Adding genistein or luteolin decreased the yield of citrinin and without reducing pigments in yam solid-fermentation by Monascus.

BACKGROUND: Chinese yam fermented by Monascus, namely red mold dioscorea (RMD), has the potential of treating diseases. However, the production of citrinin limits the application of RMD. In the present study, the fermentation process of Monascus was optimized by adding genistein or luteolin to reduce citrinin yield. RESULTS: The results showed that citrinin in 25 g of Huai Shan yam was reduced by 48% and 72% without affecting the pigment yield by adding 0.2 g of luteolin or genistein, respectively, to a 250-mL conical flask after fermentation for 18 days at 28 °C, whereas the addition of luteolin increased the content of yellow pigment by 1.3-fold. Under optimal conditions, citrinin in 20 g of iron bar yam decreased by 55% and 74% after adding 0.2 g of luteolin or genistein. Luteolin also increased yellow pigment content by 1.2-fold. Ultra HPLC coupled to quadrupole time-of-flight mass spectrometry was used for the preliminary analysis of Monascus fermentation products. It was found that the amino acid types in RMD are similar to those in yams, but there are fewer polysaccharides and fatty acids. CONCLUSION: The results obtained in the present study showed that the addition of genistein or luteolin could reduce citrinin on the premise of increasing pigment yield, which laid a foundation for the better use of yams in Monascus fermentation. © 2023 Society of Chemical Industry.

A two-year study on the occurrence and concentration of mycotoxins in corn varieties with different endosperm textures.

BACKGROUND: Mycotoxin monitoring in cereal grains has great importance in the food and feed industries. This study evaluated mycotoxin contamination in corns with different endosperm textures in 2 years of cultivation. Samples of dent, semi-dent, flint and semi-flint corns from field experiments were analyzed by high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS). RESULTS: Occurrences of fumonisins B1 (FB1 ) and B2 (FB2 ) in 2020 were 45.72% (mean 270 µg kg-1 ) and 35.89% (94.97 µg kg-1 ), respectively, and 68.98% (446 µg kg-1 ) and 45.83% (152 µg kg-1 ) in 2021. Occurrence of aflatoxin B1 was 11.96% (0.16 µg kg-1 ) in 2020 and 11.11% (0.13 µg kg-1 ) in 2021. In 2020, deoxynivalenol (DON) and zearalenona (ZEA) presented occurrences of 1.28% and 1.70%, with means of 4.08 and 2.45 µg kg-1 , respectively. In 2021, results were 8.33% (31.00 µg kg-1 ) for DON and 8.79% (4.38 µg kg-1 ) for ZEA. Citrinin, diacetoxyscirpenol and fusarenon-X did not occur in 2020 but presented 1.66%, 0.83%, and 2.50% positive rates in 2021, respectively. In 2020, flint corn presented the lowest concentration of FB1 whereas dent corn presented the highest concentration of FB1 and FB2 (P < 0.05). In 2021, dent corn presented the highest means of FB1 , FB2 and diacetoxyscirpenol (P < 0.05). Dent and semi-dent presented the highest concentration of nivalenol (P < 0.05). CONCLUSION: The endosperm texture influenced mycotoxin contamination in corn grains, especially FB1 and FB2 , which had the highest concentration in dent corn in the 2 years of this study. © 2023 Society of Chemical Industry.

[Mycotoxins in spices consumed in Russia].

Spices and herbs have been used since ancient times as flavor and aroma enhancers, colorants, preservatives and traditional medicines. As many other plant products, they can be exposed to contaminants, ones of which are mycotoxins, secondary metabolites of fungi. Such contamination can occur during harvesting, processing and storage, distribution, retailing and consumer use. Although they are used and consumed in small quantities, but added to a wide variety of products, especially ready-to-eat products. So the assessment of their contamination with mycotoxins is very important. The aim of the study was to investigate the contamination of spices and herbs with mycotoxins of fungi of the genera Aspergillus, Penicillium, Fusarium and Alternaria, as well as to assess the mycotoxins intake per person when consuming these food groups. Material and methods. Concentration of mycotoxins in 155 samples of spices and herbs was determined by ultra high-performance liquid chromatography coupled to tandem mass-spectrometric detection (UHPLC-MS/MS). The list of mycotoxins included deoxynivalenol, aflatoxins, ochratoxin A, zearalenone, T-2 toxin, fumonisins, sterigmatocistin, HT-2 toxin, diacetoxyscirpenol, enniatins, beauvericin, neosolaniol, citreoviridin, mycophenolic acid, citrinin, tentoxin, altenuene, alternariol and its monomethyl ether. Results. Among the regulated in plant products mycotoxins in the studied samples there were found aflatoxins (B1 - in 19% of samples, from 0.4 to 48.2 µg/kg, B2 - 8%, from < limit of quantitation (LOQ) to 3.2 µg/kg, G1 - 2%, 0.75-21 µg/kg, G2 - 5%, 0.5- 12.5 µg/kg), ochratoxin A (15% samples, 0.8-14 µg/kg), fumonisin B1 (8%, 16.1-722.6 µg/kg), and fumonisin B2 (14%, < LOQ - 79.6 µg/kg). T-2 toxin and deoxynivalenol were found in 10% of samples (< LOQ - 6.5 µg/kg and < LOQ - 65.5 µg/kg respectively), zearalenone - in 4 samples (1.7-106.2 µg/kg), HT-2 toxin - in 8 samples (5.4-19.8 µg/kg). Among little-studied (emergent) mycotoxins in the spices and herbs samples there were found tentoxin (in 36% of samples, in an amount from 0.7 to 10.9 µg/kg), altenuene (in 8%, 14.5-161.5 µg/kg). 10% of the samples were contaminated with alternariol and its methyl ether (from less than LOQ to 12.8 and < LOQ to 55.7 µg/kg, respectively), 4% - with sterigmatocystin (0.4-7.8 µg/kg), 5% - mycophenolic acid (13.1-297 µg/kg), 2% of the samples were contaminated with citrinin and enniatin B (< LOQ - 27.7 and 0.1-1 µg/kg), in 9 samples (6%) beauvericin was detected (< LOQ - 1.7 µg/kg). Over 60% of samples were contaminated with more than one mycotoxin. The content of aflatoxin B1 exceeded the maximum permissible level set in the EU (5 µg/kg) in nine samples. Conclusion. To the best of our knowledge, the present study is the first in the Russian Federation to report results indicating to the contamination of spices and herbs with mycotoxins. High occurrence of aflatoxins, tentoxin, ochratoxin A and fumonisin B2 has been observed. In calculating the potential exposure of mycotoxins, the possibility of high levels of aflatoxin B1 intake have been shown to be possible, which could lead to a public health risk when consuming contaminated spices, herbs and foods containing them.

Trace analysis of emerging and regulated mycotoxins in infant stool by LC-MS/MS.

Infants are sensitive to negative effects caused by food contaminants such as mycotoxins. To date, analytical methods assessing mycotoxin mixture exposure in infant stool are absent. Herein, we present a novel multi-mycotoxin LC-MS/MS assay capable of detecting 30+ analytes including the regulated mycotoxin classes (aflatoxins, trichothecenes, ochratoxins, zearalenone, citrinin), emerging Alternaria and Fusarium toxins, and several key metabolites. Sample preparation consisted of a 'dilute, filter, and shoot' approach. The method was in-house validated and demonstrated that 25 analytes fulfilled all required criteria despite the high diversity of chemical structures included. Extraction recoveries for most of the analytes were in the range of 65-114% with standard deviations below 30% and limits of detection between 0.03 and 11.3 ng/g dry weight. To prove the methods' applicability, 22 human stool samples from premature Austrian infants (n = 12) and 12-month-old Nigerian infants (n = 10) were analyzed. The majority of the Nigerian samples were contaminated with alternariol monomethyl ether (8/10) and fumonisin B1 (8/10), while fumonisin B2 and citrinin were quantified in some samples. No mycotoxins were detected in any of the Austrian samples. The method can be used for sensitive human biomonitoring (HBM) purposes and to support exposure and, potentially, risk assessment of mycotoxins. Moreover, it allows for investigating potential associations between toxicant exposure and the infants' developing gut microbiome.

Characterization and inhibition of four fungi producing citrinin in various culture media.

PURPOSE: This study aimed to investigate the effects of different fermentation conditions (culture medium, temperature, incubation time, pH value and additive) on citrinin production by four fungi. RESULTS: Among the culture media, potato dextrose medium had lowest citrinin production, followed by yeast sucrose medium and monosodium glutamate medium. The lowest citrinin contents were produced by Monascus anka (M. anka) in potato dextrose medium and yeast sucrose medium, Aspergillus oryzae AS3.042 (A. oryzae) produced the lowest citrinin production in monosodium glutamate medium. The optimum fermentation temperatures for citrinin production by Aspergillus niger (A. niger) and Penicillium citrinum (P. citrinum) were at 30 °C, whereas those by M. anka and A. oryzae were at 35 °C. Citrinin synthesis by four fungi were completely inhibited with a pH value of less than 5.4. By adding ethylene diamine tetraacetic acid (EDTA) or triammonium citrate into monosodium glutamate medium, citrinin production by A. oryzae and A. niger were totally inhibited. Ammonium sulfate completely inhibited citrinin production by A. oryzae, M. anka and P. citrinum, and ammonium nitrate completely inhibited citrinin production by A. oryzae. CONCLUSIONS: These results indicated that the suitable fermentation conditions could make considerable contributions to the reduction of citrinin production. This study provided an effective way for decreasing the citrinin production.

Rapid Detection and Quantification of Patulin and Citrinin Contamination in Fruits.

Patulin (PAT) and citrinin (CTN) are the most common mycotoxins produced by Penicillium and Aspergillus species and are often associated with fruits and fruit by-products. Hence, simple and reliable methods for monitoring these toxins in foodstuffs are required for regular quality assessment. In this study, we aimed to establish a cost-effective method for detection and quantification of PAT and CTN in pome fruits, such as apples and pears, using high-performance liquid chromatography (HPLC) coupled with spectroscopic detectors without the need for any clean-up steps. The method showed good performance in the analysis of these mycotoxins in apple and pear fruit samples with recovery ranges of 55-97% for PAT and 84-101% for CTN, respectively. The limits of detection (LOD) of PAT and CTN in fruits were 0.006 µg/g and 0.001 µg/g, while their limits of quantification (LOQ) were 0.018 µg/g and 0.003 µg/g, respectively. The present findings indicate that the newly developed HPLC method provides rapid and accurate detection of PAT and CTN in fruits.

Reviewing the Analytical Methodologies to Determine the Occurrence of Citrinin and its Major Metabolite, Dihydrocitrinone, in Human Biological Fluids.

Until now, the available data regarding citrinin (CIT) levels in food and the consumption of contaminated foods are insufficient to allow a reliable estimate of intake. Therefore, biomonitoring configuring analysis of parent compound and/or metabolites in biological fluids, such as urine or blood, is being increasingly applied in the assessment of human exposure to CIT and its metabolite, dihydrocitrinone (DH-CIT). Most studies report urinary levels lower for the parent compound when compared with DH-CIT. A high variability either in the mean levels or in the inter-individual ratios of CIT/DH-CIT between the reported studies has been found. Levels of DH-CIT in urine were reported as being comprised between three to seventeen times higher than the parent mycotoxin. In order to comply with this objective, sensitive analytical methodologies for determining biomarkers of exposure are required. Recent development of powerful analytical techniques, namely liquid chromatography coupled to mass spectrometry (LC-MS/MS) and ultra-high-performance liquid chromatography (UHPLC-MS/MS) have facilitated biomonitoring studies, mainly in urine samples. In the present work, evidence on human exposure to CIT through its occurrence and its metabolite, in biological fluids, urine and blood/plasma, in different countries, is reviewed. The analytical methodologies usually employed to evaluate trace quantities of these two molecules, are also presented. In this sense, relevant data on sampling (size and pre-treatment), extraction, cleanup and detection and quantification techniques and respective chromatographic conditions, as well as the analytical performance, are evidenced.

Lovastatin in lactone and hydroxy acid forms and citrinin in red yeast rice powders analyzed by HPTLC-UV/FLD.

For the analysis of pigment-rich red yeast rice products, a fast quantitative high-performance thin-layer chromatography (HPTLC) method was newly developed and validated. The active ingredient lovastatin, present in lactone (LL) and hydroxy acid forms (LH), as well as the mycotoxin citrinin were analyzed in 19 red yeast rice products, including powders, dietary supplements, and Chinese proprietary medicines (Xuezhikang and Zhibituo). The HPTLC method including sample preparation allows a high throughput of matrix-rich samples (10 min per analysis) and is highly cost-efficient (running costs of 0.5 Euro per analysis). For a fast protocol, application volumes up to 10 µL were selected although higher application volumes will lower still the LODs, which were 30 mg/kg for LL and LH as well as 4 mg/kg for citrinin. Thanks to the minimalistic sample preparation, the overall mean recovery rate was good (109.9% ± 5.9%; repeated measurements of the three analytes per fresh sample preparation at three spike levels). Repeated calibrations (five per analyte) in the red yeast rice matrix showed highly satisfying determination coefficients (≥ 0.9991; mean 0.9996). For three analytes at three concentration levels, the obtained mean intermediate precisions in red yeast rice matrix analyzed over the whole procedure including sample preparation were highly satisfying (≤ 2.6%). Citrinin was not detectable in the samples down to the given LOD of 4.0 mg/kg for the 10-µL sample volume applied. The mean content of lovastatin in 15 RYR powders was 8.7 g/kg, with a rang of 1.5-26.2 g/kg. The content of lovastatin in Zhibituo tablets and Xuezhikang capsules was determined to be 2.7 and 11.1 g/kg, respectively. The two commercially available RYR dietary supplement samples showed the highest lovastatin contents of 40.7 and 41.4 g/kg. By these figures of merit, the HPTLC method was proven to be suited for the control of such matrix-rich, fermented food. Graphical abstract.

Production and migration of ochratoxin A and citrinin in Comté cheese by an isolate of Penicillium verrucosum selected among Penicillium spp. mycotoxin producers in YES medium.

Moldy food products that are not subject to pathogenic bacterial contamination could be trimmed by consumers to remove fungal mycelium before consumption. However, prior to giving such recommendations to consumers, it is necessary to evaluate potential mycotoxin migration in these products. This study aimed at quantifying citrinin (CIT) and ochratoxin A (OTA) accumulation and migration in a French semi-hard Comté cheese after artificial inoculation with a CIT- and OTA-producing Penicillium verrucosum strain. At 8 °C, CIT and OTA production started after 14 days and 28 days incubation, respectively; while at 20 °C, both mycotoxins were produced from day 7. At 20 °C, maximum CIT concentration, about 50000 ng/g, was 20 fold that at 8 °C. Regardless of temperature, maximum OTA concentration was about 4000 ng/g cheese. Maximum concentrations were obtained in the upper part of the cheese, but depending on incubation time, mycotoxins were detected up to 1.6 cm in depth. As long as only white mycelium developed on the cheese surface, trimming can be acceptable, but a blue mold color (due to fungal sporulation) was associated with the accumulation of significant amounts of mycotoxins so the product should be discarded.

Soybean isoflavones reduce citrinin production by Monascus aurantiacus Li AS3.4384 in liquid state fermentation using different media.

BACKGROUND: Monascus, a filamentous fungus, produces many bioactive substances. However, in the process of fermentation, Monascus also produces the mycotoxin citrinin. Owing to the presence of citrinin, the safety of Monascus products has been questioned and their wide application limited. Using soybean isoflavones (SI) as exogenous additives, alterations in citrinin production by Monascus aurantiacus Li AS3.4384 (MALA) in different media used for liquid state fermentation were investigated. RESULTS: Results showed that the citrinin concentration was 95.98% lower than that of the control group after 16-days fermentation when 20.0 g L-1 SI were added to rice powder and inorganic salt medium. Citrinin production was reduced by 97.24% after 12-days fermentation with 10.0 g L-1 SI in starch inorganic salt medium; 82.52% after 20-days fermentation with 20.0 g L-1 SI in starch peptone medium with high starch content; 45.07% after 14-days fermentation with 5.0 g L-1 SI in starch peptone medium with low starch content; and 82.21% after 14-days fermentation with 20.0 g L-1 SI in yeast extract sucrose medium. CONCLUSION: The developed method of removing citrinin is simple, safe, and effective, and it can be applied to reduce the citrinin content of Monascus products. © 2019 Society of Chemical Industry.

Detection of trace amounts of citrinin in dried orange peel by using an optimized extraction method coupled with ultra-performance liquid chromatography-tandem mass spectrometry.

A fast and sensitive method involving ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was introduced to detect citrinin in dried orange peel. A series of extraction, purification and chromatographic conditions was also systematically examined. With the proposed method, the obtained calibration graph was linear, with an R of 0.9996 within a concentration range of 0.5-10 ng/mL. The estimated limits of detection and quantification were 0.05 and 0.17 ng/mL, respectively. Under the selected conditions, the relative recoveries in different citrus products spiked with 1-10 ng/mL citrinin were 89.4-98.7% with RSDs of <2.5%. Compared with previously reported analytical methods, the newly developed UPLC-MS/MS method showed excellent sensitivity and good precision in detecting citrinin. The results indicated that it is a reliable and effective technique for the detection of trace citrinin in dried orange peel.

Chemical Composition, Security and Bioactivity of the Red Pigment from Penicillium purpurogenum Li-3.

The chemical composition, security and bioactivity of pigments from Penicillium purpurogenum Li-3 strain screened by our group were firstly studied in this work. DPPH and the filter disc diffusion method were used to determine the biological activities of the red pigments. The pigment was characterized by UV/VIS, FT-IR, NMR and UPLC-Q-TOF-MS. HPLC/MS was used to detect mycotoxins (citrinin) in fermentation broth. An acute toxicity was detected in the embryos of zebrafish. As a consequence, the crude red pigment from the AcOEt fraction showed better DPPH scavenge capacity and antibacterial activity. Spectroscopic (UV, FT-IR, 13 C-NMR) and UPLC-Q-TOF-MS analysis revealed that the Penicillium purpurogenum Li-3 red pigment (RPs) was monascus-like pigment and its molecular weight was 439.1997. Moreover, the red pigment was shown to be weak cytotoxic against the zebrafish embryos. The yield of the red pigment increased 69 % under optimized culture conditions. These outstanding properties will enlarge the application of RPs for natural food additives, new antioxidant and antibacterial drug development.

Co-occurrence of citrinin and ochratoxin A in rice in Asia and its implications for human health.

Citrinin (CIT) and ochratoxin A (OTA) are nephrotoxic mycotoxins, produced by several Aspergillus and Penicillium species and their co-occurrence in rice may cause health effects in humans. Rice is an important food crop worldwide and is a major staple food in Asia which may be invaded by CIT and OTA producing fungal spores in the field, during harvest and storage. Humans are exposed to these mycotoxins through ingestion of contaminated rice and other food commodities. Yet, data on the combined presence to these food contaminants are still insufficient to estimate human exposure in Asia. This review describes the prevalence of CIT and OTA in rice in Asia and its implications on human health, which may help in establishing and carrying out proper management strategies against mould development on rice. From the health point of view, combined exposition of CIT and OTA should be a public concern as both are nephrotoxic and long-term exposure can pose detrimental health effects. Thus, it is necessary for local farmers and food factories to implement strict measures and to improve methods for rice preservation during the distribution to consumers, particularly in the markets. Moreover, regular surveys for CIT and OTA occurrence in rice and human biomonitoring are recommended to reduce the health effects in Asian population. © 2017 Society of Chemical Industry.

A fully automated and fast method using direct sample injection combined with fused-core column on-line SPE-HPLC for determination of ochratoxin A and citrinin in lager beers.

A new fast and sensitive method based on on-line solid-phase extraction on a fused-core precolumn coupled to liquid chromatography with fluorescence detection has been developed for ochratoxin A (OTA) and citrinin (CIT) determination in lager beer samples. Direct injection of 100 µL filtered beer samples into an on-line SPE-HPLC system enabled fast and effective sample extraction including separation in less than 6 min. Preconcentration of OTA and CIT from beer samples was performed on an Ascentis Express RP C18 guard column (5 × 4.6 mm), particle size 2.7 µm, with a mobile phase of methanol/0.5% aqueous acetic acid pH 2.8 (30:70, v/v) at a flow rate of 2.0 mL min(-1). The flow switch from extraction column to analytical column in back-flush mode was set at 2.0 min and the separation was performed on the fused-core column Ascentis Express Phenyl-Hexyl (100 × 4.6 mm), particle size 2.7 µm, with a mobile phase acetonitrile/0.5% aqueous acetic acid pH 2.8 in a gradient elution at a flow rate of 1.0 mL min(-1) and temperature of 50 °C. Fluorescence excitation/emission detection wavelengths were set at 335/497 nm. The accuracy of the method, defined as the mean recoveries of OTA and CIT from light and dark beer samples, was in the range 98.3-102.1%. The method showed high sensitivity owing to on-line preconcentration; LOQ values were found to be 10 and 20 ng L(-1) for OTA and CIT, respectively. The found values of OTA and CIT in all tested light, dark and wheat beer samples were significantly below the maximum tolerable limits (3.0 µg kg(-1) for OTA and 2000 µg kg(-1) for CIT) set by the European Union.

Development of magnetic molecularly imprinted polymers for selective extraction: determination of citrinin in rice samples by liquid chromatography with UV diode array detection.

In this work, we report the synthesis of novel magnetic molecularly imprinted polymers (m-MIPs) and their application to the selective extraction of the mycotoxin citrinin (CIT) from food samples. The polymers were prepared by surface imprinting of Fe3O4 nanoparticles, using 2-naphtholic acid (2-NA) as template molecule, N-3,5-bis(trifluoromethyl)phenyl-N'-4-vinylphenyl urea and methacrylamide as functional monomers and ethyleneglycol dimethacrylate as cross-linker. The resulting material was characterized by transmission electron microscopy (TEM), and X-ray diffraction (XRD) and Fourier transform infrared spectroscopies (FT-IR). The polymers were used to develop a solid-phase extraction method (m-MISPE) for the selective recovery of CIT from rice extracts prior to its determination by HPLC with UV diode array detection. The method involves ultrasound-assisted extraction of the mycotoxin from rice samples with (7:3, v/v) methanol/water, followed by sample cleanup and preconcentration with m-MIP. The extraction (washing and elution) conditions were optimized and their optimal values found to provide CIT recoveries of 94-98 % with relative standard deviations (RSD) less than 3.4 % (n = 3) for preconcentrated sample extracts (5 mL) fortified with the analyte at concentrations over the range 25-100 µg kg(-1). Based on the results, the application of the m-MIPs facilitates the accurate and efficient determination of CIT in rice extracts.

Anti-idiotypic nanobody as citrinin mimotope from a naive alpaca heavy chain single domain antibody library.

Compared with peptide-based mimotope, anti-idiotypic antibodies (AIds) are considered as promising biosynthetic surrogate antigen because these antibodies display stable protein conformation. Nevertheless, conventional AIds are generated by immunizing animals with heterologous idiotypic antibody in vivo; isolated AIds commonly exhibit a higher affinity to primary antibodies than target analytes because AIds undergo an affinity-matured process during immune responses, resulting in low sensitivity in competitive immunoassay. In the present study, an anti-citrinin monoclonal antibody (anti-CIT McAb) was designed as primary antibody; one ß-type AI alpaca heavy chain single domain antibody (ß-AI VHH) was selected as a citrinin (CIT) surrogate from a naive phage-displayed VHH library. The affinity constant (K D) of obtained ß-AI VHH to anti-CIT McAb (160 nM) is 2.35 times lower than that of CIT and ovalbumin conjugates (CIT-OVA) to anti-CIT McAb (68 nM). The developed VHH-based enzyme-linked immunosorbent assay (V-ELISA) can be used to perform dynamic linear detection of CIT in 10% (v/v) methanol/PBS from 5.0 to 300.0 ng/mL, with a median inhibitory concentration (IC50) of 44.6 ng/mL (n = 3); this result was twice as good as that of indirect competitive ELISA (ic-ELISA, IC50 = 96.2 ng/mL) with CIT-OVA as a coating antigen. Moreover, the precision of V-ELISA was evaluated by analyzing average recoveries and coefficient of variations of CIT-spiked cereal sample; the reliability of V-ELISA was also validated with a conventional ic-ELISA. In summary, the proposed strategy has a great potential for panning other ß-AI VHH toward small organic molecules from a naive VHH library.

Reactions of citrinin with amino compounds modelling thermal food processing.

Citrinin (CIT) is a nephrotoxic mycotoxin, produced by several species of Penicillium, Aspergillus, and Monascus. The foodstuffs most frequently contaminated with CIT include cereals, cereal products, and red yeast rice. Studies on the occurrence of CIT in food have shown that the CIT concentrations in processed cereal-based products are generally lower than in unprocessed industry cereal samples. One possible explanation is the reaction of CIT with major food components such as carbohydrates or proteins to form modified CIT. Such modified forms of CIT are then hidden from conventional analyses, but it is possible that they are converted back into the parent mycotoxin during digestion. The aim of this study is therefore to investigate reactions of CIT with food matrix during thermal processes and to gain a deeper understanding of the degradation of CIT during food processing. In this study, we could demonstrate that CIT reacts with amino compounds such as proteins, under typical food processing conditions, leading to modified forms of CIT.

Occurrence, Risk Implications, Prevention and Control of CIT in Monascus Cheese: A Review.

Monascus is a filamentous fungus that has been used in the food and pharmaceutical industries. When used as an auxiliary fermenting agent in the manufacturing of cheese, Monascus cheese is obtained. Citrinin (CIT) is a well-known hepatorenal toxin produced by Monascus that can harm the kidneys structurally and functionally and is frequently found in foods. However, CIT contamination in Monascus cheese is exacerbated by the metabolic ability of Monascus to product CIT, which is not lost during fermentation, and by the threat of contamination by Penicillium spp. that may be introduced during production and processing. Considering the safety of consumption and subsequent industrial development, the CIT contamination of Monascus cheese products needs to be addressed. This review aimed to examine its occurrence in Monascus cheese, risk implications, traditional control strategies, and new research advances in prevention and control to guide the application of biotechnology in the control of CIT contamination, providing more possibilities for the application of Monascus in the cheese industry.

Research on pear residue dietary fiber and Monascus pigments extracted through liquid fermentation.

Pear residue, a byproduct of pear juice extraction, is rich in soluble sugar, vitamins, minerals, and cellulose. This study utilized Monascus anka in liquid fermentation to extract dietary fiber (DF) from pear residue, and the structural and functional characteristics of the DF were analyzed. Soluble DF (SDF) content was increased from 7.9/100 g to 12.6 g/100 g, with a reduction of average particle size from 532.4 to 383.0 nm by fermenting with M. anka. Scanning electron microscopy and infrared spectroscopic analysis revealed more porous and looser structures in Monascus pear residue DF (MPDF). Water-, oil-holding, and swelling capacities of MPDF were also enhanced. UV-visible spectral analysis showed that the yield of yellow pigment in Monascus pear residue fermentation broth (MPFB) was slightly higher than that in the Monascus blank control fermentation broth. The citrinin content in MPFB and M. anka seed broth was 0.90 and 0.98 ug/mL, respectively. Therefore, liquid fermentation with M. anka improved the structural and functional properties of MPDF, suggesting its potential as a functional ingredient in food.

A dual-signal mode electrochemical aptasensor based on tetrahedral DNA nanostructures for sensitive detection of citrinin in food using PtPdCo mesoporous nanozymes.

Citrinin (CIT) is a mycotoxin with nephrotoxicity and hepatotoxicity, presenting a significant threat to human health that is often overlooked. Therefore, a dual-signal mode (DPV and SWV) aptasensor for citrinin (CIT) detection was constructed based on tetrahedral DNA nanostructures (TDN) in this study. Furthermore, PtPdCo mesoporous nanozymes exhibit catalase-like catalytic functions, generating significant electrochemical signals through a Fenton-like reaction. Meanwhile their excellent Methylene Blue (MB) loading capability ensures independent dual signal outputs. The RecJf exonuclease-assisted (RecJf Exo-assisted) process can expand the linear detection range, enabling further amplification of the signal. Under optimized conditions, the constructed aptaensor exhibited excellent detection performance with limits of detection (LODs) of 7.67 × 10-3 ng·mL-1 (DPV mode) and 1.57 × 10-3 ng·mL-1 (SWV mode). Due to its multiple signal amplification and highly accurate dual-signal mode detection capability, this aptasensor shows promising potential for the in situ detection.