Emerging Parameters Justifying a Revised Quality Concept for Cow Milk

Milk has become a staple food product globally. Traditionally, milk quality assessment has been primarily focused on hygiene and composition to ensure its safety for consumption and processing. However, in recent years, the concept of milk quality has expanded to encompass a broader range of factors. Consumers now also consider animal welfare, environmental impact, and the presence of additional beneficial components in milk when assessing its quality. This shifting consumer demand has led to increased attention on the overall production and sourcing practices of milk. Reflecting on this trend, this review critically explores such novel quality parameters, offering insights into how such practices meet the modern consumer's holistic expectations. The multifaceted aspects of milk quality are examined, revealing the intertwined relationship between milk safety, compositional integrity, and the additional health benefits provided by milk's bioactive properties. By embracing sustainable farming practices, dairy farmers and processors are encouraged not only to fulfill but to anticipate consumer standards for premium milk quality. This comprehensive approach to milk quality underscores the necessity of adapting dairy production to address the evolving nutritional landscape and consumption patterns.

Ratiometric electrochemical aptasensor based on split aptamer and Au-rGO for detection of aflatoxin M1

A novel ratiometric electrochemical aptasensor based on split aptamer and Au-reduced graphene oxide (Au-rGO) nanomaterials was proposed to detect aflatoxin M1 (AFM1). In this work, Au-rGO nanomaterials were coated on the electrode through the electrodeposition method to increase the aptamer enrichment. We split the aptamer of AFM1 into 2 sequences (S1 and S2), where S1 was immobilized on the electrode due to the Au-S bond, and S2 was tagged with methylene blue (MB) and acted as a response signal. A complementary strand to S1 (CS1) labeled with ferrocene (Fc) was introduced as another reporter. In the presence of AFM1, CS1 was released from the electrode surface due to the formation of the S1-AFM1-S2 complex, leading to a decrease in Fc and an increase in the MB signal. The developed ratiometric aptasensor exhibited a linear range of 0.03 μg L-1 to 2.00 μg L-1, with a detection limit of 0.015 μg L-1 for AFM1 detection. The ratiometric aptasensor also showed a linear relationship from 0.2 μg L-1 to 1.00 μg L-1, with a detection limit of 0.05 μg L-1 in natural milk after sample pretreatment, indicating the successful application of the developed ratiometric aptasensor. Our proposed strategy provides a new way to construct aptasensors with high sensitivity and selectivity.

Climate Change and Mycotoxins Trends in Serbia and Croatia: A 15-Year Review

This review examines the 15-year presence of mycotoxins in food from Serbia and Croatia to provide a comprehensive overview of trends. Encompassing the timeframe from 2009 to 2023, this study integrates data from both countries and investigates climate change patterns. The results from Serbia focus primarily on maize and milk and show a strong dependence of contamination on weather conditions. However, there is limited data on mycotoxins in cereals other than maize, as well as in other food categories. Conversely, Croatia has a broader spectrum of studies, with significant attention given to milk and maize, along with more research on other cereals, meat, and meat products compared to Serbia. Over the investigated 15-year period, both Serbia and Croatia have experienced notable shifts in climate, including fluctuations in temperature, precipitation, and humidity levels. These changes have significantly influenced agriculture, consequently affecting the occurrence of mycotoxins in various food products. The results summarized in this 15-year review indicate the urgent need for further research and action to address mycotoxins contamination in Serbian and Croatian food supply chains. This urgency is further emphasized by the changing climatic conditions and their potential to exacerbate public health and food safety risks associated with mycotoxins.

Evaluation of the pH effect on complex formation between bovine β-lactoglobulin and aflatoxin M1: a molecular dynamic simulation and molecular docking study

The aim of this work was to evaluate interaction between aflatoxin M1 (AFM1) and structural models of β-lactoglobulin (β-LG) at pH 4.0 and 6.5. This information would provide an explanation of the variability in AFM1 during cheese production. Once β-LG models were optimized using molecular dynamic (MD) simulation, it was found that a region of the Calyx cavity underwent conformational changes, at the E-F loop, from the closed conformation at pH 6.5 to the open at pH 4.0. No differences in Site C conformation were observed at both pH. The binding free energy (ΔGb) of the β-LG-AFM1 complexes at the different pHs were determined by molecular docking. The ΔGb values obtained for the Calyx cavity showed that at pH 4.0 there is a more stable complex formation compared to pH 6.5 with values of -42.6 and -32.0 kJ mol-1, respectively. On the contrary, in the complexes formed in Site C at both pH´s there were no differences. Likewise, the ΔGb in the dimer interface was evaluated, obtaining a value of -29.3 kJ mol-1, like those obtained at Site C. In addition, by the MD simulations of the β-LG-AFM1 complexes, it was observed that at acidic pH the binding of AFM1 with β-LG is more stable. In conclusion, the computational tools showed that the most stable complex was formed at the Calyx cavity at pH 4.0. This suggests that during cheese production using acidic coagulation, the whey proteins show higher affinity toward AFM1 which may explain the observed variability of mycotoxin.Communicated by Ramaswamy H. Sarma.

Detection of mycotoxins in cheese using an optimized analytical method based on a QuEChERS extraction and UHPLC-MS/MS quantification

Mycotoxins can produce toxic effects on humans; hence, it is of high importance to determine their presence in food products. This work presents a reliable method for the quantification of 32 mycotoxins in cheese. The analysis procedure was optimized based on a QuEChERS extraction process and the ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS) detection. The analysis method was validated for four cheese varieties (emmental, blue, brie and camembert) in terms of linearity, sensitivity, matrix effect, accuracy and precision. Satisfactory precision and accuracy values were achieved, with recoveries above 70% for most mycotoxins. The developed method was applied to the analysis of 38 commercial cheese samples. A high occurrence of beauvericin and enniatins were found, ranging from 31% for enniatin A to 100% for enniatin B. The ochratoxin A was detected in three samples at concentrations that may pose a risk to human health.

Occurrence of Aflatoxin M1 in Milk and Dairy Products Traded in São Paulo, Brazil: An Update

The aim of this study was to conduct an up-to-date investigation on the occurrence levels of aflatoxin M1 (AFM1) in samples of raw milk (n = 40), pasteurized milk (n = 44), ultra-high temperature (UHT) milk (n = 27), Minas cheese (n = 57), and yogurt (n = 44) traded in São Paulo state, Brazil. AFM1 was extracted from fluid milks and dairy products using immunoaffinity columns and determined by high performance liquid chromatography. AFM1 was detected at the mean level of 0.080 ± 0.071 µg/L or kg in 72 samples (34.0%) evaluated in the study (n = 212). Detectable levels of AFM1 were observed in five samples of raw milk (12.5%), 16 samples of pasteurized milk (36.4%), 13 samples of UHT milk (48.1%), 27 samples of cheese (47.4%), and 11 samples of yogurt (25.0%), although none of them had concentrations above the maximum permitted levels (MPL) for AFM1 adopted in Brazil. However, 11.7% (n = 13) of samples of raw, pasteurized, and UHT milks would have AFM1 concentrations above the MPL of 0.05 μg/L adopted in the EU. The maximum level was detected in one cheese sample containing 0.695 µg/kg. Although none of the samples exceeded the Brazilian MPL, the high frequencies of AFM1 in Brazilian milk products warrant concern about their contribution to the human exposure to aflatoxins. Because aflatoxins are among the most potent carcinogens known, the results of this trial stress the need for stringent measures in the milk production system to avoid AFM1 in milk and derived products.

A Strategy for Sample Preparation: Using Egg White Gel to Promote the Determination of Aflatoxin M1 Content in Milk Samples

The analysis of food samples is a challenging task. The high complexity of food matrices hinders the extraction and detection of analytes from them. Therefore, the correct preparation of food samples is a crucial step for their subsequent analysis, as it achieves the proper isolation and preconcentration of analytes and removes the interfering proportion of the food matrix before instrumental analysis. We aimed to develop a method that not only satisfies the requirement of detecting trace compounds in complex matrices but also achieves a “greener” approach by reducing the use of organic solvents and non-degradable materials to minimize the health hazards posed to the operators as well as pollution to the environment. In this study, we prepared egg white as a concentrated gel and used this material for the biological purification of milk samples. After the milk protein was removed by acidification and salting, the residual amount of aflatoxin M1 in milk samples was quantitatively determined by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The results showed that the novel egg white purification method possessed advantages over the immunoaffinity technique used as the reference method in extraction recovery, sensitivity, repeatability, and operability. The limit of detection (LOD) was 0.001 μg/kg. In spiked samples containing 0.01 μg/kg to 2 μg/kg of AFM1, the average recovery was 88.3–94.7%, with a precision of 6.1–11.0%. Improved repeatability was obtained by significantly reducing the operation time and resource requirements compared with the immunoaffinity technique currently used internationally. This study provides a reference for the further improvement of the relevant international standards in place for the detection of aflatoxin M1 in milk.

The prevalence of aflatoxin M1 (AFM1) in conventional and industrial dairy products (yogurt, cheese, kashk and dough) of Iran: a systematic review and meta-analysis

Aflatoxin is a toxic metabolite produced mainly by Aspergillus spp. which may occur in dairy products because of biotransformation. In this work, a systematic and meta-analysis approach has been considered on the topic of aflatoxin M1 (AFM1) content in dairy Iranian products. Based on the literature review, AFM1 was the most common aflatoxin contamination in dairy product. Additionally, studies revealed that higher levels of AFM1 were produced during cold seasons includes winter and autumn. Although, immunochemical technique (ELISA) was the frequent and rapid test, thin-layer chromatography (TLC) and chromatographic methods (HPLC) were commonly used as confirmative techniques to determine the level of aflatoxin. Meta-analyzing of the results showed that AFM1 can be found in the dairy products with overall prevalence percentage of 63.53 (95% confidence interval [CI]: 56.28-70.78) and 54.05 (95% CI: 43.09-65.02) based on the sample type and production process, respectively. The higher prevalence percentage of AFM1 of 73.96 (95% CI: 60.27-87.66) and 69.91 (95% CI: 62.00-78.83) was found in yoghurt and industrial production type of samples, respectively. In general, 17.8% of cheese, 14% of yogurt, 12.63% of kashk, and 2.1% of doogh contained AFM1 in concentrations exceeding the permitted level of standards. Totally, results showed that 88.89% of dairy products were contaminated by AFM1 exceeding from standard limits.

The Presence of Aflatoxin M1 in Milk and Milk Products in Bangladesh

As milk provides both micro- and macronutrients, it is an important component in the diet. However, the presence of aflatoxin B₁ (AFB₁) in the feed of dairy cattle results in contamination of milk and dairy products with aflatoxin M₁ (AFM₁), a toxic metabolite of the carcinogenic mycotoxin. With the aim to determine AFM₁ concentrations in milk and milk products consumed in Bangladesh, in total, 145 samples were collected in four divisional regions (Sylhet, Dhaka, Chittagong, and Rajshahi). The samples comprised these categories: raw milk (n = 105), pasteurized milk (n = 15), ultra-high temperature (UHT)-treated milk (n = 15), fermented milk products such as yogurt (n = 5), and milk powder (n = 5). AFM₁ levels in these samples were determined through competitive enzyme-linked immunosorbent assay (ELISA). Overall, AFM₁ was present in 78.6% of milk and milk products in the range of 5.0 to 198.7 ng/L. AFM₁ was detected in 71.4% of raw milk (mean 41.1, range 5.0–198.7 ng/L), and in all pasteurized milk (mean 106, range 17.2–187.7 ng/L) and UHT milk (mean 73, range 12.2–146.9 ng/L) samples. Lower AFM₁ levels were found in yogurt (mean 16.9, range 8.3–41.1 ng/L) and milk powder samples (mean 6.6, range 5.9–7.0 ng/L). About one-third of the raw, pasteurized, and UHT milk samples exceeded the EU regulatory limit (50 ng/L) for AFM₁ in milk, while AFM₁ levels in yogurt and milk powder samples were well below this limit. Regarding regions, lower AFM₁ contamination was observed in Chittagong (mean 6.6, max 10.6 ng/L), compared to Sylhet (mean 53.7, max 198.7 ng/L), Dhaka (mean 37.8, max 97.2 ng/L), and Rajshahi (mean 34.8, max 131.4 ng/L). Yet, no significant difference was observed in AFM₁ levels between summer and winter season. In conclusion, the observed frequency and levels of aflatoxin contamination raise concern and must encourage further monitoring of AFM₁ in milk and milk products in Bangladesh.

Evaluation of Cytotoxicity and Mould Contamination of Selected Plants from Meadows Covered by the Agri-Environmental Program

The aim of the study was the evaluation of selected species of meadow plants obtained from the first cut from the area covered by the agri-environmental program 'Natura 2000' in terms of the presence of cytotoxic compounds detected by the MTT test and the level of fungal contamination. The research was carried out on plant species that were evaluated differently in previously used methods for quality assessment of pasture feeds according to Klapp and Filipek. Twenty-six plant species were harvested in 2014 from meadows located in the valley of the Bydgoszcz Canal. Mycological examination of meadow plant samples was carried out according to PN-ISO 7954:1999. Cytotoxicity evaluation was performed using the MTT [3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] test. Selected samples were also subjected to evaluation of the endophytes occurrence in grasses using PCR. Natural meadow positions included in the study were dominated by moulds belonging to Humicola spp., Alternaria spp., Cladosporium spp., Torula spp., Fusarium spp. and Mucor spp. The highest level of fungal contamination was observed for Carex acutiformis Ehrh. The most infested grasses were Deschampsia caespitosa (L.) P.Beauv., Festuca arundinacea Schreb. and Lolium perenne L. The MTT test showed that the most cytotoxic species were Arrhenatherum elatius (L.) P.Beauv. (IC50 1.563 mg/mL) and Ranunculus repens L. (IC50 3.125 mg/mL). Epichloë endophytes were detected in one of 13 examined grass samples. Our own research suggests that previously used feed quality assessments should be verified by introducing modern methods of molecular biology and instrumental analysis. Results of this study may broaden the knowledge of the causes of problems resulting from feeding of roughage, mainly from natural meadows, and help in creating new rankings of the feed value of meadow sward components.

Electrochemical immunosensors - A powerful tool for analytical applications

Immunosensors are biosensors based on interactions between an antibody and antigen on a transducer surface. Either antibody or antigen can be the species immobilized on the transducer to detect antigen or antibody, respectively. Because of the strong binding forces between these biomolecules, immunosensors present high selectivity and very high sensitivity, making them very attractive for many applications in different science fields. Electrochemical immunosensors explore measurements of an electrical signal produced on an electrochemical transductor. This signal can be voltammetric, potentiometric, conductometric or impedimetric. Immunosensors utilizing electrochemical detection have been explored in several analyses since they are specific, simple, portable, and generally disposable and can carry out in situ or automated detection. This review addresses the potential of immunosensors destined for application in food and environmental analysis, and cancer biomarker diagnosis. Emphasis is given to the approaches that have been used for construction of electrochemical immunosensors. Additionally, the fundamentals of immunosensors, technology of transducers and nanomaterials and a general overview of the possible applications of electrochemical immunosensors to the food, environmental and diseases analysis fields are described.