Honey’s unique qualities should last for several years when properly stored. Therefore, it is up to manufacturers to choose the right shelf life for their product while also considering the product’s nature. Physicochemical parameters (water content, electrical conductivity, free acidity, pH, ash, water-insoluble matter, hydroxymethylfurfural (HMF), sugar content and composition, and diastase activity) were analyzed in 24 samples of sunflower honey collected from several localities in Vojvodina, Serbia. Crystallization indices were also calculated. Furthermore, the impact of eighteen months of room temperature storage (22 ± 2 °C) in a dark place on selected physicochemical parameters (water, HMF, diastase activity, pH value, and free acidity) was investigated. The results of the initial test indicated that the tested samples of sunflower honey from Vojvodina is of good quality because the parameters under examination revealed results that were within the legal bounds of both national and European legislations. Eighteen months of storage at room temperature reduced diastase activity by 2 times, increased HMF content by about 17 times, and decreased the pH value of honey from a mean value of 3.66 to 3.56. The water content was relatively stable at 17.01% before storage and 16.29% after storage. The storage of sunflower honey did not have an impact on the free acidity.

Fifty two honey samples of different floral origin from Serbia were examined in order to define their sugar composition. Our study confirmed that in the examined honey types the average percentage of fructose and glucose ranged from 36.57 to 41.64, and from 30.00 to 34.53%, respectively. The sum value of glucose and fructose, as well as sucrose content in all investigated honey samples, was found to meet European Legislation and local regulations. Besides, fructose/glucose ratio (F/G) and glucose/water ratio (G/W) were calculated for all types of honey. According to our results, acacia honey had the lowest G/W ratio and greatest F/G ratio, hence indicating scarce tendency to crystallize. Univariate data analysis and multivariate chemometric techniques were applied to determine the relationship between the values of relevant chemical parameters and the botanical origin of honey.

In the immediate vicinity of a slaughterhouse, a fishpond was built that uses treated wastewater from the slaughterhouse, and in this way integrates a new value chain in the form of purification and use of slaughterhouse wastewater in an aquaculture production system. The negative aspect of such integrated production systems is the concern related to the safety of fish meat produced in these systems. The aim of this research was to determine the activity level of Cs-137, K-40, Ra-226, Th-232, and Na-22 in water, sediment, and carp harvested from a pond that received purified water from a slaughterhouse. All samples were collected in spring and in autumn. The activity concentrations of selected radionuclides were determined by gamma spectrometry (HPG-e detector). The activity of K-40 in water samples ranged from 8.4 to 15.6 Bq L⁻¹. The specific activity concentrations of the Ra-226 in water samples ranged between 1.02 ± 0.11 and 2.76 ± 0.49 Bq kg⁻¹. The results of the activity of natural radionuclides (Bq kg⁻¹) in the sediment samples were in the following ranges: 440–629 for K-40, 10.7–15 for Th-232, 20.2–44.4 for Ra-226, and 1.08–2.04 for Na-22, with average values of 531.75, 12.3, 32.97, and 1.75, for K-40, Th-232, Ra-226, and Na-22, respectively. The average content of Th-232 (12.3 Bq kg⁻¹) did not exceed the world UNSCEAR average value of 45, while the average content of Ra-226 (32.97 Bq kg⁻¹) slightly exceeded the UNSCEAR value of 32 Bq kg⁻¹. The K-40 concentration activity of 531.75 Bq kg⁻¹ was much higher than the UNSCEAR weighted average value of 420 Bq kg⁻¹. In the fish samples, natural radionuclide Na-22 was detected only in autumn (2.74 ± 0.32 Bq kg⁻¹). Results of Cs-137 and Th-232 concentrations were below the method detection limit in all samples, ˂0.5 Bq kg⁻¹ and ˂2 Bq kg⁻¹, respectively. The activity of K-40 was in the range from 121 to 160 Bq kg⁻¹. The activity concentrations of the Ra-226 in carp samples ranged between 9.5 and 54.4 Bq kg⁻¹. The results indicate that consumption of fish meat obtained from this integrated system does not pose a significant health concern in the case of the usual consumption rate that is typical for the population of Serbia. Almost no statistically significant seasonal variations were observed.

Donkey milk is highly valued for its unique nutritional characteristics and hypoallergenic properties. However, limited data exist on its mineral composition and potential contaminants. This study aimed to comprehensively analyze the concentration of selected essential and toxic elements from Banat and Balkan donkey breeds reared under extensive organic conditions (free-range) across different seasons. The focus was on determining the concentrations of essential minerals and trace elements (Ca, P, Na, K, Mg, Zn, Cu, Se), and potentially toxic elements (As, Pb, Hg, Cd). Samples were collected monthly over one year, with nine pooled samples per season. Mineral elements were determined using a validated ICP-MS method. The mineral content ranges (mg/kg) were Ca (588.9–744.4), P (355.6–533.3), Mg (71.1–84.4), K (444.4–711.1), Na (355.6–444.4), with trace elements (mg/kg) including Zn (2.06–2.21), Cu (0.31–0.68), and Se (0.02–0.05). Potentially toxic elements were within safe limits, with the exception that Pb levels exceeded permissible limits in two samples. Statistically significant seasonal variations were observed for Ca, P, K, As, and Cu. Donkey milk from both breeds was rich in minerals and low in contaminants. This research highlights the need for further studies on the nutritional and safety aspects of donkey milk.

The Domestic Balkan and Banat donkey (Equus asinus asinus) are native donkey breeds primarily raised in the Special Nature Reserve 'Zasavica', Serbia. The study's objective was to analyze the composition of donkey's milk during the lactation period (12th to 30th week of lactation), regardless of the donkey's breed. The investigated donkey milk composition is characterized by a low content of dry matter, protein and fat and a high amount of lactose, compared to the milk of other dairy animals. The study revealed that content of dry matter ranged from 7.20 to 9.52%, fat ranged from 0.10 to 1.00%, protein ranged from 1.17 to 2.07%, lactose ranged from 4.52 to 6.71%, ash ranged from 0.28 to 0.50% and pH ranged from 6.82 to 7.46. Dry matter, fat, and ash content progressively lowered during lactation, with some oscillations. Milk protein and lactose content were not affected during the lactation stage. The pH value increased progressively during lactation with slight oscillations during the 18th and 21st week of lactation. Statistically significant differences between lactation weeks were established only for lactose content and pH values.