclusters toward practical measurement of melamine in infant formulas of samples.     

Real-time pixel based early apple bruise detection using short wave infrared hyperspectral imaging in combination with calibration and glare correction techniques

High speed data processing for online food quality inspection using hyperspectral imaging (HSI) is challenging as over hundred spectral images have to be analyzed simultaneously. In this study, a real-time pixel based early apple bruise detection system based on HSI in the shortwave infrared (SWIR) range has been developed. This systems consists of a novel, homogeneous SWIR illumination unit and a line scan camera. The system performance was tested on Jonagold apples bruised less than two hours before scanning. Partial least squares-discriminant analysis was used to discriminate bruised pixel spectra from sound pixel spectra. As the glossiness of many fruit and vegetables limits the accuracy in the detection of defects, several reflectance calibrations and pre-processing techniques were compared for glare correction and maximizing the signal to noise ratio. With the best combination of first derivative and mean centering, followed by image post-processing, this system was able to detect fresh bruises in thirty apples with 98% accuracy at the pixel level with a processing time per apple below 200 ms.     

Multi-walled carbon nanotubes-based magnetic solid-phase extraction for the determination of zearalenone and its derivatives in maize by ultra-high performance liquid chromatography-tandem mass spectrometry

A simple and rapid magnetic solid-phase extraction (M-SPE) procedure using multi-walled carbon nanotube-magnetic nanoparticles (MWCNT-MNPs) as sorbents was established for purification of zearalenone (ZEA), α-zearalenol (α-ZOL), β-zearalenol (β-ZOL), zearalanone (ZAN), α-zearalanol (α-ZAL) and β-zearalanol (β-ZAL) in maize. The main parameters affecting the clean-up efficiency were thoroughly investigated, and high purification efficiencies for all analytes were obtained. The resulting MWCNT-MNP-ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was validated for maize samples. The matrix effects were greatly minimized using the M-SPE approach, with signal suppression/enhancement values decreased from 69.9–127.6% to 92.1–103.8%. Consequently, complex matrix-matched calibration curves were not necessary and the calibrations constructed in acetonitrile could be applied for accurate quantification of the targeted mycotoxins in real samples. The average recoveries ranged from 75.8 to 104.1% and the inter- and intra-day precision values expressed as RSDs, were all lower than 14%. Limits of detection and quantification were in the range of 0.03–0.04 and 0.07–0.10 μg/kg, respectively. The analytical performance of the developed method was also successfully evaluated with maize samples, and this method was proved to be a powerful tool for monitoring ZEA and its derivatives in maize.     

Species determination of pine nuts in commercial samples causing pine nut syndrome

Consumption of pine nuts from the species of Pinus armandii has been reported to cause dysgeusia, commonly known as pine mouth, or pine nut syndrome (PNS). However, the number of reports on pine nut consumptions of the different species and PNS is limited. This leaves open the possibility that other pine species than P. armandii could be involved in PNS as well. This study investigated 18 samples involved in PNS and received at the Danish Veterinary and Food Administration in 2011 through 2012. Samples were subjected to gas chromatographic analysis of fatty acids. The content of 11 individual fatty acids was used together with the diagnostic index and the sum of Δ5-fatty acids as diagnostic parameters. Diagnostic parameters from samples were then compared to reference material and literature data to determine the species. In a limited number of samples, the diagnostic parameters matched neither our reference materials nor literature data. However, the morphology, the fatty acid analysis, and externally obtained DNA sequencing data suggest a P. armandii subspecies or a variety. With these possible P. armandii subspecies, P. armandii was identified in all analyzed samples. The application of principal component analysis (PCA) to the data set showed a satisfactory separation of the majority of the 13 pine species included in the study.     

The efficacy of disinfectant misting in the lairage of a pig abattoir to reduce Salmonella and Enterobacteriaceae on pigs prior to slaughter

Water misting/showers are used in abattoir lairages to improve meat quality, and to cool and calm pigs after transport and during hot weather. One novel approach, which has not been investigated to date, is to add a disinfectant to the misting water as a means of topically reducing Salmonella on pigs prior to slaughter, thereby potentially controlling this organism in the abattoir. The objective of this study was therefore to evaluate misting with water or with Virkon^® S (an approved disinfectant for use in the presence of animals), for their ability to topically reduce Salmonella on high seroprevalence pig herds before stunning and to reduce Enterobacteriaceae.Three experimental groups were investigated: control group (i.e., no misting); water group (misting with cold, 15–17 °C, water, herein referred to as water); and a disinfectant group (misting with 0.5% Virkon^® S). As pigs entered the abattoir, each animal was swabbed along its back before being allocated to its experimental group. Each group was randomly assigned to one of 3 lairage pens that were separated by non-trial pens. After 30 min of misting with water or disinfectant, pigs were moved to the stunning area, where each pig was again swabbed, as above. Swabs were analyzed for the presence of Salmonella and enumeration of Enterobacteriaceae.Before misting, Salmonella prevalence on the pigs was 79.0%, 72.1% and 83.6% for the control, water and disinfectant groups, respectively. After misting, Salmonella prevalence increased to 94.3% in the water group; whereas for the disinfectant group, the prevalence increased marginally to 85.9%. No change in Salmonella prevalence was detected for the control group. In line with the Salmonella results, no significant differences were observed in Enterobacteriaceae counts in the control group at either time point (4.37 and 5.01 log₁₀ CFU/cm², respectively) or in the disinfectant group before and after misting (4.02 and 4.26 log₁₀ CFU/cm², respectively). However, a 2.3 log₁₀ CFU/cm² increase in Enterobacteriaceae was recorded for the water group after misting as compared to before misting (p < 0.05).Since misting with water alone increased topical Salmonella contamination on pigs before slaughter, a risk assessment based on known Salmonella data, meat quality and welfare is recommended to determine whether its use is justifiable. On the other hand, the findings from this study suggest that misting with Virkon^® S at 0.5% could have a role in topical antisepsis of pigs contaminated with Salmonella prior to slaughter and as such this warrants further investigation.     

Aflatoxin B1 production by Aspergillus parasiticus and strains of Aspergillus section Nigri in currants of Greek origin

Aflatoxin B₁ (AFB₁) mostly produced by Aspergillus flavus and Aspergillus parasiticus, is an extremely toxic and carcinogenic metabolite. Currants are used in the Mediterranean diet as a food with antioxidant properties. Four strains of Aspergillus section Nigri have been isolated from currants originated from Crete and Corinth. In this study AFB₁ production by A. parasiticus and the four strains of Aspergillus section Nigri in Cretan and Corinthian currants (Vitis vinifera L.) is investigated. AFB₁ determination was performed by HPLC–FID. Results revealed that the four strains Aspergillus section Nigri, as well as the aflatoxigenic strain A. parasiticus produced AFB₁ (0.0052–1.31 μg AFB₁ 15 g⁻¹, corresponding to 0.0003–0.087 μg AFB₁ g⁻¹) in both type of currants (Cretan and Corinthian) on the 12th day of observation. Moreover, AFB₁ production, by A. parasiticus in the synthetic Yeast Extract Sucrose (YES) medium was also studied. The ability of AFB₁ production has been affected by the special characteristics of each isolate and the currants substrate.