Wheat is one of the world’s most commonly consumed cereal grains. It originates from a type of grass (Triticum) that is grown in countless varieties worldwide. Bread wheat or common wheat is a primary species. Several other closely related species include durum, spelt, emmer, einkorn, and Khorasan wheat. In addition to being a major source of starch and energy, wheat also provides substantial amounts of a number of components which are essential or beneficial for health, notably proteins, vitamins (notably B vitamins), dietary fibres, and phytochemicals. Wheat is a basic food product of Macedonian population. This study is mainly focused on measuring the concentration of radioactivity due to natural radioactive nuclides (226Ra, 232Th, 40K) in wheat grain samples, as well as on determining the quality of wheat used in daily diet. In addition, in this study we calculated radiation hazard indices (radium equivalent activity and internal hazard index) in the wheat sample. Average activity concentrations of 226Ra, 232Th, and 40K in the wheat samples were 0.57±0.14; 0.39±0.11; 96.55±0.86 (Bq·kg-1), respectively. The radiation hazard indices were calculated for all samples in this study where mean values ​​did not exceed safety limits, pointing out to negligible radiation hazard arising from terrestrial radionuclides that are naturally present in wheat. In terms of quality, we confirmed that all tested samples meet the requirements regarding quality in accordance with the laws in our country.

Consuming food containing radionuclides is particularly dangerous. If anyone ingests or inhales a radioactive particle, it continues to irradiate the body as long as it remains radioactive and stays in the body. However, studies on the radioactivity of consumable foods assume importance as it is necessary to estimate the ingestion dose to the public. Due to all this, the focus of this research was on determining the activity concentrations of 226 Ra, 40 K and 232 Th. Forty-nine samples in three categories of vegetables, cereals (rice, wheat, corn), and milk, were collected from local markets (city of Skopje) in the Republic of North Macedonia and they were analysed by using high-purity germanium (HPGe) detector to assess natural and artificial radioactivity. The average activity concentrations of 226 Ra, 40 K and 232 Th of the tested samples were 2.85±1.15, 2.48±0.85, and 80.64±5.45 Bq kg -1 , respectively. No artificial radionuclide was found in any of these samples. The average value of the radium equivalent activity in all samples was 12.56 Bq kg -1 , which was less than the maximum permitted value of 370 Bq kg -1 . The values of the external hazard indices for vegetables, cereals and milk samples vary with an average value of 0.11, which is less than one in all samples indicating the non-harmfulness of the samples. The mean activity concentrations of 226 Ra, 40 K and 232 Th (Bq kg -1 ) in the samples were used to calculate the absorbed dose rate whose mean value for all food samples was 6.16 Bq kg -1 . It was determined that the measured values are within the globally accepted values, i.e., they are quite lower than the data in literature. These data would be useful to establish a baseline for natural radioactivity concentrations in food products consumed in the Republic of North Macedonia.

Milk is one of the most important food products in the human diet and contains all the macronutrients, that are, proteins, carbohydrates, fat, vitamins (A, D and B groups) and trace elements, especially calcium, phosphorus, magnesium, zinc and selenium. Milk contamination is largely due to the grazing of animals on contaminated grass and drinking water. Grass is a direct source or route of radionuclides to animals and humans through the consumption of meat and milk. One of the important tasks of the veterinary activity is veterinary-sanitary supervision of the production and sale of milk and dairy products, whose main goal is the provision of biologically good milk and dairy products from healthy animals. The purpose of this study was to determine the activity concentrations of 226 Ra, 232 Th 40 K and 137 Cs in milk samples most commonly used in daily consumption in the Republic of North Macedonia and based on the results, the risk of radiation to the population can be estimated. An instrument -gamma spectrometer (Canberra Packard) with a high purity germanium detector and GENIE 2000 programme was used for measurement of the samples. On the basis of the performed tests, the main activity concentrations of 226 Ra, 232 Th, and 40 K were 1.76 ± 0.23; 1.05 ± 1.00; 31.9 ± 5.07 (Bq•kg -1 ), respectively. 40 K has the highest value compared to other radionuclides due to the process of transfer from soil to grass and from grass and water to milk. The activity of 137 Cs is below the detection limit for all tested milk types. This shows that there is no risk of radiation to the population, i.e., the safety limits are not exceeded, which points out the insignificant threat of radiation arising from radionuclides that are naturally or artificially present in the tested milk, and that reach humans through the food chain.

In Republic of North Macedonia, the production of grapes and wine has been known since ancient times. Many grape varieties are grown in this region, but one of the most important and largest regions for wine production is the Tikveš region. The aim of the research was to determine the presence of natural radionuclides, as well as total and free SO 2 that are added as additives in wine during its production. The analyses were performed by gamma spectrometry and the obtained spectra were analyzed by the GENIE 2000 programme. The sulfites were determined using OIV accredited methods after prior validation and verification. The results show that 40K is present in all wine brands with a larger size than the other radionuclides observed. 40K levels ranged from low 24.15 ± 2.30 to 38.22 ± 1.50 Bq/L for white wines and 16.28 ± 3.20 to 22.80 ± 3.50 Bq/L for red. As for sulfites, differences can be noticed in terms of the content of total and free SO 2 in all examined wines. Regarding red wines, the lowest value for the content of both total and free SO 2 is observed in Merlot wine (free SO 2 = 10.20 ± 0.54mg/L and total SO 2 = 51.79 ± 0.55mg/L) and in terms of white wines, the lowest content of total and free SO 2 is observed in Muscat Ottonel wine (free SO 2 = 6.84 ± 0.36mg/L and total SO 2 = 40.24 ± 0.43mg/L).

In the Republic of North Macedonia, the production of wine is very well known, but in the markets, there is also a variety of imported wines. Therefore, the aim of our research was to examine the basic parameters which determine the quality of the wine. A total of 106 domestic and imported wines were included in this research. The basic chemical parameters for each of the samples were examined by using standard OIV methods. Verification of the methods was done by determining its accuracy, precision, repeatability and reproducibility using standard reference material and proficiency testing. Depending on the sugar content, wines were divided into 4 groups: dry, semi dry, semi-sweet and sweet wines. The highest alcohol content was observed in dry wines originating from all countries that were subject of this research (up to 13.54 vol %) and the lowest was observed in wines originating from Italy which are mostly used as dessert wines (5.07 vol %). The semi-dry wines originating from France showed the slightest value (min.12.18 mg/L free SO 2 and min.60.20 mg/L total SO 2 ), which corresponds to their high quality and price on the market. This research is of great interest for the needs of the market and the price of the wine, due to the wine quality standards under the law of Republic of North Macedonia.