Green Ultrasound-Assisted Extraction of Bee Pollen Polyphenols for Bioactive κ-Carrageenan Food Packaging Films with Antioxidant and UV-Protective Properties

Bee pollen extracts can enhance the properties of biopolymeric films. This study is the first to extract polyphenols from bee pollen using ultrasound-assisted glycerol–water mixtures for incorporation into κ–carrageenan–based films. First, bee pollen polyphenols were extracted and optimized using Box–Behnken response surface methodology, considering glycerol concentration, sonication amplitude, and extraction time. Then, the optimized extracts were characterized. Finally, the effects of incorporating the extracts into κ–carrageenan films were assessed through physicochemical and mechanical analyses. The optimized bee pollen extracts showed total phenolic contents ranging from 609.4 to 1431.3 μg GAE/g. Higher sonication amplitude, increased glycerol concentration, and shorter extraction time increased polyphenolic extraction. The extracts also exhibited high antioxidant capacity and low cytotoxicity. The incorporation of bee pollen extracts modified several functional properties of the κ–carrageenan films. Films with these extracts showed increased antioxidant capacity, rigidity and UV protection, reduced thickness and solubility. The results indicate that films with bee pollen extract appear better suited as rigid protective coatings or wrapping films for low–stress applications rather than as flexible, stretchable packaging.