Seasonal Variation in Nutritional, Physicochemical, and Mineral Composition of Honeybee Pollen in Southern Kazakhstan

Honeybee pollen is widely recognized as a functional apicultural product due to its rich nutritional profile, but its composition is strongly influenced by seasonality and floral availability. Understanding these seasonal dynamics is critical for optimizing the nutritional and bioactive quality of bee-collected pollen. This study investigated the seasonal variation in the physicochemical and mineral composition of honeybee pollen collected monthly from April to September 2024 from an apiary in the Tulkibas district, Turkistan region, Kazakhstan. Pollen samples were analyzed for key quality parameters, including moisture, protein, fat, fiber, carbohydrates, starch, ash, and minerals (Ca, P, K, Mg, Na, Cu, Fe, Zn). Moisture, protein, fat, fiber, starch, and ash were determined using standard AOAC methods, while minerals were quantified by flame atomic absorption spectrophotometry (Ca, Cu, Fe, Mg, Zn; Analytik Jena novAA 350), flame emission spectrophotometry (Na, K), and the molybdenum blue colorimetric method (P). The moisture content decreased significantly from 10.34 ± 1.74% in April to 5.23 ± 0.86% in June ( p = 0.0030), while protein increased from 20.28 ± 2.13% to a peak of 23.66 ± 1.70% in June ( p = 0.0268). The fat content reached its maximum in July at 8.67 ± 0.11% ( p = 0.0446), and carbohydrates peaked at 14.41 ± 0.11% in the same month. Among minerals, Fe and Zn showed substantial increases, with iron rising from 47.51 ± 5.69 mg/kg in April to 143.39 ± 6.58 mg/kg in July ( p = 0.0388), and Zn from 38.56 ± 2.36 mg/kg to 57.14 ± 8.54 mg/kg ( p = 0.0302). Principal Component Analysis (PCA) and Pearson correlation confirmed strong seasonal clustering and nutrient interrelationships. These findings highlight the superior nutritional value of mid- to late-season pollen and underscore the importance of the harvest timing in optimizing the bioactive profile of bee-collected pollen for apicultural and functional food applications.