Cadmium and lead in fresh vegetables and vegetable products sold on the local market in the Republic of Serbia, 2018-2021.

Cadmium (Cd) and lead (Pb) concentrations were determined in samples of 31 species of vegetables (n = 719) and in vegetable products (n = 17), collected during the period January 2018 to September 2021. These originated from 33 countries, including Serbia. The samples were analysed by inductively coupled plasma - optical emission spectrometry (ICP-OES). Overall, Cd and Pb were found above the limit of detection in 123 (16.7%, n = 736) and 90 (12.2%; n = 736) samples, respectively. According to the former legislation, valid until the end of August 2021, the maximum levels (MLs) of Cd and Pb were exceeded in 1 and 2 samples of vegetables, respectively. Regarding the EU and Serbian legislation which is valid since September 2021 the MLs of Cd and Pb for vegetables were exceeded in 7 samples: Cd in 5 and Pb in 2 samples. In addition, 3 vegetable product samples exceeded the MLs for both cadmium and lead according to both former and current regulations.

Cadmium and lead in fresh fruits and fruit products sold on the local market in the Republic of Serbia, 2018-2021.

Cadmium (Cd) and lead (Pb) concentrations were determined in 737 samples of 39 species of fruits and of processed fruits (n = 13), collected during the period January 2018 to September 2021. Fruits and fruit products originated from 47 countries, including Serbia. Samples were analysed by inductively coupled plasma - optical emission spectrometry (ICP-OES). Overall, Cd and Pb were found above the limit of detection (LOD) in 97 samples (13.9%). Cd and Pb concentrations were below the LOD in all samples of fruit products. According to the valid regulations before September 2021, the maximum level (ML) of Cd for analysed fruits was exceeded in only 1 sample (0.14%; n = 737), while concentrations of Pb in each analysed fruit sample was below the ML. According to the legislative regulations as set after September 2021, the maximum levels of Cd and Pb for fruits were exceeded in 5, respectively 1, of the samples, so 6 in total (0.81%; n = 737).

Cadmium, lead, mercury and arsenic in fresh vegetables and vegetable products intended for human consumption in the Republic of Serbia, 2015-2017.

The concentrations of cadmium (Cd), lead (Pb), mercury (Hg) and arsenic (As) were determined in 455 samples of 27 species of vegetables and 28 different processed vegetables collected during the period from January 2015 to December 2017. Vegetables (n = 387) and vegetable products (n = 68) originated from 31 countries, including Serbia. The samples were analysed by inductively coupled plasma - optical emission spectrometry (ICP-OES). The concentrations of Cd, Pb, Hg and As in the vegetables and vegetable products were compared to the maximum levels set by the European Union and the Serbian legislation. The concentration of mercury was less than the limit of detection in each analysed sample. One or multiple measurable toxic metals (Cd, Pb and/or As) were found in 250 samples (54.9%; n = 455). According to the Regulations which were valid until the end of August 2021, the maximum levels of Cd, Pb and As were exceeded in 19 samples (4.2% of the samples of vegetable and vegetable products; n = 455), i.e. in 13 samples of vegetables: Cd in three, Pb in nine and As in one sample and in 6 samples of vegetables products: Cd in three, Pb in one and As in two samples. Regarding the new EU and Serbian legislation which is valid since September 2021 the maximum levels of Cd and Pb for vegetables and vegetable products were exceeded in 118 samples (25.9% of the samples of vegetable and vegetable products; n = 455), i.e. in 95 samples of vegetables: Cd in 67 and Pb in 28 samples and in 23 samples of vegetable products: Cd in 20 and Pb in 3 samples.

Cadmium, lead, mercury, and arsenic in fresh fruits and fruit products intended for human consumption in the Republic of Serbia, 2015-2017.

The European Commission has established legislation for toxic metals in certain foodstuffs in order to protect public health already in 1993. After several amendments, new maximum levels for cadmium and lead in certain foods were set as per 30 and 31 August 2021 for lead and cadmium, respectively. The new Serbian Regulation on "maximum levels of certain contaminants in food" is fully harmonised with this European legislation. The concentrations of cadmium (Cd), lead (Pb), mercury (Hg), and arsenic (As) were determined in 832 samples of 39 species of fruits and processed fruits, collected during the period January 2015 to December 2017. Fruits and fruit products originated from 45 countries, including Serbia. Samples were analysed by inductively coupled plasma - optical emission spectrometry (ICP-OES). Concentrations of cadmium, lead, mercury, and arsenic in fruits and fruit products were compared to these maximum levels (MLs). Overall, measurable Cd, Pb, Hg, and As were found in 377 samples (45.3%). According to the former regulations, the maximum levels of Cd and Pb for analysed fruits and fruit products were exceeded in only 10 samples (1.20%; n = 832): Cd in 6 and Pb in 4 samples, but according to the latest regulations, the maximum levels of Cd and Pb for fruits were exceeded in 196 of the samples (23.9%; n = 820): Cd in 191 and Pb in 5 samples. The increase of ML exceedances shows that attention needs to be paid for compliance of food to the recent MLs for these metals.

Artificial neural network approach to modelling of metal contents in different types of chocolates.

The relationships between the contents of various metals in different types of chocolates were studied using chemometric approach. Chemometric analysis was based on the application of artificial neural networks (ANN). ANN was performed in order to select the significant models for predicting the metal contents. ANN equations, that represent the content of one metal as a function of the contents of other metals were established. The statistical quality of the generated mathematical models was determined by standard statistical measures and cross-validation parameters. High agreement between experimental and predicted values, obtained in the validation procedure, indicated the good quality of the models. The obtained results indicate the possibility of predicting the metal contents in different types of chocolate.