Seasonal variation of aflatoxin M1 in raw milk from the Yangtze River Delta region of China

The objective of this study was to evaluate the occurrence of aflatoxin M₁ (AFM₁) in raw milk samples from 18 dairy farms in the Yangtze River Delta region during four different seasons. A total of 72 tank milk samples was collected with 18 samples for each season. Milk AFM₁ was detected using LC-MS/MS. The AFM₁ was detected in 43 milk samples (59.7%) ranging in concentration from 10 to 420 ng/L. The concentration of AFM₁ in raw milk was significantly higher during the winter (123 ng/L) than during other seasons (P < 0.05). There was no significant difference between the spring (29.1 ng/L), summer (31.9 ng/L), and autumn (31.6 ng/L) (P > 0.05) seasons. This indicates that raw milk collected during the winter is at high risk for AFM₁ and that seasonal factors should be considered for the management of aflatoxins in both the feed and milk.     

A survey on the Aflatoxin M1 occurrence and seasonal variation in buffalo and cow milk from Southern Italy

This study evaluates the aflatoxin M1 (AFM1) contamination in 804 samples of raw milk from cow and buffalo, collected randomly in Campania and Calabria regions of Southern Italy over a two years period.The competitive enzyme linked immunosorbent assay (ELISA) method was used to analyze AFM1 in the samples. AFM1 levels result above the CCβ value of 0.004 μg/kg in 51 (12.3%) cow milk samples and in 28 (7.2%) buffalo milk samples. Positive results from screening analysis were confirmed by high performance liquid chromatography with fluorimetric detection (HPLC-FLD) after a procedure of centrifugation, extraction and immunoaffinity column clean-up of milk. Only one cow milk sample exceeded the maximum limit (0.05 μg/kg) set by the European Regulation.The occurrence of AFM1 contamination was significantly (p < 0.05) higher in cold season, particularly fall, than in warm season, principally spring.Our results indicate that feedstuff used in the buffalo and cow farms were not highly contaminated with aflatoxins, determining a good quality of the analyzed milk. Therefore, the AFM1 contamination of the milk does not represent a serious public health problem in both regions in Southern Italy.     

Milk fat globule size,phospholipid contents and composition of milk from purebred and Alpine-crossbred Mid-Eastern goats under confinement or grazing condition

Milk fat globule (MFG) size and phospholipids (PL) content and composition were determined in milk collected at 65 (pretreatment), 110, 135 and 170 days of lactation from goats randomly assigned to grazing in Mediterranean brushland or fed clover hay indoors, in addition to concentrate. Daily feed intake and dietary contents of neutral detergent fibre and acid detergent fibre were higher in grazing goats, associated with milk richer in fat, with larger MFGs and 20% higher PL content. Smaller MFGs, produced by all confinement groups, was associated with 15 μg g⁻¹ fat higher milk PL content. The greatest effect was found in the Damascus goats, with over 44% higher PL concentration, on milk fat basis, in the confined compared with grazing group. Our understanding of how PL content is modulated by the interaction between genetic background and nutrition will enable to achieve either PL-rich milk or PL-enriched milk fat.     

A reliable and sensitive time-resolved fluorescent immunochromatographic assay (TRFICA) for ochratoxin A in agro-products

Immunochromatographic assays (ICAs) are considered as a suitable diagnostic tool for the detection of mycotoxins. Mycotoxins and especially, ochratoxin A are analytes with more demanding sensitivity requirements. To enhance the sensitivity of current immunochromatographic assays for ochratoxin A (OTA), a novel sensitive ICA was developed in this study. In the assay, microspheres enclosing fluorescent europium (III) [Eu(III)] nanoparticles (EuNPs) were used as a label for OTA monoclonal antibody (OTA-mAb) conjugation. Accordingly, assay was called time-resolved fluorescent immunochromatographic assay (TRFICA). The test strip was composed of three parts: a sample pad, nitrocellulose membrane and an absorbent pad. As for detection, a proper concentration of conjugated microspheres was pipetted into the microtube and sample extract was added to it. Then the strip was inserted into the tube and the fluid flow along the strip. The TRFICA results were obtained in 8 min and read by a portable TRFICA strip reader. The established method allows quantitative determination of OTA with limit of detection as low as 1.0 μg kg⁻¹ in the samples. For validation, spiked samples including wheat, maize, soybean and rice were respectively assayed by TRFICA and a standard high performance liquid chromatography equipped with a fluorescence detector (HPLC-FLD), and good agreement of results was obtained between two methods.     

Thermal markers arising from changes in the protein component of milk

Classification of heat load applied to milk requires the detection of parameters appropriately related to the intensity of the heat treatment. Current analytical methods based on heat-induced changes in the protein component of milk have been directed either to determine the amount of protein-derived products arised from heat treatments or to evaluate the extent of thermal denaturation of milk proteins. Lately, a new analytical strategy has been developed according to the occurrence of three major whey proteins, namely bovine serum albumin (BSA), beta-lactoglobulin (βlg) and alfa-lactalbumin (αla), normally soluble at pH 4.6 in raw milk, in the pH 4.6 insoluble protein fraction recovered from heat-treated milk. The results have shown that pH 4.6 insoluble BSA, βlg and αla, as detected by ELISA in milk, can be regarded as thermal markers suited for either dairy process control or regulation purposes.     

Variation of aflatoxin M1 contamination in milk and milk products collected during winter and summer seasons

Total 221 samples of milk and milk products were collected during winter (November 2011–February 2012) and 212 samples were collected during summer (May–August 2012) from central areas of Punjab, Pakistan. The samples were analyzed for the presence of aflatoxin M₁ (AFM₁) with a validated HPLC method equipped with florescence detector. The results revealed that from winter season almost 45% samples of milk and milk products were found to be contaminated with AFM₁ i.e. 40% of raw milk, 51% of UHT milk, 37% of yogurt, 60% of butter and 43% of ice cream samples and 27, 24, 25, 34 and 17% of samples were found above the recommended limit for AFM₁, respectively. However, from summer season 32% samples of milk and milk products were found to be contaminated i.e. 36% of raw milk, 31% of UHT milk, 29% of yogurt, 40% of butter and 24% of ice cream and 23, 23, 18, 20 and 5% of samples were found above the permissible limit for AFM₁, respectively. The levels of contamination in winter milk and milk product samples were significantly higher (α ≤ 0.05) than in summer season. The occurrence of AFM₁ in milk and milk products were higher, demanding to implement strict regulations and also urged the need for continuous monitoring of milk and milk products in order to minimize the health hazards.     

Risk factors associated with the presence of aflatoxin M1 in raw bulk milk from Argentina

The objectives of this study were to assess aflatoxin M₁ (AFM1) contamination in bulk tank milk, and to further identify the risk factors associated with the presence of AFM1 in raw milk in Argentina. The presence of AFM1 was investigated in 160 bulk tank milk samples collected from farms located in the most important milk production region in Argentina during one year (four seasons). Samples were analysed using immunoaffinity column (IAC) cleanup and UHPLC-MS/MS method for determining AFM1 at low levels of concentrations (LOQ = 0.003 μg L⁻¹). A survey about the potential factors associated with the presence of AFM1 in milk was performed directly in the field through a questionnaire applied to the farmers. Chi-square and logistic regression were performed with presence of AFM1 in milk as dependent variable, and potential risk factors as independent variables. Incidence of AFM1 in raw milk was 38.8% and, in all samples, AFM1 levels were lower than the Southern Common Market (MERCOSUR) Regulation (maximum level accepted = 0.5 μg L⁻¹). Commercial feed consumption (OR = 4.630, P = 0.001), soybean expeller consumption (>0.95 kgDM/cow) (OR = 3.542, P = 0.019), and cotton seed consumption (>1.5 kgDM/cow) (OR = 2.949, P = 0.089) were associated with the incidence of AFM1 in raw milk. Despite the incidence and the level of AFM1 in milk produced and commercialized in Argentina is not a serious problem for public health. The farm breeding intensification and the supplementation with commercial feed, soybean expeller, and cotton seed seems to be the risk factors that impacts on the AFM1 milk contamination. Therefore, Argentina should improve its monitoring program on mycotoxins in animal feed and milk and improve the management practices in farms.     

Aflatoxin contamination and exposure in processed cereal-based complementary foods for infants and young children in greater Accra,Ghana

In the study, aflatoxin levels were assessed in thirty five (35) cereal-based food products intended for infants and young children. Additionally, the results showed that 71% of the processed foods intended for infants contained AFB₁ (0.18 ± 0.01 to 36.10 ± 0.32 μgkg⁻¹) levels higher than the European Union permissible limits of 0.1 μg kg⁻¹. Aflatoxin intake was estimated using aflatoxin levels in the food products and the estimated individual consumption rates. The study also revealed mixed cereals as having the highest intake of aflatoxin B₁ contaminants (0.005–0.852 μgkg⁻¹bw d⁻¹; 0.004–0.657 μgkg⁻¹bwd⁻¹) with mean estimated daily intake (EDI) of 0.23 ± 0.16 μgkg⁻¹bwd⁻¹ and 0.153 ± 0.13 μgkg⁻¹bwd⁻¹ for infants and young children respectively. The estimated AFT intake recorded for infants and young children for all the cereal-based food ranged from 0.005 to 1.054 μgkg⁻¹bwd⁻¹ and 0.004–0.838 μgkg⁻¹bwd⁻¹ respectively.